Natural barriers: Integrated pest and disease management

Hello farmers! In today’s article we are going to learn some control methods, such as natural barriers, to prevent pests and diseases from entering our orchards.

Snails and slugs are one of the most common garden pests.

What is integrated pest management?

In past articles we talked about Integrated Pest Management (IPM). I remind you that Integrated Pest Management is a control strategy that basically consists of the rational application of the combination of measures, so that there is a minimum use of phytosanitary products.

For the implementation of this management, certain measures must be applied, which are:

PREVENTION.Prevention measures consist of using healthy plant material, managing the crop properly, keeping the soil clean and avoiding introductions of other crops.
APPROPRIATE FIGHTING METHODS.We have different methods of fighting that I will explain a little later (physical, mechanical, cultural, legal, biotechnical, biological control,…)
SURVEILLANCE MEASURES.They allow us to control if the fighting methods are being effective.

Of all the fighting methods that exist, today we want to give special prominence to natural barriers.

Natural barriers against pests

Natural barriers are based on placing physical barriers to prevent pests from reaching crops. The barriers can be formed by adventitious plants where natural enemies are hosted or aromatic plants that repel certain pests. It is a very effective method of control since it does not require the use of any phytosanitary product.

Example of aromatic insect repellent plants:

Aphids: honeysuckle, lupine, foxglove, mint or nettles.

White fly: calendula, Chinese carnations, tobacco or basil.

Nematodes: tagetes or marigolds.

Mosquitoes: basil, citronella or jasmine.

It is also effective to fence the lettuce beds or other leafy vegetables with ash or sawdust, preventing snails and slugs from reaching them. Another solution is to place padding or mulching to make it difficult for pests such as the potato beetle to access the soil and affect the crop.

Other methods of integrated pest management

1. Mechanical methods

We know as mechanical methods those direct or indirect methods of capturing or killing insects immediately. They can be manual methods or with tools.

Collecting insects: it consists of manually collecting insects that may be located in the different parts of our plants. For example, the potato beetle on the leaves, maggots on the fruits, tortricids on the shoots or soil insects.
Debarking: It consists of removing the bark where the pest is located to eliminate the winter forms and hinder their reproduction.
Water: It is based on washing the plants with water (or with some natural solution that we prepare) to eliminate insects and damaged fruits.
Artificial shelters to capture pests.

2. Physical methods

A physical method is used when any physical characteristic of the environment (temperature, humidity, light,…) that is unfavorable for the pest is modified.

temperature changes
Humidity Modification
alteration of the atmosphere
Meshes (nets, mosquito nets,…)
light traps
sounds.Sounds with very high intensity (between 140-160 dB) can kill insects and those between 100-130 dB can repel some animals such as birds.
chromatic traps
Insecticidal paints

3. Cultural methods

Crop rotation
labors
Sanitation (remove remains of attacked crops, pruning remains,…)
trap crops
Crop diversity
Study planting and harvesting times

4. Resistant varieties

Plant resistance to insects is the ability of a variety to grow and produce economically despite the presence of pests. In this way, the plant can alter the development of the insect. The pest dies or seeks another host plant.

5. Biological control methods

Biological control consists of using living organisms to control pests. Organisms used for biological control are called «natural enemies.» An example of these natural enemies are ladybugs (which feed on aphids) and spiders.

Trichogramma wasp parasitizing some eggs. (Source: Wikipedia)

6. Biotechnical methods

They do not cause the immediate death of a pest but they modify some physiological process or alter their form of communication. The most used biotechnical methods are:

pheromones
Attractants and Repellents (essential oils, food attractants,…)

7. Chemical control

Chemical control, despite continuing to be the most widely used method in the world, should be avoided whenever possible since it poses risks to agriculture (phytotoxicity, resistance, secondary effects…), to the environment (on fauna, soil and water contamination) and to human health.

8. Legal measures

Legal measures are mandatory requirements imposed by the government for the control of pests and diseases. To do this, it uses systems such as quarantine, inspection, eradication or regulation of crops.