EFFECT OF CHEMICAL WEED-CONTROL ON NUTRIENT-UPTAKE BY COMMON MULBERRY(MORUS-AUSTRALIS) AND ASSOCIATED WEEDS

A field study was carried out during the rainy (kharif) and winter (ra bi) seasons of 1991-92 to study the effect of chemical weed control an nutrient uptake by common mulberry (Morus australis Poiret; syn, EA, indica auct. tron L.) at Bangalore. Under unweeded condition, common m ulberry could utilize only 29.82, 2.97 and 19.1 k/ha nitrogen, phospho rus and potassium, respectively, whereas weeds removed 30.85, 11.64 an d 57.4 kg/ha. Effective weed management through diuron @ 1.25 kg/ha re sulted in an uptake of 74.47, 12.02 and 84.79 kg/ha N, P and K respect ively by the crop and allowed only 1.43, 0.3 and 4.58 kg/ha N, P and K by weeds. This treatment was closely followed by metolachlor @ 1.5 kg /ha, Pre emergence application of butachlor @ 1.5 kg/ha, alachlor @ 1. 5 kg/ha and pendimethalin @ 1.5 kg/ha also proved equally effective in increasing uptake of nutrients by the crop and also reduction in the nutrient depletion by weeds.