IPM

Integrated Pest Management, IPM, is the foundation of this guide. The word “Integrated” indicates that several types of management tactics are used against pests, and combined to make them more effective than any one tactic alone. It also means orchard management decisions impact each other, and that pest management decisions must be part of overall orchard management. 

Commonly, people think of pests as insects, but in IPM the word “Pest” has a larger meaning: a pest is any living thing that threatens the crop. Insects are pests, but so are mites, weeds, fungi, bacteria and animals such as deer, rabbits and voles.

The word “Management” implies less than complete control of pests.  Rather, IPM manages their potential risk, and keeps damage at acceptable levels. Instead of total eradication, the IPM approach stresses suppression of pest populations to levels that do not cause economic damage. Pesticide sprays and other pest control tactics suffer diminishing returns - applying more costs more and and comes with negative side-effects, such as environmental pollution. For some insect pests, it may be important to have at least some pests around an orchard to ensure that other insects, natural enemies, or natural biological controls, will be there to suppress subsequent pest infestations. A viable IPM approach attempts to minimize pollution problems, and decrease the risk of pest resistance, while maximizing the economic and environmental sustainability of an orchard.

IPM depends on growers and their pest management advisors understanding pest biology and ecology. That is, knowing when a pest is active and likely to damage a crop, and when it is most susceptible to treatment. An IPM approach combines available management tools in complementary ways to create an overall management plan that is efficient, effective, and sustainable. By using multiple tactics, the chance of successful results goes up, and the chance that a pest will adapt and overcome a management tactic decreases. Cultural practices, such as sanitation and habitat management, are a first line of defense in preventing many types of pest problems. Similarly, if feasible, an orchard can be planted with cultivars that are resistant or at least less attractive to important pests. Increasingly, commercial biological controls are being developed, and may be used as part of an IPM plan. Using forecasting models and employing weather information in pest management decisions has become easier with development of online decision support systems, which give growers a clearer picture of important pest risks at any given point in the growing season.

Generally, IPM follows this process:

• Determine how much, if any, damage may be acceptable - a threshold for damage.
• Identify pest problems that are most significant from year to year, the key pests.
• Know when and how to monitor for these pests, and do it.
• Treat with an appropriate management tactic at an appropriate time.
• Evaluate results during the season and at harvest.
• Adjust tactics if needed to improve results.

Monitoring. A good IPM program depends on having a careful observer in an orchard throughout the growing season. The word “monitoring”, or sometimes "scouting", in IPM means making regular observations of pest activity, such as the first appearance of an important insect pest, the types of weeds in tree rows, or a daily set of weather observations. Monitoring methods differ for different pests. For insects, specific traps make it much easier to tell whether a pest is reaching a potentially damaging level. For diseases, it’s generally necessary to use weather conditions to determine risk. There are times in the growing season when key pests are most likely to cause problems, as indicated by the Apple Pest Chronology Diagram for Southern New England. However, every year is different, and checking the pest management situation requires regular, even daily, updates.