During the third year of the “Delivering and Disseminating Biofortified Crops in Uganda” project, the International Potato Center (CIP), in collaboration with the National Crops Resources Research Institute, planted 100 on-farm trials to evaluate six promising orange sweetpotato (OSP) clones in Rakai, Buyende, Oyam, Isingiro, and Kabale districts:
1. ‘Ejumula (OP) 2012/3’
2. ‘Ejumula (OP) 2012/11’
3. ‘MKN1224 (OP) 2013/1’
4. ‘Ejumula (OP) 2012/9’
5. ‘Ejumula (OP) 2012/10’
6. ‘Resisto (OP) 2012/2’ .

Of the 100 trials, we harvested 60 that were planted in 2014 and conducted five palatability tests to determine farmers’ preferences for the new clones. The clone ‘MKN1224 (OP) 2013/1’ had the highest yield (9.6 t/ha), followed by ‘Ejumula (OP) 2012/10’ (8.2 t/ha) and ‘Resisto (OP) 2012/2’ (6.2 t/ha). ‘MKN1224 (OP) 2013/1’ and ‘Resisto (OP)/2012/2’ are, however, susceptible to sweetpotato virus disease (SPVD) and Alternaria blight in some of the districts (e.g., Isingiro) compared with other clones; neither is preferred by farmers. CIP has also set up the third round of curing trials using sweetpotato varieties, ‘Kabode’, ‘NASPOT 8’, ‘NASPOT 1’, and ‘SOCCADIDO’ in Masaka, Rakai, and Mukono districts. CIP established demonstration sites for Triple S technology with farmer groups in each of the four districts of Gulu, Oyam, Kole, and Lira. Sixty-three participants (36 women, 27 men) were trained in Triple S application. CIP also harvested trials of clean farmer materials (vines) for the 2014A season.

Generally, SPVD expression on foliage depends on the number of times the clean material has been replanted. The results show that after three successive seasons of recycling planting material of ‘Ejumula’—a variety susceptible to SPVD—yield significantly dropped at cycle 4 by almost five times the yield of season 1. Planting clean material, free from SPVD especially of a susceptible variety, increases root yield by more than five times in farmers’ fields. CIP also planted 2014B trials of cleaned farmer materials in Kamuli, Buyende, Mukono, and Rakai.