Optimum Nitrogen Application Promotes Sweetpotato Storage Root Initiation

Storage root formation of sweetpotato (Ipomoea batatas (L.) Lam) is a complex developmental process relating to the activity cambium. Little information available on relationship between nitrogen (N) application levels and initiation development storage roots (SRs). This study aims examine how N rates promoted/inhibited (SRs) for cultivar ‘Orleans’ during first 8 weeks after planting. Cuttings were grown in coarse river sand culture supplied with modified Hoagland nutrient solution at four different (0 (N0), 50 (N50), 100 (N100) or 200 (N200) mg L?1) N. The results showed that N100 treatment promoted primary secondary cambium, resulting significant higher rate SR 21 56 days transplanting (DAT). Due demand SRs, N200 displayed faster growth, acquisition highest efficiency use 35 DAT, but number per plant remained insignificantly lower than when differentiation adventitious was mostly completed (49 DAT), suggesting irreversible an effect initiation, which eventually affects number. suggested optimal substrate level following should be considered fertilisation scheme.