NITROGEN ECONOMY, SEED PRODUCTION EFFICIENCY AND SEED VIGOR OF PANICUM-MAXIMUM BY INTERCROPPING OF PASTURE LEGUMES

A field experiment was conducted to evaluate the performance of pasture legumes (Desmanthus virgatus, Sesbania aegyptica, Macroptelium autropurpureum, Desmodium tortuosum, Stylosanthes hamata used as in intercropped element) in terms of nitrogen economy, seed production efficiency and seed vigour potential of Panicum maximum - a grass based management maintained for 1986-88 at Research Farm, Indian Grassland and Fodder Research Institute, Jhansi under rainfed condition. Nitrogen economy under these intercropped pasture legumes was estimated on equating its value against nitrogen treatment i.e. 0, 10, 20, 30 and 40 kg N/ha. Among five intercropped legumes, Stylosanthes hamata and Macroptelium autropurpureum intercropping doubled the seed yield; S. aegyptica and M. autropurpureum brought out 46-55 per cent increase in biomass production over control value of 41.7 kg seed and 223.4 q biomass/ha respectively. These treatment showed 20-40 kg N/ha nitrogen equivalent value. Further more increased seed yield of Panicum maximum under intercropping was attributed to its better ear production, spike length and potential sink strength. Germination potential of harvested Panicum seeds under different treatments did not show variation among themselves. Potential seed production performance of Panicum maximum in the first year as compared to subsequent years might be due to its general transcript of plants and have some interaction with rainfall.