Non-chemical strategies in integrated management of wilt and stem rot diseases of chrysanthemum

Abstract

Wilt and stem rot caused by Fusarium oxysporum f sp. chyrsanthemi and Rhizoctonia solani are most devastating diseases, amounting to cause 18 -27 per cent loss under congenial environmental conditions in chrysanthemum. Due to many issues such as fungicide resistance, cost, and adverse effects, eco-friendly integrated approaches seem to be an applicable management method against the wilt and stem rot diseases of chrysanthemum. The objective of our present study was to evaluate the alternative methods such as soil amendments, biological agents and soil solarization (SS) alone and in integrated form which are cheap and easily adoptable having long-term benefits in combating the wilt and stem rot infection of chrysanthemum. Neem cake and cotton cake were found superior against Fusarium wilt pathogen with highest 68.11 per cent disease reduction while mustard cake showed highest effectiveness followed by neem and groundnut cakes to minimize the Rhizoctonia solani infection by 64.29 per cent. Fungal antagonists proved better in controlling disease compared to bacterial antagonist. For soil solarization, 25µ thickness polythene sheet resulted in less disease than 50 µ thickness. Integration of all the components resulted into excellent control of stem rot and wilt under field conditions due to additive effects. Maximum disease control (73.15 %) achieved in SS+ T. harzianum + Neem cake, SS+ T. harzianum + T. viride. A drastic decrease in the inoculums load of both pathogens recorded after two months period in solarized than unsolarized soils with varied microbial counts and almost negligible appearance of weeds in solarised plots.