Yield Response of Potato (Solanum tuberosum L.) Genotypes to Late Blight Caused by Phytophthora infestans in Uganda
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Date
2018
Journal Title
Journal ISSN
Volume Title
Publisher
American Journal of Potato Research
Abstract
Potato (Solanum tuberosum L.) is a major food and cash crop, mainly grown by small-scale farmers in the highland regions of
Uganda. Potato late blight is one of the major diseases limiting production with potential yield losses over 70%, making host
resistance a strong element in integrated disease management. This study was carried out to screen and select high yielding potato
genotypes with resistance to late blight in Uganda. Forty-eight genotypes, including advanced clones from the population B3C2
of the International Potato Centre, commercial and farmers’ varieties, were evaluated under two environments for two seasons.
Trials were laid out in an 8 × 6 alpha lattice design with three replications. Genotypes showed significant differences in yield and
resistance to blight. A higher disease severity was observed in Karengyere (56%). The average RAUDPC (= 100 max) across
locations indicated that genotypes 395,077.12 and 392,657.8, with disease severity of 12% and 14%, respectively, were the most
resistant. Genotypes Victoria (53%) and NKRN59.124 (48%) were the most susceptible. Mean tuber yield under late blight
infection was19.8 t ha−1. The best yielding genotype across sites was 395,112.32 (35.6 t ha−1) while 394,905.8 (10.3 t ha−1),
yielded the lowest. The mean marketable tuber weight was 8.9 kg with genotypes 395,112.32 and 395,109.34 having the
highest marketable weight of 16.5 kg and 15.6 kg respectively. Correlations between yield and yield related parameters
were positive (p ≤ 0.001), while those between RAUDPC were negative. The following genotypes, 395,112.32,
391,919.3, 393,220.54. 393,077.54, 396,038.107. 392,657.8, Kinigi, 395,014.17, NKRN59.58, NKRK19.17 and
395,011.2, were identified as promising parents for a late blight resistance breeding program. These exhibited high to
medium resistance to late blight disease and high yields.
Description
Keywords
Solanumtuberosum, Disease resistance, Relative area under disease progress curve, Tuber yield, Marketable weight
Citation
Namugga, P., Sibiya, J., Melis, R., & Barekye, A. (2018). Yield Response of Potato (Solanum tuberosum L.) Genotypes to late blight caused by Phytophthora infestans in Uganda. American Journal of Potato Research, 95(4), 423-434. https://doi.org/10.1007/s12230-018-9642-4