Chapter 2 - Urdbean

Abstract

Urdbean or blackgram (Vigna mungo L. Hepper.) is a nutritious grain legume largely grown in warmer regions of South and South East Asia. This review focuses on nutritive value, biology and adaptation, major production constraints, agronomy, breeding and future opportunities for urdbean improvement. Early maturing cultivars have been developed with regionally acceptable grain quality and resistance to some important diseases and pests including Mungbean Yellow Mosaic Virus (MYMV), powdery mildew (Erysiphe polygoni), white fly (Bemicia tabaci), root-knot nematodes (Meloidogyne incognita and M. javanica), bruchids (Callosobruchus maculates and C. chinensis). Earliness is important because early cultivars can escape drought and some insect infestations and can be grown in a diverse array of cropping systems. Agronomic interventions and cropping system manipulations will definitely help in increasing production and area under cultivation. Earliness, delayed leaf senescence, and indeterminate growth habit are characteristics which need to be combined to improve drought adaptation. Development of cultivars with multiple resistances to biotic and abiotic stresses is an important current breeding objective. Emerging threats due to viral diseases like groundnut bud necrosis virus (GnBNV) and Urdbean Leaf Crinkle Virus (ULCV) need to be tackled through resistance breeding and management strategies. In future, high levels of resistance to very important insect pests such as thrips (Megalurothrips distalis), maruca pod borer (Maruca testulalis), and pod bugs (Clavigralla tomentosicollis and others) need to identified. Genes from related Vigna species or genetic transformations would be necessary to develop cultivars with high levels of resistance to major insect pests. Seed systems are advocated to ensure quality seed to growers of major regions of urdbean production.