Potato (Solanum tuberosum L.) is an important crop in Uganda but production is low. There is not a well-functioning official seed system and farmers use potato tubers from a previous harvest as seed. This study investigated how effectively the seed technology positive selection enhanced yield and underlying crop characteristics across multiple seasons, compared to the farmers’ selection method. Positive selection is selecting healthy plants during crop growth for harvesting seed potato tubers to be planted in the next season. Farmers’ selection involves selection of seed tubers from the bulk of the ware potato harvest. Positive selection was compared to farmers’ seed selection for up to three seasons in three field trials in different locations in southwestern Uganda using seed lots from different origins. Across all experiments, seasons and seed lots, yields were higher under positive selection than under farmers’ selection. The average yield increase resulting from positive selection was 12%, but yield increases were variable, ranging from − 5.7% to + 36.9%, and in the individual experiments often not significant. These yield increases were due to higher yields per plant, and mostly higher weights per tuber, whereas the numbers of tubers per plant were not significantly different. Experimentation and yield assessment were hampered by a varying number of plants that could not be harvested because plants had to be rogued from the experimental plots because of bacterial wilt (more frequent under farmers’ selection than under positive selection), plants disappeared from the experimental field and sometimes plants did not emerge. Nevertheless, adoption of positive selection should be encouraged due to a higher production and less virus infection of seed tubers in positive selected plants, resulting in a lower degeneration rate of potato seed tubers.

马铃薯（马铃薯）L.）是乌干达的重要农作物，但产量低。没有一个运转良好的官方种子系统，农民使用以前收获的马铃薯块茎作为种子。这项研究调查了与农民的选择方法相比，种子技术积极选择如何有效地提高了多个季节的产量和基本作物特性。积极的选择是在作物生长期间选择健康的植物，以收获下一季要种植的种薯块茎。农民的选择涉及从马铃薯马铃薯大部分商品中选择块茎。在乌干达西南部不同地点的三个田间试验中，使用来自不同来源的种子批次，将多达三个季节的阳性选择与农民的种子选择进行了比较。在所有实验，季节和种子批次中，积极选择下的产量高于农民选择下的产量。由阳性选择产生的平均产量增加为12％，但产量增加在-5.7％至+ 36.9％之间变化，并且在单个实验中通常不显着。这些产量的增加归因于每株植物的更高产量，并且多数是每块茎的较高重量，而每株植物的块茎数量没有显着差异。试验和产量评估受到无法收割的多种植物的阻碍，因为由于细菌的枯萎，不得不从试验地块中榨取植物（在农民的选择下比在阳性选择下更频繁），植物从实验场上消失了有时植物没有出现。不过，