1976 Volume 45 Issue 3 Pages 283-288
An investigation was made to determine the effects of nitrogen forms, and pH in soils having low and high levels of Mn on the growth and flowering of carnation cv.‘Yosooi’. Treatments were arranged factorially involving Iwata and Kawazu soils, NH4-N from (NH4)2SO4, and NO3-N from NaNO3, at high and low pH levels. The number of flowering plants, plant height, and top fresh weight decreased in the Kawazu soil having a high level of Mn. The time of flowering was markedly promoted by NH4-N. The number of flowering plants, and the top fresh weight decreased at the low pH. In the later stage of growth tip burn symptoms were found on leaves of plants grown in the Kawazu soil at the low pH. The Mn in the various parts of plants grown in the Kawazu soil was markedly increased at the low pH, but was not affected by the N forms. The content of N, P and K, and the Fe/Mn in the leaves were slightly higher in the Iwata soil, while the Mg and Al were high in the Kawazu soil. At the low pH the Al in the leaves increased, while the P, K and Ca, and the Fe/Mn decreased. At the termination of the experiment the water soluble, exchangeable and easily reducible Mn increased in the Kawazu soil. The available Mn increased at the low pH, while the easily reducible Mn decreased. The various forms of Mn in the soil were not affected by the N forms. The Na, Ca, Mg and Al increased in the Kawazu soil at the termination of the experiment, while the P decreased. The NH4-N increased in the NH4-N treatment, while the NO3-N and Na decreased. The K and Al, and the value of EC increased at the low pH, while the NO3-N, P, Na and Ca decreased. From these results, the growth retardation and tip burn symptoms of carnation seemed to be highly correlated with the Mn in the plants and soils, and disassociated with the P, K, Mg and Al in the leaves, and the NH4-N, NO3-N, Na, Mg, P and Al in the soils.