Oilseed crops

This user manual presents the work of researchers on companion cropping in oilseed fields who tested three different strategies: (1) the use of trap crops around and within the field, (2) intercropping oilseeds with a legume, and (3) sowing food crops or mulching. These strategies were used to measure the effects on insect pest control, natural enemy abundance and agronomic performance. Information on the introduction of this practice and socio-economic data are also provided.

This fact sheet presents the experimental work of researchers who studied three practices about companion cropping in oilseed rape fields: undersowing nurse plants, intercropping with legume and trap cropping. Increasing plant diversity offers a new way to help farmers managing pests in the field and it could also provide other ecosystem services. Information on the context and progress of the experiment is provided.

Enhancing ecosystem services in Oilseed rape; Serbian with English subtitle

Six EcoStack measures for promoting biodiversity and reducing pests were summarized and evaluated economically. Some of the measures may be economically attractive, depending on the farm structure and support.

"The pollen beetle (Brassicogethes aeneus) is the most abundant pest of oilseed rape in spring and is potentially one of the most damaging. Adults feed on the pollen within closed flower buds and the damage leads to bud abscission, resulting in podless stalks and yield reduction. Several methods are currently used to monitor the pressure of this insect, such as counting the numbers of adults on the plants, quantifying the number of buds damaged by the insect before flowering or counting the number of podless stalks before harvest. We conducted experiments to evaluate the robustness of these sampling methods and compared their results. We also describe how pollen beetles damage the plants to understand the limitations of methods based on damage estimation.RESULTS: Methods based on adult abundance lack robustness. We observed that most of the damage to buds is caused by pollen beetles feeding on small buds (< 3 mm), and that this damage can be quantified later in the season, indicating that methods based on the count of podless stalks are robust. Different methods gave consistent results and quantification of the pressure on the primary raceme can be a good proxy for pressure on the whole plant.CONCLUSIONS: Standardised methods for assessment of pollen beetle pressure will enable comparison of pest management strategies between different studies and facilitate the development of alternative control strategies for this pest"

Insect pest management in oilseed rape (OSR) is challenging for farmers due to the lack of effective insecticides, so conservation biocontrol—reliance on natural pest control and management methods to support populations of the natural enemies of crop pests—is part of the solution for a greener future. Sown wildflower field margins are known to benefit many natural enemies of crop pests. However, the most effective natural enemies of OSR pests are parasitoids, which specialise in attacking these pests, which in turn specialise on Brassica host plants (including OSR), but few field margin mixtures contain brassicas. We screened six different species in the field to find the plants with the best potential as ‘banker plants’ to support parasitoid populations whilst not exacerbating the pests. Forage rape was the best ‘all-rounder’; supporting good numbers of pollen beetle parasitoids and also supporting parasitoids of weevil and brassica pod midge pests. Careful consideration of the brassica component of field margin mixtures could extend functionality towards enhanced biocontrol of specialist pests.