Canadian Forest Service Publications
When is controlling cone and seed insects in Douglas-fir seed orchards justified? 1983. Miller, G.E. The Forestry Chronicle : 304-307.
Issued by: Pacific Forestry Centre
Catalog ID: 2274
Data from operational applications of dimethoate at two Douglas-fir seed orchards in British Columbia were used as base-lines for a benefit: cost analysis of protection of seed from cone and seed insects. Applications were economically justifiable provided that cone crop size and increased seed yield are above critical threshold values for given seed values and application costs. Sampling techniques for estimating crop size and insect infestation levels and expected damage are requisites for efficient orchard management where crop size and infestation levels fluctuate.