Soil Incorporated Plant Residues and Nemacur affected Weed Population and Soil Nitrogen Dynamics in Asclepia Field

Abstract

Abstract : Field trials were conducted for two seasons in 2006 and 2007 to test the effect of Tagetes patula , Lantana camara , Tephrosia vogelii , Azadirachta indica and Nemacur on the growth of asclepiad, soil pH, and soil nitrogen as well as weed population dynamics . The experiment was replicated three times under complete randomized block design. Chopped plant materials were applied singly or in combination with nemacur. T. patula was applied at 300 g/m 2 , A. indica at 150 g/m 2 , L. camara at 10% w/w, and T. vogelii at 10% w/w. Organic plant materials were applied at half rate in combination with nemacur at 20 g/m 2 . Nemacur treatment alone was applied at a full rate of 40 g/m 2 . Tagetes patula with nemacur reduced weed biomass by between 33.6% and 36.6% while L. camara alone decreased the population density of Oxalis cornulata weed by between 14% and 17% compared to the untreated control. The improvement of nutrient status of the soil and the control of weeds could have led to an improvement of yield characteristic of asclepias. A combination of L. camara with nemacur may be used instead of synthetic nematicides alone to control weeds and improve soil nutrient levels.