Screening Groundnut Accessions for Rossette Virus and Leafspot Diseases in Uganda.

Groundnut (peanut) is a very important oil crop in sub-Saharan Africa for both income generation and food security. The production of the crop is however constrained by groundnut late leafspot (Phaeoisariopsis personata) and groundnut rosette virus diseases. Use of host plant resistance is by far the most effective and economical management option under resource limited farming systems in developing countries. There has been limited adoption of cultivars resistant to rosette disease and no cultivar in Uganda is resistant to leafspot disease. It is necessary to obtain additional resistance sources for these diseases to minimise the resulting losses. The National Semi-Arid Resources Research Institute in Uganda screened 75 accessions from ICRISAT for resistance and tolerance to rosette virus disease and leafspot disease at Serere, Eastern Uganda. The trials were conducted for three seasons beginning first rains of 2008 under natural disease pressure. Disease was assessed on a 0 - 9 scale at harvest. Good levels of resistance to rosette disease were observed from 17 accessions that showed rosette severity scores under 1.6 on a 0 to 9 scale. Seven accessions showed acceptable resistance to late leafspot disease, with mean leafspot severity scores of 3.5 or less on a 0 to 9 scale. Accessions ICGV-SM 01510, ICGV-SM 01514, ICGV-SM 03590, ICGV-SM 02501, ICGV-SM 03701, and ICGV-SM 01705 are recommended for further evaluation or release to farmers as rosette resistant cultivars. Accessions ICGV-SM 03590, ICGV-SM 02501, ICGV-SM 03703, ICGV-SM 01731, ICGV-SM 02709, and ICGV-SM 02715 are recommended for use in leafspot disease management. The use of these accessions in controlling the two diseases will boost groundnut production in sub-Saharan Africa and contribute to income and food stability.