Pests

: 16 June 2016; Hits: 18296

Common weed controls crop pests

Farmers can now guard their vegetables against destructive pests free of charge by growing one of Mexican malgold species that has been found to repel these crop parasites

Kakamega demonstration show ground’s Kenya Prisons Service officer in charge of farming Fredrick Misoi said a study they started in 2010 has shown that growing Teketes minuta around vegetables can reduce cost of pesticides to zero.

“Inorganic farming is fast being faced out as the market embraces organically produced harvests. In 2010, we set out to find out possible ways of dealing with vegetable pests. We stumbled upon this weed, which we realised is not affected by the destructive organisms.”

“That curiosity is what informed our research and the findings we have today,” the Kakamega Prisons farm supervisor said during 2016’s Agricultural Society of Kenya show.

Practical

The officer said the malgold was grown around a plot of about 20 feet by 50 feet in one season. Various vegetables such as black night shade, kales, spinach, spider flower, among others, were grown in lines in the ‘secured’ plot.

During the same season, a separate control experiment was done, where the same crops were grown without the malgold ‘solder’. In between the plots, napier grass was grown as a buffer.

By the end of the study, all vegetables in the control experiment had been reduced to stems. Malgold wadded off the pests. Subsequent trials, Constable Misoi said, have given similar success results.

Crop destruction enemies

Aphids, fruit flies, thrips, moths, among others attack most vegetables by drilling out sap for nutrients.

Onions, peppers, pumpkins, egg plants, beans, tomatoes, courgettes, cabbage, kales, spinach, among other crops surrounded by the soldiers at neighbouring plots of the Kenya Seed Company Limited are free from the pest attack. No pesticide has ever been applied to control the intruders.

“Besides the outside beauty the plant brings to farm with its bright yellow flowers, it will be cute to produce chemical-free yields to compete well at the international markets,” he said.

Chemical-free vegetables

The European Union, which is Kenya’s biggest horticultural market, does not allow for importation of farm produce with residue surpassing 0.02 parts of chemicals per million.

Some chemical ingredients in pesticides have been linked to cancer in Europe, hence the ban.

Surrounding orchards with the ‘weed’ would help farmers meet the stringent international market regulations as well as cut costs incurred in pest control.

Crashing and spraying of the malgold on crops too effectively controls the pests, he said.

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Clean citrus planting materials can help farmers cut chemical use in production for export

: 13 June 2016; Hits: 13188

How grafting can help citrus farmers beat EU chemical regulations

Kenyan citrus farmers exporting to Europe can now beat tightened EU pesticide laws by planting seedlings or grafting material free of greening disease caused by the African Citrus Trizoid (ACT) pest.

“Planting clean citrus seedlings is an important management strategy. Grafting of seedlings should be done using clean scion [top parts of the plant used in grafting] that have been tested and found to be free from the bacterium that causes greening disease,” said Dr Ivan Rwomushana of International Centre of Insect Physiology and Ecology (ICIPE).

Blow from importer

The new EU laws have lessened the amount of chemical residue allowed in horticultural produce by 10 times calling on farmers to re-think their pesticide use seeing that the region is Kenya’s biggest horticultural export market. In 2014, Kenya earned Sh90 billion from the EU.

The EU is barring entry into its markets of horticultural products with chemical residue of more than 0.02 chemical parts per million. The figure has been scaled down by 10 times from 0.2 chemical parts per million. The regulations were effected following studies that linked some chemical components like guazantine in pesticides to cancer.

Clean citrus planting materials can help farmers cut chemical use in production for export.PHOTO: TWITTER

Big save

According to Dr Rwomushana, clean planting materials can save between 25 per cent and 100 per cent of the crops affected by the greening disease. The bacteria attacks soft tissues of the plant, leading to reduced photosynthesis and eventual death in severe cases.

To raise clean seedlings for grafting, a farmer can plant seeds in commercially available media like Amiran Kenya’s Peat Moss and Cocopit.

These artificial ‘soils’ are neutral and disease free. A farmer is only required to add mineral nutrients to support growth of the seedlings.

Low lands

Another way to get rid of the ACT pest is by planting in low lying regions as it does not survive in areas of high temperature and humidity. However, most of Kenya’s horticultural farmers are in the high altitude regions such as Rift valley, Nyandarua, Kiambu, Kirinyaga, Meru, among others.

Dr Rwomushana cites that the best way to control the ACT pest still remains the use of systemic pesticides like imidacloprid. This is however not viable for Kenyan farmers as these pesticides contain the chemical component guazantine which has been restricted by the EU.

It is for this reason that pest control is looking to organic farming for the answer. Biopest control remains the only viable route of minimising chemical use in production.

Another pest

The False Colding Moth (FCM)-a horticultural pest that can destroy between 34 and 68 per cent of crop-has been controlled by use of a mating disruption gel. It prevents males from mating with females.

“ICIPE is testing a range of biopesticides for their efficacy against the FCM. Major in the tests is the Metarhizium anisopliae fungi, which adults will be picking and spreading through mating. Victims with the fungi would die,” said Dr Rwomushana.

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: 10 June 2016; Hits: 8877

Sh60 can save farmers up to 80 per cent harvest loss

With as little as Sh60 per growing season, greenhouse horticultural farmers can save up to 80 per cent of their produce lost to aphids and other small pests using biological remedies.

The biological, environmental friendly methods also reduce to zero the chemical component of the produce, a factor that increases likeability in major export markets like the European Union.

Aphids attack capsicum, roses, tomatoes, cucumber, courgette, pepper, pumpkin, eggplant, cabbages and kales, African black nightshade, among other greenhouse crops.

Fruit trees like citrus, beans, peas, barley, wheat, are just but a few outdoor crops affected by the aphids.

Deadlier

Catherine Gacheri of Dudutech, a Naivasha-based integrated pest management solutions international institution, says the pest is deadlier in greenhouses than in the open fields.

In outdoor farming, aphids account for 25 per cent loss. This is because continuous showers help in controlling colony multiplication and effects.

“The yield loss, however, goes up in dry seasons since aphid colonies build up without interference from environmental elements like rain. In enclosed spaces like greenhouses, they can easily lead to produce loss of more than 80 per cent if not controlled,” she says.

Dudutech supplies Aphidius spp, Beauvitech and Lecatechve biological solutions for eradicating aphids, thrips, white-flies among other pests.

Do the maths

For open field application, one acre of the crop requires 100mg of fungal based products such as Beauvitech and Lecatech. Two hundred and fifty milligrammes of the two products costs Sh2,000.

It costs Sh119 to spray a 30m by 80m standard greenhouse, which is equivalent to 0.0593 acres. The protection will last until harvest.

For Aphidius spp, a farmer will require 500 insects per hectare, costing Sh2500. This translates to 200 insects per acre, costing Sh1,000.

If this amount is broken down to a greenhouse of 30m by 80m, the farmers incurs about Sh60 for about 12 insects. These insects will provide protection into the next growing season if there is a natural plantation nearby the field.

But Dudutech will not segment the product to this level, but the farmer can use is on another piece or time.

Cancer danger? No export

Besides chemical pesticides being hazardous to the farmer while applying, they reduce export market appeal of the produce.

In 2012, the EU banned importation of horticultural produce containing dimethoate chemical levels exceeding 0.02 parts per million. The chemical, which is an ingredient of most pesticides, is linked to cancer.

The EU consumes about 80 per cent of fruits and vegetables as well as 42 per cent of flowers from Kenya.

Approved effective solution

Pests undergo genetic mutation to survive consistent chemical application with time.

“There is no way that pests are going to be resistant to biological insets unless they migrate before they are destroyed. Biological control is sustainable,” Gacheri says.

As the global horticultural market turns eyes to organic farming, biologically produced harvest would attract more market and higher prices than chemical-residue-containing harvest.

The biological control organisms are affordable and approved by the Kenya Plant Health Inspectorate Service.

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