Effect of nitrogen level on the vegetative growth and flower production of Delphinium grandiflorum, L.

Abstract

The effect of nitrogen levels, namely control, 0.5, 1.0, 1.5, 2.0, 2.5 and 3 grams nitrogen per plant was studied on Delphinium grandiflorum in 1979 and 1980. The results indicated that the highest leaf number, stem length, as well as the heaviest stem and leaf dry weight, were induced by adding 1.5 gram nitrogen per plant (7.5 grams fertilizer). Also, the length of the flowering spike, its diameter, dry weight, and the number of florets per spike were increased when the nitrogen level was 1.5 grams per plant. When the nitrogen level was increased more than 1.5 grams per plant, there was no significant decrease in most of the previous characteristics. Time taken from planting to the showing colours stage was delayed with the increase in the nitrogen level.