In vitro cellulase activity of two wilt causing soil fusaria (Fusarium solani and F. oxysporum f. sp. lycopersici) and efficacy of some pesticides against the said fusaria

Abstract: Soil-borne pathogens (Fusarium solani and Fusarium oxysporum f. sp. lycopersici) were isolated from the diseased plants of brinjal and tomato, identified by morphological analysis viz., PCM (Phase contrast microscopy) and SEM (Scanning Electron Microscopy). These pathogens produced cellulolytic enzyme in vitro and the activity of this enzyme increased with the increase in age of the culture. F. oxysporum f. sp. lycopersici produced more cellulolytic enzyme than F. solani. The activity of cellulolytic enzyme by F. oxysporum f. sp. lycopersici was more in 14^th day-old culture and decreased with the increase of culture age whereas the activity of cellulolytic enzyme produced by F. solani did not decrease and enzyme activity increased with the increase in the age of culture (23^rd day-old culture). In vitro efficacy of systemic fungicides viz., Roco (Thiophanate methyl 70% WP) and Chlorothalonil (non-systemic fungicide), herbicides viz., Syncore (Metribuzin 70% WP), 2, 4- D (2, 4- Dichlorophenoxy acetic acid) and insecticides viz., Nuvan (Dichlorvos 76% EC), Prima (Acetamiprid 20% SP) against F. solani and F. oxysporum f. sp. lycopersici were evaluated using poisoned food technique at 100, 200, 400 ppm concentrations on 7^th day of inoculation. The fungicide (Chlorothalonil) inhibited the mycelial growth of F. solani by 82.34%, while Thiophanate methyl inhibited F. oxysporum f. sp. lycopersici by 77.96% respectively at 400 ppm concentration. Herbicide (Metribuzin) inhibited the mycelial growth of F. oxysporum f. sp. lycopersici and F. solani by 75% and 62.50%, respectively at same concentration followed by insecticides Dichlorvos (56.87%) and Acetamiprid (53.12%), respectively.