Bacterial Diseases of Crop Plants in Nepal: A Review

Abstract

A literature review was carried out to explore incidence and severity of bacterial diseases in major crop plants of Nepal. The diseases appeared to be more important in two (rice and maize) cereals and many fruits and vegetables. In rice, bacterial leaf blight (caused by Xanthomonas campestris pv. oryzae) reduced 5-60% yield in terai and mid-hills during hot and humid periods. The cultivars Chandina, Bindeshwori, Chaite-2 and some others were moderately resistant. Foliar spray of 100 ppm streptocycline has been recommended against the disease. Bacterial stalk rot (Erwinia chrysanthemi) caused up to 80% yield loss along with fungal diseases in maize in the plains. Sarlahi Seto and E2 Illinois were moderately resistant. In citrus, canker (X. campestris pv. citri) and greening (Liberobacter asiaticum) were epidemic throughout the country. Proper management of orchard followed by copper fungicide spray was practiced for canker, while no specific remedy was advised against greening. Crown gall (Agrobacterium tumefaciens) was major problem in pome fruits. Root dipping in 750 ppm agrimycin before transplanting was suggested for treatment. Black rot (X. campestris pv. campestris) caused up to 24.5% infection in local cauliflower and up to 39% in mustard seeds. Bacterial wilt (Ralstonia solanacearum) incidence was recorded up to 100%, 90% and 32.5% in tomato, brinjal and potato, respectively, in terai and mid-hills under hot and humid conditions. Halo blight (Pseudomonas syringae pv. phaseolicola) was a considerable disease in common bean and bacterial pustule (X. campestris pv. glycines) and bacterial blight (P. syringae pv. syringae) in soybean. Studies on epidemiology, diagnosis, yield loss and management of bacterial diseases seems to be quite behind and have to be focused. This review would be helpful to future research works on bacterial diseases of crop plants in Nepal. J. Inst. Agric. Anim. Sci. 25:1-10 2004