Bush-control studies in the drier areas of Kenya. 3. Control of Disperma in semi-desert dwarf shrub grassland.
Abstract
Effects of controlling the shrub Disperma sp. (near D. eremophilum Milne-Redhead) by hand clearing and 3 mechanical methods on ground-cover composition at 3 sites on the El Barta plains were investigated. No method gave complete control, but hand clearing decreased Disperma cover to 3% initially. After 2 yr, average ground cover was 28% Disperma and 31% grass, compared with 39 and 17%, respectively, on untreated plots. On the driest site the final cover of Disperma was only 9% after hand clearing, and there was 25% grass cover compared with 10% on untreated plots. The grass effectively withstood re-invasion by Disperma. Clearing in June (early dry-season) was generally more effective than clearing in Aug. Effects of a foliar spray of 2, 4, 5-T at 7.2-8.8 lb a.e./ac resembled those of hand clearing. Burning led to the replacement of Disperma by Aspilia sp. It was concluded that there was no danger of the land being denuded if Disperma was eradicated. The value of Disperma as browse needed further investigation.-R.B.