Effect of farmyard manure, fertility levels and bio-fertilizers on growth, yield and quality of sorghum (Sorghum bicolor)

A field experiment was conducted during the rainy seasons (kharif) of 1997 and 1998 to assess the effect of farmyard manure (FYM), fertility levels and bio-fertilizers and their combined effect on the productivity and quality of sorghum [Sorghum bicolor (L.) Moench]. Two levels of farmyard manure (0, and 10 tonnes FYM/ha), 4 fertility levels [control, 50% recommended dose of fertilizer (RDF), 75% RDF and 100% RDF] and 4 biofertilizers [control, Azospirillum, phosphate-solubilizing bacteria (PSB) and co-inoculation of Azospirillum and PSB] were compared. Application of 10 tonnes FYM/ha significantly increased leaf-area index (LAI), chlorophyll content at flowering, plant height, dry-matter accumulation, grain yield and protein content in grain over the control. Application of fertilizer at 50%, 75% and 100% RDF enhanced flowering as well as improved various growth parameters, viz. plant height, dry-matter accumulation (DMA), LAI and chlorophyll content in leaves over the control. Grain yield was significantly improved up to 75% RDF, showing an increase of 32.35 and 11.96% over the control and 50% RDF respectively. Inoculation of Azospirilllum alone and in combination with PSB increased grain yield to the extent of 5 to 7% only. Grain yield obtained with 50% RDF in conjunction with 10 tonnes FYM/ha was at par with that of 100% RDF. Biofertilizers, i.e. Azospirillum + PSB with 10 tonnes FYM/ha significantly increased grain yield of sorghum over their individual effect.