Nursery fertilization of rice (Oryza sativa) with native weed vegetation

A field experiment was conducted on a clay-loam soil during the rainy (khar if) season of 1995 and 1996 at Maruteru, Andhra Pradesh, to evaluate the pe rformance of some succulent weeds as green-leaf manure in rice (Oryza sativ a L.) nurseries. Fertilization of nursery, irrespective of source, greatly improved the seedling height, production of leaves, biomass, root number, r oot length and seedling growth rate. Among the green-leaf manure weeds, max imum values of seedling parameters were noticed in Crotolaria verrucosa L.- treated plots which was on a par with Casia angustifolia Vahl and Calotropi s gigantea (L.) R. Br. ex. Alt. green-leaf incorporation. The seedlings wer e shorter and had sparse and thin root system in Croton sparciflorus L.-tre ated plots. The legume weed (Crotolaria verrucosa)-treated plots yielded 2. 16 times more seedling bundles (226) than unfertilized plots. Pulling the s eedlings was easy and took short time when the nursery received either orga nic or chemical fertilization, Unfertilized seedlings and those received ba sal fertilization established very quickly in the main field than those whe re N was top-dressed before pulling in the nursery. Green leaf manuring irr espective of its source suppressed the weed-seed germination of Echinochloa glabresence. Highest grain yield (52.4 q/ha) was obtained in plots receive d Crotolaria verrucosa green-leaf manuring and it was at par with other gre en leaf weeds except Croton sparciflorus.