'Plant Breeding: Sustaining the Future' Abstracts of the XVIth EUCARPIA Congress, Edinburgh, Scotland, 10-14 September 2001 THE IMPACT OF CERCOSPORA LEAF SPOT & COWPEA SEVERE MOSAIC VIRUS (CPSMV) DISEASE ON CULTIVATION OF COWPEA IN TRINIDAD AND THE INHERITANCE OF RESISTANCE H. BOOKER, P. UMAHARAN, C.R. MCDAVID Department of Life Sciences, Faculty of Agriculture & Natural Sciences, The University of the West Indies, St. Augustine, Republic of Trinidad & Tobago

Cowpea (Vigna unguiculata) an important tropical legume is grown as a grain, vegetable, or fodder crop.  Cercospora leaf spot (CLS) and Cowpea Severe Mosaic Virus (CPSMV) disease are serious limitations to cowpea production resulting in yield losses as much as 42% and, 82% respectively. An island-wide survey found these diseases in epiphytotic proportions despite the use of crop protection chemicals. The causal agents of CLS of cowpea, Cercospora creunta and C. canescens were both found in Trinidad but the ecological requirements of C. canescens were more stringent, as it was prevalent only during the wet months and almost always found in association with C. creunta.  Experiments characterizing the impact of CPSMV disease on crop physiology and yield are summarized.  The genetic basis of immunity, tolerance, and high-level resistance to CPSMV based on a three-gene model is described.