Technical Paper
Using Mass Balance Techniques to Manage Nutrition of Hydroponically-Grown Sweetpotato [Ipomoea batatas (L.) Lam]
2001-07-09
2001-01-2274
A mass balance nutrient management approach was used in controlled environment studies, to determine an appropriate nutrient solution replenishment regime for the growth of sweetpotato in nutrient film technique (NFT). Four stem cuttings (15-cm long) were planted into each of three gray PVC-1 (0.15×0.15×1.2 m) troughs in a walk-in growth chamber under a 14/10 h photoperiod, 28/22°C and 70% relative humidity. Photosynthetic photon flux at canopy level averaged 450-μmol m−2 s−1. Plants were grown with a modified half-Hoagland starter solution with an extra 3 mM of N for the first 4–6 weeks to accelerate vegetative growth, after which three refill solutions containing 1.5 (A), 4.5 (B), 0.75 (C), or 3 (A), 4.5 (B), and 6 (C) mM NO3−1-N and K, respectively, were used once per week until harvest. The level of N and K in the refill solutions did not significantly influence the number of storage roots produced.
