Flower bulbs are sensitive to fungi and bacteria during storage. In particular, the fungi Aspergillus and Penicillium spread easily in dry hyacinth bulbs and can cause major quality problems. The Business Unit Greenhouse Horticulture and Flower Bulbs of Wageningen University & Research are investigating whether these fungi can be controlled by using antagonists.
Hyacinth bulbs are harvested in the summer and are then stored. Some of the bulbs are intended for the market, another part is intended for propagation and is planted on the field again in the autumn. In both cases, the bulbs are stored for several months. In the soil, the bulbs can be contaminated with, for example, Aspergillus and Penicillium, but these infections only become serious during storage. Because of the temperature and humidity during storage, the two fungi can spread quickly.
Antagonistic fungi and bacteria
WUR is investigating whether crop protection products that are permitted during cultivation can also be effective during storage. This in particular concerns antagonistic fungi and bacteria: these compete with Aspergillus and Penicillium, for example by attacking them with toxic substances or by crowding them out. A complicating factor here is that the two fungi thrive at a different temperature: Aspergillus likes heat, while Penicillium prefers a lower temperature. The effect of the antagonists must therefore be geared to this.
For the project, WUR first inventoried existing products for their potential effectiveness and usefulness. Based on this, a small number was selected for a practical trial. That test took place last season, and it showed that the antagonists are indeed effective during storage. Further research is needed to determine the correct application. Moreover, it would be ideal if both fungi could be controlled with one antagonist. That is why the research into hyacinth is extended by at least one growing season.
For more information:
Wageningen University & Research