Effects of Application Timing and Concentration of 2‐Chloroethyl Trimethylammonium Chloride on Plant Size and Fruiting Responses of Cotton 1

I NCREASING restrictions in cotton-acreage allotments have been accompanied by trends in production practices aimed at higher per-acre yields. These include a shift to the more fertile soils, the use of higher rates of nitrogen fertilization, and the use of more deep tillage and supplemental irrigation. All of these tend to increase yield potential by producing larger plants with more fruiting positions. However, if either poor insect control or inclement weather permits early loss of forms by shedding, the poorly fruited plants grow extremely tall, bear dense foliage, and tend to lodge. This rank condition is not only conducive to the rotting of bolls as they mature, but makes it difficult to obtain good chemical defoliation in preparation for mechanical harvesting. A phase of cotton research that provides one approach to this problem centers on efforts ~:o °’tailor" the plant to a size that will facilitate defoliant application and mechanical harvesting. In field plots, various mechanical pruning treatments have been compared with foliar spray applications of an aqueous soiution of 2-chloroethyl trimethylammonium chloride (CCC) a for preventing development of excessively large plants. Although there has been some reduction in yield from the use of the dwarfing chemical, the relative effects of application timing and concentration have not been clear-cut. The purpose of this report is to present results of a greenhouse experiment carried out to observe certain growth and fruiting responses of cotton treated with CCC.