EFFECT OF STAGE OF DECOMPOSITION OF GREEN MANURE ON THE GROWTH AND YIELD OF SWEET POTATO

Abstract

The use of either soybean or mungo as green manure crop did not significantly affect the agronomic characters, yield and yield components of sweet potato except the number of marketable tubers. Stage of green manure decomposition greatly influenced vine length and leaf area index during the second and third months of sweet potato growth including the length and diameter of tubers, weight and number of marketable tubers/ha, total tuber yield, and harvest index. No significant effects on fresh and dry weights of vines as well as number and weight of non-marketable tubers were noted. Higher yield was obtained when sweet potato was planted 21 days after soybean residue had been plowed under the soil.