Improving Peanut Varieties in Africa

Summary

Groundnut rosette disease (GRD) is the most destructive viral disease of peanut in sub-Saharan Africa (SSA). The disease, which is endemic to SSA, causes greater yield losses than any other viral disease affecting peanut in the world. In addition to yield losses, GRD epidemics have a long-term debilitating impact on peanut production since farmers typically decrease production following epidemics to avoid future risk. The research derived from this ongoing international project has resulted in the development and dissemination of highly desirable peanut cultivars with resistance to GRD to peanut growing countries of SSA and has educated farmers on the use of the resistant cultivars with appropriate cultural practices to develop a management program against GRD.

Situation

GRD is the most destructive virus disease of peanut in sub-Saharan Africa (SSA), and arguably the most important pathogen disease on peanut, with yearly crop losses of approximately $156 million. The disease is endemic to SSA and is a major constraint to peanut production. GRD can cause up to 100% yield losses if infection occurs before flowering and during severe epidemics. GRD results from an intimate interaction between Groundnut rosette assistor virus (GRAV), Groundnut rosette virus (GRV), and the satellite RNA of GRV. Together the three components result in a complex etiology that is crucial to the development and transmission of the disease. The disease is transmitted by the aphid, Aphis craccivora Koch. For the disease to develop and be transmissible, all three disease agents must be transmitted together by a single aphid. Therefore, naturally occurring disease resistance, which interferes with vector transmission or with the life cycles of GRV, GRAV, or both viruses simultaneous, needs to be bred into consumer preferred cultivars to control the disease and increase yields. Insecticide control of the vector is not financially practical for the resource poor smallholder farmers of SSA.

Response

Within the last year, two improved varieties with GRD resistance, Serenut 1Res and Serenut 3RRes, are in National Performance Trials in Uganda and will be released next year. Both varieties are very popular, but were previously susceptible to GRD. In addition, introgression of GRD resistance into three landraces, Gwerinut, Erudurudu and Acholi white in Uganda was inititated. Landraces are highly preferred local and long established varieties that have adapted to the natural environment and local cultural practices. Eleven Zambian lines are also undergoing GRD improvement in Uganda as part of a multi-country collaboration to improve popular cultivars for GRD resistance and yield increases.

Impact

Breeding GRD resistance into improved varieties and landraces will allow for better management of GRD. This is especially true for movement of GRD resistance into the landraces, which will rapidly expedite acceptance of the resistance trait. The outcome of the research has and will continue to result in the development and adoption of improved cultivars that will mitigate a major biotic stress and result in increased peanut yields and increased quality.

State Issue

Agribusiness Development/Value Added

Details

• Year: 2016
• Geographic Scope: International
• County: Clarke
• Program Areas:
  • Agriculture & Natural Resources