Hot Water Immersion of Nursery Plant Cuttings for Non-Chemical Control of Insects and Mite Pests(Abstract)

摘要

Nursery managers propagate many species of nursery plant material and raise them ingreenhouse structures.The plant materials are collected from known nursery stock plants,rooted in mistchambers in greenhouses,then moved to production growing areas,also in greenhouses.If the nurserystock materials have even a slight infestation of insects or mites,they can reproduce quickly in theclosed environment of a greenhouse.Some insect and mite pests are so small or so well hidden in theplants that they often escape detection.Nursery managers would prefer to control the insect and mitepests before the cuttings are moved into the production growing areas.Dipping the nursery stock plantcuttings into a tank mix of pesticides is currently not labeled,the exposure risk to nursery workers ishigh and there is no viable method of disposing the remaining pesticide dip when the process iscomplete.Nursery stock cutting grown in mist chambers physically don't retain any pesticides as thefoliage is constantly being drenched.Systemic insecticides can't be used as the new nursery stockcuttings don't have a viable root system.An alternative method for controlling insects and mites,eventhose hidden within a plant was needed.Using hot water treatments on the nursery stock cuttings tocontrol pests is fairly simple and effective.Most of the insect and mite pests have a lower heat tolerancethan the plants themselves,so the pest die before the nursery stock cuttings are placed under the mist inthe greenhouses.Several Maryland nurseries cooperated with the researchers for five years to determinethe temperature ranges and lengths of time the nursery cuttings had to be immersed into the hot water.The nurseries themselves selected cutting stock that was prone to pest pressures.The research of thehot water bath treatments can help growers control insect and mite pests populations early in theproduction stages and the workers are exposed to fewer pesticides.