Generation of passport data on agronomic performance of sweet potato (Ipomoea batatas) clones being conserved ex situ at Makerere University agriculture research institute Kabanyolo

A field experiment was carried out at Makerere University Agricultural Research Institute Kabanyolo (MUARIK) during 2003B and 2004A cropping seasons to generate passport data on agronomic performance of 155 sweet potato (Ipomoea batatas) clones. The 2003B and 2004A seasons refer to the May - November 2003 and October - March 2004 rain seasons respectively. For each season the field experiment was set up as a Randomized Complete Block Design with 2 replications. A total of 155 clone collected from various parts of East Africa were propagated in a screen-house and later transferred to the field for agronomic evaluation. The field evaluation revealed significant variations in both growth and yield attributes (agronomic performance) of the sweet potato clones. Significant differences among clones form different regions were found for number of plants that established per plot (mean clone establishment). The poorest rates of establishment were found on clones from Mbarara, while the best establishment rates were found in clones form luweero. Most varieties started tuberculosis by 3 months after planting. Late maturing clones tuberised at 4 months after planting but the majority were early maturing. Skin and flesh color were variable. Flesh color was either cream or white; a few clones had yellow flesh and some elite clones’ form Namulonge were orange fleshed. Skin color had hues that ranged from pink, through brown, yellow and various other shades. Generally the elite clones produced significantly higher (>25 t/ha) tuber yields than local land races (>25 t/ha). During 2003B cropping season, the highest tuber yield on fresh weight basis was obtained form the clone muk 10,2 with 20.5 t/ha and the lowest from the clone mlb5,3 with 0.3 t/ha. During 2004A, a four fold average increase in tuber yield ranged from 57.9 t/ha (mpigi 3,2) to 0 t/ha (Tula s6). Mean tuber dry matter yield was 6.1 t/ha. Tuber dry matter during 2004A ranged from19.9 t/ha (Mpigi3,2) followed by muk11,4 (19. t/ha). During 2003B mean tuber dry weight at harvest was low, averaging 2.2 9t/ha). In 2004B mean foliage and stem dry weight was 3.6 t/ha). The highest and lowest dry weight of vines were recorded for Tz 309 (13.4t/ha) and mlb 5,1 (0.1 t/ha) respectively. Mean tuber dry weight was higher, during 2003A ( 7.1 t/ha) than 2004B 96.1t/ha). The highest tuber dry weights were recorded from mpigi 3,2 (19.9 t/ha) followed by muk 11,4 (19.t/ha). The overall good performance for 2004B was attributed to more favorable growing conditions, i.e much higher rainfall received than in 2003B.