Effects of Azolla Compost Versus Peat and Cocopeat on the Growth and Nutrition of Chrysanthemum (Chrysanthemum Morifolium) in Pot Culture

This experiment was performed to evaluate the application of Azolla compost in growth environments containing peat + perlite in comparison with cocopeat + perlite on the growth and nutrition of chrysanthemums in a completely randomized design with five levels of Azolla (0, 25, 50, 75 and 100% ) in three replication. It was found that the nutrients of Azolla compost substrates were richer than peat and cocopeat. The results showed that use of Azolla as compost increases the elements of phosphorus and potassium in the growing medium, but only the potassium increases in the leaves. The highest amount of leaf nitrogen and potassium was at 50% compost. Twenty five to seventy-five percent compost was not significantly different from peat or cocopeat in terms of final plant hieght, flowering branch length, number of leaves and petal carotenoids. With increasing compost, physical properties of the substrates were within the recommended range, and bulk density (0.31, 0.33, 0.30 and 0.30 g cm-3, respectively) increased compared to peat and cocopeat (0.18 and 0.16 g cm-3). One hundered percent compost had the highest chlorophyll a, chlorophyll b and total chlorophyll. Substitution of 25-100 % compost increased pH and EC of growth media. The results showed that the use of 25-75% compost could be a good alternative to peat, but was not significantly different from cocopeat. Due to the relatively high price and import of peat and cocopeat, and the negative impact of high amounts of compost on increasing growth medium EC, the use of 50% Azolla compost is economically preferred.