Relationship between Colletotrichum falcatum and Fusarium subglutinans of F. moniliforme Sugarcane Red Rot-Fusarium Stem Rot Pathogens

Abstract

Colletotrichum faclcatum and fusarium subglutinans of f. moniliforme are commononly found on the same rotted cane stalks. Relationship between Chonburi, Rayong, Singburi and suphanburi isolates of c. falcatum and f. subglutinans and sukothai isolate of c. falcatum and F. moniliforme were tested in dual culture test and stalk of susceptible cane variety. No inhibition zones were found between C. falcatum and fusarium spp. in dual cultrue. However, all tested isolates of fusarium grew dominately on agar and finally cover the C. falcatum Colonies. spores of both organisms from those colony areas were still viable in spore suspension germination test. There were some reduction on growth of C. falcatum when the agar disk took from culture of C. falcatum covered with Fusarium were transfered to the new agar or inoculated in cane stalk.
After C. falcatum and Fusarium spp. in each isolate wee inoculated seperately and together in susceptible cane stalks for 21 days, the stalks inoculated with C. falcatum alone showed most susceptible in stalk rotting and top wilting. Rot of stalk and wilt of top were reduced respectively in the stalk preinoculated with C. falcatum followed by Fusarium spp., inoculated with C. falcatum and Fusarium spp. simultaneously, preinoculated with fusarium spp. followed by C. falcatum and inoculated with Fusarium spp. alone.
fusarium spp. grew dominately on agar media while C. falcatum had higher pathogenicity in stalk rotting and top wilting of sugarcane. C. falcatum and Fusarium spp. destroyed the same cane stalk without synergistic relationship. Some reduction of stalk rotting and top wilting were found in the areas where subglutinans or f. moniliforme previously grew.