Effects of Ratios of NO₃/NH₄ and Temperature of the Nutrient Solution on Growth of Japanese Honewort, Garland Chrysanthemum and Welsh onion

Abstract

Effects of ratios of NO₃/NH₄ and temperature of the nutrient solution on growth of Japanese honewort (Cryptotaenia japonica Hassk.), garland chrysanthemum (Chrysanthemum coronarium L.) and welsh onion (Allium fistulosum L.) were studied on a practical scale. Ratios of NO₃/NH₄ in the nutrient solution were 12/0, 9/3, 6/6 and 3/9 in me/l for all vegetables. Temperature regimes of solution were 11, 18 and 25°C for Japanese honewortsand garland chrysanthemum and 14, 21 and 28°C for welsh onion.
In general, top growth of tested vegetables was increased with raising solution temperature and increasing ratio of NH₄ to NO₃ in the solution. However, too much high ratio of NH₄ to NO₃ in the solution under low solution temperature gave the possibility to cause NH₄ toxicity on the early stage of growth of Japanese honewort. The combined application of NO₃ and NH₄ provided better condition for not only enhancing growth but also changing leaf color from light green to green or dark green and lowering NO₃ content in Japanese honewort.