ABSTRACT: Field experiments were carried out in the early and late seasons of 2000 at the Teaching and Research Farm of The Federal University of Technology, Akure (327 m above sea level; Long. 70 16'N, Lat. 50 12'E), in the rainforest zone of Southwestern Nigeria, to evaluate the effects of selected weed and tree mulch materials on weed control and okra [Abelmoschus esculentus (L.) Moench] yield. Air-dried Calopogonium mucunoides, Chromolaena odorata, Panicum maximum, Aspilia africana, Pennisetum purpureum clippings and Tectona grandis leaves were each applied as mulch materials at 15 t/ha in a randomised complete block design, using three replications per treatment. Unmulched plots were included as control treatment. A. esculentus was sown at one plant/hill spaced 60 x 30 cm (i.e. 55, 556 plants/ha). Weed density, dry weight and weed control efficiency (WCE), okra growth, pod yield and nutrient contents were recorded. Tectona leaf mulch suppressed weed emergence most distinctly (p <0.05) over time, followed by Aspilia and Panicum mulch. Okra exhibited better shoot growth in mulched plots than in control plots, and early-season growth was distinctly better in Aspilia mulch than in other mulch materials. In the late season, crop shoot growth in Aspilia, Calopo, Chromolaena and Tectona mulch were at a par and significantly (p≤0.05) better than in control, Pennisetum and Panicum mulch. Residue mulching did not significantly affect okra pod size in the early season but Tectona mulch gave distinctly better pod length and pod yield, compared well with values from Calopo, Chromolaena and Aspilia mulch in pod diameter and with Aspilia mulch in pod yield. Residue mulching did not influence pod K, Ca and Mg contents in the early season and all nutrients in the late season. However, pod N in Aspilia and Chromolaena mulch, and pod P in Tectona, Calopo and Panicum mulch were distinctly higher than in other treatments in the early season. On the average, okra growth, yield and pod quality were better in
Tectona and Aspilia mulch, and these could be attributed to the distinctly superior tissue organic matter content, total exchange acidity and WCE of these mulch materials.
Keywords: Residue mulching, weeds, pod quality
JoST. 2021. 11(1): 79-88
Accepted for Publication, April 25, 2021
