Response of Tomato Germplasm and Hybridsagainst Botrytis Blight and its management through Chemicals

Botrytis blight is becoming threat for tomato cultivation in Pakistan.The severity of this disease has been increasing day by day for last few years due to changes in environment.So in present study Fifty one tomato germplasm and hybrids accessions were evaluated in open field and walk in tunnel conditions in research area of plant pathology section, Ayub Agriculture Research Institute, Faisalabad to determine their genetic response against botrytis blight. It was observed that no variety wasimmune. Among the twenty seven indeterminate varieties and hybrids eleven varieties and ten hybridsshowed moderately susceptible with (55-67) percent disease index.Five varieties and one hybridshowed susceptible response with (70-85) PDI.Among the twenty four determinate varieties and hybridstwo varieties showed resistant response with PDI of 20 and 28% respectively. Five varieties showed moderately resistant response with (36-44)PDI. Six varieties and four hybridsshowed moderately susceptible with (56-64)PDI.Five varieties and one hybridshowed susceptible response with (76-88)PDI.In-vitro five fungicides evaluated against B. cinereacabriotop (96.51%)gave maximum inhibition of the mycelial growth of pathogen followed by halonil (87.20%). Least inhibition of mycelial growth was observed in case of defeater (65.11%). In-vivo evaluation of fungicides maximum disease control with 8.00 PDI was recorded in the cabriotop treated plots followed by the (14.66) and (21.33), in plots sprayed with Halonil, Benedict, respectively. Least control of the disease was recorded in Defeater treated plots with (45.33PDI). In the control plot percent disease index was 72%.Theinformation generated from this research plan can be useful in future for the tomato growers to take management decisions about the disease.