Vol. 8, Issue 8, Part O (2024)

Abstract: Among the foliar diseases of tomato, early blight caused by Alternaria solani (Ellis and Martin) Jones and Grout, is one of the most destructive disease responsible for huge qualitative and quantitative losses. In recent years, the disease has assumed serious problems in tomato growing areas of Konkan region of Maharashtra. Therefore, with a view to reduce the losses in strategic manner integrated management of early blight of tomato with selective SAR chemicals, fungicides, bio-agents and phytoextracts is essential. Fungicides, SAR inducing chemicals, bio-agents and phytoextracts were significantly effective against early blight disease of tomato under natural epiphytotic conditions. Significantly least percent disease intensity (PDI) of 9.04% was observed due to seed treatment with captan @ 2 g/kg + 3 sprays of tebuconazole 50% + trifloxystrobin 25% WG @ 0.05 (T₉)with highest percent disease control over control by 79.95% followed by treatment T₁₀ (seed treatment with captan @ 2 g/kg + 3 sprays of propiconazole (0.1%) and T₈ (seed treatment with captan @ 2 g/kg + 3 sprays of mancozeb (0.25%) with 14.45 and 16.72 PDI and 67.95% and 62.92% disease control over control, respectively. Highest yield (31.72 t/ ha.) and increase in yield over control (73.04%) was also recorded in treatment T₉ as against control (18.33 t/ ha.). Treatment T₁₀ and T₈ were next best treatment with 29.28 t/ha. and 27.87 t/ha. fruit yield and 59.72 and 52.05 percent increase in yield over control, respectively. Seed biopriming with P. fluorescens + 2 sprays of P. fluorescens @ 1% recorded 18.26 PDI as against control with 59.51 percent disease reduction and yield of 24.20 t/ha. with 32.00% increase in yield. Next best treatment was seed biopriming with T. viride + 2 sprays of T. viride @ 1% with 22.72 PDI and 49.61 percent reduction in disease and 22.36 t/ha. and 21.97% increase in yield. Spraying of salicylic acid, benzoic acid and chitosan each @ 0.1% at two leaf stage in the nursery offered resistance to tomato plants against the pathogen up to 45 to 50 DAT, but there after there was slow development of the disease. Benzoic acid, salicylic acid and chitosan gave percent disease control over control to the tune of 34.47%, 39.75% and 23.86%, respectively. Among the phytoextracts evaluated, three sprays of neem leaf extract @ 10% recorded 26.48% disease severity.