Effect of nutrient management and antitranspirant on rainfed sole and intercropped pearlmillet (Pennisetum glaucum) and pigeonpea (Cajanas cajan)

A field experiment was conducted during rainy season of 2009 and 2010 on sandy loam soil of New Delhi to study the effect of transpiration suppressants and nutrient management on productivity, nutrient uptake and water use efficiency of sole and intercropped stand of pearlmillet (Pennisetum glaucum (L) R. Br. Emend. Stutz.)/pigeonpea (Cajanas cajan (L.) Millsp) under rainfed conditions. The experiment was conducted in a three times replicated split-plot design, in which main—plots received 3 cropping systems (sole pearlmillet at 50 cm spacing, sole pigeonpea at 50 cm spacing and paired row of pearlmillet + pigeonpea in 2:1 row ratio at 30/70 cm spacing and 3 transpiration suppressants (control, PMA at 320 ppm and cycocel 200 ppm) at 60 days after sowing (DAS) and sub-plots received 4 fertility levels (control, 25 kg N + 8.6 kg P/ha, 50 kg N + 17.2 kg P/ha and 25 kg N + 8.6 kg P/ha + Azotobacter+ PSB). Sole cropping of both pearlmillet and pigeonpea had significantly higher grain yield and uptake of N and P than their respective intercropped stand. Pearlmillet + pigeonpea intercropping system recorded significantly higher pearlmillet equivalent yield, total system uptake of N and P and nitrogen use efficiency [agronomic efficiency (AE), physiological efficiency (PE) and nitrogen harvest index (NHI)], consumptive use, water use efficiency (WUE) over the sole stand of component crops. Based on two years mean, pearlmillet equivalent yield of intercropped stand was 46.1 and 10.2% higher than the sole stand of pearlmillet and pigeonpea respectively. On an average, intercropped stand recorded 27.2 kg grain/kg N and WUE of 10.55 kg/ha-mm, which was 86.5 and 17.8% higher than pearlmillet and 287 and 126.6% higher than pigeonpea respectively. Over control, use of transpiration suppressants was found effective only during 2009. PMA 320 ppm caused 8.9, 3.7 and 7.4% increase in gram yield of pearlmillet, pigeonpea and pearlmillet equivalent yield over control during 2009, respectively. Among fertility levels, application of 50 kg N + 17.2 kg P/ha recorded significantly higher grain yield of pearlmillet than other fertility level, while it was on with 25 kg N + 8.6 kg P/ha + Azotobacter+ PSB with respect to pigeonpea + pearlmillet equivalent grain yield. Intercropped stand extracted more moisture from the lower layer as compared to sole stand of pearlmillet and pigeonpea.