Effects of Herbicide Application And Tillage On Weed Population In Sown Guinea Grass (panicum maximum jacq. Var. Ntchisi)
Abstract
ABSTRACT
Greenhouse and field experiments were carried out between 1995 and 1997 at the University of Agriculture, Abeokuta (Latitude 600 20l N and longitude 200 40l W), Nigeria to determine the effects of herbicide application and tillage on weed control and dry matter yields of sown pastures. The greenhouse experiment involved three levels each of Primextra (metolachlor + atrazine), Pursuit plus (imazethapyr + pendimenthalin), Galaxy (bentazone + acifluorfen) and Fusilade (fluazifop-butyl). Galaxy at the rate of 0.87kg ai/ha was selected for weed control in field sown guinea grass/stylo mixed swards. Tillage significantly affected the density of all the weed types only in October 1995 when grass weeds were reduced by 25% but broadleaf weeds and sedges were increased by 61% and 34%, respectively. Herbicide application increased the density of grass weeds significantly in June 1995, July 1996 and May 1997 but reduced broadleaf weeds and sedges by 17-84% and 27– 100%, respectively. Also, herbicide application significantly reduced the dry weights of broadleaf weeds and sedges by 29-83% and 68-100% respectively.
