EVALUAION OF PLANT POPULATION AND WEED CONTROL TREATMENTS ON THE MANAGEMEN OF WEEDS IN ONION (Allium cepa L.) FIELD

Abstract

Field trials were conducted in Birnin kebbi, Nigeria during the 2017/2018 and 2018/2019 dry seasons to evaluate the effect of plant population and weed control methods on the management of weeds in Onion field. The experiment consisted of three plant population (500,000, 333,333 and 250,000 plants/ha) and weed control treatments (Pre-emergence application of pendimethalin (1.0, 1.5 and 2.0 kg a.i. ha-1 ), butachlor (2.0, 2.8 and 3.6 kg a.i. ha-1 ), post-emergence application of fluaxifop-P-butyl at 2.0 kg a.i. ha-1 , oxyfluorfen at 1.0 kg a.i. ha-1 , weeding at 3, 3 and 6 WAT, weed free and weedy check making a total of 36 treatments. It was laid out in Randomized Complete Block Design replicated three times. Results showed that plant population of 500,000 plants/ha gave higher plant stand count and 333,333 plants/ha recorded the highest weed control efficiency. All weed treatments contributed to weed control, but higher plant stand count and taller plants were obtained with pendimethalin at 1.0 kg a.i. ha-1 . Weedy check and plots that received application of fluaxifop-P-butyl at 2.0 kg a.i. ha-1 recorded the highest crop injury, weed density and lowest weed control efficiency, while the highest weed control efficiency was recorded with butachlor at 2.0 kg a.i. ha-1 . Pendimethalin and butachlor at 1.0 and 2.0 kg a.i. ha-1 respectively produced similar highest fresh onion bulb yield, while hoe weeding at 3 and 6 WAT and butachlor at 2.0 kg a.i. ha-1 recorded the highest unmarketable bulb yield. From the results, application of pendimethalin and butachlor at the rate of 1.0 and 2.0 kg a.i. ha-1 are more suitable for the control of weed in onion field.