Survey, varietal reaction and chemical control of strawberry charcoal rot in Egypt

Abstract

A survey was carried out to know the occurrence of charcoal rot disease of strawberry caused by Macrophomina phaseolina in different selected locations representing different soil types during the growing season of strawberry in Badr and Kom Hamada Districts in El-Behira governorate, Egypt. Also, the effect of five chemical fungicides at five concentrations was determined in vitro and in vivo experiments against M. phaseolina compared to the control. A total of 69 strawberry samples collected from farmer's fields. Disease incidence (DI) and percentage of disease incidence (PDI) and disease index were recorded. Results revealed that percentage of disease incidence varies among the surveyed locations. Macrophomina phaseolina isolates M3 and M4 were the most destructive isolates. Results indicate that the selected Four strawberry cultivars showed different susceptibility to charcoal rot and Festival was the high susceptible cultivar. Our findings revealed that at 100 ppm concentration the most of the fungicides used inhibited the M. phaseolina mycelium growth, however the higher rate was recorded with Sendo by 91.95 % followed by 91.12% in Rhizolex-T and the least rate was recorded with Ridomil gold plus by 31.67%. At 200 ppm Rhizolex-T gave the highest inhibition by 96.67%, followed by Sendo and Sandcur by 95.96 and 95.00 % respectively while Ridomil gold plus gave the least inhibition rate by 43.06%.Results illustrated that use of fungicides markedly increased the survival of strawberry plants. The highest plant survival percentage was recorded with Rhizolex-T by 80% followed Sendo by 60%, while least plants survival percentage was recorded with Ridomil gold plus by10% compared with infected untreated control.