A welcome rainy period was received in most of the Oklahoma cotton growing area August 14-18. Oklahoma State University Extension Cotton Specialist Dr. J.C. Banks says the moisture was needed badly for this year’s cotton:
“The dryland areas in the state were really suffering and the cotton responded to the rain. Almost all cotton was at or near cutout but had continued to bloom and some small squares were on the plant.
“If the cotton was under severe stress, small bolls within seven to 10 days of blooming probably shed due to stress prior to the rain, but squares will continue to develop and the cotton is likely blooming again. It is a general rule that cotton blooms formed after September 1 on well-fruited cotton will not have much chance of making a harvestable boll, but most of the cotton did not have much of a fruit load at the time of the rain.
“If there were not many bolls on the plant, the plant will try to hold as many late developing bolls as possible. If we have a warmer than usual fall and if we can stay away from early freezes, the cotton should come back and produce an adequate yield.
“Our irrigated cotton went into the rainy period with a heavy boll load in most areas. This rainy period had about four days without any sunshine and this, combined with cooler weather, has caused many small bolls, less than 10 days old, to be shed. Again, there are many blooming sites, and the cotton has already started blooming again, but we will only have about a week and a half of additional blooming. This can add a lot of bolls prior to the first week in September, but we will have a split fruiting cycle that can delay harvest. Again, we need a good warm fall like we have had the last two years.
“Terry Pitts, Oklahoma state University IPM specialist, has been receiving calls and observing cotton fields with areas where leaves suddenly turn brown and dry up in the upper part of the plant. Often these plants are well-fruited, while plants in other areas of the field that have not been stressed with a fruit load seem normal.
“Plant samples were obtained and taken to Lubbock, and it was determined the primary problem was a pathogen called alternaria. Dr. Terry Wheeler, plant pathologist, Texas Agricultural Experiment Station, and Dr. Jason Woodward, Texas AgriLife Extension plant pathologist, identified the disease. They said it was most common when late season cotton is suddenly subjected to a very wet period of rainfall and cooler temperatures for several days.” If you have any questions, contact Pitts at 1-580-482-8880.
TALKIN’ COTTON is produced by NTOK Cotton, a cotton industry partnership, which supports and encourages cotton production in North Texas, Oklahoma and Kansas. For more information on the cotton scene, see Oklahoma Cotton Council and NTOKCOTTON website. For questions and comments on Talkin’ Cotton, contact [email protected].