The effect of fertilizer on vegetative traits of Populus deltoides Marsh. saplings and the rate of their resistance to pests and diseases in Kiashshahr nursery

In addition to industrially-compatible wood characteristics and resistance to pests and other threatening factors, plantation and development of the poplar saplings is important for production of wood products. Providing a suitable bed for feeding saplings is the next step that will be commonly achieved by fertilization in the nurseries. The purpose of this study was to determine the amount of chemical fertilizer needed for poplar nurseries, which was evaluated in complete (NPK) and incomplete (N) forms and by examining vegetative traits, as well as their resistance and sensitivity to biological disturbance agents at the end of the growth season. For this purpose, the study investigated 663 individuals of Populus deltoides 69/55 clone in randomized complete block design by five treatments in a nursery in Kiashahr, Guilan province. Statistical analysis showed that despite increasing sapling growth, fertilizer also increased the incidence of leaf spot disease. There was no disagreement on the prevalence of pests as a result of the use of fertilizers. Therefore, given the adverse consequences of the use of fertilizer, fertilizer in those nurseries is not recommended.