Genetic response of tomato germplasm against early blight and its management through fungicides

Abstract

The response of fifty one tomato accessions germplasm were tested against early blight under field and walk-in tunnel conditions. None of the test germplasm was immune or highly resistant in both conditions. In the tunnel experiment, among the twenty seven indeterminate varieties and hybrids only one variety (Beefsteak) showed resistant response with PDI 15.55, eleven varieties and five hybrids were moderately resistant, three varieties and five hybrids were moderately susceptible, one variety (Sahel) and one hybrid (Litth-568) showed susceptible response with 68-70 PDI. In the field experiment, among the twenty four determinate varieties and hybrids four varieties (Black Prince, Oregon spring, Zhezha and Bloody Butcher) showed resistant response with PDI 11-16, ten varieties and four hybrids were moderately resistant, four varieties were moderately susceptible and one variety (Napoli) and one hybrid (Lth-174) showed susceptible response with 68.88 PDI. In-vitro five fungicides, namely, Cabriotop, Precure Combi, Halonil, Topsin-M and Difenoconazole were tested through poisoned food technique against A. solani. There was a significant decrease in mycelial growth of the fungus with an increase in fungicidal concentration. At 150 ppm, Difenoconazole (91.95%) gave maximum inhibition of the mycelial growth followed by Cabriotop (64.36%). Least inhibition of mycelial growth was observed in Halonil (45.97%). The fungicides which proved to be most effective in-vitro were tested in field, maximum disease control with 11.84 PDI was recorded in the Difenoconazole treated plots followed by Cabriotop sprayed plots with 26.66 PDI. The results of the present studies will be helpful to devise management strategies for the control of tomato early blight.

Role of habitat manipulation for pest management in tomato

“…It can either be eaten fresh or processed into different products. The crop is of large importance worldwide (Abdussamee et al, 2014;Mehraj et al, 2014;Kaur and Rishi, 2014). It is an important source of nutrients (Vitamins A, B, C and E), and contributes largely to household diet and national economy (Bhowmik et al, 2012).…”