Agronomic interventions for enhanced light interception and radiation use efficiency in hybrid pigeon pea

To find out the best agronomic management options for realising optimum plant expression and yield of hybrid pigeon pea. The field investigation was conducted at International Crops Research Institute For Semiarid tropics, Hyderabad during the kharif 2021 and 2022. The objective was to analyze the impact of various establishment methods, plant geometries, and nutrient management techniques on hybrid pigeon pea, using a split-split plot design. The study employed a line quantum sensor to measure amount of light interception, photosynthetically active radiation at the stage of maximum leaf area development, and subsequently calculated radiation use efficiency. Heat maps showed that transplanted plot recorded 13.9% higher mean photosynthetically active radiation (PAR) over dibbling. Whereas, in plant geometry factor 120 cm × 120 cm recorded 10.6% higher mean PAR over 150 cm × 60 cm but which was on par with 100 cm × 100 cm. However, square transplanting at 100 cm × 100 cm combined with an integrated nutrient management approach (Vermicompost 5 t/ha, 100% (or) 150% soil test based NPK, PSB, and seed treatment with Rhizobium) resulted in the higher mean seed radiation use efficiency which was (44.2% and 31.5%) higher respectively than with inorganic nutrient management alone (100% and 150% soil test based NPK). The optimal agronomic technique for increased pigeon pea yield was determined to be transplanting of pigeon pea at 100 cm × 100 cm and implementing integrated nutrient management, which includes seed treatment with Rhizobium, soil test-based NPK, vermicompost @ 5 t/ha, and PSB.