Diversity and integrated management of weeds in highland wheat of Northern Ethiopia
Bekele AsresA and T.K. DasA,B
A Department of Plant Sciences, Haramaya University, PO Box 138, Dire Dawa, Ethiopia.
B Corresponding author: Division of Agronomy, Indian Agricultural Research Institute, New Delhi – 110 012, India.
Abstract
In a survey of wheat fields in northern Ethiopia, of 24 weed species observed nine were monocotyledons and 15 dicotyledons. Dicotyledonous weeds made up 62.5% of the individual weed species and 83.1% of the total weed population, while monocotyledonous weeds were 37.5% and 16.9% respectively. Chrysanthemum segetum L. (corn marigold), Polygonum nepalense Meisn. (smartweed), Galium spurium L. (false cleavers), Spergula arvensis L. (corn spurrey) and Phalaris paradoxa L. (bristle-spiked canary grass), were the more important weeds with a frequency >30% and a dominance >5%. Polygonum nepalense and Spergula arvensis were dominant in the experimental wheat field.
In an experimental field use of clean wheat seed gave a significant reduction in the total weed population (P ≤0.05) and an increase in wheat height, tiller and ear-bearing tiller numbers and seed yield over plots sown to contaminated seed. Clean seed + 2,4-D, or a tank-mix of 2,4-D and fenoxaprop-p-ethyl, applied at 25 days after emergence (DAE) plus hand weeding (HW) at 45 DAE resulted in a significant reduction in weed population at 70 DAE (P ≤0.05). These treatments, and treatments in which two hand weedings were employed at 25 and 45 DAE, gave higher wheat yield and net benefit and were comparable with the weed free check. Clean seed + 0.72 kg ha-1 2,4-D + HW at 45 DAE, however, resulted in the highest benefit: cost ratio.
Keywords: 2,4-D, clean seed, contaminated seed, fenoxaprop-p-ethyl, integrated weed management, wheat.
Plant Protection Quarterly (2011) 26 (1) 8-16.