Conference Proceedings 2014
Site-Specific Nematode Management With Telone II In The Mississippi Cotton Production System
Presented by Dr. Tom Allen, Associate Extension Research Professor/Plant Pathologist, Delta Research & Extension Center
Over the past decade, site-specific management technologies have proven beneficial in insect management scenarios as well as nematode management situations. Site-specific nematode management technologies allow farmers to limit input costs and maximize returns in field situations where high nematode populations exist. By utilizing GPS/GIS and measuring soil electrical conductivity (such as with a Veris EC 3100) farmers can divide fields into specific management zones based on areas that may be more conducive to supporting high nematode populations. However, soil sampling remains an integral part of the system to determine where the greatest nematode numbers are present. By building field maps containing all of the above information (GPS points, EC values, and nematode numbers) farmers can get an idea of the benefits of treating small, nematode-infested field areas within a particular field (or fields) rather than treating an entire field.
Reducing the entire area for treatment limits the expense of using a product such as Telone II at a rate of 3 gallons/A (approximately $16/gal of product). Telone is a soil fumigant with activity against all nematode species when applied at least two weeks pre-plant. The high cost of the product underscores the need for site-specific technology to reduce the overall application cost. However, without verifying the nematode component, both particular species present as well as numbers within the soil category the information won’t be utilized correctly. Relying on GPS technology and ground-truthed nematode numbers creates a reliable alternative for farmers. Treatment areas can then be effectively determined by combining all of the information (EC values, specific soil zones based on EC values, nematode number) from a field having a history of poor yield. The field can then be treated accordingly. In addition, by combining management strategies, such as Telone II and a nematode-resistant variety, farmers can increase the reliability of nematode management as well as maximizing returns on a farm scale. Site-specific nematode management has increased returns in the Mississippi cotton production system in two root-knot nematode infested fields over the past three seasons. By using a root-knot resistant cotton variety, coupled with Telone II, a 200+ pound lint increase was observed between non-Telone treated and Telone-treated strips in 2011. To verify the response of the technology, fields were treated with 24 row Telone-treated strips and compared with non-treated strips.
Why Cotton Varieties Differ In Yield
Presented by Dr. Fred Bourland, Center Director/Professor, University of Arkansas
Significant variation in lint yield has been measured in almost all of the approximately 100 cotton variety tests that I have conducted over the past 35 years. The rare exceptions occurred in non-irrigated tests or in tests that were overwhelmed by some other factor. Lint yield can certainly be affected by soil type, many weather/climatic factors, planting date, fertilizer, etc. - but these factors should be the similar for all entries in a variety test. Experimental error can also provide false lint yield results, but should randomly affect specific varieties. In this presentation, only factors that may possibly differ between varieties within a test will be considered. These factors may include variation in:
1. Seed quality and subsequent stands - Genetic variation among varieties for seed quality is poorly defined and likely very small. Environmental differences associated with differing seed sources likely exceeds genetic variation for seed quality. Also, most variety tests are seeded at relatively high rates. Since cotton is able to tolerate wide difference, variation in stands should seldom affect yield of varieties.
2. Plant resistance to insects - Other than transgenes, variation in plant resistance to insects is relatively small. Most variety tests are scouted, and insect pests are maintained below treatment thresholds. Some cottons, particularly Bt or W varieties, may incur less sub-threshold levels of pests than conventional cottons. Variation in resistance to tarnished plant bug may all some resistant varieties to produce higher yields.
3. Plant resistance to diseases - Current seed treatments generally give all varieties adequate protection from seedling diseases. Variation in response to vascular wilts and nematodes exists among varieties, and may affect yield in tests where these pathogens occur. Little genetic variation in resistance to boll rots exist. However, extent of boll rots may differ greatly among varieties within a test due to variation in boll opening relative to insipient wet weather conditions.
4. Plant response to environmental extremes – Although the environment should be the same for all entries in a test, the ability to tolerate environmental extremes, e.g. temperature and soil water, may differ among cultivars. Unfortunately, variation in plant response to environmental extreme is not well-documented or understood.
5. Plant response to nutrients – Cotton varieties may different in their ability to take up and efficiently utilize nutrients. Again, variation in plant response to nutrients is not well-documented or understood.
6. Fruit retention – Primary causes of cotton fruit loss are insect damage (see factor #2 above) and physiological shed. Physiological shed is typically associated with stress on the plant. Stress may be good (e.g. high boll load) or bad (e.g. factor that limits plant growth). Fruit retention should be considered in relation to cause of fruit loss, relative plant size, and stage of plant development.
7. Plant structure – Plant structure may be quantified by first fruiting node (FFN), plant height, degree of vegetative branching, and plant shape. The relatively low genetic variation for these parameters may be overwhelmed by variation in plant spacing. With approximately equal plant density, variation in plant height and degree of vegetative branching is usually related to maturity of varieties. Variation in plant shape (or conformation) was once given high priority in development of varieties, but not receives little attention.
8. Maturity – Cotton varieties display distinct variation in maturity, and this difference can affect relative yields in specific environments. Differences in maturity are often related to variation in plant structure and/or early fruit retention.
9. Yield components – The most basic model of lint yield is: number of seed per acre (SPA) times weight of lint per seed – with SPA have a greater influence than lint per seed. But SPA is more affected by environment, while lint per seed (lint index) is more affected by genetics. Therefore, improvement of lint index should increase yield stability of a variety.
10. Other plant physiological factors – Cotton yields of different varieties may be influenced by qualitative and quantitative variation in a myriad of endogenous plant chemicals involved in metabolism. These plant chemicals may be involved with various enzymatic reactions, and in the operations of proteins, carbohydrates, lipids and growth regulators.
So, why do cotton varieties differ in yield within a relatively uniform testing environment? Sometimes the reason is known or suspected, but most often it is not known and/or there are several factors and interaction of factors involved. A better understanding of factors contributing to yield is valuable to cotton breeders as they make selections and to producers as they choose varieties to plant. Nevertheless, much progress has been achieved without a full understanding. All commercial varieties have produced outstanding yields in certain environments. Although testing environments differ greatly, a few varieties seem to always be among the ones that produced highest yields over a wide range of environments. Such varieties are considered to be broadly adapted and highly desired. Other varieties should not be uniformly discarded, but examined closely to determine where they might best fit.
Marestail (Horseweed) - An Increasing Weed Control Problem For Cotton And Soybean Producers In Northern Alabama
Presented by Charles Burmester, Extension Agronomist, Auburn University
Incomplete control of glyphosate-resistant marestail in cotton fields has become an increasing problem in Northern Alabama. Farmers have complained that dicamba herbicide applied pre-plant with glyphosate is no longer controlling many marestail plants. In the fall of 2012, two experimental sites were established to study the effects of residual and foliar herbicides on marestail control. Only data from the Tennessee Valley site is included in this report. Fall residual treatments were applied on November 26th. Foliar treatments were applied on November 26th, March 26th and April 23rd to study the effectiveness of foliar treatments as the size of marestail plants increased (Table 1).
All residual treatments effectively controlled all winter weeds including marestail until the late April rating. This control was most likely enhanced by the two ounces of Sharpen herbicide applied with a pint of Grammoxone in November to kill all emerged weeds.
The fall foliar treatments produced surprising results. Ratings of the fall foliar treatments on December 11th indicated that all treatments, including Roundup alone, effectively controlled all emerged marestail plants (Table 2). Why Roundup alone controlled the glyphosate resistant horseweed at this stage will need further investigation. The fall foliar treatments containing Dicamba and Sharpen herbicide also produced excellent residual control of marestail through mid-March. The fall Roundup alone treatment had emerging marestail appearing in early to mid-February.
The spring herbicide results are also reported in Table 2. Results indicate that Roundup was no longer controlling any marestail plants. Dicamba control of marestail was also decreasing to about 96% with rating of the 8 and 16 ounces treatments on April 8th. These rating are most likely high due to the fact that many of the horseweeds were twisted but still survived the application. The late April test (rated on May 8th) showed a very sharp decrease in marestail control (20-35%) with dicamba treatments. Only the Sharpen and Roundup treatment still provided 100 percent control of marestail.
This preliminary data supports the theory that marestail control problems using dicamba herbicide could be related to marestail size. Increasing dicamba rates only marginally increased marestail control. In this study marestail plants six inches or taller were not effectively controlled by dicamba treatments. Why the Roundup treatment controlled glyphosate-resistant marestail in December is still puzzling and will be further investigated. Sharpen appears to be a good herbicide with foliar and residual activity on marestail. Farmers will need to apply Sharpen herbicide according to label restriction on rates and timing of Sharpen application on various crops and soil types.
Hardware And Software Tools For Irrigation Scheduling
Presented by Dr. Daniel K. Fisher, Agricultural Engineer, USDA-Agricultural Research Service
Increases in water-use efficiency are being sought in irrigated agriculture, a large user of water resources. Irrigation scheduling has long been advocated as an improved water-management technique which agricultural producers can apply to better use water resources, reduce crop stress, and improve crop yields. In addition, proper scheduling of irrigations can result in savings in energy and labor costs, and reductions in water and fertilizer runoff.
A variety of tools are available to offer guidance in making irrigation and water-management decisions. Hardware tools range from simple hand tools for periodic sampling to automated electronic sensors and dataloggers for continuous, season-long monitoring. Soil probes and augers can be used to periodically sample in the root zone to evaluate moisture conditions and estimate depth of water penetration. For periodic manual measurements, atmometers and evaporation pans can give estimates of evaporative demand and water requirements. For detailed monitoring, electronic datalogging instruments and soil and plant sensors provide continuous, automated measurements. Utilizing sensor data requires some time and effort to obtain and analyze the information, but increasing availability of wireless data transmission capability is making data-collection more convenient.
Irrigation scheduling and crop-growth models estimate crop water use and available soil-water resources using weather and crop information. The water-balance approach, in which movement of water into and out of the soil is tracked, is a commonly used method. Crop-water use is estimated from local weather data and crop-specific parameters, and combined with rainfall and irrigation information to obtain a daily accounting of soil-water reserves and irrigation requirements. Stand-alone computer software and internet browser-based models have been developed and are available for many regions around the country. Mobile/smartphone apps are being developed in several regions to offer convenient and timely information in a readily available format. Water-balance models are usually less labor-intensive to manage than hardware and sensor measurements, but require the user to estimate some model inputs.
Irrigation scheduling tools are often used to provide current, daily information on soil-water resources to enable real-time scheduling of irrigations. They can also be used for post-season diagnostic evaluation of irrigation activities and water use. Sensors are installed and measurements are collected passively throughout the season. After harvest, the sensor data are examined, in conjunction with other production information, to evaluate how irrigation and production activities affected soil-water resources and crop yields.
Early Season And Secondary Pest Management In Cotton
Presented by Dr. David Kerns, Associate Professor, LSU AgCenter
Thrips, aphids and spider mites are common pests of cotton in the Mid-South. Thrips are one of the most consistent insects affecting Mid-South cotton. Although a number of thrips species may be found infesting Mid-South cotton, the most common species encountered include the tobacco thrips, Frankliniella fusca and the western flower thrips, Frankliniella occidentalis. Both of these species can cause severe injury to seedling cotton and injury is most severe when plant growth is suppressed by cool temperatures, pre-emergence herbicides, or other stress factors. Currently, neonicotinoid seed treatments are the primary means of managing thrips in seedling cotton; however these products often fail to provide sufficient residual control and foliar insecticide applications are required. Within the past three years thrips control with seed treatments containing thiamethoxam (Cruiser/Avicta) has been poorer than expected. The reason for this lack of activity is not certain, but may be due to resistance or formulation changes, exasperated by poor weather conditions. Cotton aphid, Aphis gossypii, is commonly found infesting cotton in the Mid-South. These infestations are most common prior to bloom or during early bloom, but late season infestations do occur. Early season aphid infestations rarely justify an insecticide application but mid to late season infestations tend to be more damaging. Later aphid infestations tend to occur following insecticide applications targeting plant bugs or bollworms. Aphids often do not require insecticide applications for management due to the activity of natural control factors; namely lady beetles, lacewing larvae, syrphid flys and pathogenic fungi. Where problematic, aphids have been managed using foliar applications of neonicotinoid insecticides; however, resistance issues with neonicotinoids have shifted much of these applications to Transform (sulfoxaflor). Spider mites can be a serious pest of Mid-South cotton. The most common species of spider mite infesting Mid-South cotton is the two-spotted spider mite, Tetranychus urticae. Infestations of this mite may occur at any cotton growth stage but infestations usually are most severe once the crop begins to bloom. There are a number of factors that contribute to spider mite outbreaks; these include weather, overwintering populations and insecticide use. Managing spider mites starts with timely and adequate fall and spring burn down herbicide applications to reduce wild hosts harboring overwintering mites within or surrounding planned planting sites. Insecticides targeting other pests will contribute to spider mite outbreaks. Most notably acephate and pyrethroids, but foliar and seed applied neonicotinoid insecticides have also been shown to contribute to spider mite outbreaks. There are a number of miticides commonly used for managing mites in Mid-South cotton. The most common miticide used is abamectin. However, recent control failure and resistance issues with this chemistry in Louisiana and Mississippi have resulted in other miticides becoming more common than in past years.
Consequences Of Climate Change From Global Warming On Cotton Growth, Yield And Production Practices
Presented by Dr. Derrick Oosterhuis
Distinguished Professor, University of Arkansas
Increased temperatures from global climate change are projected to cause substantial losses in crop productivity. Global warming is the rise in the average temperature of Earth's atmosphere and oceans and its projected continuation. This warming trend is mainly the result of rising CO2 levels in the atmosphere, the levels of which are accelerating dramatically. The increased CO2 is mainly due to human activities such as deforestation and burning fossil fuels. High temperature is predominant among the factors that determine crop growth and productivity, and excessively high temperatures will be detrimental to growth and yield. “Cotton’s Tolerance to Heat and Drought” has been identified as a top concern for US cotton growers. This session will review our current knowledge about causes of extreme weather related heat, the effect on cotton growth and yield, and production practices that minimize heat damage.
Cotton originates from hot climates, but does not necessarily yield best at excessively high temperatures, and a negative correlation has been reported between yield and high temperature. Cotton is particularly sensitive to high temperatures during reproductive development, and environmental stress during floral development represents a major limitation to high yields. The ideal temperature range for cotton is from 68 to 86oF, but daily temperatures are usually well in excess of this optimum during the growing season, and this represents a major limitation to crop development and productivity. Furthermore, high temperatures can have both direct inhibitory effects on growth and yield, and indirect effects due to high evaporative demand causing more intense water stress. High, above average, temperatures during the day can decrease photosynthesis and carbohydrate production, and high night temperatures will increase respiration and further decrease available carbohydrates, resulting in decreased seed set, reduced boll size, decreased number of seeds per boll and the number of fibers per seed. Boll number and boll size, the basic yield components, are negatively impacted by high temperature, but boll retention is the most heat sensitive component.
Practices to minimize heat stress include the use of thermotolerant varieties, earlier planting dates, more attention to fertility and the use of plant growth regulators, judicious cultivation, and good water management. Increasing temperature and less available water will strongly influence both short-term and long-term fertility management. This is particularly with increasing CO2 levels which will increase photosynthesis and vegetative growth necessitating more fertilizer. The increased heat and drought will strongly influence crop growth, and the use of PGRs will need to be more carefully monitored. The cotton crop, due to its perennial nature and indeterminate growth habit can compensate for short periods of stress, such that variation in temperatures during the cropping season allows some flowers during the flowering period to escape exposure to damaging temperatures so that some bolls are eventually produced. However, changing climate will effect cotton productivity and necessitate more attention to planning for both short-term and long-term perturbations in the weather.
Irrigation, Nitrogen Fertility, And Seeding Rate Effects On Cotton Yield And Fiber Quality
Presented by Dr. William T. Pettigrew, Plant Physiologist, USDA-ARS
Not only has the price for cotton remained stagnant relative to the price increases received for other commodities, but the cost for cotton productions inputs has also steadily increased over the past few years. Rising costs have been particularly problematic with petroleum based inputs, such as nitrogen fertilizers and diesel fuel needed to run irrigation pumps. Technology fees for inclusion of desired transgenic traits and costs associated with more elaborate seed treatments bring additional expenses to the planting operation and stand establishment process. Because of these increasing input costs, it is important for producers to understand how to make the most efficient use of any input they incorporate into their production strategies. This research investigated the effectiveness of three rates of nitrogen fertilization under both irrigated and dryland conditions for 4 different seeding rates.
‘DPL 1321B2RF’ was the cotton variety grown at Stoneville, MS in 2013. The experiment was planted on 16 April, 2013. Half the plots were furrow-irrigated and half the plots were grown under non-irrigated dryland conditions. All plots received one of three nitrogen fertility treatments (0 lb N acre-1, 50 lb N acre-1, or 100 lb N acre-1). The plots were 15.2 m long and consisted of 4 rows spaced 1-m apart. The four seeding rates utilized in this research were 1 plant ft-1 of row (13,000 plants acre-1), 2 plants ft-1 (26,000 plants acre-1), 3 plants ft-1 (39,000 plants acre-1), and 4 plants ft-1 (52,000 acre-1). The experimental design was a randomized complete block design with a modified split plot treatment arrangement and 6 replicates. The irrigation regimes were the main plots and the split plots were the seeding rates by nitrogen treatments arranged factorially. Dry matter partitioning, canopy light interception, lint yield, yield components, and fiber quality data were collected.
The 2013 growing season started off with cool and damp conditions during planting and stand establishment before progressing through mild temperatures with only moderate insect pressures throughout the rest of the growing season. Although all the designed treatment factors effected growth and development of the crop, no interactions were observed among any of these factors. The added soil moisture and soil nitrogen level brought about from the irrigation and N fertilization treatments, respectively, produced greater plant stature and biomass. This aspect was reflected in taller plant heights and greater leaf area indexes for plants receiving irrigation or N fertilization. Plants grown at the 4 plants ft-1 seeding rating were taller than the lower seeding rates early in the growing season. However, as the season progressed, this trend reversed itself and the plants grown at the 1 plant ft-1 seeding rate were tallest while plants in the 4 plants ft-1 seeding rate were the shortest.
Although nitrogen fertilization produced a yield increase, the extent of that yield response was dependent upon whether the plots were irrigated or not. In 2013, the yield differential between the highest nitrogen treatment and the non-fertilized plots under irrigated conditions was almost double that observed under dryland conditions (731 lb acre-1 vs. 475 lb acre-1 difference). Nitrogen also needed to be applied to get an irrigation response. Although irrigation did not produce a yield response when nitrogen was not applied, irrigation increased lint yield production by 23% at the highest nitrogen fertility rate (100 lb N acre-1) compared to that produced under the dryland conditions.
As the future costs and input availability becomes more challenging for cotton production, producers will have to make difficult decisions as to how best to allocate their input dollars. This research indicates that when water is limited during the growing season (through the lack of precipitation, insufficient irrigation capabilities, or restrictions on the ground or surface water supply or availability for irrigation), then the applied nitrogen fertilizer may not be used as efficiently by the plant to produce yield.
New And Old Technologies In Cotton Weed Control
Presented by Dr. Larry Steckel, Extension/Research Weed Specialist, University of Tennessee
Presented by Matthew Wiggins
Graduate Research Assistant, University of Tennessee
As glyphosate resistance (GR) continues to be a problem, Mid-South producers are looking for better solutions to help combat GR species. There are now no less than ten GR weed species in the Mid-South and no less than six confirmed GR species in Tennessee, with Palmer amaranth (Amaranthus palmeri) being the most difficult of these to control. Moreover, many of these GR weed species are also resistant to numerous other herbicide modes of action. There are no new herbicides on the horizon that will control large Palmer (> 6 inches). Therefore what is needed to control GR Palmer amaranth and other GR weed species in the future is an integrated system that includes cultural practices in combination with herbicides. Current research is being conducted that evaluate cover crops with herbicides. Moreover, some of these herbicides will be “new” to the crop as new herbicide tolerant traits will become available.
Currently, Roundup Ready Flex and Liberty Link systems are the primary weed management systems in production in the Mid-South area, and are still effective in controlling many weed species. However, both of these systems do have limitations as a stand-alone treatment. These systems need to be incorporated into a weed control program consisting of PRE’s, applying multiple modes of action, timely POST applications, and integrated cultural control methods to successfully control problematic GR weeds.
Integrating cultural control methods, such as cover crops, is a viable option available for area producers to reduce herbicide selection pressure and gain early season weed control. Winter-annual cover crops have readily been used as a conservational practice to increase soil quality and to provide early season weed suppression. In our current research, the use of a high residue cover crop has controlled most winter-annual weeds. However, cover crops do not provide season long weed control without the use of herbicides. Therefore, we are continuing to research herbicide and cover crop integration to aid in making effective weed management decisions.
Coming online in the near future is Dow Agro Sciences 2,4-D + glyphosate + glufosinate tolerant trait, which can prove to be a new tool to help control glyphosate resistant weeds. This technology looks to be quite beneficial when being added to a weed control program using PRE’s, multiple modes of action, and timely application of POST’s. Also on the horizon is Monsanto’s dicamba + glyphosate + glufosinate tolerant trait, which will also prove to be a good asset in situations where glyphosate resistant populations of weeds are present. This technology also looks to show best results when being utilized in weed control programs using PRE’s, multiple modes of action, and timely applications of POST’s.
After more than a decade growing cotton in fields infested with multiple GR weeds growers and researchers have come to realize that a weed management system is needed to consistently raise a profitable cotton crop. These systems must utilize all the weed management tools available including older technologies like cover crops integrated with newer technologies.
On-Farm Evaluation Of Canopy Sensor And Soil Conductivity Driven Variable Rate Nitrogen Fertilization Of Cotton
Presented by Dr. Jac J. Varco, Professor of Agronomy, Mississippi State Univeristy
Early season detection of corn and cotton N status as an in-field indicator of spatial N availability and fertilizer N demand has been difficult with proximal sensors. A variable rate application of fertilizer N should be strongly linked to available N supply and demand. Excess use of purchased N fertilizers can lower profitability as well as result in environmental consequences due to leaching of nitrates into groundwater or transport to surface waters as well as potential gaseous losses. Fields containing significant variability in soil properties which can influence soil N availability are prime candidates for spatial optimization of fertilizer N rates to conserve resources. Our objective was to evaluate the utility of canopy reflectance and soil conductivity to drive variable N fertilization. Two study areas were established in a producer’s field north of Greenwood, MS. For what will be referred to as the ‘North’ experiment, four fertilizer N rates of 30, 60, 90, and 120 lb/a were applied on 13 June, 2013 with intended variable rate side dress treatments receiving a base rate of 30 lb/a. In a second area or ‘South’ experiment, a base rate of 70 lb/a was applied on 12 April 2013 including intended side dress variable rate treatments. On 27, June 2013, side dress N rates of 25, 50, and 75 were applied to the South experiment resulting in total N rate treatments of 70, 95, 120, and 145 lb N/a. Strategic acquisition of canopy reflectance was performed on 28 June 2013 with a YARA N Sensor mounted on a 3-point tractor hitch and set at a height sufficient to collect canopy reflectance data from rows 2 thru 4 and 9 thru 11 at an off-nadir viewing angle. Variable rate fertilization was carried out on 1 July 2013 to both experimental areas. Variable rate 1 treatment was derived solely from sensor data and variable rate treatment 2 was based on sensor data and adjusted downward 30 lb/a where soil conductivity was characterized as low for the field and upward 30 lb/a when soil conductivity was characterized as high. No adjustment was made for areas characterized as having a medium soil conductivity. A urea ammonium nitrate solution (UAN 28-0-0-5S) was banded using a liquid applicator equipped with coulters and attached liquid knives set at 9" from the row and 3" deep for all fertilizations except for the 70 lb/a pre-plant application that was broadcast and incorporated. Field plots were 12 rows wide at a spacing of 38” with a length of from 1000 to 1500 ft. Four replicates were utilized and the experimental design was a randomized complete block. Leaf samples were collected at early flowering on 15 July from experimental sites and analyzed for total N. An automated dry combustion analyzer was used to determine total N content on duplicate samples per plot following oven drying at 65 oC and grinding through a 40-mesh sieve (0.425 mm) in a Wiley mill. Cotton was harvested with a 6-row spindle-type picker and round bales from each plot were weighed and samples were ginned to calculate lint yield. Leaf N values at corresponding N rates for the North experiment were 4.23 % (120 lb N/a), 4.06 % for variable rate 1 treatment (92 lb N/a), and 4.12 % for variable rate 2 treatment (107 lb N/a) and for the South experiment they were 4.59 % (120 lb/a), 4.58 % for variable rate 1 treatment (130 lb/a), and 4.41 % for variable rate 2 treatment (132 lb/a). The grower applied N rate of 120 lb N/a yielded 1579 lb lint/a in the North experiment and 1701 lb lint/a in the South experiment. The variable rate 1 treatment yielded 1558 lb/a at an average N rate of 92 lb/a in the North experiment and 1793 lb/a at an average N rate of 130 lb/a in the South experiment. For the variable rate 2 treatment, lint yield was 1531 lb/a at a N rate of 107 lb/a in the North expe
Why Should We Improve Water Management In Rice Production?
Presented by Dr. Merle Anders, Rice Systems Agronomist, University of Arkansas
In nearly all the rice production areas of the central United States water quantity and quality has become a looming issue. Through the years there have been efforts to address water quantity concerns by simply adding new water sources in the form of new wells and larger pumps. In recent years there have been improvements in the way water is applied to the field; largely in the form of polypipe and side-inlet management. These improvements allow farmers to apply water more evenly across paddies, but do not always result in reduced irrigation water use. Current research has shifted more towards evaluating ways to manage irrigation water that will result in significant reductions in irrigation water use and not result in low grain yields. In our work we have found that using ‘alternate wetting and drying’ (AWD) of the rice paddy can significantly reduce irrigation water use without large reductions in grain yield. In AWD management we do not drain the field but allow it to dry, naturally, to designated soil moisture and then re-flood the field to a 4” depth. Because there can be large nitrogen losses when a field is dried we apply all nitrogen to a dry field at the 4-5 leaf stage and immediately flood the field and hold the flood for 10 days; after which we allow the field to begin the wetting and drying process. Over three years grain yields for CLXL745, XL723, and XL753 averaged 203, 201, 192, and 177 bu. a-1 for the flood, AWD/40-Flood, AWD/60, and AWD/40 treatments, respectively. These yields include a continuous rice comparison in 2013. Irrigation water savings compared to the flood treatment were approximately 39, 33, and 52% for the same three treatments. In addition to these savings we found that, for the rice-soybean rotation, Global warming potential measured as the kg CO2 eq. Mg-1 rice was reduced from 301 for the flood treatment to 181, 36, and 72 for the AWD/40-F, AWD/60, and AWD/40 treatments, respectively. For the continuous rice rotation these values were 476 for the flood treatment and 235, 50, and 69 for the AWD/40-F, AWD/60, and AWD/40 treatments, respectively. Between rotations, nitrous oxide emissions were greater in the rice-soybean rotation while methane emissions were greater in the continuous rice rotation. For both rotations total GHG emissions and GWP decreased as the amount of irrigation water applied decreased. We have also found that arsenic levels decrease as irrigation water decreases. Together these findings illustrate three clear benefits to growing rice under AWD management. They did so without significantly decreasing grain yields.
Contributing Authors: Chris Henry, Shelly Kerr, David Hendrix
Using Rice Futures In Marketing Rice
Presented by Dennis R. DeLaughter, Principal, VantageRM, LLC
Let me be clear. I am not going to be talking about trading rice futures. I am going to talk about using the futures in a marketing plan for rice. That is not the same thing. You may never trade a contract on the Board of Trade but you can still use futures in your marketing decision process.
Years ago when I started using the futures in my marketing program, I went through every course I could find on charting. I was always amazed at how the chart formations would occur over and over again. Then I read a book that brought the logic behind charting to life. What we look at when we see a formation on a chart is nothing new. It has been seen almost since the beginning of futures trading. No it’s not magic and it certainly is not fool proof. The fact is we are not just looking at lines and formations on a chart; we are looking at Human Nature. While human nature is far from being perfect, it can be predicable.
Now you may read that twice to make sure you saw it right but it is a very real situation as all charts and formations we see are just pictures of human nature. Since us as humans keep doing the same things over and over again, it makes sense that similar patterns should emerge when looking at trading activity and they do. While those patterns do not always indicate for sure a certain outcome will happen, they do offer us a reason to believe the market may do something which can put the odds in our favor.
There are other tools we can use to look at futures and determine if there is a hint that the risk in the market has grown and we should be looking to do something to reduce our exposure. One of the best tools we can use is what we refer to as indicators. Indicator unlike chart formations, are based on pure mathematics. A simple example would be a moving average. If the price of rice drops under the average price of the last 10 days closes then one could say that there is enough weakness showing up in the price to indicate we may be headed lower. Of course that is too simple and I assure you it will not work; however, there are some very good mathematical indicators that can also show a pattern that when seen indicate a possible outcome in price direction.
This may sound complicated but it really is not. When we take indicators and plug them in to chart formations, we can get a picture that will help us get an idea of what the market may be telling us regarding price risk and direction. What we will do in this short session is talk about the market and the logic behind chart formations and indicators. We will look at what to use, how to get them and when to pull the trigger without ever trading a single contract.
It works for rice as well as anything traded on the futures markets but we will focus on rice. Hopefully, you will see how you can use rice futures in a comprehensive marketing program.
Rice Insect Management In The Upper Mid-South
Presented by Dr. Jeff Gore, Assistant Professor, Mississippi State University
Contributing Authors:George Awuni, Andrew Adams, and Don Cook, Mississippi State University
Insect pests can significantly impact rice yields in Mississippi. To help minimize or eliminate the possibility of economic losses associated with these pests, the development of a sustainable management strategy is needed.
Rice water weevil is a key insect pest of rice throughout the mid-South. Research in Mississippi and other Mid-South states has shown that insecticide seed treatments (including Cruiser Maxx, Dermacor X-100, and Nipsit INSIDE) are effective for rice water weevil control. More research is needed to further identify the strengths and weaknesses of these new insecticide seed treatments. Potential factors that may influence the effectiveness of seed treatments on rice water weevil control include the time from planting to permanent flood and the number of times a field needs to be flushed between planting and permanent flood. These factors were investigated as part of a recent graduate student project. Results suggested that time from planting to permanent flood did not impact the efficacy of insecticide treatments. However, Cruiser and Nipsit INSIDE were negatively impacted in rice that required at least two flushes between planting and permanent flood. Another factor that may influence the efficacy of insecticide seed treatments in rice is seeding rate. In some situations, seed treatments did not perform as well on hybrid rice planted at low seeding rates. Additional research has been conducted to determine if supplemental foliar applications of currently labeled insecticides can provide additional benefits in situations where the efficacy of seed treatments may have been compromised. In that trial, the number of rice water weevil larvae per core was reduced on CruiserMaxx treated hybrid rice sprayed with a pyrethroid at the time of flood compared to unsprayed rice that had been treated with CruiserMaxx. Additionally, the application of a foliar pyrethroid improved yields of CruiserMaxx treated hybrid rice.
Rice stink bug is another important pest of rice in Mississippi. Rice stink bugs have piercing-sucking mouth parts and feed on developing grain after panicle emergence. Rice stink bug infestations can result in yield losses as well as reductions in grain quality depending on stage of panicle development at the time of infestation. Peck in rice can severely limit the marketability and profitability of rice in Mississippi. Rice stink bug is an important contributor to grain quality and is often blamed for peck in rice. Results from previous research suggest that thresholds for rice stink may need to be refined. The current threshold for rice stink bug in rice is 5 per 10 sweeps during the first two weeks after panicle emergence and 10 per 10 sweeps from the third week of panicle emergence until cutout. Current research showed that yield losses and injury (peck) from rice stink bug was similar from panicle emergence through the soft dough stage. This would suggest that the threshold for rice stink bug should not change from flowering through the soft dough stage. Additionally, the current threshold for the first two weeks of heading is based on panicle and grain development on a conventional variety. Because of low seeding rate used, hybrid rice flowers over a longer period of time due to the increased number of tillers. As a result, a large percentage of grain remains susceptible to rice stink bug injury and yield loss longer than two weeks when rice is planted at a low seeding rate.
In conclusion, foliar applications may be needed in some situations to supplement insecticide seed treatments for rice water weevil control. This is especially true in hybrid rice with a low seeding rate and where multiple flushes are need before the permanent flood is established. Also, current research suggests that changes are needed with the current rice stink bug threshold. In Mississippi, the threshold will be changed to read, " Treatments should be made when you find an average of 5 stink bugs in 10 sweeps from panicle emergence until 50% of panicles are at soft dough. After that point, treatments should be made when you find an average of 10 stink bugs in 10 sweeps".
When Rice Shakes The World: How The Secret World Of Rice ReallyOperates
Presented by Milo Hamilton, President, Firstgrain, Inc.
We think we understand the rice market in Asia, its history, its current situation and where it is headed. We do not know; trust me.
You can never know everything about anything but I know a lot about the little white grains that feed three billion souls.
I have tested and tasted global rice samples every day for 18 years at 11am. I have bought rice from almost every country in the world and up to 30 percent of the non-coop rice in the South. I can say with pride that I worked for the largest user of rice for retail products in the world
About three years ago, I became concerned about the rice industry in Asia and a lot of partially correct information put out by various groups who claim to understand rice. Those who know are not telling and those who tell do not know. I know and I am telling.
As a result of my concern about all this rice misinformation, I wrote a book on the world rice market with the title, "When Rice Shakes the World," which will be published this January on Amazon.com.
The book condenses into 169 pages my 33 years in the rice business as a buyer and then an owner of rice several businesses. I have been in Asia many times and have spent many fascinating months there.
My talk, which keys off of the content in my book, is about what is happening in rice and where the market is headed. Anyone who is involved in growing or marketing rice should hear my talk and let your families read my little rice book. Then they will understand why the rice farmer is wrongly the least appreciated businessperson in the world today.
I have never made a presentation remotely like the one I plan to give at the 17th Annual National Conservation Systems Cotton & Rice Conference, the Southern Corn & Soybean Conference and the Southern Precision Ag Conference.
My talk is not so much an "outlook" for the rice price as a "lookout" for how the world of rice will shake the world economies in the next few years. It is about markets, geography, demography and the politics of 2.5 billion people. It is a talk about migration and water. When you grow rice you are simply converting water into rice starch. It connects the politics of water with the politics of rice production and trade.
I offer a step-by-step method to a “better way” for all of us in the rice industry.
This fall, everyone was very bearish on rice and many say the price will remain low for years and years. The story in my opinion we are witnessing is rather a great upheaval in rice policy that will impact India and China, where 53% of the world rice market is located.
Here are 24 “did you knows?” to consider:
1. Rice will shake China and China will shake the world economy because of its ownership of debt and other assets.
2. Rice farming in Asia must change from a physical world to a digital and physical world in less than 15 years in China or some will starve or cause riots.
3. Within 15 years, $700 drones, iPhones and iPads will be as essential as seed and fertilizer on each of the 200,000,000 rice farms around the world. Upwards of one billion people live on or serve rice farms, making rice farming the largest single employer on this planet and covering an area about the size for France. For those of you who do not know it, Texas is larger than France!
4. In the next five years 3 billion people will come onto the Internet with smart phones, many who now live on rice farms.
5. Across the blue ocean of the Pacific is a blue ocean of new digital and agricultural business opportunities for all of us.
6. Did you know that there are 200,000,000 rice farms in Asia and about 2,000,000 total farms in the USA?
7. The rice market is the glue, which holds Asian societies together, politically and agriculturally.
8. The Great Wall of China is actually glued together with sticky rice and rice hull ash.
9. Demand is growing rapidly for rice and it will be difficult for the world to expand rice acreage in Asia (up just 6% in the last decade).
10. A lot of unreported rice is being imported across the border into China, now the largest importer of soybeans and rice.
11. Rice needs water. About 70% of China’s groundwater resources are used for the rice industry. It takes China 5 to 20 times more units of water per units of Gross Domestic Product than the industrialized west. Rice and water are joined at the hip in China rice and is grown in heavily polluted water and soils.
12. India uses 34% of its total water resources every year to grow rice, China 20%, the US uses 16% and Brazil, Russia and Myamar use less than 5% of their water. Guess where rice and wheat will be exported from and imported to? Isn’t it obvious? Indian rice exports are a passing fad.
13. Some farmers in China will not eat the rice they grow because of toxic metal pollution of their soils. Do know any farmer who will not eat what he grows?
14. About 250 million Chinese farmers, many that grow rice, will move from the farm to the city in the next 15 years.
15. Asian nations are getting older. Japan now sells more Depends than Pampers, China is not far behind.
16. China controls the glacier-fed rivers that grow rice in Pakistan, India, Burma, Cambodia and Vietnam. Tibet’s ice grows the rice of South Asia.
17. The Indian navy controls the flow of crude oil tankers from the Middle East to China. Will this be the location of the next world war over oil and water and rice?
18. Dam building in South China for hydroelectricity will slow the flow of rivers there.
19. Climate Change is reducing the ice fields of Tibet.
20. In the next 15 years a population in Western China the size of the entire USA will go from zero grocery stores to perhaps 15,000 stores. It took the US 80 years to go from zero grocery stores in 1930 to 37,000 stores today. That food will come from the Ukraine, Iowa, Arkansas and Rio Grande do Sul farming operations, where the soils are clean and the water is still potable.
21. India and China are implementing huge changes in social transfer payments and in China, expanding farmer ownership of the land they till.
22. Farmers making less than $2 per day will not feed the gleaming cities of China.
23. Rice farming must turn from a way of life to a business or millions will go broke or starve in Asia.
24. During the September-December 2013 period there has been more change to agriculture and food programs in 53% of the world rice industry (‘Chindia’) than in the previous 500 years.
If you already knew the above 24 points, you need to write the book on rice and send me a copy. If not, let’s talk.
Yes, we will have more rice acreage in the South but also, yes, the rice market is becoming very interesting after five years of a big price yawn.
Factors To Focus On In Rice Production
Presented by Dr. Jarrod T. Hardke, Rice Extension Agronomist, University of Arkansas
The success of rice production is dependent upon commodity price and the cost of production in addition to satisfactory yields. In recent years, the development of new cultivars, combined with new research information and technologies, have improved the ability of rice growers to produce a successful crop and improve profitability while minimizing risk. Topics to be addressed include recent research in rice cultivar selection, insecticide seed treatments, seeding rates, planting date, fertility management, and irrigation.
Cultivar selection has improved as more research has been conducted on recently released lines. Selecting the best cultivar for a particular field situation is often the first step toward having a successful season. Soil type, history of disease, and irrigation capability should play a significant role in cultivar selection. The decision to treat seed with an insecticide prior to planting increases upfront costs but also provides what some describe as “cheap insurance”. Further research into the effects of insecticide seed treatments on reduced seeding rates provides new possibilities to minimize the upfront cost of these treatments. New research will be discussed that suggests insecticide seed treatments may help buffer more stress than we realize. Planting date studies indicate that planting earlier generally leads to higher yields, but not all cultivars are created equal in this regard. When you plant can have a significant impact on yield, but what cultivar you plant and whether you use an insecticide seed treatment at that time may be just as important.
Recommendations for fertility management are also undergoing changes with the development of the N-STaR program. New recommendations from research evaluating preflood and midseason nitrogen applications may also help to decrease inputs and improve profitability.
Irrigation management can also affect profitability. Multiple-inlet irrigation has the potential to reduce water use and irrigation costs while maintaining production. Options also exist for irrigation strategy, such as continuous flood, straighthead drain, intermittent flood, and flush/furrow irrigation.
This presentation will highlight ongoing research into these and other factors that should assist in improving agronomic production practices of rice.
Farmer Adaptation Of Intermittent Flooding To A Commercial Rice Production System In Mississippi:
Water Use, Grain Yield And Milling Quality And Nitrogen Response
Presented by Dr. Joseph Massey, Associate Professor, Mississippi State University
Contributing Authors:, Tim Walker & Cade Smith, Mississippi State University
Merle Anders, University of Arkansas
Use of intermittent rice flooding is increasing in Asia, but its adoption in the U.S. is limited owing to a number of agronomic and scalability concerns. This study used replicated trials established in producer-managed fields to determine if the practice is compatible with commercial rice production practices used in Mississippi. When intermittent flooding was coupled with multiple-inlet irrigation, the quantities and qualities of rice yields were maintained, relative to continuously-flooded controls, for five commercial rice varieties and one hybrid. Only one variety exhibited a decrease in total head rice when milled, this after being subjected to five or more wetting-drying cycles over ~80 day flood periods. Water savings over the three year study averaged 32% above that of comparable systems not using intermittent flooding and were on par with zero-grade, traditionally the most efficient rice irrigation system used in Mississippi. The positive yield responses of CL162 to intermittent flooding and pre-flood urea-nitrogen rates, particularly the zero-nitrogen controls, support research showing that rice tolerates well, and may actually benefit from, properly-timed wetting and drying periods. Our results further suggest that when rice is grown on clay soils, 24 A-in of applied irrigation is a realistic target under most production settings in Mississippi. Even partial adoption of intermittent flooding to improve rainfall capture could reduce demand for rice irrigation and, thus, help to alleviate overdraft of the Mississippi River Valley Alluvial aquifer, a resource of national and international significance.
Preventing Kernel Fissuring During The Rice Drying Process
Presented by Dr. Terry Siebenmorgen
University Professor and Director, University of Arkansas
Contributing Author:Gregory Baltz
Due to the economic importance of milling yield, it is critical to prevent kernel fissuring during any stage of rice production and post-harvest processing. Recent research has resulted in a hypothesis being formulated that addresses rice kernel fissuring during the drying process. Key to this hypothesis is the glass transition temperature (Tg), the temperature at which a material state transition occurs due to either a moisture content (MC) or temperature change. The material states that a kernel, or regions within a kernel, can exist during the drying process are either a "glassy" or a "rubbery" state. Figure 1, from Siebenmorgen et al. (2004), shows the inverse relationship between the Tg and MC of brown rice kernels. For a given MC, if the rice kernel temperature is below Tg, the starch in a rice kernel exists in a glassy, more brittle state; if the kernel temperature is increased above Tg, the starch exists in a rubbery state with much greater diffusivity (the rate at which water can move or diffuse), specific heat, specific volume, and thermal expansion coefficient (Perdon et al., 2000). The state of the kernel plays a significant role in the formation of fissures (Cnossen and Siebenmorgen, 2000) and in determining the rate at which moisture can be removed from the kernel; Cnossen and Siebenmorgen (2002) found that the moisture removal rate was much greater if the rice kernel temperature was above Tg.
Figure 1. Glass transition temperature relationship for brown rice kernels, indicating the glassy and rubbery regions, as well as the general property trends associated with each region (Siebenmorgen et al., 2004). [20oC=68oF, 40oC=104oF, 60oC=140oF]
Figure 2 shows hypothetical temperature and MC gradients created within a rice kernel during drying. When drying with air temperatures above Tg, the rice kernel transitions from a glassy to rubbery state. As indicated above, this transition dramatically changes kernel material properties, with the thermal volumetric expansion coefficient being of particular relevance (Perdon et al., 2000). In addition to thermal changes during high-temperature drying, the periphery of the kernel will dry much more quickly than the kernel center, causing an MC gradient within the kernel. Extended drying causes a sufficient volume of the kernel surface to transition to the glassy state (fig. 3). This surface volume behaves as a glassy material, with one set of property levels, while the center behaves as a rubbery material with another, very different set. The Tg hypothesis predicts that if the thermal and hygroscopic property values of the surface and center volumes are sufficiently different in magnitude, and the surface glassy region increases to a sufficient volume relative to the center rubbery region, then fissures will initiate at the interface of the two volumes due to hygroscopic stress differences between the two regions.
Figure 2. Hypothetical temperature (T) and moisture content (MC) distributions within a rice kernel during the drying process. Points C, M, and S correspond to the center, midpoint, and surface locations of the rice kernel, respectively (Cnossen and Siebenmorgen, 2000).
Figure 3. Hypothetical temperature and moisture content gradients within a rice kernel at the locations shown in figure 2, after extended high-temperature drying. [20oC=68oF, 40oC=104oF, 60oC=140oF]
In addition to the just-mentioned scenario caused by extended drying, the Tg hypothesis predicts that fissures can also be created during post-drying tempering and/or cooling. Depending on the temperature to which the kernel is exposed immediately after drying (fig. 4), a sufficient volume of the outer kernel may be forced to transition to the glassy state due to the rapid movement of the intra-kernel cooling front, while the center remains in the rubbery state. This causes the surface and center portions of the kernel to experience different magnitudes of material properties, which can cause fissure formation, as described above (Cnossen and Siebenmorgen, 2000).
Figure 4. Hypothetical tempering situations above and below the glass transition temperature (Tg) for a rice kernel that had been dried using air temperatures above Tg. Surface (S), midpoint (M), and center (C) correspond to the kernel locations shown in figure 2.
[20oC=68oF, 40oC=104oF, 60oC=140oF]
During tempering, if kernels are cooled below Tg before the MC gradient is allowed to subside, fissures will occur due to the surface and center volumes not being able to conform to the different hygroscopic stress levels; this is shown with situation B in figure 4. If the kernel is allowed to temper at a temperature above Tg, allowing the MC gradient created by drying to subside, rice kernels can be cooled to temperatures below Tg without incurring fissures, as depicted by situation A in figure 4.
The presentation is intended to complement a companion presentation by Mr. Greg Baltz, who has incorporated the Tg hypothesis into the design and operation of his on-farm, continuous-flow drying system.
Cnossen, A. G., and T. J. Siebenmorgen. 2000. The glass transition temperature concept in rice drying and tempering: Effect on milling quality. Trans. ASAE 43(6): 1661-1667.
Cnossen, A. G., and T. J. Siebenmorgen. 2002. The glass transition temperature concept in rice drying and tempering: Effect on drying rate. Trans. ASAE 45(3): 759-766.
Perdon, A., T. J. Siebenmorgen, and A. Mauromoustakos. 2000. Glassy state transition and rice drying: Development of a brown rice state diagram. Cereal Chem. 77(6): 708-713.
Siebenmorgen, T. J., W. Yang, and Z. Sun. 2004. Glass transition temperature of rice kernels determined by dynamic mechanical thermal analysis. Trans. ASAE 47(3): 835-839.
Effects Of Planting Date On Bacterial Panicle Blight Disease Of Rice
Presented by Dr. Yeshi Wamishe, Assistant Professor, Extension Rice Pathologist, University of Arkansas
Bacterial panicle blight (BPB) has been a threat for rice production in southern United States in recent years. BPB appears to be a weather-associated disease. Weather conditions in 2010 and 2011 were favorable for the disease to be severe enough to cause devastating yield loss up to 50% in susceptible varieties. Symptoms are not easily detectable at the earlier stage of the crop. Artificial foliage inoculation has been effective with either seed inoculation or foliage inoculation. The foliage inoculation has given adequate infection level when sprayed between boot split and flowering. In natural infection or seed inoculation, panicle symptoms (Picture1) typically develop late in the season. Therefore, predicting disease outbreak is difficult. Occasionally reddish-brown stem discoloration is associated with the disease. However, heavily-infected panicles remain upright due to lack of grain fill with some of the florets showing brownish discoloration at their lower half. Consequently this disease decreases both grain yield and milling quality. To date, there are no chemical options registered in the U.S. to protect or salvage the crop from the disease. Although Jupiter and hybrids are moderately resistant to BPB, most of our non-hybrid commercial varieties are susceptible. Therefore, field studies were initiated in 2012 to examine whether a range of planting dates could be used to manage this disease.
In 2012, artificially inoculated seeds with Burkholderia glumae, the major causal agent, were planted on March 20 as early, April 24 as average, and May 24 as late. Two rice varieties were used: Bengal (susceptible variety) and Jupiter (moderately resistant variety). Treatments were randomized and the experiment replicated four times. Plots across all three planting dates were managed similarly with regards to fertility, water, seeding rate, and herbicide application. To obtain measureable disease data, upright panicles with typical disease symptoms were counted as 100 percent infected but those with symptoms on the lower half the panicle as 50 percent infected. Moreover, yield and milling quality data were collected for all three planting dates. In 2013, regardless of the wet and cold spring that made planting very difficult, the 1st and the 2nd planting were done on March 19th and April 23rd both one day ahead of last year’s planting. The 3rd planting was done on May 29th four days after last year’s 3rd planting date. All treatments were maintained similar to 2012. Panicles with greater than 50% infection were counted and yield and quality data were also collected.
In both years, the disease level was increasing as you go towards late planting. The bacterial panicle infection was higher in 2012 possibly due to the dry and hot season than 2013 which was wet and cold season. In 2012, nearly 99 percent of the Bengal plots in May planting had bacterial panicle blight as opposed to 2013. In both years, Bengal had higher infection level than Jupiter (Picture 2). Likewise, yield and milling quality were highly affected in May planted plots. A 41% yield loss was calculated for May-planted Bengal and 33% yield loss for Jupiter when compared to the April planting in 2012. In 2013, yield comparisons were difficult to make due to bird feeding damages in both the March April planted plots. Head rice yield were similarly reduced for May-planted plots compared to the earlier planted plots.
Picture 1. Bacterial panicle blight on Jazzman 2 in commercial field
in Lee County, 2013
Picture 2: Experimental plots of Jupiter, moderately resistant (left) and Bengal,
susceptible (right) to bacterial panicle blight in 2012
Update On Rice IPM Research
Presented by Dr. M.O. Way, Professor of Entomology, Texas A&M AgriLife Research
Contributing Authors:Becky Pearson, Suhas Vyavhare, Bill Odle and Chip Graham
One of the benefits of a conservation tillage system is early planting which allows for early harvest of the main crop and a better chance of producing an excellent ratoon crop. However, early planting obviously can coincide with cool soil and air temperatures which are not conducive to rapid rice seedling growth and development. This delay in growth can increase the likelihood of disease and insect problems associated with producing poor stands of rice. In addition, decrease in seeding rate is a recent trend for southern rice farmers (e.g. hybrid and Clearfield varieties); thus, protecting seed from diseases and insects can be critically important to producing a profitable rice crop in a conservation tillage system.
Insecticidal rice seed treatments are becoming increasingly popular in southern rice-producing states. We estimate over 50% of Texas rice acreage is planted with 1 of 3 insecticidal seed treatments. We continue to investigate the efficacy of old and new rice insecticidal seed treatments compared to foliar insecticidal treatments which provide another good pest management option for rice producers.
Materials and Methods
Experiments were conducted at the Texas A&M AgriLife Research and Extension Center at Beaumont (Beaumont Center) in 2013 and were designed as randomized complete blocks with 4 replications. Plot size was 18 ft by 7 rows with 7 inches between rows. All plots were surrounded by metal barriers to minimize movement of fertilizer and pesticides among plots. Presidio was drill-planted at 80 lb/A. Fertility and weed management practices were followed according to recommendations in the latest Texas Rice Production Guidelines. Rice stand counts were taken in all plots during early tillering. The flood was applied about 3 weeks after emergence of rice through soil. Plots were sampled for rice water weevil (RWW) beginning about 3 weeks after flood. Sampling was performed using standardized methods developed by the Entomology Project at the Beaumont Center. During the milk stage of grain maturation, whiteheads were counted in the middle 4 rows of each plot. Whiteheads are a measure of stalk borer damage. At maturity, plots were harvested with a small plot combine. Yields were adjusted to 12% moisture and count data transformed using square root of (X + 0.5). All data were analyzed by ANOVA and means separated by LSD.
Seed Treatment Experiment
Seed treatments were provided by Bayer CropScience. EverGol Energy contains 3 fungicides aimed at controlling seedling diseases. The active ingredient in Poncho 600 and NipsIt INSIDE is clothianidin. The active ingredient in Cruiser 600FS is thiamethoxam. CruiserMaxx contains 2 fungicides aimed at controlling seedling diseases plus thiamethoxam.
Foliar Treatment Experiment
The active ingredient in Karate Z is lambda-cyhalothrin. The active ingredient in Belay 2.13SC is clothianidin. NipsIt INSIDE is a seed treatment containing clothianidin. Foliar treatments were applied with a 3 nozzle (800067 tips) boom (spray swath 4 ft) CO2 pressurized spray rig. All foliar treatments included a non-ionic surfactant.
Seed Treatment Experiment
Rice plant stands were not affected by the seed treatments (Table 1). All treatments provided good control of RWW on all sample dates. None of the treatments provided control of stalk borers as evidenced by whitehead counts. All treatments significantly increased yield compared to the untreated. EverGol Energy did not appear to negatively or positively affect insect control or yields.
Foliar Treatment Experiment
Rice plant stands were unaffected by the treatments (Table 2). In general, foliar treatments applied closer to flood provided better control of RWW. Thus, treatments applied immediately before and 7 days after flood provided the best control of RWW and the highest yields. Number of whiteheads was not significantly different among treatments.
Managing Nitrogen For Irrigated Corn In The Midsouth - Preplant To Pre-Tassel
Presented by Dr. M. Wayne Ebelhar, Research Professor and Agronomist, Mississippi State University
Managing nitrogen (N) fertility needs in corn probably receives more consideration and creates more questions than any other aspect of corn production in the Mid-south. Research a Mississippi State University conducted at the Delta Research and Extension Center near Stoneville, Mississippi has addressed many of the issues over the last several years and continues a robust program today. Area of interest and investigation have included, N sources, N rates, application timing (from pre-plant [PP] to pre-tassel [PT]), application ratios, starter materials, uptake enhancers, along with chemical and biological transformation inhibitors (nitrification and volatilization). These factors have been evaluated in rotations with cotton and soybean, on different soil types, across cultivars, in single-row (SR) planting patterns and twin-row (TR) planting patterns, on the experiment station and in producer fields. All research has been aimed at producing optimum yields with the most economical inputs and maximized returns on investments. Since 1980, corn production has ranged from as little as 28 bu/acre in 1980 (88,000 acres harvested) to 180 bu/acre (815,000 acres harvested) in 2013. The lowest acreage harvested (55,000) for grain occurred in 1983 while the largest acreage harvested in recent years (910,000) occurred in 2007. Cotton acreage has dropped significantly as the corn acreage has increased. The shift in crop mix has also brought about shifts in the infrastructure of the region. Cotton gins have been closed and on-farm grain bins and grain dryers have appeared on the landscape. Many fields have been land-formed to grade and irrigation wells established. Irrigated acres of all crops have greatly increased. Along with the shift to corn planting, soybean production has seen a dramatic shift to the Early Soybean Production System (ESPS) that incorporates early planting and earlier maturing soybean to provided significant gains in soybean production. This coupled with supplemental irrigation has led to significant yield increases in soybean. In recent years, some producers have approached the 100 bu/acre plateau. With the advances in production and shifts to grain, fertilizer use has also increased. In most situations, N requirements for corn can be double that of cotton. Nutrient removal for high-yielding corn and soybean, compared to cotton, have led to a greater need for soul testing and fertilizer use. Nitrogen use efficiency for corn has actually been shown to have increased in the last 20 years as yields have increased yet N applications per acre have not shifted dramatically. Crop rotation with soybean can be credited with at least a partial decrease in the required N per bushel. In the early 1980's, N recommendations called for as much as 1.7 lb N/bushel of expected yield but has been reduced to 1.3 lb N/bushel. However, in some years such as 2013, 250 bu/acre corn yields have been achieved with 180 to 210 lb N/acre following soybean in rotation. With more and more N, phosphorus (P), potassium (K), and sulfur (S) being removed from the field in the harvested crop, the greater the potential need for supplemental fertilizer. In many areas, for example, soybean has been grown for years with no fertilization. Soil reserves continue to be depleted and more nutrient deficiencies have been observed.
The focus of this review is N management from all aspects from early application through pre-tassel N applications. Initial research with corn was designed to evaluate N rates and application timing. The research was conducted under irrigated conditions as is the recommendation for corn production in the Mississippi Delta to maximize yield potential. Many areas of dryland (rain-fed) corn continue across the state but yields have not been consistent. Much of the initial research showed no clear advantage to split N applications. Most researchers agree that split applications are better with respect to actual N use efficiency compared to s single application. With high N rates, a single application, especially when applied prior to plant (PP), can be adversely affected by climate and the environment. Nitrogen use by corn plants is minimal from planting through the first few weeks of seedling development. Nitrification, denitrification, leaching, and volatilization can all lead to N loss before the plant can utilize the applied N. Some producer have been known to delay all N applications until V5 or V6 which could jeopardize potential yields. Single applications could be further delayed or losses greater if surface applications are used rather than some type of incorporation. Rate studies have shown little advantage to go above 240 lb N/acre in most situations. Rarely does rates above 250 lb N/acre result in significant grain yield increases. In some cases, a significant grain yield increase was not an economical yield increase. Research on-farm with twin-row production demonstrated this in three of four years. The studies were designed to evaluate increasing seeding rates and increasing N in twin-row corn. While both factors significantly increased yield independent of the other, only increasing seeding rates was deemed economical. Both the cost of N and the cost of seed as related to corn prices have to be considered in the valuation.
Over the last several years, many questions have been posed as to the validity and economic implications of N applications after the time that it physically possible to operate equipment across a corn field. Producers have always been interested in Atouching up= fields that had low spots or other drainage issues. Aerial applications of urea or ammonium nitrate have been used for many years without determination of whether the practice actually resulted in an economic benefit. About five years ago, a replicated field trial was initiated to evaluate urea applications just prior to tassel emergence. Urea was pre-weighed, then hand applied to simulate aerial application of 0, 20, 40, or 60 lb N/acre followed by rainfall or irrigation to incorporate. A series of traditional N rates (120 to 280 lb N/acre) were applied as the standard system with 120 lb N/acre applied prior to planting and the remaining 0 to 160 lb N/acre applied at the V5-V6 growth stage. Summarized data has shown no significant interaction between the standard N rates and the PT N rates. The statistical analysis of main effects did show a significant response to PT N with the greatest gains at the lower standard N rates. Results from this study has shown that the corn plants continue to take up N later into the growing season than previously thought and that N applications as urea could be effective in significantly increasing grain yields. These results do not suggest delaying N applications until tasseling as the typical means of N management but does suggest that the practice could be effective where N losses have occurred during the growing season. Further work is underway in an attempt to further refine the timing of the PT nitrogen application. This research involves simulated aerial applications from as early as V9 through VT and relating the growth stage to growing degree day units. The practices are also being evaluated on varying soil types and textures.
Nitrogen losses in the field are generally weather-related (both temperature and moisture) and can take the form of gaseous loss through denitrification and volatilization or leaching and run-off. In any case the losses prevent the primary goal of plant uptake. Multiple products are available in the marketplace to address these gaseous losses include Agrotain7 (Koch Agronomic Services) and Aborite7AG (Gavilon Fertilizer, LLC). Both products contain NBPT (N-(nbutyl)thiophosphoric triamide) responsible for slowing the conversion of urea to ammonia (urease inhibitor) that results in the volatilization loss of N. Other products that can be used to slow or disrupt biological transformations include nitrapyrin (InstinctJ and N-Serve7, Dow Agrosciences) and DCD (dicyandiamide, SKW Trostberg AG). These products inhibit the conversion of ammonium to nitrite (first step of nitrification process in soils). Some attention has been focused on NutriSphere-N (Specialty Fertilizer Products) which has also been proposed to enhance N uptake (mechanism is unclear). The other area of interest relates to polymer-coated materials such as ESN (Environmentally Smart Nitrogen7, Agrium Advanced Technologies) either used alone or in combination with other fertilizer N material such as urea. The ESN is a urea granule coated with a flexible polymer coating. The polymer coating protects the N from loss mechanisms and releases N based on temperature and soil moisture. Several of the above mentioned products or amendments have been and are currently being evaluated as possible N management tools. The ESN could allow for a single PP application that slow releases N for uptake closer to the time the plants need it. Volatilization inhibitors are effective in doing just that as long as conditions are present for volatilization losses. Where rainfall or irrigation is available to facilitate incorporation, the amendments should not be needed.
Managing N in corn may be more of an art than a science as many systems work equally well if the right conditions prevail. The goal for good nutrient stewardship provides the framework to achieve cropping goals, no matter what the crop. These goals are increased production, increased profitability, enhanced environmental protection, and improved sustainability. To achieve these goals, the 4R concept incorporates the Right fertilizer sources, applied at the Right rate, at the Right time and in the Right place (The Fertilizer Institute [TFI] and International Plant Nutrition Institute [IPNI]). Many factors can influence the outcome but profitability is the driving force.
Practical Strategies For Increasing Nitrogen Use Efficiency
Presented by Dr. John S. Kruse, Research Agronomist, Koch Agronomic Services
Granular urea is a widely used source of nitrogen for Mid-South rice producers, but is not the predominant nitrogen source for corn producers in that same geographic region. Urea has a greater nitrogen content (46% N) than other nitrogen sources such as liquid urea-ammonium nitrate (UAN), and can be applied with a rapidly-moving fertilizer spreader that will apply it in swaths up to 80 feet wide, making it more efficient than slower-moving UAN applicators that may only apply in swaths up to 40 feet. As farms continue to consolidate, producers are searching for options that allow them to apply inputs more quickly and efficiently. A major concern to corn producers considering switching to surface-broadcast urea is the potential loss of nitrogen due to volatilization – the result of urea hydrolysis converting the nitrogen to ammonia gas.
One practical option to protect against nitrogen loss available to growers in irrigated corn production is to water in the surface-broadcast urea within two days after the fertilizer application. Research from a University trial (Holcomb et al., 2011) suggests a minimum of one half inch of rain or irrigation is necessary to water in the urea deep enough to protect against volatilization. A similar study conducted in Louisiana revealed that surface broadcast urea that is not irrigated or incorporated volatilized more than fifteen percent of the nitrogen applied by two weeks after application (Harrell, 2013), highlighting the loss potential of unprotected urea.
AGROTAIN® nitrogen stabilizer is a urease inhibitor marketed by Koch Agronomic Services, LLC that affects urea hydrolysis, reducing the potential for nitrogen loss through volatilization. The active ingredient in AGROTAIN® nitrogen stabilizer is n-(n-butyl) thiophosphoric triamide, or NBPT, and has been thoroughly tested by researchers (Rawluk et al., 2001;). The mechanism by which it affects urea hydrolysis is well understood, and its efficacy in Mid-South rice production has been demonstrated through several research studies (Dillon et al., 2011; Norman et al., 2009). Mid-South corn producers are requesting similar research results in corn production, so that they can better evaluate the potential value of the technology in this crop. Field studies are currently underway in several Southern Universities that will help corn growers characterize the value of surface broadcast urea that has been protected with AGROTAIN® nitrogen stabilizer.
Several University research trials have already been conducted in corn production. A three-year trial conducted by the University of Kentucky (Schwab and Murdock, 2010) examined corn yields based on applications of urea 2 weeks after planting applied at a low and high rate, compared to an application of AGROTAIN® stabilizer-protected urea at a low application rate. Urea was surface broadcast in a Randomized Complete Block arrangement at 75 and 100 pounds of nitrogen per acre, while AGROTAIN® stabilizer-treated urea was surface broadcast at 75 pounds of nitrogen per acre. Overall yields for the three years were 140 bushels per acre for urea applied at 75 pounds of nitrogen per acre, 155 bushels per acre for urea applied at 100 pounds of nitrogen per acre, and 160 bushels per acre for AGROTAIN® stabilizer-treated urea applied at 75 pounds of nitrogen per acre. In all three years, yields for the stabilizer-treated urea was significantly greater (P=0.05) than urea applied at the same nitrogen rate, and numerically greater than yields from urea applied at the higher nitrogen rate. In a five-year study conducted in Illinois on non-irrigated silt loam soil (Ebelhar, 2009), yields increased by three bushels per acre for AGROTAIN® stabilizer-treated urea over untreated urea, and by five bushels per acre for urea infused with both a urease inhibitor and a nitrification inhibitor, over untreated urea. All treatments were surface broadcast at planting, and the average yield for the entire study (all treatments, N rates and years) was 158 bushels per acre.
Dillon, K.A., Walker, T.W., Harrell, D.L., Krutz, L.J., Varco, J.J., Koger, C.H., and M.S. Cox. 2011. Nitrogen Sources and Timing Effects on Nitrogen Loss and Uptake in Delayed Flood Rice. Agron. J. 104:466-472.
Eberhar, S.A., C.D. Hart, J.D. Hernandez, L.E. Paul, J.J. Warren and F. Fernandez. 2009. Evaluation of new nitrogen fertilizer technologies for corn. Illinois Fertilizer Conference Proceedings, 2009.
Holcomb, J.C., Sullivan, D.M, Horneck, D.A., and G.H Clough. 2011. Effect of irrigation rate on ammonia volatilization. Soil Sci. Soc. Am. J. 75:2341-2347.
Harrell, D.L. 2013. Rice Research Annual Report, Rice Research Station, Crowley, Lousiana.
Norman, R.J., Wilson, C.E., Slaton, N.A., Griggs, B.R., Bushong, J.T., and E.E. Gbur. Nitrogen Fertilizer Sources and Timing before Flooding Dry-Seeded, Delayed-Flood Rice. Soil Sci. Soc. Am. J. 73:2184-2190.
Rawluk, C.D.L., Grant, C.A. and G.J. Racz. 2001. Ammonia volatilization from soils fertilized with urea and varying rates of urease inhibitor NBPT. Can. J. Soil Sci. 81:231-246.
Schwab, G.J. and L. Murdock. 2010. Nitrogen transformation inhibitors and controlled-release urea. U. Kentucky Coop. Ext. Bull. AGR-185.
Corn And Soybean Yield Response To Bed Height And Longevity In A Rotation For No-Till Production On A Silty Clay Loam Soil
Presented by Dr. Normie Buehring, Agronomist, Mississippi State University
A long-term study in progress was initiated in the fall of 2005 to evaluate corn and soybean yield response to continuous no-tillage without raised beds, deep tillage with raised beds and raised beds with no deep tillage in a crop rotation for no-till production on a silty clay loam soil in North Mississippi. This site had been land formed in 2003 with a 0.15% slope. Bed heights were formed with a bedder implement equipped with coulters (setup in front of each buster), 11-inch busters, furrow shields (u-shaped plastic shields 2 ft. in length, mounted behind the buster and in front of the buster shank that helped to move the soil out of the furrow for improved drainage) and bed rollers attached to the rear of the toolbar. Five to 6-inch, 8 to 9-inch and 10 to 11-inch bed heights on a 38-row spacing were formed by adjusting the depth of the buster shank. The bed and deep tillage-bed treatments were either applied annually in the fall of each year or delayed after bed formation until yields were significantly lower than the annual fall deep tillage-bed and bed treatments. The deep tillage (10 to 12-inch in the row subsoil depth) bed treatments were applied with a TerraTilll® (in-row subsoil-bed-roller) one-pass implement (Bigham Brothers, Lubbock, TX). This research was done in a controlled traffic system. All tillage, planting and harvesting equipment wheels were aligned to travel in the bed furrows.
The no-till planter used in the study was equipped with trash wheels (moved the crop residue away from the planted row), double disk opens, inverted disk closing wheels with a flat press wheel and adjustable down pressure springs on each planter unit. The harvest combine was equipped with a straw chopper that distributed the crop residue on the soil surface in a uniform manner. All treatments for both soybeans and corn were planted no-till (no spring tillage) 3 to 4 weeks after a burndown herbicide had been applied. Old corn stalk residue interfered with proper soybean planter alignment over the row. A chain harrow operated at 7 mph with 3 rows of spikes touching the soil surface effectively moved the stubble away from the bed surface which allowed soybean planting on the old beds without affecting planter alignment or planting depth.
Corn was more responsive to bed height and deep tillage than soybeans. The TerraTill treatment with an initial 8 to 9-inch bed height resulted in more consistent higher corn yields than the 5 to 6, 8 to 9 and 10 to 11-inch annual fall bed treatments. However, there were no corn yield differences between the TerraTill applied every year, every other year or every 4th year. Five of 8 years (2006-2013), no-till corn planted flat (no bed) had the lowest yield.
This was in contrast with soybeans where 5 of 8 years no-till soybeans planted flat (no beds) yields were equivalent to TerraTill and all other bed treatments. No-till soybeans had the lowest 8-year yield average while TerraTill applied every other year or every 4th year had the highest 8-year yield average which was equal to continuous TerraTill applied every fall. The 3 years of low soybean yields for the no-till flat planted soybeans were related to wet soil conditions at planting and/or high rainfall during emergence that often resulted in stand reductions and poor early season growth. Two (2009 and 2013) of these 3 years, the soil surface on the beds had a dry crust while the no-till flat planted soil surface was a little sticky and stuck on the planter depth control wheels. These 2 years no-till had lower populations, less early season growth and lower yields than the bed treatments. In 2008, high rainfall and wet soil condition following planting resulted in low populations, less early season growth and lower yields than the bed treatments.
In summary, no-till production on old beds can be successful on a silty clay soil when using a controlled wheel traffic system and as long as beds are at least 3 to 4 inches tall. Initial bed heights higher than 8 to 9 inches did not increase yield. Deep tillage with raised beds applied every 4th year is sufficient for high yields with corn and soybeans. However, soybeans most often only showed a significant yield response to beds and deep tillage with beds when adverse spring planting conditions with wet soil conditions and/or high rainfall during seedling emergence and early growing season. This resulted in reduced plant populations, plant heights and yield for the no-till planted flat (no bed) system
Improving Irrigation Application Timing And Efficiency In Mid-South Soybean Production Systems: A Discussion On Irrigation Scheduling Tools, Phaucet And Surge Valves
Presented by Dr. L. Jason Krutz, Associate Extension/Research Professor, Mississippi State University
Means to improve irrigation application timining and efficiency exist, but the adoption rate among Mid-South Producers is negligible. The objective of this break-out-session is three-fold: 1) discuss the benefits of using soil moisture sensors for scheduling irrigation events; 2) define irrigation application efficiency; and 3) describe how PHAUCET and Surge Valves improve furrow irrigation application efficiency and bottom lines.
4Soybean Disease Identification And Management In Reduced-Tillage Production Systems: New Challenges
Presented by Dr. Boyd Padgett, Regional Director/Plant Pathologist, LSU AgCenter
DISEASE IDENTIFICATION AND DEVELOPMENT:
Specific environmental conditions for disease development are listed in table 1.
Aerial Blight (Rhizoctonia solani) (sheath blight in rice): Initial symptoms appear as water-soaked greasy blotches on the leaflets (usually in the lower to mid canopy). As the disease progresses, adjacent leaflets can be stuck together by fungal mycelium (white cottony in color). If favorable conditions persist, the foliage becomes brown and pods will have reddish-brown lesions and can abort from the plant. The disease is usually evident during and after the early reproductive stages of growth. The fungus survives in the soil and on plant debris.
Cercospora Blight/Purple Seed Stain (Cercospora kikuchii): The foliar symptoms are usually not evident until the mid to late reproductive stages of growth, but infection can occur early in the season. Initial symptoms are small chocolate brown lesions on the petioles near the leaflet. Foliar symptoms occur as a reddish brown to tan discoloration on the upper leaf surface in the upper canopy. Leaves have a leathery appearance. The fungus can sporulate in older lesions (resemble ashes). Advanced stages of this disease result in premature defoliation, discolored pods, and reduced seed quality. The seed phase is evidenced by purple-stained seed. The pathogen survives on seed, some weeds, and plant debris.
Downy mildew (Peronospora manshurica) is not a major threat to Louisiana soybean. Symptoms can be confused with soybean rust. Symptoms initiate as small pale green to yellow spots on the upper leaf surface. Older lesions may turn reddish to gray to dark brown. When the disease is active, grayish tufts of fungal mycelium (similar to dryer lint) can be found on the underside of the leaf opposite the yellow spot.
Frogeye leaf spot (Cercospora sojina): Symptoms are found predominately on the leaves, but can occur on the petioles, stems, and pods. Initially, small chocolate brown to purplish spots are present on the leaflets. Mature lesions have light brown to gray centers with a reddish brown to purplish margin. Stem lesions while rare are elliptical with red centers and dark brown to black margins. Pod lesions are circular to elliptical, sunken, and light gray to brown. Seeds infected with this pathogen exhibit grayish to light purple lesions. The pathogen survives on seed and infected plant debris.
Soybean Rust (Phakopsora pachyrhizi): Symptoms initiate in the lower canopy as small brown to tan raised pustules (volcano-like) on the lower leaf surface. Spores produced in the pustules resemble sand and are tan in color when young. Older spores are darker in color. As the disease progresses, the pustules can coalesce and cause the leaflets to defoliate. Symptoms are usually evident when soybean is in the mid to late reproductive growth stages. Pustules can also occur on petioles and pods when disease is severe. Kudzu is another host for this fungus.
Anthracnose (Colletotrichum truncatum): Early infections can result in pre- and postemergence damping-off. Foliar symptoms include petiole cankers, leaf rolling, necrosis of the laminar veins, and premature defoliation. The fungus can produce acervulli (fruiting bodies / black specks) on the stems and pods. If the disease continues to develop on the pods, seed quality will be compromised. The fungus overwinters in crop debris or infected seed.
Charcoal rot (Macrophomina phaseolina): Infected seed may not germinate or seedlings may die soon after emergence. Symptoms from plants with latent infections or mid to late season infections die prematurely during hot, dry weather. Symptoms can be associated with dry spots (sandy areas) in the field. The roots and lower stems are deteriorated, and the epidermal and sub-epidermal tissue will be silvery in color and dotted with black pepper-like sclerotia (survival structures). The fungus may survive in the seed coat, in host residue, or in the soil.
Phytophthora rot (Phytophthora spp.): Soybean may be affected during any growth stage. This disease is most common on heavy, tight soils prone to flooding. The fungus overwinters on crop residue in the soil. Symptoms include wilting and a chocolate brown lesion at the base of the stem. This lesion can extend several inches above the soil line.
Pod and Stem Blight (Diaporthe phaseolorum var. sojae) occurs frequently on the pods and stems. Infection can occur early in the season; however, signs of the disease are not evident until late season (R7). Pycnidia (fruiting bodies / black specks) occur in linear rows on the stems and pods. If favorable conditions persist, seed quality will be compromised. The fungus overwinters in crop residue or on seed.
CULTURAL PRACTICES, GENETIC RESISTANCE, AND FUNGICIDES
Tillage practices impact the initial inoculum present at planting and during the growing season. Reduced tillage practices result in more plant debris in the field. This plant debris can harbor plant pathogens and increase the risk to Cercospora foliar blight, pod diseases, and aerial blight. Rotate fields periodically to a non-host to reduce the initial inoculum. Plant when conditions favor rapid germination and seedling establishment. A healthy plant is the first step toward optimizing yields and preventing disease. Improve drainage within the field. This helps reduce the risk to some soilborne diseases such as Phytophthora rot. Practices that promote air movement within the canopy reduce the leaf wetness period and lessen the risk to some foliar diseases.
Disease resistant varieties should be the foundation of any disease management strategy. The LSU AgCenter conducts variety evaluations on research stations located throughout the state. When genetic resistance is not available, fungicides can be utilized for managing diseases. However, resistance has been documented in SOME, BUT NOT ALL, pathogen populations. Consult labels for proper rates and timings.
Increasing Farm Profitability Using Automatic Section Control (ASC) On Planters
Presented by Dr. Michael Buschermohle, Precision Agriculture Specialist, University of Tennessee
Precision agriculture technologies enable producers to increase profits by applying crop production inputs such as seed, fertilizer, pesticides, growth regulators and defoliants on a site-specific basis in the field. There are several technologies commercially available today to apply production inputs based on the location of farm equipment in the field. One example of this technology is Automatic Section Control (ASC) for row crop planters.
ASC for row crop planters has been on the market for several years. ASC eliminates double-planting in areas of fields where planter overlap normally occurs such as end rows, point rows, and around internal field obstacles. ASC utilizes the Global Positioning System (GPS)/Global Navigation Satellite System (GNSS) location of the planter and previously planted coverage maps to control individual planter units or sections of planter units. As the planter travels across the field, the controller continually checks to see if the planter units are passing over previously planted areas or areas that have been mapped as no plant zones. When the planter units pass into these areas, it is turned off automatically and turned back on when it passes back into areas that are unplanted (Figure 1). By eliminating planter overlap, ASC has the potential to reduce seed input costs and yield losses resulting from harvesting inefficiency.
Figure 1. Field planted with Automatic Section Control
There are several economic benefits of equipping planters with ASC. A recent study in Tennessee showed the potential of reducing seed costs in cotton production systems with ASC. In this study, the Real-Time Kinematic (RTK) GPS position of the planter and planter status (i.e. planting or not planting) was monitored every 1/10th of a second in 52 cotton production fields that totaled 1725 acres. Percentage of minimum double-planted area was found to range from as low as 0.1% to as high as 15.6% with an average of 4.6% across all 52 fields. The total minimum double-planted area across all fields was 54.7 acres. With seed cost of $110 per acre, planting with ASC would reduce seed cost by over $6000 a year for this 1725 acres.
Another benefit of planting with ASC is the potential to eliminate harvest losses in these double-planted areas. In cotton production systems, end rows are typically picked in one direction and then stalks are mowed with a rotary cutter. The Tennessee study showed cotton yield losses in double-planted areas resulted from this harvesting method. Treatments used for this study included single-planted rows that would result from using ASC on the planter and three double-planted treatments at angles of 30°, 60°, and 90° in relation to the straight rows not using ASC. All treatments were picked in one direction and weighed to determine if yields differed among treatments. As shown in Figure 2, the two year average lint yields from the single-planted treatments were statistically different from the double-planted treatments. The two year average lint yield from the single-planted treatments was 1389 lbs/ac compared to 917, 943, and 1033 lbs/ac for the double-planted treatments with rows crossing at 30, 60, and 90 degrees, respectively. These differences in yield were attributed to the fact that some cotton plants in the crossing rows were not harvested (Figure 3a) on the first pass due to the configuration of the picker header (Figure 3b). However, the angle at which the picker intersected the cross rows did not have a significant impact on the amount of cotton left behind in double-planted plots after a single harvest pass.
Figure 2. Two year average lint yield in lbs/ac per treatment.
Figure 3. (a) Cotton not harvested during the first pass of double-planted plots and (b) picker header limitations when harvesting crossing rows.
The amount of double-planting that occurs in fields is dependent on several factors such as field size, field shape and planter width. Fields that are more irregular in shape tend to have higher incidences of double-planting. Also, as farming operations become larger, producers are purchasing wider planters to speed up planting. As planter width increases, a potential risk of increasing planter overlap, especially in end rows and point rows, can occur. This talk will demonstrate the Automatic Section Control for Planters Cost Calculator (ASCCC) that was developed by The University of Tennessee (http://economics.ag.utk.edu/asccc.html). This computerized decision aid tool estimates the number of years it will take to pay off investing in ASC on planters based on a producer’s farming operation.
Using Commercially Available Wireless Soil Moisture Systems On-Farm In Cotton
Presented by H.C. (Lyle) Pringle, III, Associate Agricultural Engineer, Mississippi State University
Cotton Incorporated funded an irrigation demonstration project in 2011 in Mississippi to access the usability of commercially available wireless soil moisture systems. A producer was selected that was concerned about the declining aquifer in the area and was interested in using the data from soil moisture systems to make irrigation decisions that could help him save water. He was also interested in seeing how well the wireless communications systems worked for some of his remote fields.
Two different types of soil moisture sensors were selected for the project. A Decagon EC-5 soil water content sensor, which measures capacitance and is correlated with volumetric water content and an Irrometer / Watermark 200SS soil water potential sensor which measures resistance and is correlated to the negative pressure that the plant has to put on the soil to remove water.
Being 45 miles away from the project site and considering the traffic in a cotton field we did not want these soil moisture systems to become an obstruction in the field where they could get damaged or had to be temporarily removed from the path of the equipment, so we selected the manufacturer’s associated dataloggers and wireless equipment to minimize their footprint in the field. The Decagon sensors were instrumented with an EM50G cellular datalogger. It was placed in the drill within the canopy and below the height of the tool bar of cultivation and spray equipment so the only thing above the canopy was a bicycle flag denoting where the unit was in the field. The Irrometer/Watermark sensors were instrumented with an Irrometer 950T radio transmitter that was also placed in the drill within the canopy but was modified such that the antenna was mounted above the canopy on a bicycle flag using an extension cable which was flexible enough to not be damaged.
The sensors were placed at depths of 8, 16, & 24 inches in the drill. The Decagon system was set to collect data every 2 hours and to send data 4 times a day by cellular transmission to the Decagon server where data would be stored. The data would then be available for download on-line from this server to each participant’s computer where it could be charted and summarized with Decagon’s Data Trac software. The Irrometer system came pre-programmed to radio data from each site to a central receiver whenever changes occurred in the data. This central receiver would store the data on site then send the data to the Irrometer server using a cellular gateway where the data was put in tabular and graphical form and could be accessed on-line by all participants.
This year both Irrometer and Decagon offered an option to monitor a reduced set of the data collected from a tablet or smart phone. The producer utilized this option on his I-Pad and we tested it out on an Android tablet and phone with success.
In general, these wireless communication systems worked well but needed some attention from time to time. Failure to transmit data occurred when there were issues with poor cellular signal strength, mechanical damage to the antenna or cabling, moisture in the enclosure, and poor battery/sensor connections. With proper installation and handling these issues can be minimized.
This project was located at a different group of fields each year. The producer was asked to initiate irrigations in each of the three to four irrigation sets approximately a week apart if no rainfall occurred, starting the first set at the time he felt was proper. Once initiated, he was to determine the timing of subsequent irrigations for each set. Soil sensor data was monitored throughout each growing season. The Decagon units were placed half-way down the furrow irrigated row in similar soils in each of three or four irrigation sets. The Irrometer units were placed a few rows over from the Decagon units ?, ?, and ? down the row. The producer became more comfortable using this data to schedule irrigations each year.
The data from the Irrometer units that were placed at three locations down the row surprised the producer that he was not getting the lower end of the field watered as well as he thought. Basically he was stopping the irrigation shortly after the water had reached the end of the field, not giving these silt loam to loam soils which have low infiltration rates, enough time to wet the sensor at the 8 inch depth. We discussed surge flow as an option to improving his irrigation uniformity down the row, by surging to get the water across the field faster, then using shorter soak cycles to allow more time for water infiltration while reducing runoff.
Over the three years of this project, the results were similar. The later initiations resulted in the highest yield samples collected with less total water applied. The sensor data indicated that the plant had removed more water at the time of initiation at the 24-inch depth of the later initiations than the earlier initiations. Thus, the rooting depth of these soils was definitely 24+ inches during the years of this project. Proper irrigation scheduling to maximize yield with the least amount of water makes use of what water the soil can provide throughout the active rooting zone.
The producer monitored the sensor data regularly throughout all three seasons, and was pleased with the easy access to the data and the results that the later initiations could save him an irrigation, time, and energy in most cases on these soils without reducing yields.