Influence of some agrochemical products on Loquat inflorescence blight, leaf spot and fruit rot diseases.

Document Type : Original Article

Authors

1 Plant Pathology Research Institute, Agricultural Research Center, 12619, Giza, Egypt.

2 Plant Pathology Research Institute, Agricultural Research Center, 12619, Giza, Egypt

Abstract

Inflorescence blight, leaf spot and fruit rot are the most important diseases that significantly decrease the production of loquat trees in Egypt. The typical symptoms were observed on loquat trees cv. Emanuel (15-years- old) grown in the Experimental Farm at El-Qanater El-Khairia Horticultural Research Station (EHRS), Agricultural Research Centre (ARC), Qaloubiya governorate during 2021/2022 and 2022/2023. Disease incidence and disease severity were higher during 2022/2023 than 2021/2022 under natural field infection. Alternaria alternata (Fr.)Keissler and Monilinia fructicola G.Wint. fungi were isolated from diseased inflorescences, diseased spotted leaves and fruits furthermore, Fusarium solani Mart. fungus was isolated from spotted leaves. M. fructicola showed the highest frequency among fungi isolated from diseased inflorescences and leaves but A. alternata was the highest isolated fungus from rotted fruits. Pathogenicity test showed that A. alternata and M. fructicola were able to induce inflorescence blight, leaf spot and fruit rot diseases on loquat. On the other hand, little spots were appeared on leaves inoculated by F. solani. In vitro, the efficacy of four agrochemical products (Score 25%, Scar Nat 70%, Pyrmadol 40% and Decent 32.5%) was measured on the linear growth of the isolated fungi. Generally, growth of the isolated fungi was totally inhibited with Score (25% EC), Scar Nat (70% WP), Pyrmadol (40% SC) and Decent (32.5% EC) at the rate of 1ml or 1g/L. Score and Decent were more effective than Scar Nat and Pyrmadol. In vivo, under filed conditions, treatment with Score (100 ml/100 L water) significantly decreased inflorescence blight, leaf spot and fruit rot diseases during the two experimental seasons followed by Decent (100 ml/100 L water) and the lowest efficacy was obtained with Pyrmadol (100 ml/100 L water).

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