Small scale organic farmers apply an environmentally conscious approach to managing insects, weeds and disease. The Saoso Standard for Organic Production and Processing give requirements for the organic pest, disease and weed control.

They use biological, cultural and mechanical means. They do not use synthetic or chemical preparations which are harmful to the soil, water, air and the biodiversity in the fields.

Cultural and Biological Means

The establishment and maintenance of healthy soil provides the foundation for healthy plants, which will be better able to withstand threat of insects and diseases.

Organic operators choose well adapted crops and vegetable varietals for their ability to thrive in local conditions.

Intercropping – planting more than one kind of crop within the same patch – helps to confuse insects and disrupt their breeding cycles. Crop rotation also has the same effect.

Companion planting works by planting different plants next to each other because they are mutually beneficial. Some plants repel certain insects. Others attract predator insects. Some attract insects and are used as sacrificial plants, to protect other plants.

Different mulches offer different forms of protection from attack.

Wild vegetation in borders around and corridors within fields act as ecological buffer zones, creating habitats for a variety of predators.

Living soil teeming with beneficial microbes and fungi brings about biological control of plant diseases. These natural agents inoculate leaves and tissues as new emerging seedlings push through the soil. There are many kinds of Bacillus, which are bacteria naturally occurring in healthy soil, which combat some diseases and insects.

It is vitally important to remove dead, diseased, or infested plants from a growing area. Weak or ill plants send messages to other plants that they ae struggling. Insects can pick up these messages and they then attack all the plants.

Mechanical Methods

organic pest, disease, weed control
Cover the plants with nets to protect them from attack.

Mowing or using a small cultivator between plant rows keeps the weeds down. Old fashioned weeding with a hoe is also effective.

The organic Standard allows the use of traps, barriers, light and sound.

Traps include:

  • sticky traps, where strips of sticky paper or plastic catch insects;
  • coloured traps, which work on the basis that insects are either attracted or repelled by certain colours;
  • pheromone traps, which are baited with the chemicals that are used by insects and other animals to communicate with each other;
  • trigger traps work when an insect triggers some sort of closure device;
  • light traps, that lure and kill insects.

Barriers include row covers, nets and collars, all of which protect the plants against insects and birds.

Organic farmers are allowed to use sound in the form of ultrasonic pest repellents. These are devices that produce sound at a level that will repel, deter or kill unwanted pests like insects, birds and rodents.

Smallholders can also make use of predators such as chickens, ducks and geese. They enjoy slugs and snails, caterpillars and many beetles. When allowed to roam in pastures with livestock they are helpful in keeping worm and fly larvae down.

Use of Preparations for Organic Pest, Disease and Weed Control

The Standard lists crop protectants and growth regulators which are allowed for organic pest, disease and weed control. They are from plant and animal origin, mineral origin, microorganisms, biodynamic preparations.

But what about old “boereraad” remedies and other home-brewed concoctions? The answer will depend on their ingredients.

For example, one of the oldest “home remedy” soil disinfectants, namely a weak solution of Jeyes Fluid poured on the ground, is most certainly not allowed. Jeyes Fluid, while a remedy dating back generations is carbolic acid and as such is most certainly not organic, nor kind to the soil.

Neem (Azadirachta indica) oil is very popular as it combats a large variety of insects as well as certain fungal diseases.

organic pest, disease, weed control
Use Diatomaceous Earth against poultry parasites.

The organic farmer is permitted to use food grade diatomaceous earth (DE). DE is effective in discouraging numerous insects that threaten vegetables. It is also well known as a remedy against both internal and external parasites and worms in poultry and livestock.

There are preparations available but the organic operator needs to ensure that they are organically certified.

The Standard also lists substances for pest and disease control and disinfection in livestock housing and equipment.

This is part four of a five-part series on organic growing. For more, click here.

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