Study on agrometeorological indices for barley crop under different growing environments

An investigation on various heat summation indices viz., accumulated growing degree days (AGDD), accumulated helio-thermal units (AHTU), photothermal units (APTU), radiation use efficiency (RUE) and heat use efficiency (HUE) in relation to phenology of barley variety-BH-393 was conducted-at Research farm of CCS Haryana Agricultural University, Hisar during rabi season of 2005-06.The 10(th) November sown crop consumed more heat units at early stages of crop growth as compare to other two dates of sown crop. In early sown crop, higher values of AGDD, AHTU and APTU were accumulated to attain physiological maturity as compared to later sown dates. RUE and HUE increased gradually till crop reached milking stage and then decreased towards physiological maturity among all three dates of sowing as well as four row spacing. All the row spacings have shown variation RUE and HUE.