Every grower of Fraser fir Christmas trees in western North Carolina has had to deal with pest damage. Pesticides can minimize damage, but only when applied properly. Some growers apply pesticides when they are not sure if the pest is present as "insurance"; others use pesticides after the pest has already caused costly damage. At times, the use of a pesticide may even increase damage by allowing other pests to reproduce without checks from natural predators. With an integrated pest management (IPM) approach to pest control, growers can be assured they are using a pesticide only when necessary.
 

What is IPM?

Integrated pest management is a "sustainable approach to managing pests by combining biological, cultural, and chemical tools in a way that minimizes economic, health, and environmental risks."
    The term "sustainable" means that by adopting IPM practices, the production of high quality Christmas trees or other crops can continue on the land for many years to come. It also means that the groundwater and streams are less likely to be polluted by fertilizers and pesticides.
    The words "managing pests" is key to IPM. It has never been possible to eliminate all pests, nor is it necessary since low levels of some pests are tolerable.
    The aim is to maintain pest populations at less than damaging numbers. The pest level at which a tolerable amount of damage occurs is called the treatment threshold.
    "Combining" different control practices is also key to IPM and to sustainability. Reliable pest control that will stand up to the test of time rarely depends on a single control strategy, such as pesticide use. Integrating control strategies is essential.
    "Biological" pest control is often viewed as releasing insect predators, such as lady beetles, something few Christmas tree growers do because it doesn't give the level of pest control needed. However, biological control should mean much more than that. One key component is conserving the native predators that are already present in every Christmas tree field, providing free pest control. Creating a healthy environment for these "natives" by adjusting control strategies, particularly pesticide use, can reduce problems with aphids, spider mites, and scale insects.
    "Cultural" practices include all the activities that go into growing a Christmas tree from proper site selection, to plant spacing, to fertility, to ground covers. Often, chemical controls don't work because cultural practices create an environment favoring the development of pest problems. Of all cultural practices, maintaining proper fertility through soil sampling is one of the most important to promoting plant health. Ground cover management is one of the most important cultural practices affecting natural predators. A healthy, vigorously growing plant is much less likely to have problems with pests.
    The "chemical tools" are pesticides. However, in IPM, a pesticide application is only made when found to be necessary based on scouting results. Pesticides are chosen to be as specific as possible to the pest species, used at the lowest effective rate, and alternated with other chemicals to help prevent pest resistance.