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Studies on Response of Varieties and Different Dates of Sowing on Productivity of Aerobic Rice

Ningaraju GK

A field experiment was conducted during rainy seasons of 2011, 2012 and 2013 at Zonal Agricultural Research Station, V. C. Farm, Mandya, Karnataka, to study the effect of varieties and their different dates of sowing on growth and yield of aerobic rice. Aerobic rice is a new method of growing rice characterized by direct seeding condition without standing water. The experiment was laid out in split plot design with three replications and treatment consisting of two dates of sowing (20th and 30th July) assigned in main plots and six varieties (MAS-26, MAS-946, BI-33, KMP-175, KRH-2 and KRH-4 early and medium duration varieties and hybrids) in sub-plots. The results revealed that aerobic rice sown between 20thand 30thof July resulted non-significant differences in all the three years of study. Among varieties/hybrids evaluated, KRH-4 rice hybrid recorded higher plant height (108.77 cm), more tillers/m2 (79.97 m2 ), lower weed dry weight (8.42 g), more panicle number (472 m-2), higher panicle weight (3.50 g), higher grain yield (6209 kg ha-1) and resulting in higher net returns and B:C ratio (Rs. 51516 ha-1 and 2.05 respectively) which was on par with KRH -2 and found significantly superior to other varieties/hybrids. The lower yield was recorded in MAS- 946-1 (5032 kg ha-1). The higher water productivity was recorded with KRH-4 (54.47 kg ha cm-1) and KRH-2 (53.25 kg ha cm-1) compared to MAS-26 (43.95 kg ha cm-1) and MAS 946-1 (43.71 kg ha cm-1).