Greenhouse revolution: New farming methods take suburbs by storm

For instance, not every tomato variety is recommended for a greenhouse. Kari is conducting research to develop varieties of tomatoes for greenhouse agriculture and to determine the type of manure to be applied. Dr Wasilwa said contrary to using the recommended one hour of drip irrigation a day, many farmers flood their greenhouses with water.

“Drip irrigation in a greenhouse is efficient because the water is sprinkled to the roots and it helps to manage weeds. Some farmers are flooding the greenhouses, which is not good. They should keep them wet to avoid soil-borne diseases. They should keep the soil moist but not let it get waterlogged,” he said.

And although diseases are generally manageable in a greenhouse, he said, pests are still a major problem. But fungal diseases don’t affect greenhouse crops as much as those grown in the open air. “For fungal diseases to thrive they require water to germinate and infect the plant. In a greenhouse, because of the heat, the water dries up quickly,” said Dr Wasilwa. “That’s why, with greenhouse agriculture, diseases among capsicum and tomato has decreased.”

Gilad Millo of Amiran Kenya, an Israeli horticultural firm, said the company sells a farmer’s kit for Sh139,600. The greenhouse costs an additional Sh94,500. “Approximately 40 kits have been sold in the Nairobi area, together with an additional 25 greenhouses, making the total number of greenhouses 65,” he said.

A farmer could install an Amiran farmer’s kit with up to four greenhouses, all irrigated from the same drip,” said Mr Millo, whose company has imported the Israeli technology.