Effects of Nitrogen Fertilizer and Application of Compost on Azalea Growth Indices

Azalea is cultivated as a shrub plant with high capability of potting culture in greenhouse. Decrease in production cost and increase in plant growth affect highly the economic production of Azalea. Bed of cultivation and nutrition with nitrogen are two main factors affecting directly the economic production of Azalea. In 2000 an experiment was implemented in factorial effects of six levels of nitrogen, 0, 3.5, 7, 14, 28.5 and 57 mmoll-1 on three type of growth media consisted of peat, 1/3 peat + 1/3 tea waste compost + 1/3 sand and 3/4 tree bark compost + 1/4 tea waste compost were studied. Results showed that 14 mmoll-1 nitrogen in two growth media, peat and 1/3 peat + 1/3 tea waste compost + 1/3 sand, and 28.5 mmoll-1 nitrogen in 3/4 tree bark compost + 1/4 tea waste compost were the most effective treatments on growth indices of height, diameter, flower number, fresh weight and dry weight. The growth bed, 1/3 peat + 1/3 tea waste compost + 1/3 sand with respect to 66% decreasing of peat intake, could be suitable for production of Azalea.