کارایی فرمولاسیون پایه آب چند سویه باسیلوس در کنترل بیماری کپک خاکستری میوه توت فرنگی پس از برداشت

One of the most important strawberry diseases is gray mold caused by Botrytis cinerea Pres: Fr. which is the main cause of fruit rot. The disease develops on the strawberry fruit in the field and during transportation, leading to rot and reduced shelf life during storage. To evaluate the antagonistic ability of 15 Bacillus subtilis complex strains from Plant Protection institue, some tests were done in vitro. To screen the effective bacterial strains based on non-volatile metabolites method, a 0.5 cm2 block of a five-day culture of the pathogenic fungus was cultured in the middle of the Petri dish with 5 μl of each antagonist bacterial strains at four points of Petri dishes. Petri dishes were also placed at 28°C for seven days. Three strains with more inhibitory ability were selected for subsequent experiments. Selected bacteria were cultured in LB medium for formulation. To create a suitable environment for preservation and maintenance of bacterial cells, 20 g of polyvinyl pyrrolidone (PVP) and 400 mL of glycerol, and some accompanying materials such as 2 g of tween 20 were transferred to the suspension. 0.3 g of Xanthan gum and 0.5 g of carboxymethyl cellulose (CMC) were also used as binders. To evaluate the effectiveness of formulations on fruit rot control, experiments were performed in a completely randomized design with three replications and each replication consisted of three fruits. Ripe fruits which inoculated with spore suspension with a concentration of 1×105 of the causative fungus, were sprayed with formulated Bacillus solutions 2 days after inoculation. Signum and Serenade fungicides with concentrations of 1gr/1L and 5mL/1L, respectively, were used for comparison, as well as infected and healthy controls. Each of the treated fruits was transferred to disposable cups and stored for 24 hours at 20 °C, then for 72 hours at 10 °C, and then for 24 hours at 25 ° C to simulate the standard post-harvest conditions. The severity of gray mold was then assessed on a quantitative scale. Although all of the studied treatments had a substantial effect on disease control, the results revealed that the 522f1 formulation with 93.4% reduction in the fruit rot had the best influence on the disease and the lowest performance dedicated to the 526f1 formulation with 8.6% reduction, also, the effect of Signum and Serenade pesticide were 68.4% and 55%, in controlling the disease respectively.