STUDIES ON STRAWBERRY LEAF SPOT DISEASE IN EGYPT

Ahmed, Faten; Younis, Sayed; Tawfeek, Amira; Koriem, Ali; Elian, Mohamed

doi:10.21608/jpd.2023.318947

STUDIES ON STRAWBERRY LEAF SPOT DISEASE IN EGYPT

Document Type : Original Article

Authors

¹ Plant Production Department, Faculty of Technology and Development, Zagazig Univ., Egypt.

² Department of Plant Prod., Faculty of Technology and Development, Zagazig Univ., Egypt.

³ Department of Plant Production, Faculty of Technology & Development, &lrm;Zagazig University, Egypt.&lrm;

10.21608/jpd.2023.318947

Abstract

        Fungal diseases of strawberry are important worldwide and occur in all parts of the plant. Alternaria alternata and Botrytis cinerea are the major causal agents of the leaf spots.
        Survey and distribution of strawberry leaf spot were carried out in EL-Sharkia and EL-Ismailia governorates. 12 and 20 samples were collected from two governorates with 25 and 35 average of disease incidence, respectively. Isolation and identification of the causal pathogen. Alternaria alternata and Botrytis cinerea were identified as the causal organisms of strawberry leaf spot disease.
        Pathogenicity test show that A. alternata was the most effective on inducing strawberry leaf spot disease followed by B. cinerea. Susceptibility of different strawberry cultivars to A. alternata and B. cinerea showed that Fortuna and Winter star were the lowest infected cultivars whereas Festival and Sunsation were the most infected cultivars and also, Florida cultivar was the moderately infected.
        All the tested fungicides for controlling leaf spot disease gave sufficient control against the causal organisms, in comparison with control in vitro. The results indicated that the fungicide Topsin M70has the superior effect followed by Captan.
           Conclusively, concerning phenolic compounds, it was found that total, free and conjugated phenols and oxidative enzymes peroxidase, polyphenol oxidase and catalase occurred at high levels in resistant cultivars in comparison with susceptible one. The accumulation of phenolic compounds occurred more rapidly in inoculated resistant leaves than in inoculated susceptible one.

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