Leek (Allium porrum) totals about 30.000 ha in Europe. Belgium is one of the main producers of leek together with France and Poland. Nowadays, the Belgian leek area stabilizes at about 5.000 ha. One of the major diseases in leek is Phytophthora porri, which causes yield and quality losses in autumn and winter.
A good integrated pest management (IPM) program for P. porri consists of different levels of control strategies. The basis of an IPM program for P. porri is disease control by technical management such as crop rotation, a well-drained soil, well-considered nitrogen fertilization and good sanitation measurements. Besides technical management, germplasm management is probably the most valuable tool to resist P. porri. Though no resistant cultivars are available yet, the very newest cultivars are less susceptible to P. porri (so far?).

When technical and germplasm management are not sufficient to inhibit or suppress the pathogen, chemical control measurements can be considered. The insights in the disease cycle of P. porri and the mode of action of the different fungicides resulted in a practically feasible webmodel for treatments with fungicides against P. porri. Based on field specific input (crop history, cultivar, crop rotation,…) by the growers and the metereological data of a nearby weather station, the webmodel advices when to spray. On average the same level of disease control was reached as control fields, but with fewer fungicide applications (up to 3 applications less).
Check out the webmodel:
www.prei-info.be.
The project was funded by the IWT Flanders (The institute for the promotion of innovation by science and technology in Flanders). The project was a cooperation of inagro (Rumbeke, West-Vlaanderen), Ghent University, PCG (Provinciaal Proefcentrum voor de groententeelt, Kruishoutem, Oost-Vlaanderen) and PSKW (Proefstation Sint-Katelijne-Waver, Antwerpen).
Afdeling vollegrondsgroenten – verantwoordelijke Danny Callens