Cotton -- The University of Georgia









UGA Georgia Cotton Newsletter

May 21, 2002 - Click here for a printable copy

In this issue

  • What the New Farm Bill Means to Georgia Cotton Producers
  • Crop Situation
  • Irrigation
  • Scout Schools
  • Early Season Insects
  • The Limits of a "Textbook Case":Early Season Disease and Nematode Issues for 2002
  • HADSS (Herbicide Application Decision Support System) Free for GA Extension Agents, etc
  • Touchdown plus Dual Magnum Labeled for Use in Roundup Ready Cotton
  • Pointers with RR Technology
  • Glyphosate vs. Glyphosate plus Staple (Staple Plus) vs. Touchdown plus Dual Magnum
  • New Farm Bill Fertilization - Same as for Drought
  • What the New Farm Bill Means to Georgia Cotton Producers (Shurley) A new farm bill has become reality and will be effective for the 2002-2007 crop years. For the cotton producer, there are many aspects of the bill which should be beneficial. Let me briefly summarize each:

    Update Base Acres and Payment Yields. A cotton producer's base acreage is currently the 3-year average of acres planted and considered planted in 1993-95. The new farm bill will allow farms the election to update base to the 4-year average acres planted and considered planted in 1998-2001. This should result in bringing bases closer to actual plantings and thereby improve the income safety net by bringing program benefits more in line with crop income. Georgia producers planted 46% more cotton in 1998-2001 than in 1993-95. Also, farms that did not plant cotton until 1996 or after do not have a base. Under the new farm bill, these farms will qualify for base and payments on base acres. Farms that elect to update bases may also elect to update FSA payment yields.

    Counter Cyclical Payments. The 1996 farm bill provided planting flexibility to producers but did not provide an adequate safety net in years of low commodity prices. As a result, Congress had to administer supplemental assistance in recent years. Some of this assistance came in the form of additional (double) AMTA payments. The new farm bill institutes "counter cyclical payments" which are designed to provide additional protection from low prices and eliminate the need for supplemental/ad hoc legislation.

    Payments and Payment Limits. The earlier Senate version of the farm bill contained the Grassley-Dorgan amendment which proposed to reduce payment limitations, eliminate multiple entities, and count gains through use of marketing certificates against the payment limit. It also would have included both peanuts and cotton under the same single payment limitation. This would have severely hampered even moderate sized farms producing both cotton and peanuts. In House-Senate conference, these Senate provisions were defeated. The new bill contains a $40,000/person limit on Direct Payments (called "AMTA" under the old farm bill), $65,000/person on Counter Cyclical Payments, and $75,000/person on LDP's/POP's and marketing loan gains (MLG's). The spouse and multiple entity rules are maintained and use of certificates without gain is maintained.

    Many Georgia cotton producers also produce peanuts. The opportunity to update cotton base acres along with the decision that must be made about assignment of peanut base presents a critical decision for many producers. Legislation states that total crop bases for a farm plus peanut base plus CRP (and wetland reserve) acres may not exceed the available cropland acres for the farm. Double crop history is considered. This rule may not impact most producers unless it involves the assignment of peanut base. Table 1 illustrates a purely hypothetical example of Direct Payments (DP) and Counter Cyclical Payments (CCP) by crop per acre of base.


    Producers should evaluate their situation closely. CCP's will vary when market price is above the loan rate for the crop so these payments may change during the 6 year life of the farm bill. If desired bases including assignment of peanut base are above the FSA allowable acres, crop base will have to be reduced or peanuts assigned to another farm.

    The new farm bill appears to offer increased payments and income safety net compared to the 1996 bill (Table 2). The combination of updated base and counter cyclical payments, in the example shown, increased return to management, fixed cost, and overhead by 112%. Of course, a portion of this increase was due to increased base acres. Farms without as large an increase in base will not realize the same proportional increase.

    Producers are also reminded that CCP's decline at prices above the loan rate. Under the new farm bill as with the ‘96 bill, the only guaranteed payments are the Direct Payments (DP). Also, total benefits of the new farm bill will not accrue to the producer if land rent rates increase as a result of increased payments.


    Crop Situation. (Brown) As of May 20, about 65 percent of the Georgia crop is planted. Parts of the state, particularly that which was established early in central and south Georgia, are off to an excellent start. Extreme drought had halted planting in early to mid-May, but showers occurred across Georgia over the weekend. The relief was welcome but temporary. More rainfall is needed in most places. Thrips have been heavy in many fields, revealing the good and bad of control measures. In addition to planting the remainder of acres, growers' primary focus now is weed control. Lessons learned or re-learned to date:

  • Initiating planting in mid-April when moisture is adequate and when prevailing temperatures are reasonable is a solid strategy for non-irrigated producers.
  • Re-running a planter unit over the row is an acceptable substitute for a rotary hoe where crust busting is needed. Properly timed, the planter slices through the crust with little harm to emerging plants.
  • Irrigation. (Jost). For cotton producers the timing of the first irrigation, as well as the frequency of subsequent irrigations, is always a difficult management decision. As far as when to start, many growers hold to the old adage "I want my cotton to stress a little so it will peg down". This phenomena may be true and may work for some growers in certain areas, especially where the water holding capacity of the soil is greater than it is here in Georgia. However, does this "pegging down" really help us later in the season, or do we lower yield potential by stressing these young plants?

    Dr. Craig Bednarz has conducted studies examing the soil wetting depth achieved by irrigation. A common amount for Georgia producers to apply is 1" of water per irrigation. Dr. Bednarz found that this amount of water will effectively wet the top 6 inches of soil. In this same study a 2" irrigation a couple weeks later wet the soil to a depth of 12 inches. It was not until a 1.4 rainfall a couple weeks after the last irrigation did the soil profile wet to an 18" depth.

    Therefore, if we stress the plants to make the roots grow deeper and then apply a light irrigation, did we really help the crop? While there are still some unanswered questions, it may be that we need to look at starting the water sooner and more often. Studies in the San Joaquin Valley have shown that turning the water on too early does not have nearly the negative effect on yield as does waiting too long. Once the cost of installation, equipment and interest are incurred it makes sense to use the system.

    Water availability can complicate the issue though. If a grower only has enough water to irrigate the crop a set number of times, then when is the best time to irrigate? While this too can be debated, much work has been to show that the peak demand time for water in a cotton crop is during the bloom stage.

    Scout Schools. (Roberts). Several scout schools have been conducted to date. However there are still several programs scheduled in various parts of the state. Contact the coordinator at respective locations for more information. See the UGA Cotton Calendar for a list of locations, dates and contacts.

    Early Season Insects. (Roberts) Historically, cotton planted during April and early May tends to have more thrips injury compared with late May and June plantings. Higher incidence of injury on early planted cotton is due to two factors, 1) slow plant growth and 2) higher thrips populations. Thrips feeding in the terminal bud on unfurled leaves results in the characteristic cupping and crinkling of expanding leaves. If plant growth is slow, slight injury may occur, even though the preventive insecticide treatment is working. Preventive insecticides used for thrips control are systemic and thrips must feed on the plant to receive a toxic dose. If plant growth is slow and migration of adults into the field is high, limited feeding prior to thrips mortality by high numbers of thrips will cause slight injury. The same may also be true if seedling growth is reduced due to moisture stress. Additionally, dry soil conditions are not conducive for plant uptake of the preventive insecticide. Foliar treatments are typically only needed when the preventive treatment is failing (ie immature thrips infesting seedlings, eggs hatched on the seedling and immature thrips are developing). At this time all fields should be monitored for thrips and plant injury. Foliar sprays are recommended if thrips number 2-3 per plant, especially if immature or wingless thrips are observed. Immature thrips are a light creme color and lack wings compared with adults which may be black or yellowish-brown and have two pairs of fringed wings. A hand lens will aid in separating adults and immatures. Damage from thrips is less likely to occur once plants reach the 4-5 leaf stage and are growing rapidly. Foliar treatments for thrips control include Orthene, Bidrin, and dimethoate. After a foliar application is applied, the next 1-2 leaves may continue to exhibit thrips damage symptoms since thrips were feeding in the terminal bud which contains several unfurled leaves. Foliar thrips insecticide treatments should only made if needed.

    High populations of grasshoppers have been observed in some reduced tillage fields. Insecticide treatment for grass-hoppers should be based on plant feeding and if the stand is threatened. If extremely high populations are present at planting, a preventive spray may be justified. Immature or wingless grasshoppers are very susceptible to insecticide, but adults (winged) are difficult to control. If treatments are made, pyrethroids at a medium to high rate appear to be a good option.

    The Limits of a "Textbook Case":Early Season Disease and Nematode Issues for 2002. (Kemerait) County agents have likely grown weary of hearing specialists preach the importance of cool and wet weather for seedling diseases of cotton and proper sampling dates in the fall of the year for accurate nematode reports. A cotton training would be incomplete without the interjections that "seedling disease in cotton is favored by cool and wet soils at planting," and "nematode samples should not be pulled during the winter or early spring as the population of parasitic nematodes is likely to be too low to make any recommendations for the grower." Both of these statements are generally true, but perceptive observations by a number of county agents have shown that "generally" is not always good enough.

    Seedling disease and weather: There is no question that seedling diseases of cotton are more severe when conditions favor the growth of the pathogen and slow the germination and development of the seedling. Cool and wet weather is often associated with poor stands as the seeds rot before emergence or young plants do not survive well. Such conditions are very favorable for losses to the water mold, Pythium sp. This year, although we have not had cool, wet weather during planting, seedling diseases have been common in some fields. For example, a trial at the Midville Station has been severely affected by seedling disease and at least one field in Dooly County was replanted in recent weeks because of losses to seedling disease. What factors are at play here?

    The most common pathogen of cotton seedlings that growers in Georgia face is Rhizoctonia solani. Unlike Pythium, this fungus is less often associated with seed or root rots and is most often associated with "soreshin" where the fungus attacks the tender hypocotyls just below the soil surface. Once the hypocotyl is girdled, the seedling wilts, and often topples over. Rhizoctonia solani is able to cause significant amounts of disease in poorly rotated fields even when planting occurs where soil temperatures appear sufficiently warm and dry enough to avoid stand loss. For this reason, growers should consider field history as an important indicator for the need of an in-furrow fungicide at planting.

    Sampling for Nematodes: To best identify potential nematode problems in a field, growers should pull and submit soil samples to the nematology lab in Athens either at the time the trouble appears during the season (trouble shooting samples) or at harvest in the fall. Populations of nematodes are normally greatest at the end of the season and this will give the specialist and the agents the best opportunity to identify fields with problems. However, as several agents have pointed out, nematode samples that are pulled during the winter or prior to planting are not necessarily "worthless". These samples are just less likely to provide useful information. To make this case, I draw upon examples from Colquitt and Burke Counties this year. In both cases, nematode samples were pulled and submitted to the nematology lab in the early spring. Both samples came back with counts of root-knot nematodes that exceeded the economic threshold and the sample from Burke County also identified levels of Reniform nematode that were completely unexpected. In these examples, the samples clearly provided information of importance to both the grower and the agent. Therefore, if samples submitted during the winter or spring show high populations of parasitic nematodes, then the grower can be certain that he has a problem. The risk is that fields with nematode problems will not be identified when samples are pulled in the winter because the populations are simply low at this time of year. For example, if a sample was pulled during the early spring and it came back with the diagnosis that parasitic nematodes were below the threshold level, the agent could not be sure if this was because populations were always low, or simply low at this time of the season and would quickly rebound to damaging levels when the cotton was planted. The best time to sample for nematodes remains in the fall after harvest. However, samples collected in the winter or spring, especially after a mild season, may still provide answers for growers in some instances.

    HADSS (Herbicide Application Decision Support System) Free for GA Extension Agents, etc. (Culpepper) HADSS is a family of weed control decision aids developed by North Carolina State University, with databases customized for different states by weed scientists from those states. These decision aids have been designed to assist extension agents, growers, consultants, and pesticide applicators in making economically sound weed control decisions for both postemergence and soil-applied herbicides.

    Over the past two years, Dr. Ted Webster and I have been trying to validate HADSS for use in Georgia cotton. The computer decision aid model is not perfect but it may be of some assistance in making weed control recommendation in cotton.

    For extension agents interested, go to Along the left hand side of the page select the "order-special" option. Select Georgia - HADSS and fill out your contact information. Beside "KEY" type in your county so your request can be verified. In the comment section type in that you are a county agent.

    For other interested parties (non-county agents), order online, by mail, or by phone by selecting the proper option along the left hand side of the web page ( The program will cost $95.

    Touchdown plus Dual Magnum Labeled for Use in Roundup Ready Cotton. (Culpepper) Last week Georgia obtained a supplemental label allowing a mixture of Touchdown and Dual Magnum applied to Roundup Ready cotton. Click here for a copy of this supplemental label. For additional information regarding this mixture view the April 19, 2002 Georgia Cotton Newsletter.

    Pointers with RR Technology. (Brown) Georgia producers have wholeheartedly embraced Roundup Ready (RR) technology as indicated by surveys which show that over 85 percent of the 2002 crop is expected to have the RR gene. A few points to remember:

  • Conventional, Bt, and stacked varieties are often superior in yield performance to RR varieties, suggesting that straight RR offerings are not the best choice in irrigated fields with high-yield expectations.
  • Don't be tardy with over-the-top applications. The label allows over-the-top applications until the 5th leaf exceeds the size of a quarter. Late (mis) applications reduce yields 15 to 20 percent of the time, while affects on fruiting occur with about 40 percent frequency. An easy way to reduce yield potential is to abuse the label.
  • While there is a tendency to delay treatment until every weed has emerged, established weeds can exert serious competitive influence on young cotton. Competitive effects of weeds may be much greater under dry conditions. Spray early! Don't let a field reach "jungle" status before spraying glyphosate or glyphosate mixtures.
  • A glut of glyphosate products is available. Many provide excellent weed control and crop safety. Only a couple of new generic products, foreign entries which are not cleared for over-the-top use in RR cotton, have caused foliar damage on RR cotton. Adjust for differences in lb/gal AI (for example, 1.6 pt of Roundup Ultra Max, a 5.0 lb/gal product, provides equivalent glyphosate as 2 pt of 4.0 lb/gal formulations).
  • If thrips control is needed, acephate (Orthene, etc.) has worked well as a tank mix partner.
  • Glyphosate vs. Glyphosate plus Staple (Staple Plus) vs. Touchdown plus Dual Magnum. (Culpepper) Early postemergence weed control options in Roundup Ready (RR) cotton are generally limited to three practical labeled choices: glyphosate alone, glyphosate plus Staple, or Touchdown plus Dual Magnum. Choosing between these three options is usually a field by field decision considering weed infestations and cost of the herbicide treatments.

    Glyphosate applied alone controls most weeds very effectively. Those weeds that are most commonly missed by glyphosate applied alone include morningglories greater than 3 inches, hemp sesbania, dayflower species, tropical spiderwort, and florida pusley. However, the most common complaint with glyphosate applications usually involves the weeds that germinate and emerge as soon as the sprayer leaves the field.

    Staple plus glyphosate improves control of emerged morningglory (except tall), hemp sesbania, dayflower species, and tropical spiderwort compared to glyphosate alone. In addition, residual activity from Staple, if activated by rainfall or irrigation, provides good control of pigweeds, morningglories, redweed, poinsettia, Florida beggarweed, and bristly starbur. Mixing Staple with glyphosate occasionally causes temporary leaf yellowing, bronzing, and/or leaf crinkling when applied over-the-top of RR cotton. Research in GA and across the Southeast indicates this injury is transient and cotton recovers quickly as long as the application is made to RR cotton between the 1 and 4-leaf stage of growth.

    Dual Magnum plus Touchdown does not improve postemergence control of weeds compared to glyphosate applied alone but provides residual weed control if activated by rainfall or irrigation. Weeds that are sensitive to Dual Magnum include most annual grasses (but only suppression of Texas panicum), pigweed species, tropical spiderwort, Florida pusley, and yellow nutsedge. Mixing Dual Magnum with Touchdown and applying over-the-top of RR cotton often causes pin-point necrotic speckles on leaves present at time of the application. Again, research indicates this injury is transient and cotton recovers quickly as long as the application is made to RR cotton between the 1 and 4-leaf stage of growth.

    The advantages of mixing Staple or Dual Magnum with glyphosate often go unnoticed when herbicide applications are made in a timely fashion. However, for those growers who are 7 to 10 days late with directed applications, one of these tank mix partners may be of great benefit by reducing weed size at time of the directed application.

    Do not apply Dual Magnum plus Staple overtop of cotton as SEVERE injury will occur.

    New Farm Bill Fertilization - Same as for Drought. (Harris) During the winter meeting season, a farmer asked "What should I do different this year ?" As far as fertilizing and liming, I don't think much has changed compared to last year. Cotton prices are about the same and it looks like we're off to another dry weather start. So it's "back to the basics" again to make every fertilizer and lime dollar count.

    Lime and pH Some people didn't believe the numbers out of Atlanta that said we cut lime usage in half last year. Others said they made sense and that times are so tough that we are withdrawing on lime where we previously invested. We should soon know the truth. Watch out for early stunting, yellowing and poor growth. All are signs of low soil pH. Whole fields may not be affected but large irregular shaped areas may. Especially watch for weak, sandy spots that are also probably low in potassium.

    Nitrogen This is probably the one nutrient we have a chance to save the most money on without sacrificing yields. The name of the game here is fertilizing for a realistic yield goal and using split applications. Factor dryland vs. irrigated into the realistic yield goal side of the equation. Yield goals of 1250 and 1500 assume irrigation or a proven yield track record if dryland. Another dryland trick is to be more conservative on sidedress N. If good weather (rainfall) continues, you can finish the crop off with foliar N. If dry weather prevails, you saved some money by not sidedressing with an (irrigated) high-yield N rate. And always use split applications. About 20-30 lb N/a at planting followed by 50-60 lb N/a at sidedress in general is hard to beat.

    Potassium We didn't seem to have as many potassium problems last year, probably because most places finally got some decent rains. One thing we should have learned by now is that applying all the recommended potash at planting is superior to split applications, especially on dryland. The jury is still out on foliar K, or to be more accurate, we are still learning when foliar K will pay and when it won't. Is a little foliar K better than a little extra applied to the soil with sidedress N ? We're still looking at that one. Stay tuned.

    Sulfur Don't forget sulfur. If you didn't put 10 to 20 lb S/a with your preplant fertilizer, you still have time to put some in with your sidedress N. If using granular fertilizer, put some ammonium sulfate or K-Mag in with that ammonium nitrate. If using liquids, use one that contains 3-5 % S derived from ammonium sulfate or ammonium thiosulfate. "28-S" is a popular sidedress material for good reason.

    Manganese I get a lot of calls every winter about soil test recommendations for manganese. High soil pH and low soil test Mn is the situation to watch out for. Even in this case , we know that large amounts of soil applied Mn are just not economical. Putting smaller amounts of Mn in with a starter and/or by foliar is the better way to go. If you are running your pHs too high, you may be able to let them come down a little and avoid a problem. In those borderline cases where you are not sure you will have a problem, the best strategy is to tissue sample soon after first square and correct with a foliar feed if needed.

    Boron Money spent on boron is like good insurance, and it's cheap. There are a lot of formulations out there and they all work about the same. So base your selection on availability, % B, ease of handling, and above all - cost. Application costs often are higher than the cost of B material. When we used to spray for insects a lot, it was easy to "cost share" by tank mixing with insecticides. Now with Bt cotton and (in general) low worm pressure, it's harder to foliar feed boron. Early Pix sprays may be too early, and late stink bug sprays, too late for B. Preplant B on "stiffer dirt" or anything but deep sands should work. An even better technique is too include some B with your sidedress N. Liquid B mixes with liquid N real well. Just don't let your friends say to you what my cotton team friends say to me – "don't forget the boron you moron!"

    Snake Oils Don't use em. ‘Nuff said.

    Edited by: Philip H. Jost, Extension Agronomist-Cotton & Ag Crops

    Contributions by:

  • Steven M. Brown, Extension Agronomist-Cotton
  • Stanley Culpepper, Extension Agronomist-Weed Science
  • Glen Harris, Extension Agronomist-Soil and Fertilizer
  • Philip H. Jost, Extension Agronomist-Cotton & Ag Crops
  • Bob Kemerait, Extension Plant Pathologist
  • Phillip Roberts, Extension Entomologist-Cotton
  • Don Shurley, Extension Economist-Cotton

  • Putting knowledge to work
    The University of Georgia and Fort Valley State University, the U. S. Department of Agriculture and counties of the state cooperating, The Cooperative Extension Service offers educational programs, assistance and materials to all people without regard to race, color, national origin, age, sex or disability. An equal opportunity/affirmative action organization committed to a diverse work force.