Crop Weather Relationships of Fodder Sorghum Varieties under Different Sowing Times in Southern Agro Climatic Zone of Andhra Pradesh

Field experiment was carried out during summer, 2018 at S. V. Agricultural College, Tirupati, Acharya N. G. Ranga Agricultural University to study the crop weather relationship of fodder sorghum varieties under different times of sowing. The experiment was in four dates of sowing (I Fortnight of January, II Fortnight of January, I Fortnight of February and II Fortnight of February) with varieties (CSV 21 F, CSV 30 F and CSV 32 F). Results are revealed that among the four times of sowing, different meteorological indices GDD, HTU, PTU, and TUE varied across the different growth stages. Early sowing (I Fortnight of January) had favorable agro-climatic conditions particularly temperature, day length and sunshine hours interms of required accumulation of GDD, PTU and HTU from sowing to harvest compared to other dates of sowing. Total requirement of accumulated GDD, HTU and PTU showed increasing trend with extension of sowing time from I Fortnight of January to II Fortnight of February. The CSV 32 F variety accumulated maximum GDD from sowing to until harvest.