2020 Volume 89 Issue 2 Pages 151-155
Excessive vegetative growth, leading to decreased yield of sweet potato (Ipomoea batatas (L.) Lam.), is common in wet lowland soils. In this study, we found that both the yield and the quality of storage roots of the cultivar “Kenroku” grown in an unflooded paddy field were comparable to those of plants grown in an upland sandy loam field. Compared with fertilization at the time of transplanting, delayed fertilization at 8 weeks after transplanting in an unflooded paddy field significantly increased the average weight and total yield of the storage roots, although it decreased the number of storage roots. The surface corrugations that are frequently observed on storage roots grown without fertilization and that decrease the productivity of processing were rare in cultivation with delayed fertilization. Different fertilizer application methods did not affect the sugar and β-carotene contents of the storage roots. These results strongly suggest that “Kenroku” is a feasible candidate variety in paddy–upland rotations without the needs of drainage measures such as permanent conversion of fields or farmland consolidations.
