Coating and impregnating with endrin protects field‐sown douglas fir seed

摘要

AbstractChemically treated and untreated Douglas fir seed was evaluated in the laboratory and at four locations on National Forests in Oregon and Washington. Seed was treated by coating with endrin or endrin‐thiram and by impregnation with endrin. In the laboratory, germination was adversely affected by impregnation and by field exposure. Also, bioassays of treated seed showed no differences in consumption by deer mice among endrin treatments, but more seed was eaten after exposure in the field than before. Deer mice were the most common seed eaters found on all field study areas, and their numbers exceeded the level prescribed as a minimum requiring protection prior to seeding. Observations during and at the end of two growing seasons indicated that seedling production and stocking were much greater from endrin‐treated than untreated seed, but there were no significant differences among the three endrin treatments. In addition, performance of treated and untreated seed differed by area, with best results at the two locations known for favourable climatic conditi