Organic practices in greenhouse tomato operations significantly reduce pest populations while maintaining comparable yields to conventional methods, according to a recent study. By promoting natural predators of pests, organic greenhouses hosted up to 97% more beneficial insects than conventional greenhouses, highlighting the biodiversity benefits of organic practices. 

Tomatoes, particularly in greenhouses, are highly susceptible to pests like aphids and whiteflies, which thrive in humid and enclosed environments. Conventional greenhouse operations typically rely heavily on synthetic pesticides, but these chemicals can inadvertently harm beneficial insects and, over time, lead to pesticide-resistance in pest insects, which can cause an increase in pests. Organic greenhouse operations by contrast avoid synthetic chemicals and when they create biodiverse conditions that support natural enemies, they can leverage their services for pest control. 

The study examined insect populations and pest damage in paired organic and conventional greenhouses, some of which were enhanced with flower islands (basil, marigold, and alyssum) to attract natural predators of pests. Insects were identified and counted using sticky traps and direct observation on tomatoes and flower islands.  

Organic practices achieved a lower pest-to-predator ratio, with just 9 pests for every predator compared to 38:1 in conventional systems. This balance, alongside slower pest population growth in organic greenhouses, highlights the critical role of predatory insects in controlling pests. As a result, tomato plants in organic operations experienced significantly less pest damage. 

What’s more, despite avoiding synthetic fertilizers and pesticides, organic farms achieved yields comparable to conventional systems, challenging the perception that conventional yields always outpace organic. By choosing organic tomatoes, you not only enjoy healthier produce but also support farming practices that prioritize biodiversity and vital ecosystem services that reduce the need for harmful chemical inputs.