Effect Of Commonly Used Fungicides On Arbuscular-Mycorrhizal Association With Apple Roots

In Himachal Pradesh apple crop is attacked by various pathogens of which Dematophora necatrix causing root rot and Phytophthora cactorum causing collar rot are most destructive. To control these two to three drenching of fungicides like carbendazim, mancozeb, copper sulphate and aureofungin are recommended. Arbuscular-mycorrhizal fungi (AMF) are beneficial fungi which also live in association with apple roots. In the present investigation the effect of these commonly used fungicides was observed on the association of local isolate of AMF, Glomus spp. with apple roots in pot cultures. The different fungicide solutions at various concentrations were applied in two ways one before one week of AMF inoculation (pre-inoculation treatment) and another after one month of AMF inoculation (post-inoculation treatment). All the fungicides tested inhibited the AMF colonization significantly over control. The effect of fungicides reduced significantly with time. Amongst the fungicides, mancozeb application resulted highest reduction in the AMF colonization followed by aureofungin and copper sulphate whereas carbendazim resulted lowest reduction.