Effect of leaf harvesting frequency on growth and yield of sweetpotato in the Lake Zone of Tanzania

The objectives of this study were to assess the effects of leaf harvesting frequency on growth and yield of sweetpotato (Ipomoea batatus L.); to determine the suitable varietal types for use as source of leaf vegetable and to determine the suitable leaf harvesting frequency(ies) for reduced detrimental effects on growth and yield of sweetpotato. Two narrow leafed varieties Budagala and Mwananjemu and two broad leafed varieties SPN/O and Biganana were used in a randomised complete block design with 3 replications. Plot size was 8.4 m2 . Tip cuttings of 20 cm long were used as planting materials. The fully expanded top and tender leaves were plucked, counted and weighed. Tender leaves were harvested once, twice and three times during the growing period. Results showed that there were small differences between varieties and harvesting frequencies, however, harvesting at one month intervals for three times gave the highest leaf vegetable production although the yield was affected tremendously. Harvesting twice in a growing period proved the best in leaf production as well as root yields. Overall, there were significant differences between varieties and harvesting frequencies. Key Words: Ipomoea batatus, leaf harvesting, Tanzania, tuber and vine yields (African Crop Science Journal 2001 9(1): 97-103