Assessment of National Performance Trials of Potatoes in Mid-Altitude Regions of Kenya

Potato is the second most important food crop in Kenya after maize. It is a valuable cash and food crop mainly grown by small-scale farmers. Potato is cultivated mainly under rainfed production conditions at altitudes between 1500 and 3000 metre above sea level (masl). Consequently, National Performance Trials (NPTs) test sites are located in these highlands. Recently, potato production has spread to the mid-highlands (1200-1500masl) mostly due to high food demand occasioned by population increase, and migration of small scale farmers from the densely populated highlands to the more spacious midlands. Consequently, there is increased need to breed potato varieties that can grow profitably in the warmer mid-altitudes. This development called for identification of new conventional NPT test sites located in the mid-altitudes. Six mid-altitude sites were identified and client-managed conventional NPTs carried out. Twenty six potato genotypes were evaluated for two seasons. First season crop was planted in 2016 while the second season crop was planted in 2017. There was a significant (p≤ 0.001) effect of genotypes, environments and genotype x environment interaction in the first season. Trans-Nzoia was the highest yielding site. All genotypes yielded between 10 and 25 ton/ha. In the second season, only environments showed significant (p≤ 0.001) effects. Again, Trans-Nzoia was the highest yielding site. Across the two seasons, Trans-Nzoia gave an average yield of 26.96 ton/ha followed by Kabete at 18. 21ton/ha. All the other four sites yielded less than 10 ton/ha. The high yields at Trans-Nzoia and Kabete could be due to higher altitudes in these two sites compared to the others. In order to develop potato varieties that can produce profitably in the warm mid-altitudes, breeding and early generation selections activities should be based in these areas.