Effect of municipal waste compost and growth-promoting bacteria fertilizers on some morphological and physiological characteristics of mulberry tree (Morus nigra)

The mulberry tree can grow in a variety of climates. Mulberry leaf is a food of silkworm and plays an essential role in silk production. Therefore, improving the quality and quantity of mulberry leaves is very important in terms of silk production. The aim of this study was to investigate the effect of growth-promoting bacteria and municipal waste compost on morphological and physiological characteristics of mulberry tree. To conduct this research, 27 mulberry seedlings were prepared from the National Silk Research Institute. This research was conducted as a randomized complete block design with three replications. The treatments used included two levels of municipal waste (2 and 4 percent), two levels of Pseudomonas (106 and 5×106 cells per gram of soil) and control. Some physiological properties such as phosphorus, nitrogen, potassium, protein and sugar were measured in the leaves. Also, some morphological characteristics of the plant including fresh weight, leaf area index, specific leaf area, leaf length, etc. were measured. The results showed that the highest amount of protein and leaf area in the combined treatment of the second level of compost and bacteria were 22.57% and 2005 mm2, respectively. The results showed that with increasing the amount of compost and bacteria in the soil, leaf quality increased significantly physiologically and morphologically. In general, the results showed that the combination of organic and bio-fertilizers can be used instead of chemical fertilizers to provide the elements needed by the mulberry plant.