Studies on arbuscular mycorrhisation on papaya

Abstract

Carica papaya L. is known to exhibit a strong growth response to colonisation by arbuscular mycorrhizal fungi; yet it is generally believed that mycorrhizal growth effects are primarily nutritionally mediated and are inversely related to improved soil fertility, especially available soil P, which affects the fungus symbiotic effectiveness. This study was, therefore, undertaken to evaluate the influence of selective arbuscular mycorrhizal fungi on vegetative growth of Carica papaya L. Studies were carried out in India on mycorrhization of Carica papaya var. Surya seedlings. The experiment comprised of un-inoculated seedlings, seedlings inoculated with Glomus intraradices, seedlings inoculated with Glomus mosseae and seedlings inoculated with mixed inoculum [Glomus intraradices plus Glomus mosseae]. Inoculation with arbuscular mycorrhizal fungi significantly (P less than 0.05) increased all the growth parameters viz., plant height, stem girth, leaf area and root length. Mycorrhizal plants exhibited significant increase in fresh and dry weights of shoot and root systems. A higher root: shoot ratio was also observed in mycorrhizal plants than the control plants. Glomus mosseae was the most effective species of arbuscular mycorrhizal fungi, recording the highest root colonisation and exerting profound influence on growth of papaya.