Effects of fertilization and herbicides on growth of young loblolly pine and infestations of Nantucket pine tip moth (Lepidoptera: Tortricidae)

摘要

A 2-year-old pine plantation was selected to receive treatments of fertilizers and herbicides to evaluate effects on Nantucket pine tip moth infestations and the tree growth parameters of height, diameter and volume increment. Nitrogen and phosphorus fertilizers, and hexazinone and sulfometuron methyl herbicides were used in creating six treatments: (ⅰ) control; (ⅱ) phosphorus; (ⅲ) nitrogen and phosphorus; (ⅳ) phosphorus and herbicide; (ⅴ) nitrogen, phosphorus and herbicide; and (ⅵ) herbicide. Treatments were applied in 1987 and 1988. In 1987, trees treated with nitrogen, phosphorus and herbicide had significantly greater height, diameter and volume growth than trees not receiving fertilizer treatments, but did not have significantly higher tip moth infestations than control trees. Treatments receiving phosphorus only had much lower tip moth infestation rates than other treatments except nitrogen and/phosphorus. In 1988, tip moth infestations were uniformly low, with no differences in treatment effects observed.