Mosquito nets offer a safety net for farmers

Jason Mwangi, a fruits farmer and seller, retrieves mosquito nets from garbage sites. [Photo, File]

Use of recycled mosquito nets by small garden vegetable farmers is a common practice. Most of the farmers who use the nets do it to protect the crop from predators (chicken mostly) destroying the crop. What they don’t realise is that the nets protect the crop from invasive pest too.

A vegetable garden can be affected by several constraints, key among them are insect pests. It is therefore important that farmers look for safe and cost-effective control methods.

When a crop is infested by insect pest, farmers quickly resort to use of chemical pesticides. But, with the change in consumers tastes and preferences, alternative control methods should be considered.

Consumers prefer vegetables that have been produced free of chemicals. This is because chemical insecticides have been found to be detrimental to the environment with high risk on human and animal health. Additionally, insect pests have developed resistance to these chemicals making it hard to control them.

Use of shade nets is the alternative farmers are looking for. The nets are not only environmentally friendly, but also cost-effective. Already farmers are recycling used mosquito nets to fence their vegetable gardens. As the determination towards organic farming grows, more local farmers are warming up this idea.

The technology involves the physical installation of nets over crops. The net can protect the crop from pests, predatory birds and free roaming poultry. Additionally, the net provides a protective cover from direct sunlight and hailstones.

Use of shade nets should be combined with other biological control methods such as the use of plants like Mexican marigold and lemongrass, which have impulsive scents that repel pests from plants, as an alternative to pesticides. The shade nets can also be complemented by drip irrigation which will not only save labour for watering the plants but also minimise the usage of water.

Mulching is another cultural practice that will save moisture and smoother weeds. This technology is most appropriate for production of high value crops like tomatoes. The benefits of shade nets are many. Besides shielding the crop from invasive pests, the nets also provide shade for the crop from different unexpected calamities. Research shows that it enhances the rate of photosynthesis which results to increased output. It also helps in controlling temperature, light, water and moisture. This enhances the growth and yield of the crops.

What research says

Farmers who have used the shade nets attest to the fact that a lot of invasive insects such as whiteflies infestation has tremendously reduced. And use of pesticides has significantly reduced.

Studies also reveal that the yields of crops planted inside the net are six times more than those grown in an open field. It is estimated that these nets can save farmers up to 30 per cent of harvestable yield losses.

Because the nets produce heat for the crops, there is a substantial reduction in the maturity period. The technology is effective in mitigating pest infestation compared to the exposed crops.

Word of caution

Although the technology has many advantages, farmers need to take precaution when using the nets. Monitoring and scouting for pests although the season is important.

Holes in the shade nets will expose your crops to pest attack. Again not all pests can be controlled by shade nets. Use of nets can be helpful to farmers in complying with the Minimum Residue Levels (MRLs) and access the fresh vegetable export markets.

[The writer is an expert on sustainable agriculture and agricultural solutions [email protected]]