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Grass becomes more robust against root-feeding insects

The development of the first commercial grass plants carrying natural root protection against the infestation of pests will lead to a reduction in the use of pesticides and strengthen the Danish commercial seed production.

2015.10.06 | Janne Hansen

Grass can stave off pests that eat their roots with the aid of certain fungi. Photo: Colourbox

 

Golf courses, football turfs, lawns, and grass pastures the world over are sown with seeds from Denmark, but just a few centimetres below the surface the dangers are lurking: grubs of crane flies and Chafers. These and similar pests love eating the roots of grasses and this kills the grass plants. Result: The green lawn or pasture turns yellow and dies.

This is a problem that scientists from Aarhus University are now trying to do something about. In a new project along with the seed company DLF-TRIFOLIUM they aim to develop the first ever turf and forage grass varieties that are robust against root-feeding pests such as the grubs of crane flies and Chafers.

The method which they will be using are naturally occurring endophytic fungi. These fungi live in the wild in symbiosis with grass inside the plants where they produce a variety of substances without harming the host plant.

Some of the substances that the endophytic fungi produce are directly beneficial to the plant and protect it from drought, insect attacks, and foragers such as sheep, cattle and horses.

Robustness against insects

The project partners are particularly interested in the loline compounds – these are some of the compounds produced by endophytic fungi in the meadow fescue species. Lolines make grass plants more robust by deterring insects. Lolines are harmless to mammals and can also make the grasses more drought-resistant.

The first step in the project is to collect a variety of meadow fescue plants with endophytes and screen the endophytes for their production of loline. The endophyte-grass combinations have been developed through natural selection and are sourced from nature.

In the next phases of the project, these selected grass plants will be tested. Initially they will be studied in greenhouse and climate chambers to measure: 1) how much loline they produce, 2) the best growing conditions for the production of loline and 3) how endophytes develop in the plants. The scientists will also look at whether the loline-producing endophytes increase the drought-tolerance of the grass plants.

Finally, the grass will be tested on golf courses against the root-eating insects. The insects will be collected and introduced to ryegrass and festulolium in the laboratory. The effect of the insects on grass plants with and without loline-producing endophytes will be compared. The selected plants will also be planted on selected golf courses that currently have problems with beetles. This is done in cooperation with the Danish Golf Union (DGU) who will also be participating in the project. The following spring plant robustness against attacks by the grubs will be recorded.

The project builds on the materials and skills developed in previous joint projects between DLF-TRIFOLIUM and Aarhus University.

- If we succeed in developing these more robust grass varieties it will significantly strengthen the competitiveness of Danish grass varieties and increase the earnings of Danish seed growers and DLF-TRIFOLIUM. Plus it will reduce the consumption of pesticides, says project leader Senior Scientist Birte Boelt from the Department of Agroecology at Aarhus University.

The three-year project is a collaboration between Aarhus University and the seed company DLF-TRIFOLIUM and is supported by a grant to the tune of 3.7 million Danish kroner from the Green Development and Demonstration Programme under The Danish AgriFish Agency.

For further information please contact: Senior Scientist Birte Boelt, Department of Agroecology, e-mail: birte.boelt@agro.au.dk, telephone: +45 8715 8276, mobile: +45 2228 3328

Agro, DCA