Comparison between conventional and organic weed management: growth and yield of leek (Allium porrum L.)

Leek is a weak competitor against weeds. A field experiment was conducted to determine the effects of herbicides and mulching on weed flora, growth and yield of a leek crop. A randomized complete block design was employed with five replicates per treatment (control, mulching with barley straw, post-transplant application of the herbicide oxyfluorfen at 360 g a.i./ha and pre-transplant application of pendimethalin at 1,650 g a.i./ha). The order of weed sensitivity to mulches was black nightshade (72-85%), venice mallow (80%) > redroot pigweed (70-74%), barnyardgrass (67-77%) > jimsonweed (65%) > common purslane (42-45%). Oxyfluorfen had the highest control of jimsonweed, venice mallow and common purslane. There were no significant effects of the pendimethalin treatment on weed control ratings of jimsonweed, venice mallow and field bindweed. Injury symptoms (small white spots) appeared on leek leaves exposed to oxyfluorfen. The highest yield of leek was recorded with the oxyfluorfen application. Our results indicate that mulching and oxyfluorfen application provides satisfactory control of weeds. The use of mulching is an option for the weed management in organic leek crop.