LWV23103 Future-proof and biocontrol-based chrysanthemum production along the international value chain (TS-02-219-003)

The greenhouse horticultural sector is transitioning from chemical pesticides to biological control, particularly in the international value chains of floriculture crops. Dutch companies in East-Africa, growing mother plants for cuttings, struggle to establish predator populations in their greenhouses, making biocontrol of pests like thrips ineffective. Challenges include high temperature fluctuations, constant harvesting, and lack of additional food for predators. Consequently, broad-spectrum pesticides are still used, complicating biocontrol in the Netherlands when infested cuttings are imported.

In the Netherlands, aphid control is increasingly difficult due to reduced availability of chemical products and rising aphid resistance. Short cultivation times and low pest tolerance in crops like chrysanthemum and potted plants further complicate biological control. Weekly releases of Aphidoletes aphidimyza and parasitoids are insufficient due to interference from predatory mites and hyperparasitoids. Additionally, aphid predators sensitive to diapause cannot establish in short-day crops like chrysanthemum and kalanchoe.

This project aims to develop new strategies for establishing predator populations in East-Africa using species tolerant to high temperature fluctuations. It also seeks to create a 'first line of defense' against aphids and thrips in the Netherlands using diapause-free generalist predators. The international value chain of cut chrysanthemum will serve as a model system, with main production locations in Uganda and Tanzania. The project will focus on translating biocontrol strategies to other crops, integrating them with complementary IPM strategies, and evaluating their environmental footprint within the chrysanthemum value chain.