Evaluation of the efficacy of plant extract and fungicides against Fusarium oxysporum f. sp. lycopersici under in vitro conditions

Abstract:

Tomato (Lycopersicon esculentum Mill.) is an important vegetable crop severely affected by Fusarium wilt caused by Fusarium oxysporum f. sp. lycopersici. The present investigation was carried out to evaluate the efficacy of different plant extracts and fungicides against the pathogen under in vitro conditions by poisoned food technique. Seven plant extracts viz., Azadirachta indica, Asparagus racemosus, Polyalthia longifolia, Withania somnifera, Allium cepa, Zingiber officinale, and Allium sativum were tested at 10, 20, and 30 per cent concentrations, while seven fungicides viz., Azoxystrobin, Propineb, Thiophanate methyl, Difenoconazole, Mancozeb, Mancozeb + Thiophanate methyl, and Boscalid + Pyraclostrobin were evaluated at 250, 500, and 750 ppm concentrations. The experiment was conducted in Completely Randomized Design (CRD) with three replications. Among the plant extracts, Allium sativum proved most effective and recorded maximum mycelial growth inhibition of 66.46 per cent at 30 per cent concentration, followed by Azadirachta indica with 62.02 per cent inhibition. Polyalthia longifolia was found least effective against the pathogen. Among fungicides, Thiophanate methyl exhibited highest inhibition of 95.24 per cent at 750 ppm concentration followed by Mancozeb + Thiophanate methyl with 92.86 per cent inhibition. Azoxystrobin was comparatively less effective than other fungicides tested. The results revealed that garlic extract and Thiophanate methyl were highly effective in suppressing the growth of F. oxysporum f. sp. lycopersici under laboratory conditions. Therefore, these treatments may be utilized as effective components in integrated management of Fusarium wilt of tomato.