Pigeonpea Sterility Mosaic Virus (PPSMV): Epidemiology, Pathogenicity and Control Measures
Résumé
The pigeonpea crop has a direct impact on the economic and financial well-being of subsistence farmers in the subcontinent as it is a low-input, rainfed crop that provides economic returns from every part of the plant. Sterility mosaic disease is the major constraint to pigeonpea production in the Indian subcontinent. Pigeonpea sterility mosaic virus (PPSMV) belongs to the genus Emaravirus and causes sterility mosaic disease. PPSMV is prevalent in Asian countries, such as Bangladesh, Nepal, Thailand, Myanmar, Sri Lanka, and China. PPSMV is transmitted by the eriophyid mite, Aceria cajani (Channabasavanna). PPSMV and the vector eriophyid mite A. cajani are specific to pigeon pea and the wild species C. scarabaeoides and C. cajanifolius. The symptoms of this disease include mosaic and sterilility with malformation or no flower symptoms, hence the name of the disease as ‘sterility mosaic. ’Resistant/tolerant cultivars can be used to manage various diseases. The spread of PPSMV involves pathogenic viruses, mites, host plants, and environmental factors. PPSMV is an endemic disease that varies with the season and locality. Inter or mixed cropping of pigeon peas with sorghum or millet influences the incidence of the disease. The ratooning of crops also increases disease incidence. Shade and humidity favor a high multiplication of mite populations, mostly in hot summer weather. Removal of infected plant debris, isolation of new crops from perennial pigeon pea, and crop rotation could control the disease.