Incidence of Beet Leaf Spot Caused by Neocamarosporium betae in Korea

Gyo-Bin Lee¹ Hong-sik Shim¹ Wan-Gyu Kim¹ Weon-Dae Cho^1,*

¹Global Agro-Consulting Corporation, Suwon 16614, Korea

Abstract

From June to August 2021, we surveyed diseases affecting beet (Beta vulgaris subsp. vulgaris) plants in Cheolwon, Hoengseong, and Pyeongchang regions in Gangwon Province, Korea. We observed severe leaf spot symptoms, such as brown to dark circular or irregular spots on the leaves, in plants. Disease incidence in the plant leaves in the fields investigated at the three locations ranged from 1 to 80%. Five single-spore isolates of Phoma sp. were obtained from the diseased leaves and identified as Neocamarosporium betae based on their cultural, morphological, and molecular characteristics. Three isolates of N. betae were subsequently tested to confirm their pathogenicity in beet plants via artificial inoculation. The tested isolates caused leaf spot symptoms in the inoculated plants, similar to those observed in the plants in the investigated fields. Therefore, our findings revealed N. betae as the pathogen causing beet leaf spot in Korea.

Figures & Tables

Fig. 1. Leaf spot symptoms in beet plants. A and B: Symptoms observed in the investigated fields. C: Symptoms observed in the plant artificially inoculated with a isolate in a pathogenicity test. D: A non-inoculated plant (control).