Didymella bryoniae in cucumber: an integrated control strategy

J. De Win, S. Van Laethem, R. Aerts, M. Frans, P. Karsmakers, S. Van Kerckhove, A. Paeleman, S. Verhelst, P. Bleyaert, S. De Groote, S. Fabri
Didymella bryoniae (synonym Stagonosporopsis cucurbitacearum) is a necrotrophic fungus which can cause internal and external fruit rot in cucurbits. Infection of living material occurs by mycelium growth starting from dying material or by infection via the flower. This results in important production losses due to rotten and malformed fruits. A set of control measures has been evaluated, which resulted in an advice to the growers based on a combination of both preventative and curative measures. Out of 12 fungicides and six biocontrol organisms tested for their effectiveness against D. bryoniae in a semi-commercial crop, four chemical crop protection products showed a good result. These treatments are, however, a temporary solution. Differences in plant infections depend mainly on cultivation methods, plant morphology, fruit charge and climate. Moisture plays an important role. Climate and infection data of 6 growers show that problems occur when the humidity deficit is low. This finding was confirmed in a greenhouse trial. In addition, irrigation should be reduced in the evening and the night. It was demonstrated that air circulation has a limited but positive influence in preventing infections and inhibiting fungal growth. The results of these trials were combined in an integrated control strategy for D. bryoniae in cucumber.
De Win, J., Van Laethem, S., Aerts, R., Frans, M., Karsmakers, P., Van Kerckhove, S., Paeleman, A., Verhelst, S., Bleyaert, P., De Groote, S. and Fabri, S. (2020). Didymella bryoniae in cucumber: an integrated control strategy. Acta Hortic. 1294, 105-112
DOI: 10.17660/ActaHortic.2020.1294.13
Mycosphaerella rot, Didymella bryoniae, Stagonosporopsis cucurbitacearum, Cucurbitaceae, climate, humidity, cultivation method

Acta Horticulturae