Vol. 11, Special Issue 5 (2022)

Author(s):
Botha Prashanthi, Dr. PVN Prasad, Dr. K Srinivasulu, Dr. P Venkata Subbaiah and Dr. S Ratna Kumari

Abstract:
Field experiment was conducted during kharif season of 2020-21 at Agricultural College Farm, Bapatla to assess the impact of different seed rates and knockdown days of sesbania on drymatter production at different growth stages in direct seeded rice. The experiment was laid out in split plot design, the main plot treatments includes brown manure species dhaincha (Sesbania aculeata) sown at three seed rates (20, 30 and 40 kg ha^-1) and sub plot treatments comprising knockdown of dhaincha at four stages (20, 25, 30 and 35 DAS) using 2,4-D at 0.5 kg ha^-1. At 30 DAS, maximum drymatter production in rice was associated with the dhaincha seed rate @ 20 Kg ha^-1. At 60, 90, 120 DAS and at harvest it was recorded with the dhaincha seed rate @ 40 Kg ha^-1. At 30 DAS of rice maximum drymatter production was registered by killing sesbania at 20 DAS. While at 60 DAS of rice the higher values of drymatter accumulation in rice was recorded with knockdown of dhaincha at 30 DAS. However at 90 DAS, 120 DAS and at harvest of rice it was observed with the killing of dhaincha at 35 DAS. The interaction of main and sub plots was significant at 90 DAS of rice. The growing of Sesbania with 40 kg seeds ha^-1 along with its knocked down at 35 DAS was seen best to maximize the drymatter accumulation having better performance of rice over other interactions.