Effect of seed size and fungicidal protection of potato seed from different sources on growth and tuber yield in Uganda

Poor seed quality is a major bottleneck to sustainable production of potato (Solanum tuberosum L.) in Uganda. This is primarily due to over reliance on informal seed sources, most of which are characterised by poor seed types and quality. The objective of this study was to determine the effect of fungicide protection of seed from informal sources on potato growth and tuber yield in Uganda. The study was conducted at three locations in south-western Uganda (Kabale, Rukiga and Mbarara) for two seasons September-December 2018 (2018B) and March-June 2019 (2019A). Treatments included: three seed sources (certified KaZARDI-control, own saved and local market), two seed sizes (large and small) and two levels of seed fungicide treatment (treated with the fungicide Victory 72 WP and untreated). Parameters evaluated included: number of main stems, plant height, late blight incidence and total tuber yield. Results revealed that the certified KaZARDI source generally had the highest values for most of the measured parameters. This was followed by own saved source while the local market source provided the lowest quality values. Large sized seed exhibited superior performance to the small seed for most of the parameters. Also, fungicide-dressed seed showed better performance for most of the assessed parameters, than the undressed counterparts. These results suggest that fungicide dressing will improve the performance of potato seed supplied by informal sources, particularly the own saved large and small seeds. Key words: Own saved seed, Solanum tuberosum, Uganda