Tomato growing is an $80bn per year industry and very popular with residential gardeners. Losses to pest insects can be up to 30% so gardeners and growers often spray pesticides to get rid of the pests. This translates into a lot of pesticide sprayed. There are environmentally sound alternatives such as companion planting where plants that the pests don’t like are planted next to tomato. This companion plant is so revolting to the pest (even though it can be quite nice to humans) that the pest won't go on tomato when the companion plant is next to it. We recently confirmed that marigolds (which are quite nice to humans but whiteflies hate them) repel tomato whiteflies from tomatoes but there are no reliable companion plants to drive off other major tomato pests. The purpose of this project is to identify and trial companion plants to repel these other pests, make sure all the companion plants we identify work together in a mixture to repel multiple pests from tomatoes, and promote these new methods to gardeners and growers.
This is a 9-month research project to develop a companion plant mixture that will repel 3 major insect pests of tomato (whiteflies, spider mites, thrips). It will eliminate the need for gardeners and growers to use pesticide on their tomatoes to control these pests and will increase plant and insect diversity in residential gardens and market gardens. All gardners will have to do is grow these companion plant next to their tomatoes and this should be enough to keep pests from thier tomato plants. We have already shown that marigolds planted next to tomatoes repel whiteflies (this work is being prepared for publication in a scientific journal) and now we want to find plants that will repel spider mites and thrips. Growers should be able to take the findings from our research and use them to easily protect their tomatoes from insect pests in a completely natural, chemical-free way that is good for the beneficial animals and plants that live in gardens.
The money donated will pay the salary of a postdoctoral scientist for 9 months. The first three months will be used to assay different plant species with the pests in the lab and the remaining 6 months will be used to run glasshouse trials at Stockbridge Technology Centre in York, England. All costs except the salary of the postdoc scientists have already been met. Experiments will be run throughout 2017.
This is a completely profit-free project. The purpose of the project is simply to develop and share a technique that benefits gardeners, growers and the environment.
The project leader is Dr Colin Tosh, an internationally renowned ecologist based at Newcastle University, England.
Here are a couple of recent publications by Dr Tosh covering the whitefly pest, Trialeurodes vaporariorum, and its host, tomato:
McDaniel T, Tosh CR, Gatehouse AMR, George D, Robson M, Brogan B. Novel resistance mechanisms of a wild tomato against the glasshouse whitefly. Agronomy for Sustainable Development 2016, 36(1), 14.
Tosh CR, Brogan B. Control of tomato whiteflies using the confusion effect of plant odours. Agronomy for Sustainable Development 2015, 35(1), 183-193.
The postdoctoral scientist on the project will be Dr Dan Reed, who recently obtained his PhD under Dr Tosh's supervision.
These are the three pests our research will protect tomato plants from. We will discover and glasshouse-trial several human-edible or ornamental plants that the pests find unpleasant and that can be planted next to tomatoes to repel the pests from the precious tomato crop. We have already show that marigolds repel the whiteflies from tomato but we need to complete this work by finding suitable companion plants that will repel spider mites and thrips:
The glasshouse whitefly, Trialeorodes vaporariorum.
The two-spotted spider mite, Tetranychus urticae.
Various thrip species. Shown in the picture is the onion thrip, Thrips palmi, which regularly attacks tomato plants.
This is an experiment Dr Tosh and colleagues did summer 2016 to determine whether planting certain edible plants next to tomato can keep glasshouse whiteflies from infesting the tomato plants.
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