Efficacy and economics of weed management strategies in aerobic rice (Oryza sativa L.)

Aerobic rice is a new concept of rice (Oryza sativa L.) cultivation to decrease water requirements in rice. Weeds are perceived to be the most severe constraint to the direct-seeded aerobic rice as compared to transplanted rice. The investigation was undertaken, primarily to identify the most suitable method for managing weed problem in aerobic rice during summer 2013 at College of Agriculture, Vellayani. Weeds resulted in 45.46% reduction in grain yield of rice under aerobic condition. Broadleaved weeds were the most dominant group followed by sedges and grasses. Preemergence application of oxyfluorfen @ 0.15 kg a.i ha⁻¹ + one hand weeding at 20 DAS recorded the highest weed control efficiency (89.43%), higher grain yield (3500 kg ha⁻¹), net income ( 31967 ha⁻¹) and benefit: cost ratio (1.62). The grain yield recorded by this treatment remained at par with hand weeding (3889 kg ha⁻¹). The net income and benefit: cost ratio were 44.6 and 22.7% higher than hand weeding, respectively.