Effect of different media and temperature on mycelial growth of Pestalotiopsis sp., incitant of leaf spot and blight disease of cashew in western part of West Bengal

Author: Adhikary P., Sarkar U., Jash S., Ray S.K. and Dutta S.

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Abstract

Cashew leaf spot and blight disease caused by Pestalotiopsis sp. in the western region of West Bengal, where cashews are grown, is one of the most prevalent and emerging foliar disease and primarily affects older leaves. It severely affects the yield of the crop. The knowledge of the influence of temperature and nutritional factors on mycelial growth, sporulation and pathogenic fitness is of utmost need for understanding the physiology of this dreaded pathogen. Cultural and physiological studies of Pestalotiopsis sp. were conducted at Plant Bacteriology Laboratory, Department of Plant Pathology, Bidhan Chandra Krishi Viswavidyalaya during 2021-2022. The cultural studies were conducted to know the effect of different media on growth and sporulation of Pestalotiopsis sp. Among the different media, the maximum mycelial growth of Pestalotiopsis sp. was observed on Oat meal agar (OMA) medium (8.9 cm) followed by Potato dextrose agar (PDA) at 6 days after inoculation. Irrespective of different media, the highest mycelial growth rate (13.84 mm / day) and AUMPC (174.72) of Pestalotiopsis sp. was recorded at 22oC followed by 27˚C. However, highest sporulation was observed on potato dextrose agar (3.14 × 10-5/ mm2) followed by oat meal agar (2.35×105/ mm2) whereas it was least on Czapeck’s dox agar medium (7.85 × 10-4/ mm2). The present findings thus, indicated that 22-25oC was found to be the favorable temperature for mycelia growth of Pestalotiopsis sp. causing leaf spot and blight disease of cashewnut. Pathogenicity testing of Pestalotiopsis sp. was done on three different hosts (Mango, cashew and jackfruit) through detached leaf assay. Among these three hosts, jackfruit is found to be the most susceptible host for Pestalotiopsis sp sym-1 (cashew) isolate.

Keywords

Leaf spot, Blight, Growth rate, Pestalotiopsis sp., Sporulation

Conclusion

In the current investigation, a total of four different culture media were tested to assess their influence on mycelial growth and sporulation of Pestalotiopsis sp. Colony diameter (8.9 cm) was significantly highest on Oat meal agar at 6 days after inoculation. Similarly, the highest mycelial growth rate (13.84 mm / day) and area under mycelial progress curve (AUMPC) (174.72) of Pestalotiopsis sp. was recorded at 22oC followed by 27˚C. Pathogenicity studies were observed on different hosts and jackfruit is found to be the most susceptible host of Pestalotiopsis sp. cashew isolate.

References

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How to cite this article

Adhikary P., Sarkar U., Jash S., Ray S.K. and Dutta S. (2023). Effect of different media and temperature on mycelial growth of Pestalotiopsis sp., incitant of leaf spot and blight disease of cashew in western part of West Bengal. Biological Forum – An International Journal, 15(10): 359-364.