Synergistic Effects of Arbuscular mycorrhizal Inoculation and Soil Moisture on Leaf Nutrients and Physiological Performance in Cashew (Anacardium occidentale L) Biotypes

Abstract

A controlled greenhouse study was conducted during the 2020/2021 dry season at the Cocoa Research Institute of Nigeria (CRIN), Ibadan, Nigeria, to evaluate the effects of arbuscular mycorrhizal fungi (AMF) inoculation and soil moisture on nutrient acquisition and physiological performance of three cashew (Anacardium occidentale L.) biotypes. The experiment was arranged as a 3 × 3 × 2 factorial in a completely randomized design, comprising three biotypes (Jumbo, Medium and Madras), three soil moisture levels (40%, 60% and 80% field capacity), and two AMF treatments (inoculated and non-inoculated), with three replications. AMF inoculation significantly improved foliar nutrient concentration and nutrient uptake of N, P, K, Ca and Mg, although the magnitude of response varied with biotype and moisture regime. The highest nutrient uptake and foliar nutrient concentrations generally occurred in AMF-inoculated Jumbo seedlings at 80% field capacity. AMF inoculation also improved chlorophyll content, relative water content and stomatal conductance, with the highest physiological values recorded under 80% field capacity. Jumbo generally showed the strongest response, whereas Madras recorded comparatively lower values. The findings demonstrate the potential of AMF inoculation to improve nutrient acquisition and physiological performance of cashew seedlings under varying soil moisture conditions, with the response depending on the cashew biotype and moisture regime.