Models to elucidate crop-weather association in turmeric (Curcuma longa L.)

Abstract

Weather is a non-monetary and highly variable input in crop production. In this paper attempt was made to study the influence of weather elements on turmeric yield. The data on turmeric dry yield (kg ha–1) and weather parameters viz., maximum temperature (TMAX) and minimum temperature (TMIN), rainfall (RAIN), maximum relative humidity (RHMAX) and minimum relative humidity (RHMIN), solar radiation (RADN), bright sunshine hours (SUNS), wind speed (WIND) and evaporation (EVPN) were collected from official records for 1979–80 to 1999–2000. The second-degree polynomial regression was fitted between yield and weekly weather variables. Weather changes gradually during life span of turmeric and accordingly response also varies for different weather elements. The response was negative for TMAX, SUNS, WIND and EVPN throughout the growing period. The response for TMIN, RAIN and RADN was negative during establishment and vegetative phases and positive during later part of crop growth i.e., maturity phase. RHMAX and RHMIN have showed a linear association with negative influence at establishment and positive effect at vegetative and maturity phases. The study gave a tentative estimation of parameters for greatly simplified functional relationships postulated in equations and it is possible to explain variations of turmeric yield on the basis of change in weather.