Etiology epidemiology and management of anthracnose of grapevine

Abstract

Investigations into etiology, epidemiology and management of anthracnose caused newlineby Elsinoe ampelina (de Bary) Shear, a potentially important disease of grapevine revealed newlinethe involvement of Sphaceloma ampelinum, Gloeosporium ampelophagum and newlineColletotrichum gloeosporioides in the causation of the disease: These were isolated from newlinedifferent locations surveyed over northern parts of Karnataka, parts of Maharashtra and newlineAndhra Pradesh states. The disease was severe during April pruning stage as compared to newlineOctober pruning stage. The places Badachi, Jumnal, Tidagundi, Hosur (all in Karnataka) and newlineSadashivpet (Andhra Pradesh) were identified as hot spots for this disease. newlineVirulence studies employing detached leaf technique revealed that isolates Ea13, newlineEa20 and Ea21were highly virulent whereas cultural studies showed vigourous growth of newlineEa11 and Ea8 isolates on Sabouraud s agar. Ea5 and Ea21 produced the highest mycelial newlinegrowth on host extract medium. newlineRAPD analysis of 12 anthracnose isolates showed two clusters and revealed newlinesignificant molecular variability. The isolates exhibited 100 per cent polymorphism with OPF- newline12, OPF-14 and OPF-19 primers. newlineSensitivity tests to carbendazim by poisoned food technique as well as inhibition of newlinespore germination revealed Ea11 to be the most sensitive isolate while Ea15 was found to be newlinethe most resistant. Further it was observed that the isolates were more sensitive to newlinehexaconazole than other chemicals and Ea15, a carbendazim resistant isolate exhibited cross newlineresistance. newlineThe pathogen survived in old grape stalks for more than 21/2 years. The spore trap newlinestudies in relation to weather factors and disease incidence revealed a positive influence of newlinerainfall and relative humidity. September- October period was highly conducive for disease newlinedevelopment. A forecasting model D= -1.4+ 2.6RH2+2.0 S was developed. newlineChlorothalonil 75 WP (non-systemic) and hexaconazole 5E (systemic) and onion newlineextract 10% (botanical) as well as Trichoderma harzianum (bioagent) inhibited the newlineanthracnose pathogen in