Interactions between Soil Cultivation in Darkness, Flaming and Brush Weeding When Used for In-Row Weed Control in Vegetables

ABSTRACT

The interacting effects of combining seedbed harrowing and sowing in darkness, pre-emergence flaming and post-emergence brush weeding for in-row weed control in seeded onions(Allium cepa L.) and kale(Brassica oleraceae L. var. acephala DC. subvar. laciniata L.) were studied in field trials in 1994 and 1995. In 1994, only seedbed harrowing and sowing in darkness, and brush weeding significantly reduced weed number and none of the factors studied interacted significantly. The combination of seedbed harrowing and sowing in darkness, and brush weeding reduced weed number by 90% in onions and 84% in kale. Soil cultivation in darkness had no effect on weed numbers in 1995. As in 1994, brush weeding reduced in-row weed number strongly and the combination of flaming and brush weeding reduced weed number in onions by 85%. In kale the combination of seedbed harrowing and sowing in darkness and brush weeding was most effective with a 72% reduction. Contrary to 1994, flaming interacted strongly with crop in 1995, as weed number was significantly reduced in the slow emerging onions but not in the fast emerging kale. Generally, brush weeding did not interact with the other methods, meaning that the pre-emergence methods had neither increased nor decreased the effects of brush weeding. However, in this study the overall effects of combining pre- and postemergence methods have shown promise for obtaining significant reductions in the time required for in-row hand-weeding in row crops grown without herbicides.