Seed health studies in tomato Solanum lycopersicum L cv PKM 1

Abstract

Early blight of tomato caused by Alternaria solani is the most commonly newlineprevalent disease in the conventional tomato growing areas of Tamil Nadu. It is a major newlineseed borne disease, it leads to leaf and stem blight which causes defoliation resulting in newlinedrastic reduction of yield up to 79 per cent. Survey was conducted at major tomato newlinegrowing areas of Tamil Nadu viz., Coimbatore, Dindugal, Salem, Dharmapuri and newlineKrishnagiri during 2018 and 2019 to assess the early blight disease intensity in tomato. newlineIn each district twenty fields were selected, in each field 100 leaves were assessed at newlinerandom. Among the surveyed districts Krishnagiri recorded maximum per cent disease newlineindex (PDI) this was followed by Dharmapuri. The minimum disease incidence was newlinerecorded in Coimbatore. newlineThus, it could be concluded that the pathogenic variability occurs in the tomato newlineearly blight pathogen Alternaria solani across different regions of Tamil Nadu. Seed newlinemycobiome studies revealed the presence of several fungal pathogens, among them newlineAlternaria solani was found to be predominant. Among the various seed health testing newlinemethods, Standard Blotter Method (SBM) was found to be more precise. Amid the newlinebotanicals used, zimmu leaf extract 10% performed well. Between the various plant newlineoils, 4% Thyme oil achieved well. Among the mushroom fungi tested, Ganoderma newlinelucidum performed better. Amongst the different cold plasma treatments, tomato seeds newlinetreated with 40 W performed greatest and between the different PMF treatments, tomato newlineseeds treated for 20 days performed better. Among the different sonication treatments, newlinetomato seeds treated at 40 kHz for 30 minutes achieved best. Under the pot and field newlinecondition studies the zimmu leaf extract 10% performed better than the other treatments newlineit is closely followed by the hexaconazole treatment. Seeds treated with zimmu leaf newlineextract and stored in the aluminium foil pouch performed better than other treatments. newline