Pestalotiopsis leaf spot: an important foliar disease in cashewnut seedling incited by Pestalotiopsis oxyanthiin West Bengal, India

Autor: Patsa, Rakesh, Jash, Subhendu, Dutta, Subrata, Barman, Ashis Roy, Poduval, Mini, Ray, Sujit K.
Zdroj: Indian Phytopathology; September 2023, Vol. 76 Issue: 3 p713-725, 13p
Abstrakt: Cashewnut leaf spot is an important foliar disease in cashewnut seedling in West Bengal, India. The present study was aimed to identify and characterize the causal organism associated with cashewnut leaf spot and also to find out its best management strategies. Two cashewnut nurseries at Jhargram and Mohanpur were surveyed and four isolates of the pathogen were isolated from infected leaf tissue. The pathogen was identified as Pestalotiopsis oxyanthi(Thumen) Steyaert based on morphological features and ITS sequence data. Phylogenetic analysis using sequence data placed the four isolates in a single clade. Disease progress rate was positively correlated with the weather parameters like maximum relative humidity (RH), mean RH and rainfall data in both years. Pyraclostrobin inhibited mycelial growth of the pathogen most followed by thiophanate methyl and carbendazim + mancozeb against pathogen with ED50values of 0.362, 0.839 and 1.137 ppm, respectively. All the tested fungicides revealed significant effect on disease severity of leaf spot and reduced disease severity after four sprayings. It has been observed from two years pooled data that pyraclostrobin treated seedling showed lowest disease severity (DS), area under disease progress curve (AUDPC) and highest percent disease reduction over untreated control of 23.00%, 1200.00 and 61.02%, respectively.
Databáze: Supplemental Index