Cotton Defoliation – Temperature Warning – Dr. Darrin Dodds

By Carol Bullard | Published: September 3, 2010

For those that are in the process of defoliating cotton, nighttime temperatures in the upper 50’s and low 60’s are predicted for Friday,Sept.3rd,  Saturday, Sept. 4th and Sunday night, Sept. 5th.  After Sunday night, nighttime temperatures are predicted to be above 70 degrees.

Consider delaying defoliation applications and enjoying the holiday weekend without worrying about whether or not your defoliant is going to work as desired and make applications toward the beginning of next week once weather conditions begin to warm.

Cooler temperatures can seriously limit of several defoliants, particularly thidiazuron.  Additional messages will be sent out as necessary.

Have a great holiday weekend.

Darrin

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Soybean loopers still a problem in some acres – Dr. Angus Catchot

By Carol Bullard | Published: August 27, 2010

Soybean Loopers continue to plague the remaining crop that is still susceptible to loss of yield from defoliation. Mississippi has traditionally been a very early planted soybean state. Because of this we have missed major problems from soybean loopers since loopers migrate up later in the year and our crop as a whole is finished before large acres are exposed to the loopers. Over the last several years, as more grains are being planted, we have shifted some of our acres to later maturing varieties and later planting dates to spread the harvest. As a result we are seeing more and more acres being exposed to migrating looper populations and are treating significantly more acres for this pest. To date approximately 15% of our acres are still susceptible to yield loss from defoliating pests. We have treated numerous acres in the Delta and many more than usual in the hills this year. Also, we are seeing high numbers of green cloverworms and velvetbean caterpillars in some areas of the hills now. There have been many questions regarding how late to protect foliage from defoliating pests. We currently recommend protecting foliage until R7 growth stage is reached. Actually, when you reach R6.5 there is very little yield loss associated with defoliation. The problem is what is R6.5? Generally depending on planting date and variety there are 7-14 days between R6 and R7. A safe assumption would be that 7 days past R6 you could lose your foliage without appreciable yield loss. The problem is nearly every field has variability within the field on growth stages and there are some plants at R6 and some at R7 and all stages in between. Knowing that a looper takes 12-14 days to complete its larval cycle, and that they consume 90% of the foliage they will eat in the last few days as a larva, a population that comes in at R6 will likely not cause extensive defoliation for at least 7-9 days which puts you at or very near R7 before major defoliation will occur. I would likely let them go in that situation. Keep in mind that they may take all the foliage but you will not get your money back from treatment. With that said, there are many things to consider. For example if you are running very high numbers, foliage loss will happen more rapidly simply based on the numbers alone. I have had reports of some counts as high as 250 loopers per 25 sweeps. The bottom line is there are several factors to consider and this has to be done as a field by field decision, not as a blanket rule. Also, there is still considerable variability between people judging growth stages and that has to be considered. The safe thing to do is terminate applications for foliage feeders when R7 is reached and there will be no “guess work” involved. If you need help with this feel free to call.

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You Probably Already Knew This – July, 2010 – Warmest on Record

By Carol Bullard | Published: August 17, 2010

NOAA: Second Warmest July and Warmest Year-to-Date Global Temperature on Record

August 13, 2010

The combined global land and ocean surface temperature made this July the second warmest on record, behind 1998, and the warmest averaged January-July on record. The global average land surface temperature for July and January–July was warmest on record. The global ocean surface temperature for July was the fifth warmest, and for January–July 2010 was the second warmest on record, behind 1998.

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Soybean Looper at Threshold Levels

By Carol Bullard | Published: August 13, 2010

Dr. Angus Catchot

Soybean loopers are beginning to show up at threshold levels now in many places across the state. As we traveled the state this week, we had no trouble flushing numerous looper moths from soybeans and cotton and many are reporting threshold numbers of larvae. I would expect many more acres that are still susceptible will be treated within the next 7-10 days. Soybean looper moths lay their eggs singly on the underside of leaves. The eggs resemble a budworm/bollworm egg but are somewhat “flattened” in appearance. Eggs usually hatch in about 3 days. The larvae go through six instars and generally take 12-14 days to complete development. Soybean loopers pupate in silken cocoons on the underside of the leaves for approximately 7 days prior to the adult emerging. Like most foliage feeding caterpillar pest, the larvae will consume 90% of the food they will eat in the last 2-3 days of their life cycle. This is important to consider when making management decisions and why our threshold is based on larvae ½ inch in size or greater. Small larvae cause very little damage, leaving you several days to make a decision. The threshold for soybean loopers is 19 loopers per 25 sweeps or 20% defoliation in reproductive beans. Termination for all foliage feeders in soybeans is R7. As of yesterday (8/12) Belt insecticide received registration in soybeans. The labeled rated is 2-3 oz per acres. Belt has activity on nearly all caterpillar pests and good residual.

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Cotton Crop in Good Shape Despite the Weather: Dr. Darrin Dodds

By Carol Bullard | Published: August 9, 2010

Dr. Darrin Dodds Crop Update:

According to USDA-NASS, 55% of the Mississippi cotton crop is in good to excellent condition. Extended periods of drought and higher temperatures have been detrimental to a portion of this crop. Irrigated cotton constitutes the majority of the good to excellent cotton in the state; however, dryland fields are variable depending variety planted and level of rainfall received. Many of the fields that I have walked over the past few weeks have a fruiting gap typically occurring on nodes 9 – 12. Several reasons exist for this including weather conditions and irrigation timing. In addition, excessive heat over the past week has led to high levels of fruit shed in upper portions of the plant in many fields. Retained fruiting structures develop into bolls that are malformed as well. Excessive heat reduces pollen viability which can lead to poor pollination and the appearance of hawk billed or parrot beaked bolls. In general, bolls are beginning to open more and more and a few instances of bollrot have already appeared.Cavitation is also occurring in many fields and warrants further discussion.

Cavitation: There are many fields with young bolls turning brown and hanging on the plant; however, the severity of cavitation changes from field to field. Some fields have no cavitation present whereas one field in Yazoo county had cavitation appear on 10 of the 16 fruiting structures on the plant. There are two schools of thought about the cause of this. Some Plant Pathologists have described this as “Phomopsis.” This organism has been isolated from the petiole wound. Whether it is the cause or is secondary is still up for debate.

This has also been described by some Physiologists as a form of “xylem cavitation” or “vascular cavitation.” This occurs when the plant has a burst of elongation, or growth, after a period of stress. Actually, when the flower opens there is a corresponding increase in transpiration rates of the fruiting structure. This is due to several factors which include a sharp increase in surface area, development of the ovule, and the beginning of fiber elongation. This rapid increase in transpiration puts a tremendous demand on the xylem tissue. If conductive tissue secondary cell wall (thickness) development has not been able to keep pace with elongation and transport demand, stress may cause a rupture. When this happens the fruiting form basically dies before an abscission layer forms and the dry fruiting form hangs on the plant by a dangling piece of tissue. This is where we get the term “boll dangle.”

Cavitation injury has been seen before and visual observations indicate that it occurs on some varieties at a higher frequency than others. To the best of my knowledge, hard data regarding susceptibility of a given variety to cavitation does not exist as occurrence of cavitation is unpredictable. The fact that it is physiological in nature and related to a plant may account for why it may be more pronounced on some varieties than others. In addition, there is no “cure” for this problem. After it has occurred the grower should be prepared to manage the crop as a “later maturing” crop. This is because as first position fruit on the lower and central fruiting branches cavitate, the plant may produce rapid vegetative growth.

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Budworm numbers high in soybeans – Dr. Angus Catchot

By Carol Bullard | Published: July 31, 2010

Dr. Angus Catchot reports on budworm larvae in soybeans:
Over the last several weeks we have had numerous reports of tobacco budworm moths being flushed in soybeans in the delta region of the state. Ryan Jackson and Clint Allen with USDA-ARS in Stoneville have been collecting populations of bollworms missed with pyrethroids in soybeans. Three populations collected this week in the delta behind a pyrethroid application turned out to be 7%, 28%, and 60% tobacco budworms. Tobacco budworms are resistant to pyrethroid insecticides in MS. Although, in some areas of the state budworm numbers may be high in soybeans, most populations are low compared to the bollworm numbers. If high numbers of larvae are left behind pyrethroid application it is recommended to get a positive ID on the larvae before retreating the field. Some have chosen to let remaining worms cycle given the cost of treatment for tobacco budworm.

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Bollworms continue in high numbers in soybeans

By Carol Bullard | Published: July 26, 2010

Dr. Angus Catchot reports on bollworm activity in soybeans

Bollworm treatments are continuing to go out on late planted soybeans. While many are treating threshold levels there are some facing unbelievable numbers (greater than 100 per 25 sweeps). We are leaving more worms in the field this year than in years past with straight pyrethroids. Some can be explained with coverage, others cannot. Ryan Jackson’s pyrethroid monitoring is not showing anything unusual in MS to date with respect to resistance, however, LA testing program is showing extremely high levels of survival in their test. There is also budworm populations mixed in at low levels this year in some places (confirmed) and there have been several consultant reports of flushing fairly high levels of budworm moths from soybeans. Budworms generally make up a small percentage of the overall population. Two years ago, we had a population from Clarksdale that was 15% budworms in soybeans. We are seeing better control of bollworms when adding 0.5 lbs of Orthene with the pyrethroid. Although Orthene alone has little to no activity on bollworms in MS, when mixed with a pyrethroid control is better than with either one alone.

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2011 MACA Annual Conference – Date Change

By Carol Bullard | Published: June 8, 2010

The 2011 MACA Annual Conference will be held on January 25 and 26, 2011 instead of the previously announced date of February 1 – 2, 2011. A conflict of dates with the National Cotton and Rice No-Til Conference to held in Baton Rouge, LA caused this change. The Conference will be held at Bost Extension Building as it has been in the past.

The building will be open on Monday, January 24, 2011 from 1:00 – 5:00 p.m. for exhibitors to set up their trade show booths.

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MACA 2010 Board and Committee Assignments

By Phil McKibben | Published: February 18, 2010

2010 Officers and Directors

President: Bert Falkner                                       President-elect: Virgil King

Sec-Treasurer: Brian Hayes                              Director: Dee Boykin

Director: Nick King                                               Director: Jeff North

Director: Tim Sanders                                        Ad-hoc member: Tim Richards

Nomination Committee

Bob Stonestreet, Chair                   Bert Falkner                           Virgil King

Allen McKnight                                  Jeff North                               Tim Sanders

Membership & Rules Committee

Herbert Jones, Chair                        Pete M. Baughman                 Jason Grafton

Tim Richards                                       Ed Whatley

Scholarship Committee

Bill Pellum, Chair                                Ty Edwards                            Justin George

Phillip McKibben                               Will Price                                 Stoney Stonestreet

Regulatory & Legislative Committee

Billy Price, Chair                                  Dee Boykin                             Mike Sartor

James Simpson                                    Homer Wilson

Allied Industry Committee

Tucker Miller, Chair                         Pete M. Baughman                   Trent LaMastus

Bruce Pittman                                     Will Price

Program Committee

Virgil King, Chair                             Dee Boykin                                Bert Falkner

Brian Hayes                                       Tucker Miller                           Jeff North

Bill Pellum                                          Bruce Pittman                         Tim Richards

Grievance Committee

Tim Richards, Chair                       Herbert Jones                            Phillip McKibben

Jeff North                                           Joe Townsend

Research & Education Committee

Dee Boykin, Chair                              Winston Earnheart                Andy Graves

Allen McKnight                                  Jeff North                                  Joe Townsend

Public Relations Committee

Bruce Pittman, Chair                        Jim Arrington                          Phillip McKibben

Tucker Miller                                       Joe Townsend

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MACA 2010 Annual Meeting

By Phil McKibben | Published: February 4, 2010

The 37th annual MACA conference was recently held at the Bost Extension Center on the MSU campus.

The highlight of the meeting (except for when the projector exploded) was the presentation by John McGillicuddy from Iowa.  We had given him the last slot on the program, hoping to allow him the time to begin to scratch the surface of what he knows about corn.

After two and a half hours, he asked “Do you want me to keep going or should we quit now?”.  The crowd of consultants yelled “Keep going!”

We eventually took a break, he eventually had to quit, and I am not sure that we quite reached the point where he began to scratch the surface of what this man knows about corn.

To be descriptive, John McGillicuddy could be dubbed a ‘forensic agronomist’.  But the interesting thing was that the principles that he shared about corn, the crop that he knows inside and out, can also be applied to cotton, to soybeans, and to almost every other row crop that we can grow.

Understanding the growth habits of a crop, the physiology, and it’s reproductive and survival strategies are all key to understanding which factors have limited the productivity of a field or farm, and are critical to figuring out how to re-capture that lost yield.

Our group of consultants has been perfecting that science for 40 years in cotton, for the past 15 years or so in soybeans, but has only recently begun to offer in-depth consulting for the state’s corn crop.

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