Control of Western Dwarf Mistletoe with the Plant-Growth Regulator Ethephon

摘要

Ethephon (Ethrel), an ethylene-releasing plant-growth regulator, was applied witha hydraulic sprayer to ponderosa pine (Pinus ponderosa) infected with dwarf mistletoe (Arceuthobium campylopodum) in the Emmett Ranger District, Boise National Forest. Abscission rates of 60 to 100 percent of dwarf mistletoe shoots were consistently achieved with applications in both July and August of 2,400 p/m of ethephon plus surfactant. Ethephon did not kill the endophytic system of the parasite in the host tissue; new shoots began developing on some of the infections within 2 months after treatment. One year later, most of the female and all the male plants flowered. Results indicated a shorter period of shoot abscission for this dwarf mistletoe.