Monitoring Pansy Mottle Syndrome


PO 024 - Monitoring Pansy Mottle Syndrome

Start Date: 
Completion Date: 
Project Leader: 
Jill England, RSK ADAS Limited
PO 024

Industry representative: Gary Woodruffe, Bordon Hill Nurseries

AHDB Horticulture Cost: £40,000


Pansy mottle syndrome (PaMS) is recognised as a measureable or visible change in plant growth and function.  Symptoms typically include leaf distortion, mottling, bleaching, stunting and apical blindness, and appear to follow environmental stress events. This project aims to advance understanding of the environmental conditions that trigger PaMS symptom expression through environmental monitoring of commercial pansy crops on three sites, using 30MHz wireless environmental sensor and alarm systems to predict plant stress. Window Pane analysis will be used to determine the correlation between environment events, e.g. high air / plant temperature and VPD, and symptom expression.  Sharing the knowledge gathered from across these sites and accumulated experience will provide growers with a better understanding of the influence of glasshouse environment on plant development, and how adjustments can reduce plant stress and mitigate the risk of symptom development. 

Maintaining optimum water availability for Pansy plugs is difficult to achieve as they are produced in small cells, which can lead to poor root development and plants less unable to respond to extreme environment events. Gravimetric techniques will be used to determine the irrigation requirements of pansy plugs, which will be subjected to five irrigation regimes (optimum and sub-optimum) to demonstrate implementation of best practice. Grower workshops will be hosted to demonstrate these techniques, including matching irrigation with plant demand, and monitoring and management of the glasshouse environment to reduce incidence of PaMS.  A Grower Implementation Group will be formed to focus on ensuring outcomes are commercially relevant and suitable for commercial uptake.


Aim: To identify the environmental conditions that trigger the onset of Pansy Mottle Syndrome (PaMS) in-situ on a commercial nursery and to deliver the results and recommendations to industry in a practical format


• Monitor environmental factors in-situ at nurseries that have previously experienced problems with PaMS.  Monitoring will be undertaken on three sites, and at two crop growth stages: the young plant (plug) stage, and the growing on stage (finished plants).

• Host two irrigation demonstration events at grower nurseries demonstrating irrigation best practice to quantify levels of water applied to crops and the impacts on crop quality and to aid in the mitigation of PaMS.