Cultivar differences for nitrogen uptake and dry matter partitioning in hydroponically‐grown sweet potato

‘Centennial’ and ‘Jewel’ sweet potato [Ipomoea batatas(L.) Lam.] plants were grown in hydroponic sand culture in either 3.5 or 15 mM nitrogen solutions for 65 days. Petioles, leaf blades, stems, fibrous roots, and fleshy roots were analyzed for dry weight and Kjeldahl nitrogen (N) determinations. Whole plant dry weights of ‘Centennial’ and ‘Jewel’ plants averaged 81.4 and 38.8 g plant‐1, respectively, when grown in 15 mM nitrogen solutions. High ? fertility was associated with a 60 and 48% reduction of fleshy storage root dry weight in ‘Centennial’ and ‘Jewel’, respectively. Total ? concentrations in blades, stems, and fleshy roots were greater for both cultivars when grown in 15 mM nitrogen solutions. Total ? contents of ‘Centennial’ and ‘Jewel’ plants grown in 15 mM nitrogen solutions were 2473 and 1186 mg N plant‐1respectively. These results demonstrate that intraspecific variability for ? absorption and utilization efficiency exists within sweet potato.