Faiz Ahmad creator text xx In: Symposium on agronomy aspects of the cultivation of natural rubber (Hevea brasiliensis) Beruwela, Sri Lanka, 5-6 November 1996 1997 9999 monographic und

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Weeds cause serious problems during the immature phase of rubber since their competition for nutrients and water retard crop growth and prolong the immaturity period. In mature rubber areas, woody weeds may interfere with accessibility for tapping, latex collection and fertilizer application. This paper reports on the efficacy of herbicides for effective control of weeds along planting strips and also on selected weeds in the interrows of mature and immature rubber. Mixed weeds, comprising grasses and broadleaves along the planting strips, were effectively controlled with glyphosate + dicamba at 0.54 + 0.27 kg ae/ha, glyphosate + fluroxypyr at 0.54 + 0.09 kg ae/ha, glyphosate + metsulfuron at 0.54 kg ae/ha + 0.075 kg ai/ha and imazapyr at 0.375 kg ae/ha. Glufosinate ammonium at 0.5 kg/ha or paraquat + diuron at 0.6 + 0.6 kg ai/ha gave a shorter duration of control compared with glyphosate mixtures or imazapyr. Imperata cylindrica and pennisetum polystachion, which are common in immature rubber, can be effectively controlled with glyphosate at 2.16 kg ae/ha, imazapyr at 0.75 ae/ha and glyphosate trimesium at 2.16 kg ae/ha. Woody shrubs, such as Clidemia hitra, Chromolaena odorata and Melastoma malabathricum, are more common in mature rubber than in immature rubber. These weeds were effectively controlled with triclopyr at 0.375 kg ae/ha, fluroxypyr at 0.2 kg ae/ha and metsulfuron methyl at 0.15 kg ai/ha. The ferns Dicranopteris linearis and Stenochlaena palustris were effectively controlled with paraquat and glufosinate ammonium each at 1.0 kg ai/ha respectively. Herbicides Rubber Weed control 220216