Plant resistance to Polyphagotarsonemus latus (Acari:Tarsonemidae) in ornamental plants (WEEKHUIDMIJT)

Broad mites (Acari: Tarsonemidae) are pests that cause economic losses in floriculture. Due to restrictions in the use of broad spectrum crop protection agents they are hard to control. The aim of this project is to test if it is possible to preventively suppress the proliferation of the broad mite. To do so we use a combination of plant physiology, plant breeding, culture techniques and entomology. ILVO is looking for answers to the following questions: What are the population dynamics and the spread of broad mites in azalea nurseries? Is resistance already present in the azalea gene pool?  What is the possible role of the jasmonic acid cycle in the defense mechanism?

First, we develop adapted quantitative infection techniques and detection protocols for broad mites. We validate these techniques and we map the lifecycle of P. latus in the azalea culture. Because the azalea is cultivated as a cold culture, we also determine the necessary amount of degree-days for the mite’s development. We monitor the population dynamics and the spread of broad mites in controlled experiments as well as in azalea nurseries. We then look for possible resistance in the Rhododendron family against broad mites. We determine the background of these resistance mechanisms. Last, we perform a detailed study of the induced defense mechanisms including the role of jasmonic acid.

These research results (for example, knowledge about degree-days and population dynamics) result in more thoughtful and precise use of chemical and non-chemical treatments in the short term. In the long term, knowledge about resistance and adapted screening techniques via later breeding and selection work result in the development of new, more durable cultivars. Confirmation of our hypothesis about the use of jasmonic acid elicitors and analogues to induce the defense pathways would lead to many innovations related to integrated pest management against broad mites. Various results from this project are also applicable to other branches of horticulture.

Funding provider(s)
IWT - Instituut voor de aanmoediging door wetenschap en technologie in Vlaanderen

External partner(s)
PCS - Proefcentrum voor de Sierteelt