Effect of manually operated weeders on growth and yield of irrigated maize.

摘要

A field experiment was conducted in Coimbatore, Tamil Nadu, India, during the kharif of 2006 to study the effects of weed control by manually operated weeders on the growth, yield attributes and yield of maize. The treatments consisted of weeding with 4 manually operated weeders, i.e. crescent hoe (T1), multi tyne weeder (T2), wheel hoe (T3) and rotary peg weeder (T4), at 25 and 45 days after sowing (DAS). These treatments were compared with hand weeding at 25 and 45 DAS (T5), pre-emergence application of atrazine (0.5 kg/ha) at 3 DAS with one hand weeding at 45 DAS (T6) and unweeded control (T7). T6 recorded the highest leaf area index (LAI) at 90 DAS (6.45). At 90 DAS, dry matter production was greatest under T6 (9186 kg/ha), T5 (9022 kg/ha), T3 (8869 kg/ha) and T2 (8606 kg/ha). The effect of the treatments on yield parameters was not significant except on cob length, for which T6, T5 and T3 were superior (19.3, 18.6 and 18.5 cm, respectively). The highest grain yields were obtained with T6 and T5 (5429 and 5227 kg/ha).