Weekly in-season Updates
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INFORMATION |
July 17, 2006 Talkin’ Cotton
Cotton needs both heat and moisture to develop bolls. Moisture without heat results in slow development and causes the plant to grow vegetatively at the expense of fruit production. Heat without moisture results in a plant that will continue to develop nodes and branches, but will not grow vegetatively. This is the situation we are in in dryland cotton or cotton that has only limited irrigation water. At this time of year, one of the first indicators of drought stress is the appearance of blooms in the top of the plant. Vegetative growth has stopped and fruiting has progressed up to the top of the plant. The cotton plant will try to hold the first two or three bolls, but later set fruit will be aborted from the plant within a week of blooming. Any bolls that are larger than thumb size will probably stay on the plant unless stress is very severe. At this time of year, if the cotton has cut out due to stress, if ample moisture is received from rainfall, the cotton plant will attempt to recover and start fruit development. If given enough season length (a warm fall and delayed freeze), a reasonable yield can still be made. There will normally be a flush of vegetative growth from drought stressed cotton if ample rainfall has been received, and if this growth is excessive, and soil moisture prospects remain good, an application of a mepiquat based growth regulator may be warranted. Our next question may be, where do we go from here. If cotton is irrigated, look for blooming out the top of the plant, and if this is observed, tighten up on the irrigation schedule or apply more water per irrigation if possible. On dryland cotton, all we can do is wait for rain, and if it comes early enough, the plant can start the fruiting cycle over again.
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