Effect of phosphorus levels and bioinoculants on growth and yield of long duration pigeonpea [Cajanus cajan (L.) Millsp]

A field experiment was conducted during rainy season of 2008–09 and 2009–10 to study the effect of phosphorus levels (0, 25, 50 and 75 kg P2O5 per ha) and bioinoculants (untreated control, PSB, PGPR and PSB + PGPR) on growth and yield of long duration pigeonpea. The results showed that the application of 75 kg P2O5 per ha recorded the maximum plant height, branches/plant, dry matter production/plant, chlorophyll content (SPAD), leaf area, LAI, grain yield, stalk yield, biological yield and harvest index, which were significantly superior over 25 kg P2O5 per ha and control (without phosphorus application) but at par with 50 kg P2O5 per ha during both the years of experiment. Among the bioinoculants, dual inoculation of PSB + PGPR significantly increased higher growth attributes such as plant height, branches plant, dry matter production, chlorophyll content, leaf area, LAI, grain yield, stalk yield, biological yield and harvest index, which were significantly superior over alone application of PSB, PGPR and control (without seed inoculation) during both years of experimentation. Combined application of 75 kg P2O5 per ha + PSB + PGPR was found significantly superior to 25 kg P2O5 per ha + PSB + PGPR and control (without phosphorus application + without seed inoculation), which was at par with 50 kg P2O5 per ha + PSB + PGPR during both years in respect of dry matter production (g), grain yield (kg/ha) and stalk yield (kg/ha).