The effects of far-red light on plant-arthropod interactions and the implications for greenhouse tomato cultivation

Summary

The use of LEDs with different colors of light is becoming increasingly popular to manipulate plant growth and productivity in greenhouses. Subsequently, changes in plant chemistry can affect plant-arthropod interactions, with consequences for pest management and natural pollination. In this thesis I investigated how the supplementation of far-red LEDs and the consequent changes in plant morphology and physiology affect the performance of pest arthropods, the ability of biological control agents to control pests and the behavior of pollinating bumblebees. We find that far-red light increases the performance and proliferation of multiple arthropod pests. However, we also show that, under supplemented far-red light, biological control can still effectively mitigate the increased pest numbers leading to good pest control. Similarly, far-red light does not interfere with pollination by domesticated bumblebees. This thesis indicates that the use of far-red LEDs can be combined with biological pest control and natural pollination.