An Overview of Diseases Affecting Pigeon Pea (Cajanus cajan (L.) Millsp.)
Aayush Gupta
Navsari Agricultural University, Navsari, India.
D. H. Chaudhary
Navsari Agricultural University, Navsari, India.
L. S. Chaudhary *
Gujarat Natural Farming Science University, Halol, India.
M. G. Chaudhary
Navsari Agricultural University, Navsari, India.
K. V. Chaudhary
Gujarat Natural Farming Science University, Halol, India.
Nimavat Harsh
Navsari Agricultural University, Navsari, India.
*Author to whom correspondence should be addressed.
Abstract
Pigeon pea (Cajanus cajan (L.) Millsp.) is an important pulse crop cultivated mainly in tropical and subtropical regions of Asia and Africa. The crop contributes significantly to food and nutritional security because of its high nutritional value and suitability for rainfed and less intensive production systems. A variety of biotic stresses, however, limit its productivity, with Fusarium wilt, sterility mosaic disease and Phytophthora blight being among the important diseases. The causal organisms, modes of transmission, environmental requirements and epidemiology of these diseases vary widely, and they require disease-specific as well as integrated management approaches. Fusarium wilt is a soil-borne vascular disease caused by Fusarium udum that can cause severe losses in susceptible cultivars. Sterility mosaic disease (SMD) of pigeon pea is caused by the Pigeon pea sterility mosaic virus-I (PPSMV-I) and Pigeon pea sterility mosaic virus-II (PPSMV-II) and is vectored by the eriophyid mite Aceria cajani, which causes mosaic symptoms, excessive vegetative growth and partial or complete sterility. Excessive rainfall, high humidity and waterlogged conditions favour the development of Phytophthora blight of Pigeon pea caused by Phytophthora drechsleri f. sp. cajani. Recent studies have revealed considerable variability among F. udum isolates and among viruses associated with SMD, highlighting the importance of broad-based host resistance. New opportunities for disease management are emerging, owing to advances in molecular diagnostics, genome-wide association studies, validated molecular markers and biological control. This review summarises the major diseases of Pigeon pea, their symptoms, causal organisms, epidemiology, host resistance screening and management options, with special emphasis on host resistance, biological control and integrated disease management.
Keywords: Pigeon pea, Cajanus cajan, Fusarium wilt, sterility mosaic disease, Phytophthora blight, host resistance, pathogen variability, molecular diagnostics, biological control, integrated disease management