Fungus in wheat can be reduced without using chemicals

Problems with the fungus Fusarium and the toxin it produces can be minimised. It is necessary to combine various strategies, but the positive aspect is that the problem can be controlled without the use of chemicals.

Disease in wheat caused by Fusarium fungi is an important problem in several European countries and is also important in certain crop systems in Denmark. In order to solve the problem it is necessary to approach it from several angles. A new folder published by the European collaborative project ENDURE describes strategies that can contribute to solving the problem. Scientists from the Faculty of Agricultural Sciences, Aarhus University, have helped prepare the folder.

"Infection with Fusarium in wheat is an important problem because the fungus produces toxins - mycotoxins to be more specific - and they can be harmful for farm animals and humans", says senior scientist Lise Nistrup Jørgensen from the Faculty of Agricultural Sciences at Aarhus University, who has helped write the folder.

The fungus prefers humid weather, so seasons with plenty of rain in the wheat's flowering period provide optimal conditions for the fungus to spread.

Foreign and Danish data show that the risk of Fusarium infection and mycotoxin in the grain is increased if maize and winter crops precede the wheat. The scientists behind the folder particularly emphasize avoiding sowing wheat after maize, since this carries the greatest risk. It is even worse if maize followed by wheat is combined with reduced tillage and direct drilling.

Plant material left on the ground is a source of infection. However, if the farmer ploughs the field, the risk of infection will be markedly reduced- even if maize has been grown prior to the cereal crop.

Using wheat varieties that are resistant to Fusarium is another good way of preventing and reducing the problem. However, only few cultivars have high levels of resistance so in situations with a high risk of infection, resistant varieties alone will not be able to keep the toxins down at an acceptable level.

Controlling Fusarium with fungicides during the grain's flowering period is a solution that can help reduce infection and toxin content. The effect of fungicides is seldom more than approximately 50 percent, so when growth conditions for the fungus are optimal, the fungicide will seldom alone be able to reduce the problem sufficiently. In general, the recommendation is to regulate the problem and the risk of Fusarium infection using crop rotation, soil tillage and resistant varieties before using the fungicide solution.

Besides scientists from the Faculty of Agricultural Sciences at Aarhus University, the ENDURE group collaborating on fungus in wheat consists of scientists from the Netherlands, Italy, France, Hungary, Germany, Great Britain and Poland.

The folder "Strategies to Control Fusarium Ear Blight and Mycotoxin Production in Wheat" can be downloaded from the ENDURE website.

ENDURE, European Network for the Durable Exploitation of Crop Protection Strategies, is a so-called "network of excellence (NoE)" which is financed by EU's 6th Framework Programme.

The aim of ENDURE is to create a European research network that will also exist after the funding of ENDURE ceases at the end of 2010. The research activities aim to achieve a better understanding of pest biology and the interaction between plants and their pests and, based on this knowledge, to develop new, innovative control strategies in which dependence on effective pesticides is reduced compared to the present. This can be achieved by combining analytical and system-based approaches and by promoting collaboration between biologists, agronomists, economists and sociologists. Another important goal of ENDURE is to ensure that new knowledge is communicated to all relevant parties: farmers, advisers, the industry, politicians and, not least, consumers.