Soil borne pathogens are a major challenge in vegetable production because they are very difficult and expensive to control. The soil acts as a reservoir for their inoculum where they can thrive for very long periods. Chemical control, the mostly used method is rarely effective against such pathogens, is expensive and is abused by most local farmers which results into environmental and human safety concerns. The most commonly encountered soil borne diseases in Uganda causing significant losses to vegetables are nematodes (mainly root knot nematodes; Meloidogyne spp.), bacterial wilt (Ralstonia spp.), root rot, collar rot and damping off (oomycetes especially Pythium spp. and Rhizoctonia spp.; fungi like Fusarium spp. and Phytophthora spp.).
Since management of such pathogens is very disturbing, raising healthy vegetable seedlings enhanced with biological control agents like Trichoderma spp. and Bacillus spp. is one way we can overcome such pathogens. The seedlings are raised in seedling trays using cocopeat that is treated and free of soilborne pathogens, they are also enhanced with biological control agents (BCAs) right away from priming the seeds to regular drenching during seedling growth. In this way the seedlings are protected from pathogen attack, the BCAs also work as growth enhancers and stimulants of systemic plant resistance in seedlings. The seedlings are raised under a screen house that provides protection from pest and disease attack. In the end, few or no pesticides are required to protect the seedlings form pests and diseases until they are transplanted to the main garden.
Another advantage of raising seedlings in the seedling trays, rather than ordinary nursery beds, is that during transplanting, seedlings are picked attached to the growth medium, keeping roots intact (avoiding damage to roots) and retain some water hence do not suffer much from transplant shock compared to seedlings raised in the nursery bed. In this way the seedlings grow faster and vigorously with a higher yield expectation hence more income to farmers, reduced losses due to soil borne diseases, reduced cost of production as less agro-chemicals will be required for disease control. Finally, and most importantly, healthy vegetables are produced with less environmental and human health concerns.
The first step to achieving this is establishing a healthy seedling incubation center to provide farmers with access to healthy vegetable seedlings through out the year. This means setting up a screen house, acquiring materials like cocopeat, seedling trays vegetable seedlings and BCAs. The incubation center will then supply farmers with healthy seedlings who in turn will realize higher profits from vegetable production. To make the project more sustainable, farmer training will be conducted at the incubation center on raising healthy seedlings, proper use of pesticides, disease identification and management among other good agronomic practices in vegetable farming.
In the long run, farmers will earn more from vegetable production hence improved their livelihoods. Consumers will get access to safer vegetables (with less chemical contamination) and there will be less environmental degradation due to misuse and overuse of synthetic pesticides by vegetable farmers.
The goal of my academic research is to developing working protocols for Trichoderma spp. and Bacillus spp. I spent one year with the International Institute of Tropical Agriculture, Uganda training farmers on raising healthy seedlings and helping them appreciate the technology through demonstration gardens. Unfortunately, though the technology was much appreciated, there was little adoption by farmers due to lack of resources. It is therefore from this background that I think setting up a commercial healthy seedlings incubation center would be ideal for farmers to access healthy seedlings and continue learning better farming techniques.
Ivan Sekanjako, Uganda