Role of Some Biological Methods in Inducing Total Phenols and Sugars in Strawberry Plants Infected with The Pathogenic Fungus Rhizoctonia solani

Abstract

Rhizoctonia solani was isolated on PDA from strawberry plants that showed yellowing, wilting and discoloration in the crown area. Laboratory results showed the effectiveness of antagonistic bacteria Pseudomonas stutzeri, Pseudomonas fluorescens and Bacillus sonorensis in inhibiting the growth of the pathogen fungal colony. Laboratory results showed the efficiency of antagonistic bacteria in inhibiting the growth of the pathogen fungal colony, as the diameter of the colony of R. solani when treated with the bacteria Pseudomonas stutzeri reached 0.4 cm, with the bacteria Pseudomonas fluorescens 0.63 cm, and with the bacteria Bacillus sonorensis 0.68 cm. The chemical pesticide gave a high efficiency in inhibiting the growth of fungal hyphae, as the diameter of the fungal colony reached 1.4 cm, with an inhibition rate of 84%, four days after treatment, compared to 9 cm, for the control treatment. Field results for determining total phenols showed that the garlic oil extract (Oil 2) + B3 treatment (B. sonorensis) outperformed all other treatments, as the average total phenols reached 33.2 mg/g fresh weight under the influence of the pathogenic fungi, whereas it gave the lowest content of phenols when treated with rosemary oil (14.32 mg/g). Results obtained also showed that the treatment B3 + oil 2 produced the highest level of total sugars in strawberry fruits, reaching 12.32 mg/g of fresh weight, whereas the lowest total sugar content was obtained following the treatment with plant oil extracts, which reached 4.62 mg/g for rosemary oil, and 5.64 mg/gm for neem oil. The treatment B1+alga (P. stutzeri + marine algae) excelled in increasing the average yield of strawberry fruits, reaching 1628.3 g/plant, whereas the treatment B1 bacteria + P. stutzeri gave the lowest average yield of strawberry fruits of 955 g/plant.

Keywords:

Root rot, strawberry, Rhizoctonia, beneficial bacteria, seaweed.