CONTROL OF ACYLALANINE-RESISTANT PYTHIUM SPP. DURING FORCING OF TULIPS IN GLASSHOUSES

Since 1979 fungicides belonging to the chemical group of acylalanines (viz., furalaxyl, metalaxyl, cyprofuram) have been used in glasshouse soils to prevent a root-rot disease in forced 5°C tulips, caused by Pythium spp.
Excellent control of this disease by these compounds was observed until recently, when pathogenic strains of Pythium, resistant against these fungicides, were isolated from an increasing number of tulip samples with diseased roots.

Therefore, experiments were conducted to find other disease-controlling fungicides.
Of the chemicals tested, viz., etridiazole, fenaminosulf, fosethyl-al₂ and hymexazol, fenaminosulf, when incorporated in the soil (2–6 g/m²) before planting, consistently led to a satisfactory control of the root-rot disease.
Variable results were obtained with etridiazole, fosethyl-al, and hymexazol against resistant strains.

IV International Symposium on Flower Bulbs

A.Th.J. Koster, P. Vink, L.J. van der Meer

https://doi.org/10.17660/ActaHortic.1986.177.77