Sustainable pest control - comparing tritrophic interactions in organic and conventional production systems

Lead Research Organisation: Rothamsted Research
Department Name: Unlisted


This cross-disciplinary project will combine chemical, ecological and modelling techniques to determine whether cabbages grown under an organic regime differ in terms of pest dynamics and plant chemistry. There is increasing pressure to de-intensify agricultural practice and organic approaches are becoming more popular and widely adopted. However, there are very few, if any, detailed scientific investigations into the claims made about improved pest control. Insects destroy 14% of all food in spite of billions of pounds of insecticide being used every year. Growing cabbages organically is very hard due to significant pest damage, yet there is a strong desire for organic cabbages as conventional crops receive a lot of insecticide. We will use lab and field studies to see whether organic plants defend themselves better and are less attacked/damaged by pests. We will use a model system involving two major pests (a chewing caterpillar, the diamondback moth, and a sucking/piercing greenfly, the cabbage mealy aphid) and the natural enemies of these pests, in order to conduct scientific investigations which will allow us to determine whether organic cabbages are better defended, and if they are why? Finally, we will develop a mathematical model which will explain our observations in numbers. What is really useful with the model is that it will allow us to run many more experiments on a computer saving us lots of time and money. This will allow us to develop a picture of how to optimise the positives of our system whilst reducing the negatives. The approach we will adopt on our model system could be extended to other crops and will hopefully ensure that we can produce the quantity and quality of food we desire whilst leaving a smaller ecological footprint.


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