Cotton ranges from 4 leaf stage to 13 true leaves with square set good at +90%. As of today, I have not seen any blooms. I do anticipate seeing blooming fields by July 18th. I am basing this on the fact that our most mature field in the scouting program has 5 first position squares. We typical go into bloom with 8 nodes above white flower. To do this, we need to form 4 additional squares. It will take 3 days per square to form, this equates to 11-12 days. This places first bloom on about July 18th on this more progressed field. Majority of fields will be after this date.
Cotton insect pests remain very quiet. In the IPM Scouting Program I have noted only an occasional fleahopper, and no Lygus or stink bugs. We can find grasshoppers on field margins near rangeland. Beneficial insect and arachnid numbers are surprisingly good in some fields, though limited food source is available. I suspect these are feeding on those elusive single cotton aphids which are usually there but sometimes hard to find. Weeds continue to be the most dominate pest. A long varied list of weed species noted throughout all three counties. Of course, Palmer amaranth is at the top of the list. If you need help identifying a weed and coming up with a control plan give me a call. Remember, these weeds serve as host to many of our cotton pests.
Most cotton has begun to make good progress over the last week or so, since we have had a slight break in the high temperatures. Obviously there have been major hurdles to get to this point and most likely some of those will continue. I am still optimistic for most of our area dry-land and irrigated cotton. But we must have good general rainfall in July.
Priorities for the next several days:
1. Continue chipping away at weed control.
2. Get fertility program going and match it up to potential, including dryland. Have a goal to wrap up fertilizing by end of this month!
3. Scout for square robbing insects in cotton.
4. Scout for Sugarcane aphid in milo.
5. Protect developing peanut pods from disease 60 days from planting.
Cotton Fleahopper The cotton fleahopper is the insect of concern right now in cotton. Though I do not anticipate wholesale problems with this pest I think it is important that we cover some of the biology and management here. Adult fleahoppers are about 1/8 inch long and pale green. Nymphs resemble adults but lack wings and are light green. They move very rapidly when disturbed. Adults move into cotton from weed hosts when cotton begins to square.
Both adults and nymphs suck sap from the tender portion of the plant, including small squares. Pinhead size and smaller squares are most susceptible to damage. Management and decision making The decision to apply insecticide should be based on the number of fleahoppers present, the squaring rate and the percent square set. If conditions are conducive to the rapid buildup of cotton fleahoppers in alternate hosts, scouting intervals should be shortened (i.e., monitor fields every 3 to 4 days).
During the first week of squaring, the economic threshold is 25 to 30 cotton fleahoppers per 100 terminals combined with less than 90 percent square set. In the second week of squaring, the economic threshold is 25 to 30 cotton fleahoppers per 100 terminals combined with less than 85 percent square set. Starting with the third week of squaring up to first bloom, the economic threshold is 25 to 30 cotton fleahoppers per 100 terminals combined with less than 75 percent square set.
As plants increase in size and fruit load, larger fleahopper populations can be tolerated without yield reduction. In most years treatment is rarely justified after first bloom. However, occasionally, when cotton plants do not set an adequate square load during the first 3 weeks of squaring, fleahoppers can prevent the square set that is needed for an adequate crop. ***** West Plains IPM Update is a publication of the Texas A&M AgriLife Extension Service IPM Program in Hockley, Cochran, and Lamb Counties.
Editor: Kerry Siders, Extension Agent-IPM