Agronomy Notes

November, 2003

CONTENTS:

CORN
WHEAT
FORAGE
SOYBEANS
COTTON
CALENDAR OF EVENTS

 

 

CORN

Dr. Erick Larson

New Yield Level for Soil Tests - The MSU Soil Testing Laboratory has updated our soil test recommendations to reflect nutrient demand for higher yielding corn. The recommendation categories are still the same, but the recommendations reflect nutrients demanded by a dryland crop of approximately 150 bushels per acre, or an irrigated/high yielding crop of 200 bushels per acre or more.

Hybrid Trials Available Online - The MSU Corn for Grain and Grain Sorghum Hybrid Trials are posted online at , Variety Testing section http://msucares.com/crops/variety/index.html under "Preliminary Yield Data." Later this month the data will be transferred to "Published Trials" when the publication is finished.

Crop Rotation - One method every producer can use to increase profitability is crop rotation. The reason is simple -- crop rotation significantly increases productivity of all your crops in the long run, while reducing input costs. Reports consistently indicate 10-20% yield advantages for cotton or soybeans grown in rotation with corn on Mississippi farms. Crop rotations normally improve yields because many weed, insect, nematode and disease problems build up when using the same management program every year in continuous cropping. Crop rotation systems effectively disrupt many of these cumulative effects, preventing problems and reducing input costs. Crop rotation allows the producer to attack the predominant weed problems by altering tillage systems, changing herbicide chemistry, and disrupting weed life cycles. Corn rotations can also improve soil physical structure by recycling more organic matter and changing from a tap-rooted crop to a fibrous root system. Numerous other beneficial effects of rotation have been reported, including improvements in soil fertility, soil moisture, soil microbes, and phytotoxic compounds and/or growth promoting substances originating from crop residues. Growers can maintain these benefits by continuing to rotate crops on a yearly basis. A crop rotation system also spreads risk in case of unpredictable problems.

How long should I grow corn? - The rotational benefits described above generally diminish every year after the first year in a rotation system. Additional yield, soil improvements, weed control, and nematode benefits are sometimes realized by a two year rotation, particularly if the field has been continuously cropped for a long time. However, yields will gradually decline and pest problems substantially arise the longer corn is grown continuously. This reduces potential gross return, while substantially increasing potential risk and/or input costs. Thus, I do not suggest not growing corn in the same field for more than two years.

WHEAT

Late Planting - If wet weather or other factors delay wheat planting, wheat growers in the south may still achieve high yields if wheat meets vernalization requirements (accumulation of cold temperature needed to trigger head development the following spring) and tillering doesn't suffer. Producers can compensate for these problems by increasing seeding rate and planting varieties with a relatively short vernalization requirement. Fall application or late winter nitrogen application (15-20 pounds per acre) can also be used to stimulate tillering of late-planted wheat. Diammonium phosphate (DAP 18-46-0) is an excellent fall fertilizer source to broadcast on late-planted wheat because it supplies both nitrogen and phosphorus, which will promote vigorous growth and advance maturity - essentially serving as a "starter fertilizer."

FORAGE

Dr. David Lang

Forage Research and Extension Changing at Mississippi State

Dramatic changes in forage research and extension are in store over the next couple of months here at Mississippi State University. My long-time forage research technician, Mr. Robert Elmore retired October 31st. We will have a retirement lunch for Robert on November 20th at the MAFES Conference Center on Hwy. 82 in Starkville. The conference center is known to many of you as the Bull Barn. The luncheon will be held on the same day as the MAFES livestock sale, so stop by and wish Robert well if you are in town that day. If you would like to make a contribution toward his retirement gift you can send it to Emily Rose, Dept. of Plant and Soil Sciences, Box 9555, Mississippi State, MS 39762. RSVP to Emily at 662-325-2701 if you are planning on attending for food preparation. Robert's position will not be replaced by MAFES due to continuing budget shortfalls, so we will need to find creative ways to get the forage variety testing accomplished.

Ryegrass is well on its way to good early growth. There may be lingering signs of Blast (grey leaf spot) in ryegrass if you had it last year and if you've received several rainfall events since you planted. Small grains such wheat, oat or rye are not susceptible to Blast, so include one of these in your ryegrass mixture as a precaution. If you need to replant ryegrass, use wheat; it will provide winter forage planted in November to early December. Planting rates for wheat are 90 to 120 lbs per acre. It makes excellent forage through April, but it yields about 1/2 of what ryegrass will yield.

The other big change in the forage extension program is the hiring of Dr. Richard Watson, effective January 1, 2004. He is currently the Forage Agronomist for Ampac Seed Company in the mid-Atlantic region. Prior to joining Ampac Seed, he was part of the forage program at the University of Georgia. Richard worked on the development of MAXQ tall fescue while at Georgia with Dr. Joe Bouton. Incidentally, Dr. Bouton is a distinguished Alumni of Mississippi State University and native a Leland, MS. Dr. Watson has extensive experience with grazing systems. He is a native of New Zealand. He'll have a lot to teach us about forage systems and we look forward to having him on board. Be sure to give him a warm Mississippi welcome!

Late fall is a time for precaution with sorghum and johnsongrass. After a frost they contain prussic acid that releases cyanide. Do not graze the re-growth of sorghum until 3 weeks following a good hard freeze. Let it dry out completely before grazing or baling johnsongrass. Once johnsongrass or sorghum dries out completely it no longer contains prussic acid. This problem is caused by cool nights, particularly when there is a light frost. It does not occur in the summer unless there is a 4 to 6 week period without rain. Otherwise, johnsongrass makes excellent hay and can be safely grazed. Other annual grasses such as pearl millet or browntop millet do not contain prussic acid are safe to graze in the fall. A good legume to incorporate with johnsongrass is red clover. Clovers can be planted in November/December and also in February with success. Planting rate for red clover is 8-10 lbs of seed per acre.

SOYBEANS

Dr. Alan Blaine

The 2003 Mississippi soybean crop is history with harvest essentially completed the first few days of November. The October crop report had Mississippi's state average yield predicted at 36 bushels per acre, although this is our best ever this number is still off. Based on reports coming in from around the state, I have no doubt that we have a 38-40 bushel state average.

I hope the final report will reflect this number, but regardless this was our best crop. Sure, there were exceptions/problems but as a whole this was a tremendous crop.

Preliminary yield information is available on the web at http://msucares.com/crops/variety/yield/. We are currently in the process of sorting through yield trials and trying to make some varietal decisions for next year. Our plans are to have all our varietal decisions made by December 1 for our verification fields.

We want to complete this task so producers participating in our verification program can go ahead and secure seed for the upcoming growing season. The top performing varieties will be in high demand so getting an early start should prove beneficial.

Several concerns have surfaced this year regarding varieties particularly questions surrounding two diseases: late season cercospora and stem canker.

Late season cercospora seems to be on the increase the last couple of years, but that is by no means an indication that it will be a problem every year, nor has it been a major problem in the past. However, it was more evident this year than ever before.

Varietal resistance to late season cercospora is not what it used to be. It appears that many of the varieties we grow today are more susceptible than most would like, but keep in mind this lack of resistance has allowed yields to achieve levels most only dreamed about in years past.

Late season cercospora has not been a major yield robber but the lack of resistance and the reduction of some other diseases may be allowing it to get a better foothold. Quadris will not control late season cercospora at the rates we are using in soybeans. We have not personally tried higher rates but this appears to be one of Quadris's weaknesses.

Some have described Quadris as a cercospora fertilizer. If you are not certain if you have late season cercospora, you will have no doubt about its presence following a Quadris application. As for an increase in severity, it appears that as other diseases such as frogeye leafspot, anthracnose, and pod and stem blight are reduced, the severity of cercospora increases. This is probably because the competition is reduced.

We are currently evaluating other products and tank mixes with Quadris, and hopefully we can get some additional compounds labeled in the near future to help with control.

Look for varieties that have resistance/tolerance to late season cercospora. Continue to utilize early maturing varieties and the early planting system. Given this disease's inconsistency it will behoove you to pick the best variety for your farm, regardless of resistance. Manage the crop to the best of your ability and scout for this problem. I admit it was quite widespread this year, but that does not mean it will occur next year, nor has this disease been consistent in comparison to other diseases.

An additional scenario that is contributing to the increased incidence of foliar disease in particular late season cercospora is plant health. Under scenarios of high fertility levels, the effects of various diseases can be minimized. Do not misunderstand that this means control, it does not. But a healthy plant is less susceptible or better able to combat disease pressure. I have no doubt that many fields over the last few years would have experienced less yield loss if higher levels of P and K were available.

Several years ago Dr. Fred Jones and Dr. Normie Buehring conducted some research looking at the effects of varying fertility levels/foliar fungicides and their effects on yields. The amazing thing was where potash levels were high they observed less late season cercospora versus medium levels. In addition, they were able to pick up 6-7 bushel yield differences when the plants exhibited no deficiency symptoms. (These differences were only detected through tissue testing). Plants grown in a high fertility environment were overall healthier and produced higher yields, even though visual deficiencies were not observed between high and medium testing soils.

Last year in our SMART Program over half the fields sampled needed a maintenance application of P or K or both. Do not misunderstand this as saying that fertility is a major problem, but after years of continuous cropping and the removal of several big crops we need to give this area some attention. We often find it is not whole fields, but areas in a field, so smaller sampling size/variable rate applications will be viable options when trying to correct problems.

The second disease that caused concern is stem canker. Stem canker can cause more widespread yield loss than any other soybean disease. Sure, there are numerous diseases that cause problems; however, they are often in an area of the field or scattered not field wide. In addition, other diseases may be slowed or controlled by the use of foliar fungicides.

Stem canker resistance is available in a number of varieties. Many may remember the old Asgrow variety 5980. It was one of the first high yielding varieties many ever grew; however, it had one weakness, stem canker. Susceptible varieties grown today are not as susceptible as those grown in the past. This is not to say that we should plant susceptible varieties just that improvements in resistance have been made.

We know a lot about stem canker. When the problem occurred in 1980, University/ Company breeding programs jumped on top of it and provided much needed resistance. Given what we know about stem canker and planting dates, I contend that we could still grow 5980 if we knew how it responded to early planting, but most definitely we could plant it behind wheat and in a late planting scenario with little problem due to stem canker.

Stem canker appears to be the most devastating on plantings that occur between April 25 and May 25. If you plant earlier than this or later it can still effect the crop just not to the same degree. In addition, earlier maturing varieties are not effected to the same degree as later maturing varieties.

Crop rotation will help, but this disease can carry over onto a crop of beans following rice. If you are planting in the window I mentioned early, do not drop your guard, choose moderately resistant to resistant varieties. The worst case scenario is where you had a problem previously and following beans.

Early/Late planting acts as an avoidance mechanism. You may see some stem canker on early plantings, but it does not have the time to fully develop as it does on full season varieties or varieties planted from April 25 to May 25. We see very little stem canker in double cropped beans, but you do not need concentrate on delaying planting as an option to avoid this problem.

Another point to keep in mind is that southern stem canker was first identified by Dr. Billy Moore and Dr. Wayne Jordan in 1973 in Clay County, MS. Given our long history, we have a more virulent strain than neighboring states. Also, it is more severe in the hill area (when it occurs) than in the Delta.

When making varietal decisions, use Dr. Sciumbato's numerical ratings which are available in the Mississippi variety trial disease reaction tables. The ratings in Mississippi are more representative of our potential problem than other ratings, and I think after this year many of you may have a better appreciation for these ratings.

Every year we collect samples of stem canker and Dr. Sciumbato uses these collections to obtain inoculum for inoculating plants. If someone in Missouri is using a strain from that area they are not accurately able to evaluate what we have here. That has become very obvious with several popular varieties over the past 3 years.

These numerical ratings actually represent a worst case scenario because they are taken on plots that have been tooth pick inoculated but this should leave no room for surprises. I am not saying that company information is not accurate; just that if they are not using Dr. Sciumbato's inoculum they have not covered all the bases. Dr. Sciumbato's stem canker screening trial is funded by the Mississippi Soybean Promotion Board with your check off dollars, a wise investment for your benefit. Given available resistance there is no need to let this devastating disease wipe out large acreages of soybeans. Log onto the internet for current variety trials or contact your county extension office for a printed copy.

COTTON

Dr. Will McCarty

The 2003 cotton production season has been another one to remember. And, for a few growers, the harvest is not over as this is written. From a statewide perspective 2003 looks like a year to remember, this time for the right reasons. It looks like Mississippi soybean and corn growers will set new record yield per acre marks. Cotton growers may do so as well. The October USDA Crop Report estimated that Mississippi cotton growers would harvest 1,100,000 acres and average 916 pounds of lint per acre. I feel we can make that mark, and perhaps exceed it. If so, it will be a new record. The previous record was (is) 901 pounds of lint per acre from some 970,000 acres in 1997.

Growers in the south and central delta and the central and southern hills picked very good yields. In many cases growers set their personal records. The northern delta and northeast hill areas had a relatively late crop. Rains during the planting season necessitated a lot of replanting and caused stunted growth thus delaying maturity. While these areas did not produce a bumper crop, yields were better than many expected.

What are the contributing factors to the success of the 2003 crop? Weather is perhaps the number one factor. Temperatures were mild and rainfall was somewhat adequate in most areas. Insect pressure was light, with the exception of plant bugs. Credit must be given to an upturn in the productivity capability of cotton varieties, transgenic technology and of course boll weevil eradication efforts. I feel, that with boll weevil eradication, new technologies and new varieties we are about to see sustained per acre yield increases.

Getting Ready for 2004

Variety Selection: Variety selection is one of the most important business decisions cotton growers make. The longstanding and ongoing position of the MSU Extension Service is to extend variety trial research results, coupled with direct professional experience, to allow cotton producers to make their own informed variety selection decisions.

General guidelines for variety-related recommendations by MSU-ES scientists are these:

  • Crop producers combine MAFES variety trial information with on-farm personal experience to select varieties that will perform well on their farms.
  • Crop producers try new varieties only on a very limited acreage.
  • Crop producers plant the bulk of their commercial acreage in proven performers.
  • Growers evaluate fiber quality as well as yield.
  • Crop producers critically evaluate the need for value-added traits in transgenic varieties.

Variety selection for 2003 will need to be done very soon.

Other Fall Jobs: Monitor Soil Fertility Levels - Fall is an excellent time to test soil. Cotton is an intensely managed crop and requires high levels of fertility to produce acceptable yields. While cotton farmers generally practice good soil fertility programs, there is still a lag in soil fertility levels. If pH levels are low and soil test recommends lime, it is critical that it be applied. If pH levels are low, applied nutrients such as nitrogen, potassium (especially phosphorous) will not be as effective.

Low Soil pH = Low Yields. Fall is the preferred time to apply lime; fall is also an acceptable time to apply mixed fertilizers to soils with a CEC of greater than 7. On soils with a CEC of less than 7, leaching of fall-applied fertilizer may be a concern.

Growing cotton in low pH soils can lead to root growth problems, nutrient deficiencies, and/or toxicities. Liming acid soils will improve plant growth and significantly increase the efficiency of applied fertilizer nutrients. In fact, if pH levels are in the low 5's or high 4's, applying fertilizer nutrients may be almost a waste of money. If lime is required, it should take precedence in a fertility program.

Selecting lime material is also important. When selecting lime materials, be sure they meet the requirements for Grade A as set by the state's lime law; this law, which is for your protection, regulates the quality of material that can be sold as agricultural lime. Particle size and calcium carbonate equivalent (CCE) are the major considerations, and of these two, particle size is perhaps the more important. The larger the particle size, the slower the material will react and the poorer the quality of the material.

Be careful as you select materials. Pelletized lime and/or liquid lime materials can be good sources, but consider the CCE and quantity of application. If the recommendations call for 1 ton per acre of a 90-percent CCE material, applying 500 pounds per acre of a 95-percent CCE material will not meet the requirements. Always consider the CCE of the material you select.

Nematodes - Populations of nematodes, especially Reniform, have been going up each year. If you have not had your soil sampled for nematodes, you should-especially if growth and yields have been erratic in fields or parts of fields. Using nematicides and/or rotating with corn/grain sorghum have proven to provide significant yield increases in Reniform infested fields. However, infestations must first be detected before any control strategies can be implemented.

CALENDAR OF EVENTS

The 20th Annual Cotton Production Short Course will be held December 3-5, 2003, at the Mississippi State University, Bost Extension Center, Building B. Pre-registration deadline is November 25, 2003. Pre-Registration fee $75.00 and Registration fee is $100.00 (on-site). For more information contact Emily Rose at (662) 325-2701. See below for registration form.

The Annual Tri State Soybean Forum will be held in Greenville, Mississippi, at the Washington County Convention Center on January 9, 2004. For more information please contact Alan Blaine at (662) 325-2701 or Dan Poston at (662) 686-9311.

The Mississippi Agronomic Professional Continuing Education Workshop and the Mississippi Chapter American Society of Agronomy (Winter Meeting) will be held February 10-12, 2004 at Mississippi State University, Bost Extension Center, Building B. For more information, please contact Emily Rose at (662) 325-2701.

The first ever Soybean Short Course will be held February 11, 2004, in conjunction with the Mississippi Agronomic Professional Continuing Education Workshop and the Mississippi Chapter American Society of Agronomy. For more information, please contact Alan Blaine at (662) 325-2701.

The Annual Delta Ag Expo will be January 20-21, 2004, at the Bolivar County Exposition Center in Cleveland, MS. The annual event features more than 100 commercial and educational exhibits and includes morning and afternoon update sessions on the latest production recommendations for Delta agriculture. Doors open at 8:30 a.m. Admission is free. For exhibitor or attendance information, contact the Bolivar County Extension Office at (662) 843-8361.

Department of Plant and Soil Sciences
Box 9555
Mississippi State, MS 39762

Will McCarty, Ph.D.
Extension Leader

 

Cotton Short Course Registration Form

 

Print name to appear on badge _____________________________________

Institution or Firm _________________________________

Address - Street/P.O. Box ________________________________________

City - State - Zip Code _____________________________________________

Phone # _________________________________

E-mail Address _______________________________________

Pre-Registration Fee - $75.00
(Post marked by November 25, 2003)

Registration Fee - $100.00
(After November 25, 2003)

Please indicate:

Will be attending lunch, December 3rd ______

Will not be attending lunch, December 3rd ______

Please make check payable to: MSU-ES Cotton Short Course and send complete registration form with payment to the following address:

20th Annual Cotton Short Course
Attention: Emily Rose
Box 9555
Mississippi State, MS 39762

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