Effects of Planting Date and Different Amounts of Nitrogen Fertilizer on the Yield and Yield Components of Two Marigold Varieties (Calendula Officinalis)

This study was carried out to assess effects of different planting dates and nitrogen fertilizers on the growth and yield of Calendula officinalis. The experiment was done in the research field of Agricultural Sciences Faculty of Shahed university as factorial with use of randomized complete blocks design with three replications in 2006. Planting dates were including April 10th, April 20th and April 30th and levels of nitrogen fertilizer were 0, 30, 60 kg/ ha and two Marigold varieties were used. Statistical analysis of results showed that, different planting dates and different levels of nitrogen fertilizers had significant effects on the yield and yield components of Marigold varieties. In the experimental climate of research region, a variety with low leaves, produced more flower, but on the other hand the variety with more leaves produced bigger flowers. Effect of planting date on the number of flowers in each plant, plant dry weight, flower yield, harvest index and etcwas significant and it had no significant effect on the plant height and average number of flowers in plant. Results showed that in the first planting date (April 10th), Marigold plants had higher height and they had more flowers in each plant and in the third planting date, dry and wet yield of flowers were higher. In climate condition of experiment region, the variety with low leaves produced more flowers in hectare. Use of nitrogen fertilizer had significant effect on the yield and yield components of Marigold so that, lack of fertilizer led to increase of yield and number of flowers in each plant significantly. Using 60 kg nitrogen per hectare produced plants with higher height.