Influence of Rainfall Distribution on the Productivity of Groundnut in Bhavnagar District of Gujarat State

The district-wise average yield data of groundnut and daily rainfall data were used over a period of 38 years, i.e., from 1970-2008. Five broad approaches namely: (1) Aggregate rainfall, (2) Monthly rainfall, (3) Fortnightly rainfall, (4) Week-wise rainfall, and (5) Crop phase-wise rainfall were tried to study the influence of rainfall distribution on the productivity of groundnut. Comparison of different regression equations with respect to the coefficient of determination (R2) revealed that the equations, which considered weekly rainfall variables as a set of predictor variables exhibited the highest predictability (R2 values). The regression equation, using crop phase-wise approach suggested that Flowering and Peg initiation stage was the most critical phase for moisture requirement of groundnut.