Relationships of Cotton Productions and High Temperatures for Lee County, Arkansas.

Temperature can directly impact the overall yield of any developing crop.  Cotton (Gossypium hirsutum L.) in Arkansas is not immune to the effects that higher temperatures may have upon productive yields.  Cotton is most sensitive to heat stress during periods of flowering.  Flowering begins in the Mid-South region about 65 days after planting and continues throughout the remainder of the season.  This sensitive period of cotton flowering overlaps the summer season when maximum daily temperatures can exceed the optimum values of cotton.  Cotton flowering in temperatures higher than optimal have negative effects upon the  potential yields.  However, studies have been limited in publishing weather effects of high temperatures upon actual cotton productions for the Mid-South Region.  Research is necessary to associate cotton yield to temperature stress.  The objective of this study was to document and quantify the temperature range over a thirty year period for Lee County, Arkansas and compare that to the annual productions of cotton in the area.   It was hypothesized that higher temperatures would impair cotton productions.

The archived weather data was collected from the Marianna, AR weather station for a thirty year period from January 1980 through December 2009.  Cotton productions for Lee County, Arkansas was collected from the USDA Quick Stats website (http://quickstats.nass.usda.gov/).  The maximum high temperature data was recorded into spreadsheet form for better analysis.  Days that did not have information present were assigned a null value to minimize effects upon the averages.  Results indicated a negative relationship between high temperatures and yield over the study time period for both July and August.  The highest negative correlation occurred in July, cotton’s most sensitive period.