Control of root rot of Russell prairie gentian (Eustoma grandiflorum) in hydroponic culture using a mixture of azoxystrobin and metalaxyl M.

Abstract

For the stable production of Russell prairie gentian (Eustoma grandiflorum) flowers in hydroponic culture, we tested various applications of a granular mixture of azoxystrobin and metalaxyl M. The results indicated that application of 0.25 or 0.5 g/seedling of the mixture to the top of each peat block in the cell tray soon after transplantation of seedlings suppressed root rot caused by Pythium spinosum. This concentration of fungicidal ingredients in the nutrient solution is lower than the regulatory limit imposed by the Japanese government. The tests were repeated over 2 years, and similar results were obtained. Based on these results, we can control of root rot in Russell prairie gentian with a granular mixture of azoxystrobin and metalaxyl M.