Integrated control of Phytophthora cryptogea in lettuce and belgian endive in hydroponics

Phytophthora cryptogea or root rot is a common problem in lettuce (61% of total lettuce production) and Belgian endive (90% of total Belgian endive production) in hydroponics. This oömyceet is a soil-borne pathogen that can survive for several years in the soil, but also thrives in hydroponics. Infection occurs in Belgian endive in the field, but symptoms usually only appear in hydroponics. P. cryptogea occurs mainly on wet parts of a field with a poor soil structure. These are often places where water remains on the field for long periods. Under these conditions, P. cryptogea can develop very rapidly and infect Belgian endive roots. In lettuce hydroponics, the origin of the problem is not yet known. In both lettuce and Belgian endive in hydroponics, P. cryptogea can spread very quickly due to humid conditions and infect even non-infected roots. As a result, the economic cost can quickly increase. Chemical crop protection agents are increasingly being phased out, which makes the sector demand for rapid detection methods and alternative control strategies. The main objective of the project is to strengthen the integrated control of P. cryptogea in hydroponic cultivation. The project is therefore built around three pillars: prevention, detection and control. The control strategies that are made practicable within this project are selected on sustainability, effectiveness and applicability in hydroponic cultivation. This will allow us to absorb the disappearance of chemical crop protection agents, but also to further reduce the residues in the end product. We want to achieve this main objective through various actions and innovations that are divided into three parts. In the first part, detection methods will be developed that allow an early detection of infections. In addition, knowledge will be gathered about the spread and development of the pathogen in order to be able to work in a more preventive manner. The second part of the project focuses on preventive measures that can be implemented in the short term. Knowledge will be gathered on the sensitivity of varieties and innovative technologies that can decrease the development of P. cryptogea. Finally, resistance mechanisms in lettuce will be investigated. This knowledge will contribute to the optimisation of breeding programmes for lettuce with increased resistance to P. cryptogea. The third project part looks at innovative control techniques with the main focus on the application of biological control organisms for the hydroponic cultivation of lettuce and Belgian endive. In addition, an evaluation and validation of the effectiveness of water treatments for reduction of P. cryptogea in irrigation water in the hydroponic production of Belgian endive will be investigated, as well as an evaluation of the side effects of the selected water treatments on a selection of biological control organisms. Furthermore, alternatives for reducing the inoculum when storing Belgian endive roots will be evaluated. Finally, a validated overall strategy for sustainable control of P. cryptogea for hydroponic lettuce and Belgian endive cultivation will be developed, integrating all research which will be applied on farms. By means of a demo platform and a guidance trajectory, a group growers will implement an elaborated control strategy or combination of strategies. Finally, the aim is the broad dissemination of knowledge and the registration of crop data as a basis for experience-based improvement of integrated pest management. The knowledge developed via cultivation guidelines will be integrated into an existing application, whereby an evaluation module will be linked to the cultivation guidelines so that the developed IPM framework can continue to be improved and reinforced after the project.

Keywords:Gewasbescherming

Disciplines:Agricultural plant protection, Horticultural crop protection