Crop Coefficients for Cotton in Northeastern Louisiana
Daily crop coefficients (Kc) were determined for irrigated cotton (Gossypium hirsutum L.) at the Louisiana State University (LSU) AgCenter Northeast Research Station near St. Joseph, Louisiana, in 2007. Kc values were calculated using daily crop evapotranspiration (ETc), which was measured using paired weighing lysimeters, and daily reference evapotranspiration (ETo), which was calculated using the Standardized Reference Evapotranspiration Equation (SREE) for a short crop. Meteorological data for input into the SREE were obtained from a nearby Louisiana Agriclimatic Information System (LAIS) weather station and an on-site portable weather station. Averaged Kc values were 0.15, 0.64, and 1.39 for the initial (day 22 to 29), development (day 30 to 69), and mid-season (day 70 to 136) stages. The beginning of the mid-season stage corresponded closely with first flower (FF), maximum internode length, and 80 percent crop canopy cover. Also, the relationship between Kc and day after planting was determined for each stage. Kc values from this study can be used to estimate ETc for irrigated cotton in a clay soil in northeastern Louisiana.
Advisor:Ernest Clawson; Robert Rohli; Barry Keim; David Brown
School:Louisiana State University in Shreveport
School Location:USA - Louisiana
Source Type:Master's Thesis
Date of Publication:05/07/2009