The following article is the first of two on Integrated Pest Management (IPM) in gardening and cash crop production. The articles in this series are based on a presentation made by Ms. Elizabeth R.B. Church, a pest control adviser from California, USA, who holds an MSC in Agriculture, with emphasis on Plant Protection Science, and who visited Guyana and interacted with farmers recently, under the Partnership of America (POA) Farmer-to-Farmer programme. What is IPM?
Integrated Pest Management (IPM) is said to be the careful consideration of all available pest control techniques and subsequent integration of appropriate measures that discourage development of pest populations, and keep pesticides and other interventions to levels that are economically justified and reduce or minimize risks to human health and the environment.

IPM emphasizes the growth of a healthy crop with the least possible disruption to agro-ecosystems, and encourages natural pest control mechanisms.

Ms. Church says that IPM is basically about the farmer going about managing pests in a manner in which using the harsher chemicals is the last thing he or she does. She said there are lots of pest control tools a person can use before getting to the point of using chemicals.

What does IPM involve?
IPM involves three steps. Firstly, pest identification; secondly, monitoring; and thirdly, management.

Identification means knowing the insect and the damage it causes; monitoring involves catching the problem early; and management involves using preventative measures, or a mix of biological, cultural, physical/mechanical and (as a last resort) chemical tools.

Biological control is the use of natural enemies — predators, parasites, pathogens, and competitors — to control pests and their damage.

Cultural controls are practices that reduce pest establishment, reproduction, dispersal, and survival. They involve crop rotation, cleanliness, etc.

Physical/mechanical controls kill a pest directly, or make the environment unsuitable for its survival. Traps for insects are examples of mechanical control. Physical controls include mulches for weed management; solarization, or cooking or baking of the soil, for disease/pest management; or barriers such as screens to keep insects out. Chemical control is the use of pesticides.

In IPM, pesticides are used only when needed, and are used in combination with other approaches for more effective long-term control.
Monitoring and timing of sprays are essential in IPM.

Know the enemy
Know who you are fighting. A large part of this is to be able to identify what pests you have on crops in the shade house or the garden.

You need to make sure that you know what they look like.

The four main insect pests for gardens and shade houses in Guyana, Ms. Church said, are whiteflies, aphids, leaf miners and caterpillars. There are also thrips and mites, but she has not seen many thrips or mites.
Some of these pests are so small that it is difficult to see them with the naked eye. A magnifying glass is a useful tool for seeing them, but the best approach is to know what the damage they cause looks like.
Church said: “You will most likely see the damage on the plant before you see the insect, so you have to know that that damage belongs to white flies, or aphids, or leaf miners, or caterpillars, etc., etc.”

Caterpillars reputedly defoliate almost everything that has leaves. White flies attack  tomatoes, eggplants, peppers, hibiscus and other flowers. Aphids attack lettuce, parsley, celery, eggplants, pepper, and crops such as broccoli and cauliflower. Leaf miners attack lettuce, tomatoes and onions.