By: Linda Dede Nyanya Godji Incoom
As concerns grow over pesticide exposure in greenhouse farming, a Senior Lecturer and a greenhouse expert from the Kwame Nkrumah University of Science and Technology (KNUST), Dr. Eli Afetsi Gaveh, is emphasising that following proper management protocols in greenhouses is key to safe and chemical-free farming.
A research titled “Occupational Exposure to Pesticides and Associated Health Effects Among Greenhouse Farm Workers” has highlighted health risks from prolonged exposure to pesticide residues in enclosed greenhouse environments, reporting that workers face increased risks of respiratory issues and skin conditions due to frequent pesticide applications in confined spaces.
However, in an interview with agrighanaonline.com, Dr. Gaveh acknowledged that the issues raised in the report may stem from poor management practices rather than inherent problems with greenhouse technology.
According to Dr. Gaveh, the fundamental principle of greenhouse production is to create barriers against pests and diseases, which should dramatically reduce chemical requirements. Well-managed greenhouse operations can use as little as 10% of the chemicals required in open-field farming.
“If you follow good management practices, you may not even have any pests entering the greenhouse. And that also means that you are not spraying your vegetables with any pesticide to control pests,” he explained.
Speaking on concerns with greenhouses in tropical zones like Ghana, Dr. Gaveh outlined specific design standards: ventilation areas must comprise at least 20% of floor space, with heights exceeding three meters to ensure proper airflow and heat management. These specifications address the heat buildup and poor ventilation issues that some farmers have experienced.
Beyond design considerations, Dr. Gaveh emphasized the importance of integrated pest management (IPM) protocols, where you examine your crops periodically and localize treatments such that you don’t have to spray chemicals in the whole greenhouse when it is not necessary.
He also stressed proper sanitation practices, including equipment sterilization between plant handling, immediate removal of diseased plants, and restricted access to prevent contamination.
Despite acknowledging the challenges some farmers face, Dr. Gaveh highlighted the potential of proper greenhouse management through field results exceeding 100 percent yield as compared to open-field farms.
“Some countries with even better practices can get as much as 100 to 120 tons per hectare of tomatoes in greenhouses,” he added.
Greenhouse farming also facilitates organic production more easily than open-field agriculture. “Greenhouse production is one of the easiest ways to do organic production,” Dr. Gaveh said, noting that organic operations can utilize plant-based extracts like neem oil while completely eliminating synthetic chemicals.
Given both the challenges and opportunities, Dr. Gaveh advocates for expanded greenhouse adoption coupled with proper training and support.
As the greenhouse farming sector continues to expand in Ghana, Dr. Gaveh suggests that success lies not in abandoning the technology due to safety concerns, but in ensuring proper training, appropriate tropical designs, and strict adherence to established management protocols.
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