Effects of Time of Weed Removal on Weed Species Composition and Crop Performance of Okra (Abelmoschus esculentus (L.) Moench)

Abstract

The effect of time of weed removal on weed species composition and crop performance of okra (Abelmoschus esculentus (L.) Moench) was assessed in the early and late seasons of 2002 in Ondo (07° 05’N, 04° 55’E). Okra plots weeded at 2, 4. 6, and 8 weeks after planting (WAP) were compared with weed free (WF) and weedy (WY) okra in a randomized complete block design and replicated three times. Weed removal (WR) at 8 WAP was similar to weedy check with regards to crop growth parameters. Plant height, stem girth, nodes per plant, total dry matter, shoot dry matter, mean root length, number of roots, root dry weight, shoot/ total dry weight ratio (SWR) and root/total dry weight ratio (RWR) were superior in the early season to the late season. However number of leaves/plant, number of branches/plant and leaf area/plant were better in the late season than in the early season. Pod number, pod length and fruit yield/plant were also higher in the late season than early season, except weedy throughout and WR at 8 WAP.  WR at 4 WAP gave comparable values of plant height, number of leaves per plant, leaf area per plant, mean root length, root dry weight, pod number, pod length and pod yield with WF. The order of pod yield was WF >WR at 4 WAP >WR at 6 WAP >WR at 8 WAP >WY. The critical time of weed removal in okra production under the condition of this experiment was 4 WAP. Uncontrolled weed infestation in okra resulted in 39 % and 84 % reduction in potential okra fruit yield compared with the maximum obtained from the WF okra in the early and late seasons, respectively. It is suggested that plot be weeded early (4 WAP) for optimum growth and yield of okra.

Keywords: weed removal, weedy check, weed species, okra, weed- free