Influence of dates of sowing on growth and yield of direct wet sown early ahu rice (Oryza sativa L.) varieties under flood prone lowland ecosystem of Asom

Abstract

A field experiment was carried out during early ahu (summer) season of 2013 and 2014 at the research

farm of Regional Rainfed Lowland Rice Research Station, Gerua, Asom to study the influence of

dates of sowing and varieties on growth and yield of direct wet sown rice during early ahu season

in flood prone lowland ecosystem. The treatments consists of three dates of sowing viz., 5th Feb., 15th

Feb. and 25th Feb. in main plots and two varieties viz., ‘Abhishek’ and ‘Naveen’ in sub-plots. Growth

and yield attributes like days to 50% flowering, panicles per unit area, grains per panicle, test weight

and grain filling percentage showed significant response to different dates of sowing. The crop

sown on 15th February recorded higher grain yield of 5.41 t/ha. The high yield was due to more

panicles per unit area, grains per panicle, test weight and grain filling %. Delay in sowing to 25th

February resulted low grain and straw yield. This was due to poor grain filling % which in turn was

due to high rain fall during flowering and grain filling stage. Among the two varieties tested,

‘Abhishek’matured early by 6 days and yielded (5.07 t/ha) compared to ‘Naveen’ (4.95t/ha). The

later variety had more panicles per unit area (317.2 vs. 305.8) but less test weight of grains (20.5 vs.

22.2 g). Sowing of early ahu rice on 15th February recorded higher gross return and B:C ratio as

compared to early or late sowing.