RAINFALL VARIABILITY ANALYSIS AND ITS IMPACT ON CROP PRODUCTIVITY- A CASE STUDY'

The weekly rainfall data for 39 years (1958–1996) recorded at Main Dry Farining Research Station, G.A.U., Targhadia were analysed for seasonal and weekly periods, weekly rainfall probabilities and yield prediction models using rainfall and productivity (1960–1995) worked out. The mean seasonal rainfall was 567 mm (CV 52%) which received in 27 rainy days. The seasonal rainfall indicated that there is 33% chance of drought with variable intensities and 38% chance of getting more than normal rainfall. The mean weekly rainfall was 26 mm with a CV of 73%. Initial probabilities exceeded P = 0.6 of receiving > 20 mm rainfall week was observed in mw 27 and CV was also low. Sowing of Kharif crops should be undertaken during this period. Significant and positive correlation between yield and rainfall was observed for groundnut, pearlmiIlet and sorghum. The predictability of productivity of crops using seasonal rainfall is low at the centre for all the crops except groundnut which explained 56% variation in productivity