One small-scale tomato farmer, who repeatedly suffered losses due to deadly soil-borne diseases and pests, is using artificial soil to raise healthy seedlings for greenhouse propagation.
Nathan Mala incurred expenses in applying chemicals to control nematode pests, bacterial wilt diseases, among other deadly infections, which can destroy up to 100 per cent of the crop.
The Kiambu County farmer learnt of the cockpit substrate germination of seedling as the best way of raising clean planting materials for transfer to sterilised fields.
The cockpit is rich in nutrient and is disease free. One bag of the cockpit that can fill six trays costs Sh1,000 while one tray goes for Sh200 at Amiran Kenya.
“Good harvest after four months starts at the nursery bed. Field hygiene does help if the soil is infected. You can plant normal nursery bed raised seedlings, but before or soon after flowering, the infections descend and wipe out everything. It happened to me severally,” he said.
The Lari Sub-county farmer has been in the vegetable growing agribusiness since 2012, with his much concentration being on tomatoes.
The substrate is filled in 66-capacity holed trays before the seeds are planted. In 28 days, the seedlings are ready for transplanting.
He has 11 of these trays, from which he expects to get 720 seedlings for his 8m by 30m greenhouse in two weeks.
After taking samples of soil for testing at the Kenya Agricultural and Livestock Research Organisation (KALRO) laboratory, Mala learnt that bacteria wilt and nematodes are present in the greenhouse. KALRO charges Sh1,000 for this service.
He has collected heaps of soil, which he intends to steam or ‘roast’ to kill the pathogen.
“The greenhouse is ready. I will package the steamed soil in planting bags before transplanting the seedlings. I will place the bags on a polythene paper to prevent contact with the unsterilised soil on the ground,” he says.
The trays are suspended on rails to avoid contamination with soil.
The seedlings are likely to grow their roots into the soil if the trays are placed on the ground. One will be forced to cut the roots during transplanting, further weakening the seedling,” he says.
At the same time, seedling are least disturbed when raised in these trays because transplanting will include carrying all the roots in lamp-some.
Watering is done with a knapsack sprayer, which releases small jets that do not threaten the firmness of the gentle seedlings.
Foliage fertiliser is also applied through the sprayer to boots development of leaves as well as the roots. Irrigation is done in the morning and evening, although sometimes the weather determines.
The trays notably have openings at the bottom for draining excess water, therefore, preventing logging. Excess water denies the young roots breathing space.
Seedlings raised in this manner seldom die if transplanted into clean seedbed.