Cotton ranges from just starting to bloom to hard cut-out (0 nodes above white flower). Ideally, cotton will be blooming out-the-top by now, because we have reached that point when the odds of a bloom developing into a quality/yield contributing harvestable boll will drop considerably over the next few days. In fact, producers have probably noticed fields beginning to shed squares and some small bolls this week. This is a normal process of the plant making a final adjustment in what the plant can naturally hold and mature out. Though, producers should make sure that this fruit shed is natural and not induced by some insect like worms or Lygus. I have seen a few bollworm eggs around, but, between heat and beneficial insects and spiders, I am not finding any larva. I can still find a few cotton aphids as well and whiteflies. Most of these aphids are few and far between mostly due to the same beneficials working on the worms.
I would encourage producers to continue scouting for a few more weeks. By September 1 most cotton acres should have well over 400 heat units accumulated since reaching more than five nodes above white flower stage (August 5). This gauge of time tells us that a crop is safe from most insect damage.
Here of late, questions about irrigation have been more prominent. I will admit I get conservative with irrigation as we move into the last days of August and would rather err on the side of being too dry than too wet going into September. However, as hot and dry as we have been for the last four to six weeks, I am encouraging most to stay with the irrigation as long as is feasible. We have already had our chance of making quantity, now it is a matter of achieving quality through maturity. The last bolls set during this time need to be relatively stress free for 20 days (approximately September 8). So, if the plant recovers quickly from any wilting during a 90+ degree day then those last bolls formed should mature properly. Forty to 45 days after the last harvestable boll is formed (approximately September 30), the plant can nearly go into permanent wilt without impacting yield or quality.
So, bottom line, I am encouraging producers to stay with the water for another 10 to 14 days at least. ***** 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 Contact information: 1212 Houston St.,Suite 2, Levelland, TX 79336 806) 894-3150 (office), 638-5635 (mobile) ksiders@tamu.edu (E-mail)