Assessment of Weather Parameters for Groundnut (Arachis hypogaea) in Alfisols of Karnataka - a Regression Approach

Abstract

In field trials of six years (2009-14) the influence of weather parameters on groundnut (The varieties: TMV-2, JL-24, K-134 and C-2) under varied sowing environments (July as normal sowing and August as late sowing months) was studied at Bengaluru, Karnataka in alfisols. Rainy days (RD), bright sun shine hours (BSS), total pan evaporation (EVP. in mm), growing degree days (GDD) and rainfall, the cumulative of all measured during crop period were found to influence significantly the growth and yield of ground nut in alfisols across the genotypes. Whereas, potential evapo-transpiration (PET) and length of growing period (LGP) during the cropping period did not show such significant influence. For achieving maximum yield, the optimum value of annual rainfall from the fitted quadratic curves, was found to be 650 mm. BSS, pan evaporation and GDD during the cropping period showed negative correlation with pod yield. Among the 11 multiple linear regression models established, model III was found to be the most reliable in judging the yield potential of groundnut in alfisols of southern Karnataka (Pod yield in kg/ha = -3058.24**+ 6.55 (RD) -2.01 ** (SSH) + 3.98* (GDD) -6.25 (evaporation in mm) + 8.01** (PET) -21.98** (LGP) + 3.38 ** (LAD) with R2 value of 0.86**. Model IV and XI were effective in predicting the yield (R2 =0.86**& 0.60**, respectively), however of the second order.