Effect of <i>Azolla</i> Compost and Various Biofertilizers on Growth and Quality of Zinnia flower (<i>Zinnia Elegans </i>Thumbelina)

Abstract

Zinnia is an annual plant with the long flowering period from late spring to mid-autumn. It is a popular plant for landscape. In the present study, the effect of two types of growth promoting bacteria and <em>Azolla</em> compost on some ornamental characteristics of <em>Zinnia</em> were evaluated in pot cultivation and greenhouse conditions. The factorial experiment was conducted in three replications based on a completely randomized design with two factors, including <em>Azolla</em> compost in 6 levels (0, 10, 20, 30, 40, 50 percent) and growth promoting bacteria in 3 levels (without bacteria, <em>Azospirillum</em> and <em>Azotobacter</em> bacteria). The results showed that growth promoting bacteria (<em>Azospirillum</em> and <em>Azotobacter</em>) and <em>Azolla</em> compost had a significant effect on the investigated factors. Treatment of 50% <em>Azolla</em> compost and <em>Azospirillum</em> compared to other treatments had higher leaf and root fresh weight, leaf nitrogen and plant height. Moreover, 10% <em>Azolla</em> compost and <em>Azospirillum</em> was the best treatment in terms of leaf and root dry matter content. According to conducted evaluation, <em>Azospirillum</em> with less percentage of compost had a significant effect on dry weight and <em>Azospirillum</em> with a higher percentage of compost had a significant effect on fresh weight. Besides, a higher percentage of compost in <em>Azospirillum</em> in treatment <em>Azospirillum</em> and 50% compost had a significant effect on leaf nitrogen and height of the stem.