Announcing Alabama Scouting Schools

Announcement: Alabama Cotton Scouting Shortcourses Meeting Sites and Dates

• June 12^th (Tuesday) 2012; Autaugaville, Alabama- County Agricultural Center
• June 13^th (Wednesday) 2012; Headland, Alabama- Wiregrass Research Center
• June 19^th (Tuesday) 2012; Belle Mina, Alabama- Tennessee Valley Research Center

All meetings begin at 8:30 AM

Contact Person: Dr. Tim Reed (256-627-3450) or Dr. Ron Smith (334-332-9501)

Note: Dr. Austin Hagan will discuss cotton diseases at the Autaugaville and Headland sites. Dr. Tim Reed will cover soybean insects at all three sites.

Following are thirteen questions that represent the type of information that will be discussed.

1.      Why are grasshoppers easier to control in March/early April than May?

2.      If a foliar is needed for thrips suppression, when is the ideal stage of cotton to apply it?

3.      If you see damage to cotyledon stage cotton (no till) planted behind corn residue, what is the most likely culprit: snails, slugs, or pill bugs?

4.      What is the best method to determine when plant bug controls are needed in pre-bloom cotton?

5.      How would you measure the number of tarnished plant bugs in post bloom cotton?

6.      You are at week four or five of bloom, what would be the threshold for stink bugs?

7.      Under what conditions (situation) would a phosphate insecticide give better control of stink bugs than a pyrethroid?

8.      What new thrips insecticide entered the market this season and does not flare aphids or spider mites?

9.      Suppose you find high numbers of fall armyworms feeding on grass in your cotton field border- should you prepare to spray the cotton?

10.   How old does a green boll need to be to be safe from stink bug damage?

11.   Under what conditions would aphids be more of an economic pest or problem?

12.   At what stage is cotton normally beyond thrips injury?

13.   How long should you wait to evaluate control behind a stink bug spray?

Thrips Damge in Cotton

Thrips pressure is quite variable based on the location and field. The two most significant factors affecting thrips damage seem to be planting date and rainfall. Thrips trials at Prattville, AL, planted on April 16, are showing low to moderate thrips injury even without a foliar application on top of seed treatments at planting. Trials planted a week earlier, April 9, are showing heavy thrips injury behind all seed treatments. Rainfall occurred on all trials during 5 of the first 10 days of May.

Most April-planted cotton should be out of the thrips damage window within 10 days or less. Cotton planted in April had three true leaves or more with the fourth or fifth emerging on May 11.

Growers planting behind the rainfall that occurred between May 7 and May 11 will likely not have to be concerned about making a foliar spray for thrips at the first true leaf stage. Seed treatments alone should provide adequate thrips control.

Cotton up and growing should be beyond grasshopper damage. The concern about pill bug damage in the one field in Talladega County this week turns out to be primarily damage from slugs and not pill bugs.

Grasshoppers and Pill Bugs in Cotton

The most common concern in cotton insects continues to be grasshoppers. The most significant change in the past 2-3 weeks is the fact that a percent of the population now are adult grasshoppers. Adults are much more difficult to control so current recommendations call for higher rates of whatever insecticide chosen. Several consultants are now applying one of the least expensive pyrethroids at higher labeled rates. Even then, a small percent of the adult population will escape controls.

Growers should be reminded that cotton planted in April with seed treatments will profit from foliar insecticides at the 1^st true leaf stage. This is especially true in conventional tillage dry land situations.

A rare question was received today about controlling pill bugs in cotton. This situation usually occurs when cotton is planted in reduced to no-tillage behind corn. Pill bugs seem to only occur in high residue, high organic matter conditions. Little research or experience is available to base a pill bug recommendation on. After several phone calls, the best chemical options seem to be: Bidrin at 0.25-0.33; Orthene at 0.5; or Sevin at 0.5-0.75 lbs per acre. This is a question that will likely occur again on an infrequent basis. Dry weather and high temperatures should help solve this infestation. However, the next 48-72 hours may not present this situation.