Resistance development in Colletotrichum truncatum to carbendazim and thiophanate, and growth and sporulation in resistant strains.
Strains with high degree of resistance to carbendazim and thiophanate were obtained with relative ease when the conidial suspension of C. truncatum were exposed to U.V. source from a 15 watt lamp for 1 to 5 minutes. The resistance was highly stable. Resistant strains, in general showed increased sensitivity to copper oxychloride, man-cozeb, carboxin and triadimefon. The growth of isolates Ct3 and Ct1 was on par with sensitive isolate while others had significantly low growtli on PDA. All the five resistant isolates were poor sporulators compared to sensitive isolate. The rate of conidial germination, especially in the initial stages, was significantly lower in case of resistant strains.