Avital part of crop production is pest control. However, pesticides should be used responsibly to prevent harming farmers, workers, consumers, and the environment.

Guidelines for action


  • Keep pests at a manageable level rather than killing them as well as their natural enemies.
  • By using pesticides in the right way, you can try to keep pests from getting used to them and becoming resistant.

There are a number of ways to accomplish this:

  • Use pesticides from various groups or pesticides that combine biological and chemical control methods.
  • Never use too much pesticide. Carefully follow the instructions on the label.
  • By implementing Integrated Pest Management (IPM).

Integrated Pest Management (IPM) is the application of multiple techniques to reduce pest populations and keep them below levels that cause economic harm.

Using pesticides incorrectly can lead to:

  • The annihilation of beneficial natural enemies of pests. As a result, pest infestations will continue to rise.
  • Resistance to pesticides.
  • Death or serious illness. Pesticides are extremely harmful to the environment. In food, pesticide residues can harm people’s health, pollute the environment, and get into drinking water sources.

The most important characteristics of IPM instruments

Instruments in the IPM family fall into the following categories:

  • Cropping, cultivation, and plant breeding methods Effect: Pest pressure decreases, yields increase, and pesticides become more cost-effective as a result
  • Methods of control based on mechanical and physical mechanisms Effect: Stabilisation of yields and reduction of risk
  • Natural insecticides and biological plant protection methods Effect: Stabilisation of yields and reduction of risk
  • Methods based on chemicals Effect: Stabilisation of yields and a reduction of uncertainty.

Pesticides must be used in a way that minimises their potential to cause harm to people. (Image source: pexels.com by Laura Arias)

Methods of cultivation, crop production, and plant breeding

Choose the right crop for the right site

Soil, climate, and location all play a role in promoting healthy crop growth and reducing the risk of insect pests.

Tilling the soil

Soil tillage is a highly effective method of combating soil-borne pests and pathogens. Tillage, for example, destroys the eggs of locusts and grasshoppers, as well as a wide variety of caterpillars.

Selection of hardy cultivars

Selecting crop varieties that are resistant to some local pests and diseases is critical. As with all things, there are advantages and disadvantages to each variety. When it comes to reducing your exposure to risk, mixing and matching different kinds is recommended.

Maize beetles eating the tassels of maize.

Fertiliser application to increase plant resistance

Plants that receive adequate nutrients during their early stages of growth are less vulnerable to pests during this period. Plant resistance will be improved, in particular with the availability of potassium.

Rotation of crops

A properly designed crop rotation system should be implemented in order to prevent the build-up of soil-borne pathogens. The more crops there are in a field, the more stable it is.

Harvesting date and method

Harvest as early as possible and shorten the time between harvesting and storage. Reduced storage time helps to keep pests at bay.

Set traps and plant border crops as a preventative measure

Insects prefer certain plants to hide or live in, and this preference is based on their biology. As a result of this knowledge, “trap plants” and natural enemies are used to control insect pests. For instance, including some rows of tobacco or maize in a cotton field acts as a trap for African bollworms. The trap crops are used to control the bollworms that have made themselves at home there. Similarly, selective spraying of the bushes around the field where armoured bush crickets spend the day can keep them from moving.

Shorten the time between harvest and storage by harvesting as early as possible.

Pest control through horticultural methods

Pests benefit from crop residues when the weather is unfavourable. The African bollworm in cotton and the stem borer in maize and sorghum can be significantly reduced by destroying crop residues. Those ecological niches are destroyed when crop residues are piled up and used as animal feed or when the leftovers are ploughed into the soil after harvest. Compost piles should be at least 30 metres away from vegetable fields in order to avoid “airborne” fungi contamination. Make sure that the compost-making location is facing the major wind direction. By using pesticides in the right way, you can try to keep pests from getting used to them and becoming resistant.

Never plant seeds that you’ve collected yourself. They may already be infected with harmful pathogens when you use them.

Control methods based on mechanical and physical principles

A mechanical approach is usually the best option for farmers who have limited resources or whose crops suffer from low levels of pest infestation. However, because of the time and labour involved, this method is only appropriate for small-scale farmers.

In a garden, a simple physical collection and destruction of armyworms, armyworm crickets, armoured crickets, and creeping locusts should be carried out immediately after they are discovered. It is also possible to cut and remove parts of plants that are infected.

Biological methods of pest control

Living organisms

Pests can be controlled using biological means, such as using living organisms.

The advantages of biological control over chemical methods are:

  • It is very specific. Only one pest is being targeted by this method of control.
  • It is non-toxic.
  • Once natural enemies are introduced, they become part of the landscape.
  • It makes good financial sense in the long run. Initial expenditures, however, are prohibitively expensive.
  • When a chemical’s selective action is known, it is possible to use it with other kinds of systems.

Pesticides that are made from natural ingredients

The Melia tree (Melia azedarach) and/or the Neem tree can be used to make the most common natural pesticide, a plant extract, which can be used to control pests. Namibia is home to a large population of Melia (Cape syringa). The Neem tree has been established in several locations at Omahenene Research Station and Ogongo College. Neem or Melia plant extracts are highly effective in small vegetable production.

The Melia tree, which bears yellow fruit, can be used to make the most widely used natural pesticide. (Image source: plantsystematics.org)

The following is the procedure to be followed:

  • In March, the fruit is ready for picking. Ideally, they’ll have a yellowish hue.
  • They need to be dried and then crushed in a mortar to make an extract suspension.
  • Crush the Neem or Melia fruit and add water to the mixture (500 g crushed seeds in 10 litres of water). After 24 hours, use the solution to control a wide range of vegetable pests, including armyworms and locusts.

The information in this article is credited to the Namibia Agricultural Union and Namibia National Farmers Union who published the Crop Production Manual in 2008.