ANTHRACNOSE CROWN ROT DISEASE OF STRAWBERRY PLANTS IN EGYPT AND ITS CONTROL

Isolation and identification of fungal pathogens were purified and identified as: Colletotrichum acutatum, Alternaria tenius and others. C. acutatum and A. tenius were the most frequent fungi that isolated from samples of strawberry plant materials which collected from the different locations in both seasons 2013/ 2014 and 2014/ 2015. Susceptible strawberry cultivar Florida was highly susceptible one where infection reached to 100% infection by Colletotrichum acutatum isolate. 2. Also, Alternaria tenius was pathogenic to c..v Florida, but came in the second rank in pathogenicity tests. The most effective bioagent was T. viride. Also, treating strawberry plants with different concentrations of organic acids affected greatly C. acutatum and A.tenius Ascorbic acid at 200 ppm concentration is the best effective concentration in controlling both pathogens in vitro .. Gall extract affected greatly the growth of. both pathogens in all daily records from 1-6 days, followed by both plant extracts Mustard and Clove.. Two fungicides (recommended for up ground diseases of strawberry plants); i.e., Bellis 38% WG (with three doses; 0.4 g/L., 0.8 g/L. and 1.6 g/L.) and Amistar 25% SC (with three doses; 2.5 ml/l., 5 ml/l. and 10 ml/l.) were used in this experiments. . Complete inhibition of fungal growth was noticed in both high concentration of the tested fungicides and little growth was happened in the low concentration of Bellis and Amistar. A. tenius was revealed as less tolerant to fungicides than C. acutatum. All tested treatments against both pathogens in vitro under laboratory conditions were applied in vivo under field conditions on strawberry plants cv. Florida to investigate their effects on plants under natural infection in field. All growth characteristics of different parts of strawberry cv. Florida like leaves number, lateral branches, flower number, green fruits, colored fruits, TSS% and fruits weight were affected as a result of infection with pathogens and treated with different chemical, biological and agricultural treatments, there were great variations among all applied treatments in this respect, The best treatments were fungicides, followed by gall extract and un-mulched control treatment comparing with other treatment and control treatment (un-treated) , All disease symptomson strawberry cv. Florida were calculated on plant leaves, flower parts, vegetative fruit characteristics. Black spot, irregular spot, black margin, petiole lesions and dead leaf were calculated during the period ranged between 3-15 days at 15 Pth P 30Pth P March, 2015. Both chemical fungicides (Bellis 38% WG and Amistar 25% SC) controlled completely the leaf infection symptoms, followed by Galls 10%. Treating plants with Kocide 2000, Ascorbic acid 5% and T viride protected plants with various degrees of infection.