Influence of AM fungi and inorganic phosphorus on fruit and root characteristics, root colonization and soil phosphorus in okra-pea cropping system in Himalayan acid Alfisol

Abstract

In Himalayan acid Alfisol, the influence of arbuscular mycorrhizal fungi (AMF) on fruit and root characteristics in okra-pea cropping system was assessed at varying inorganic phosphorus and irrigation regimes (40 & 80% available water capacity). In okra, AMF inoculation significantly improved the fruit length, fruit girth and fruit weight besides enhancing rooting depth (13%), root volume (7%), root dry weight (7%) and root weight density (6%) over non-AMF treatments. In pea, AMF sharply increased the average pod weight (10%), rooting depth (9%), root volume (16%), root dry weight (13%) and root weight density (12%) over non-AMF counterparts. AMF enhanced mycorrhizal root colonization by 2 to 2.3-fold both in okra and pea besides significant improvement in available soil-P pool (21%). ‘AMF + 75% soil-test based P dose (STB-P)’ at both irrigation regimes remained statistically alike with generalized recommended nutrient-cum-irrigation dose (GRD) and ‘AMF + 100% STB-P’ with respect to fruit and root parameters in okra-pea system, thus, indicating an economy of about 25% applied-P through AMF inoculation in acid Alfisol. Hence, AMF had positive influence on fruiting and root characteristics, fertilizer-P economy and availability in Himalayan okra-pea production system.