By Pelony Nampanzye
Integrated Pest Management (IPM) is a concept that has gained increasing popularity in the agricultural sector due to the environmental benefits that it offers. Plant pests and diseases have long been an issue for farmers as they can wipe out all the hard work and resources put into the production of crops. Pesticides were the quick go to solution but with the possible harmful effects that they might have on the environment, IPM offers a more sustainable solution. IPM uses a combination of techniques; cultural, biological, physical and chemical for the sustainable control of pests and diseases in agricultural production. In a broad sense, IPM can be defined as the careful consideration of all available pest control techniques and subsequent integration of appropriate measures that discourage the development of pest populations and keep pesticides and other interventions to levels that are economically justified and reduce/minimize risks to human health and the environment. Securing food production and community concerns for environmental and human health are the key drivers of IPM.
The Five Basic Principles of IPM
If you are a farmer and want to practice IPM then the following 5 principles should be considered. The principles take maximum advantage of farming practices that promote plant health and allow crops to escape or tolerate pest injury.
1. Cultural Practice
It is imperative to practice cultural activities to discourage pest development. This ensures preventing the pest problem even before it begins. Cultural practices in this regard would mean appropriate site selection, proper soil selection (this depends on the type of crop and the location, e.g. green pepper does well in sandy loam soils), use of resistant cultivars, pruning, thinning, mulching, watering, trellising, weeding and adhering. Practicing all these for the right crop will help to reduce pest development.
2. Pest identification
Pest identification is a key step in managing pests. One should be able to distinguish between pests and beneficial organisms, and identify damage and possible culprits. This can be achieved by knowing when the pest is in season as well as the life cycle of the pest. Knowledge of what pests attack what crops at specific time periods play a major role in prevention. Typically, pests are more prevalent during the hot season. An example is Diamondback Moth (Plutella xylostella) also known as the cabbage moth. This pest is fairly at manageable thresholds throughout the year but causes economic loss to the cabbage crop during the hot season when weather favors its reproduction. If a farmer is able to identify a pest and know how and when to act, controlling it becomes easier and often more effective. Information on agricultural pests and control measures can be easily accessed at Ministry of Agriculture offices as well as through the District camp/extension officers.
Monitoring is a key step in the IPM process as it aids in the identification of potential threats (pests). Some common monitoring techniques include trapping, sampling, writing records and indexing weather taking into account maturity of the crop and vulnerable stages. Taking trapping as an example, a trap can be set up in a tree (figure 1) or a location near your crop field where the pests will get trapped and you will be able to determine which pests are in the area and are most likely attacking your crops. These traps can be found in agricultural shops or can be made using simple materials; an old container, a plastic, an elastic band and desired bait. In addition, scouting techniques such as diagonal, end-to-end or zigzag methods and adhering to principals of starting from the youngest to oldest plants or starting a few lines from the crop boarders help to ensure an accurate picture is given about the presence of pests. In order for monitoring to be effective it should be conducted on a regular basis and pests should be properly identified as recommended above (principle 2).
Figure1: A pest trap hanging from a tree
4. Economic threshold
The economic threshold can be best understood as the decision-making point in IPM. Once monitoring has been concluded, you will then need to decide on whether or not action is required and how much damage to the crop can be tolerated. If action is required a desired treatment will need to be decided upon to avoid the pest reaching an Economic Injury Level (EJL), that is, a point which will result in economic loss.
5. Prevention and Suppression
Prevention is the adoption of measures to reduce the chances of occurrence of a pest. Suppression on the other hand is reducing the impact of the pests. Prevention and suppression can be done by applying different techniques. The methods involve preventing the spread of harmful organisms by hygiene measures (e.g., by regular cleansing of machinery and equipment). One of the methods of prevention and suppression is crop rotation, which would break the life cycle of the pests. Prevention and suppression also include the use of adequate cultivation techniques (e.g. stale seedbed technique, sowing dates and densities, under-sowing, conservation tillage, pruning and direct sowing). If prevention/suppression does not work then action will need to be taken. Action controls should be selected carefully with the environment, economy and social aspects considered. It is recommended that less risky controls should be applied before the more risky ones. Less risky controls would include weeding, trapping and the disruption of pest mating. The spraying of pesticides is a more risky control and should only be considered when all other controls are not working.
Why Integrated Paste Management (IPM)
You may be thinking to yourself, is it really necessary for me to adopt IPM in my agricultural practices? Well here are some aspects that will help you realize just how beneficial IPM can be:
1. Lower cost intervention
The use of pesticides to control pest invasions can be very costly, especially for a new farmer who is just getting set up or for smallholder farmers. IPM has economic benefits in that most of the practices can be done using easily accessible resources, for example, Do-It-Yourself (DIY) pest traps can be made using materials around you such as old containers; crop rotation will disturb the pests life cycle as well as prove beneficial for your soils; weeding will cut on costs needed to purchase pesticides.
2. Benefits to the environment
The use of the pesticides are often linked to degradation of the environment seen through the contamination of soil and water and it may prove harmful to beneficial vegetation and organisms such as birds. IPM is an eco-friendly approach and the effects on the environment are always considered before the application of any intervention. Methods such as crop rotation, minimal use of pesticides, pest traps and conservation tillage all play a key role in protecting the environment and ensuring climate smart agriculture is practiced.
Pests tend to become resistant to pesticides especially if the same pesticide is continuously used. The IPM model therefore counters this resistance. It discourages the use of chemicals and thus creates less cases of anti-resistance. Pesticides are used only when the other alternatives are not satisfying.
All things considered IPM requires a holistic approach to achieve sustainable crop husbandry. The methods, techniques and means utilized in order to achieve this are to be sound and progressive. IPM is a first line of defense in protecting the resources that are essential for a healthy and functional ecosystem. Therefore, in ensuring that we have a healthy and economically valuable crop it is essential to practice IPM to prevent excessive pest outbreaks and ensure the environment that we depend on is always protected.