Pests

: 25 August 2020; Hits: 3763

Farmers’ Friend: controlling yellow sigatoka (yellowing disease) in bananas

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By George Munene

The banana plant is a low maintenance hardy herbaceous crop, but the yellow sigatoka is amongst the few diseases that severely effects it. Caused by a fungus, mycosphaerella musicola, it is often characterised by yellow spindle shaped spots on the surface of banana foliage.

The disease is also referred to as leaf spot, leaf streak, sigatoka disease, sigatoka leaf spot, mycosphaerella leaf spot and mycosphaerella fijiensis.

Symptoms

Yellow sigatoka is most prominently characterised by:

The earliest symptom are light yellow spots starting with the third and fourth leaves from the top, i.e., the youngest leaves.
If unchecked, some of this spots turn dark brown, widen, and become oval shaped.
The centre spot where the leaf is most afflicted eventually turns light grey with a ring of brown and withers.
At its most severe, many of this spots merge and weather the entire leaf.

Yellow sigatoka is especially contagious in higher altitude regions over the rainy season and when temperatures are above 21°C

Effects

Decrease in photosynthetic area leading to reduced bunch sizes
Shortened green life—period between harvesting and ripening.

The flesh of fruits from infected plants exhibit a pinkish hue and keep poorly.

How to control/ treat yellow sigatoka

Cultural methods

Ensure your farm is properly drained and there is little water logging
Removal and control of weeds
Deleafing- sanitary removal of entire diseased leaves or parts of them
Cutting out diseased suckers
Avoid overpopulating your bananas. Use the recommended spacing for planting different banana varieties
Cut off and burn old dried infected leaves

The conidia/spore of the fungus is passed on by rain water, wind and old dry infected leaves

Chemical methods

Dithane M-45 (in water)
Dithane M-45 WP (in an emulsion of oil and water)
Foliar spray of Copper Oxychloride (3 g/litre of water)
Thiophanate Methyl (1 g/litre of water)

Alternate chemicals to avoid the disease building up tolerance.

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: 20 August 2020; Hits: 3789

Farmers Friend: organic remedies for early blight

Early blight of tomato

By George Munene

Early blight is one of the common and hazardous tomato diseases. It however also hits potatoes, peppers and eggplants. It is caused by a fungus; Alternaria solani.

Symptoms

The first tell that your plants are affected by early blight are dark spots on the underside of older leaves near the ground
These spots then turn brown. They are concentric, up to half an inch in diameter
The spots grow larger and yellow, forming a ‘bull’s eye’ pattern on foliage
The leaves eventually completely wither and turn brown, they drop off or hang onto the stem
Fruits nearer to the stem are first to be infected by early blight. They develop leathery black lesions that are raised and concentric
Severely infected fruits rot and drop off

Prevention, Management/ Treatment

Early blight thrives over the rainy season, and in areas with 15-27 °C, it is even more of a problem when temperatures hit 28-30 °C with humidity levels over 90 per cent; these are the optimum conditions for the fungi to flourish

Cultural controls

Use of resistant cultivars (Resistance doesn’t denote immunity, rather, these varieties are more able to ward off early blight)
Buy seeds from an accredited agro-dealer, inquire about what variety offer the most resistance to early blight in your region
Use authenticated seeds for planting. Alternatively, ensure that the seeds you collected for planting are pathogen free
To prevent the spread of disease causing spores to the rest of the healthy plants, pluck out, burn/bury infected plants
Rotate out crops of the solanaceae/nightshade family for at least one planting season
Use the recommended amount of fertiliser and manure to ensure your crops are vigorous which gives them some measure of disease resistance
Do not work on your farm when it has just rained, your crop has been irrigated or is dewy—this only serves to spread the fungi’s spores
Disinfect your pruning shears/knife with a 1:4 bleach to water mixture after dealing with infected plants to avoid spreading the fungi to other healthy crops.
Keep the plant dry by opting for a drip rather than overhead irrigation system
Keep the soil at the base of the plants free of debris. You can use mulch or organic compost as a barrier preventing the spores from splashing back up on the vegetation
Use the appropriate spacing during planting and stake your tomatoes/ capsicums/ eggplants. This helps avoid contact between plants. It also allows for proper air circulation, preventing the creation of humid conditions which keep leaves and stems wet allowing for fungal build-up
A vinyl film that absorbs ultra violet light has been shown to reduce incidences of early blight in greenhouse grown tomatoes by up to 50 per cent
Fermenting your tomato seeds. This keeps them viable for up to six years but also helps rid them of seed-borne diseases

Organic treatments

Garlic treatment—blend 10 cloves of garlic in one pint of water and strain the mixture. Use this mix as a foliar spray
Mix in one tablespoon of the baking soda/baking powder into a litre of water with some droplets of soap or vegetable oil to make the mixture adhesive

Commercial organic treatments for early blight are mainly copper based fungicides. These are the store bought cures for early blight available to Kenya’s organic farmers:

Champ Flo SL distributed by Anset International Ltd (specifically for tomatoes)
Cobox 50 WP-Kijani Agencies Ltd (vegetables)
Copper Nordox-Farmchem (K) Ltd (vegetables)
Cuprocaffaro Micro 37.5 WG- Farmchem (K) Ltd (potato and tomato)
Cuptocaffaro WP-Farmchem (K) Ltd (potato and tomato)
Isacop-Twiga Chemical Industries Ltd (potato and tomato)
Nordox 75 WG-Farmchem (K) Ltd (tomatoes)

Tomatoes are delicate crops; if you are looking to grow organic produce, preventative measures will be even more important than curatives given the virulence of early blight.

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: 06 August 2020; Hits: 3890

Smallholders get new, professional spraying service from Sh50 a farm to ensure safe pesticide use

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By George Munene

Kenya has emerged as a pilot nation for a new spray service, known as SprayPros spray service providers (SSPs), now numbering more than 1000 trained pesticide professionals, who recommend the right pesticides, spray them with full protective equipment, and handle their correct disposal, for a charge to farmers of typically around Sh100, but sometimes as little as Sh50 per farm, according to SSP Anthony Mutua.

The SprayPros are now available in 23 counties across Kenya. Their fees vary slightly from sprayer to sprayer, but all have been trained to give access to professional pesticide applications for smallholders at a price the small-scale farmers can afford. Their professional training by the Agrochemicals Association of Kenya, counties and government bodies, has equipped them to provide the following services:

Scouting, consultancy and making recommendations

Here, they investigate what you want sprayed and give you information on the best pesticide to use and the right dosage.

For consultancy alone, the farmer is charged as much as Sh500. If the Ssp has to travel a long distance to your farm, you’ll have to cater for their transport costs.

Related News:Superior spraying tech tames water loss

2. Field spraying

The standard charge is Sh100 per pump. Costs can range from Sh70 per pump for light sprays such as foliars to Sh200 a pump for more concentrated toxic pesticides such as Glyphosate that’s used to kill weeds.

1 acre sprayed to clear weeds can take up to 2 hours to cover.

Peter Maina the Ssp for Nyeri counsels that such sprays need expert handling, even their smell he says, can linger on your clothes for days after washing.

Spraying of trees is done at a charge of Sh50 a tree for less than 10 trees. If they exceed 10, the farmer is charged Sh30 per tree.

In Makueni, Judah Kimeu who’s the SSP for the region, usually sources the chemicals to spray on trees himself as few farmers have adequate information on how to tend to them.

3. Pruning

Farmers are charged Sh50 for every tree.

4. Grafting

This costs Sh25 per graft.

5. Budding

It’ll cost a farmer Sh20 for every budding.

6. Training

Farmers are trained by spray service providers at a cost of Sh1500 for a group, usually of 15 people, or as a cooperative of up to 70 people at a charge of Sh20 per person.

7. Soil and water conservation

This is offered to farmers in the form of digging of trenches designed to regulate runoff water as well as topsoil. For every 10 meters dug(1 peg) a farmer is charged Sh10

Water pans, used for harvesting water in small scale irrigated farming are dug for farmers at a cost of Sh200.

8. Proper waste control and disposal

The SprayPro spray service providers also give farmers information on the best ways to handle and dispose of chemicals with minimal environmental degradation.

At a time like this, when kids are at home, it’s especially important to keep these hazardous chemicals out of their reach.

Judah, SSP, Makueni: 0720 328194

Maina, SSP, Nyeri: 0703 754370

Keter, SSP, Kuresoi: 0739 748707