EFFECT OF DIFFERENT HERBICIDAL CONCENTRATIONS ON WEED DENSITY, TREE GROWTH AND FRUIT YIELD OF “STARKING DELICIOUS” APPLE

An investigation on chemical control of weeds was carried out at Pangla in Shimla district during the year 2007 and 2008. The treatments included glyphosate 41 SL and paraquat 24 SL at 0.3, 0.4 and 0.5 % concentrations along with weedy check, arranged in a randomized design with four replications. The herbicide was sprayed twice (10 May and 10 July) in the tree basin using 15 L of water per basin.  It was found that for a period of 15 to30 days the herbicide treatments did not differ much among themselves and all of them were superior to untreated control. But after 30 days the weed population under treatment differed significantly. Even 0.3 % concentration of glyphosate and paraquat were effective in lowering down the weed population but the most desirable and prolonged effect on weed population, growth and yield with quality fruits were found to be at 0.5 % concentrations of both herbicides.