AGRICULTURAL RESEARCH DIVISION
P.O. Box 829, Maseru 100, Lesotho.
The release of Puseletso, a Russian wheat aphid-resistant cultivar in Lesotho.
Lieketso Moremoholo.
Wheat is among the best adapted crops in Lesotho. It is the third most important staple food after maize and sorghum and is grown for home consumption. In the two seasons (winter and spring), wheat is planted under dryland conditions with the residual moisture of autumn rains and winter precipitation (snow), respectively. The RWA is one of the major production constraints. Other major constraints are soil acidity (more than 30 % of the arable land), drought, sprouting-susceptible cultivars, hail damage at critical stages, and a shortage of combine harvesters. Puseletso, which means 'the regaining of that which we have lost' (due to an outbreak of the RWA), was released in April 1992. This cultivar has the RWA-resistance gene Dn1 and is a backcross of Tugela (Kavkaz / Jaral 'S') with Dn1 (SA 1684) from ARC-Small Grain Institute, South Africa. Puseletso, which also is acid tolerant, was donated by the Small Grain Institute of the Lesotho Ministry of Agriculture in 1992 to replace susceptible and poorly adapted or outdated cultivars.
Does this mean that RWA and acidity problems are solved in Lesotho? Not at all. The amount of seed available is not yet sufficient for all farmers and resistant biotypes of aphids can form when constantly exposed to resistant cultivars. Because Lesotho practices dryland farming, it will always be subjected to drought and higher temperatures during September, which will cause a rapid increase in RWA numbers. Because not all Basotho farmers have adopted Puseletso and liming, they still suffer large yield losses from acidity. However, Puseletso has shown excellent adaptation to Lesotho conditions and already has made a significant contribution.