Author(s): H. KALITA AND R. CHAKRABARTY

Abstract: A field trial was conducted at RARS, Shillongani, Nagaon to study the performance of grass pea (Lathyrus sativus L.) varieties (Ratan, Nirmal, Prateek and Mahateora) under varying seed rates (50, 55 and 60 kg ha^-1) in winter rice (Oryza sativa L.) relay cropping situations during Rabi 2014-15 and 2015-16. The varieties were sown on November 15 and 17 in respective years in standing rice field (15 days after 50% flowering of the rice crop) when the soil was in moist conditions. Among the varieties, ‘Prateek’ performed very well under rice-utera conditions. It gave the highest grain yield (863.89 kg ha^-1 in 2014-15 and 791.67 kg ha^-1 in 2015-16). Seed rate 60 kg ha^-1 accrued in better crop stand and thus, the highest grain yield (895.83 kg ha^-1 in the first year and 842.36 kg ha^-1 in the second).When seed rate was increased by 5 kg from 50 kg ha-1, the yield increase was 14.2 (average) per cent. Further 5 kg increase in seed rate resulted in an average yield advantage of 13.2 per cent. Interaction of variety with seed rate showed that ‘Nirmal’ with 60 kg seed ha^-1 (969.44 kg ha^-1) recorded the highest grain yield, closely followed by ‘Prateek’ with 60 kg seed ha-1 (955.55 kg ha^-1) in 2014-15. However, in the second year, ‘Prateek’ sown using 60 kg seed rate produced the highest grain yield (986.11 kg ha^-1), closely followed by ‘Ratan’ with 60 kg seed/ha-1 (877.78 kg ha^-1). Soil moisture conservation and microbial population build-up were considerably better under ‘Prateek’ and ‘Nirmal’ sown using the seed rate of 60 kg ha^-1. Higher populations of fungi (49 x 104 and 43 x 104 cfu/g^-1 soil) and bacteria (52 x 107 and 48 x 107cfu g^-1 soil) at harvest were recorded in soil where ‘Prateek’ was grown by seed rate of 60 kg ha^-1 in both the years of experimentation. In this variety aphid and wilt incidence were the lowest.

Download Full Article: Click Here