Effect of Pre-emergence Herbicides on Weed Control in Pungam (Pongamia Pinnata L.) Nursery

Field experiments were carried out to evaluate two different pre-emergence herbicides on weed control efficiency, germination and seedling growth of pungam (Pongamia pinnata) nursery. Three days after sowing, pre-emergence herbicides viz. atrazine (50% WP) and fluchloralin (45% EC) were applied at different concentrations on the nursery bags using rose cane. Thirty days after application of herbicides, observations were made on germination percentage and 50 days after application of herbicides, number of predominant weeds (broad leaved, grasses and sedges), weed dry weight(g), weed control efficiency and ischolar_main length (cm), shoot length (cm) and dry matter production (g seedling^-5) of pungam seedling in each treatment were recorded. The results revealed that the compatibility of application of pre-emergence herbicide of atrazine at 0.10% - 0.20% can be used effectively to control broad leaved weeds, without impairing the germination and seedling growth of Pongamia pinnata.