Moisture and Cotton at Harvest Time in the Mississippi Delta

The moisture coutent of cotton at time of l~arvest has a dirwt effect 011 cotton quality. Weather, in particular relative humidity, strongly inHllences variation in cott,on moisture content. This paper sur~lmarizes three years of obsrrvatiorls of n-cather in and around cotton fields at harvest time in the hhsissippi Delta. Detailed studies of t,hc variation of relative humidity, tc~mpcrature, wind, sunlight, dew, and evaporatiou have bccn made in lcafcd fields and in ficlds where leaves were removed artificially. Single weather variahlcs and combinations of variables have been related to dew intensity and to the rate of evaporation. Surface w e a t h c ~ maps are presented to show the average pressure patterns associatcd with estren1c.s in drxw and c,vaporation. A prclirninary cotton picking guide, dr.vfJloped joiutly by t,he \Irrxatbcr I3ureatt and the Cotton J3arvesting Section of t h c [J.S. Departtncnt of Agriculturc, which gives tho farrncr a11 ohjmtivc cxstimat,e of when to start picking cotton 011 thv basis of weathclr variation, illustrate5 how weathw information can improve farm ofFtcict1c.y.