Integrated Pest Management: a more environmentally friendly method

Introduction

For the past 40 years, crop protection against pests has given, in often diverse and sometimes contradictory forms, an increasing importance to the concept of integrated pest management, or IPM. This evolution is due to the need to renew defense strategies against mites, insects, weeds, rodents, micro-organisms, nematodes, viruses, certain birds, etc., while better respecting the resources of the biosphere and responding to the laws of the market and the needs and aspirations of society.

Integrated pest management (IPM) is a shift from a reactive, treatment-oriented system to an active, preventive system. The two systems differ in the priorities given to the different measures applied. In fact, it is a change of approach: usually the farmer asks which pesticide to use to kill which insect or weed. In IPM, the farmer will ask himself how to manage this or that insect among all the other insects, or control this or that plant among all the other plants.

Simply treating the symptoms by dumping tons of chemicals on the crops creates major environmental problems such as depletion of natural gas reserves (since nitrogen fertilizers are made from natural gas), contamination of food and water by nitrates, and ozone depletion by nitrous oxides and accelerated decomposition of soil organic matter. It is important to note that IPM is different from organic agriculture, which does not use synthetic pesticides. Integrated pest management is more akin to what is known in industrialized countries as integrated agriculture, which is a method of cultivation and breeding whose primary objective is to reduce the quantity of chemical substances used and to minimize their impact on the environment by using them selectively, but not to eliminate their use completely.

This allows the following definitions to emerge:

Integrated Pest Management: a system of managing pest populations that uses all appropriate techniques, in as compatible a manner as possible, to keep those populations below levels that cause economically significant damage.

It is not a simple juxtaposition or superposition of two control techniques (such as chemical and biological control) but the integration of all control techniques adapted to the natural regulatory and limiting factors of the environment

Integrated pest management: phase of approach of integrated pest management consisting in a progressive development of chemical control through the use of economic tolerance thresholds and the reasoned use of specific or not very versatile products.

1 Characteristics of IPM

As explained in detail in interview No. 1 “What is integrated pest management?”, “integrated” pest management is a planning and management approach that involves different methods of reducing pest populations to acceptable levels. To achieve this goal, IPM has several methods: prevention of pest proliferation, cultural methods (such as crop rotation or varietal resistance), biological control using natural enemies of pests, and moderate application of pesticides, preferably natural – i.e., plant-based – pesticides with low residuals, and ultimately synthetic pesticides used in a targeted manner.

This interview addresses an important concept in IPM, that of pest thresholds, also called tolerance and intervention thresholds: as the agricultural engineer interviewed explains, pests can be found on a plant without being considered as pests. It is therefore a question of determining the threshold, the quantity of a given living being present in the field, that is harmful. He cites the case of rice cultivation in Burkina Faso, where the threshold to be reached before starting treatments has been set at five percent of attacks per square meter. IPM has great advantages for the small-scale African farmer: