Productivity and plant stand of perennial lucerne (Medicago sativa) under different weed-control measures during establishment year

A field experiment was conducted during 1998–99 to 2000–01 at the Indian Grassland and Fodder Research Institute, Jhansi, using different weed-control measures in perennial lucerne (Medicago sativa L). Pre-emer-gence application of pendimethalin at 0.5 kg/ha with hand-weeding at 6-week-crop stage was found superior to other measures for lower weed dry matter (2.5 tonnes/ha) and weed intensity (72 weeds/m²), and higher weed-control efficiency (77.2%) without phytotoxic effect on lucerne crop. Moreover, it also produced higher green fodder (60.7 tonnes/ha), dry matter (13.2 tonnes/ha), crude protein (2,192 kg/ha) yields and plant stand (70 plant/m²) during first growing season. Imazapyr and metribuzin with and without hand-weeding were found phytotoxic to the lucerne and resulted in lower yields due to poor initial and final plant stand despite, very good in controlling weeds. Combination of herbicides and hand-weeding resulted in more yields than chemical, mechanical and manual measure alone.