SWEDEN

Open field day. Presentation of organic and conventional weed management research projects at SLU, Alnarp 15th of June

The 15th of June, 29 people attended an open field day arranged by Partnership Alnarp at the Swedish University of Agricuktural Sciences, SLU, Alnarp, Sweden. Farmers, consumers, advisors and researchers were informed about on-going projects concerning crop mixtures, under-sowing and mechanical weeding projects and also visited the organic research fields of the COBRA-project. At Alnarp we have two trials within the Cobra project, one winter and one spring trial mainly concerning weed competitive ability in cultivars, cultivar mixtures and populations, but diseases, yield stability and others as baking quality are also observed. We only visited the winter wheat trial this time. In winter wheat CCPs from ORC grown at Kassel University both conventionally and organically for 11 generations, breeding lines selected from the CCP in generation F4 as high allelopathic, mixtures of the breeding lines, two approved cultivars and the mixture of them were studied. Similar trials are also conducted in Estonia and Scotland. The visitor could observe informative mixture effects of yellow rust infections. The first picture shows the tolerant Harnesk, the sensitive Kranich and the mixture of the two (to the right).

The 2nd picture shows three breeding lines selected from the CCP (lower right). Both the examples with cultivars and the mixture and the breeding lines selected from the CCP show that mixtures and populations may improve disease tolerances.

 

Scoring of yellow rust (0-9) 29/5 to 8/6 (mean of three observations)
 Scoring of yellow rust (0-9) 29/5 to 8/6 (mean of three observations)

The differences in yellow rust tolerance could easily be observed. Weed competitive ability was more difficult to observe although there were differences according to the samplings done of weed biomass. In earlier studies differences in weed biomass among cultivars varies with early vigour growth, but also with allelopathic activity. In this trial, however, only the allelopathic activity measured as the rye root growth inhibition when grown together with wheat on agar. In spite of very different weed flora in the two years the trials has been conducted, similar relationships are observed between weed biomass and allelopathic activity. The graph is showing means of the two years. Nimbus show high allelopatic activity. This cultivar has a 1R translocation from rye and this may explain the high allelopathic activity. Kr09-28 also has a rye-translocation, but yet a high weed biomass. The reason for this is probably a very low early vigour.

 Relationship between allelopathic activity (PAA) and weed biomass at heading, Means from two years organic field trials at AlnarpRelationship between allelopathic activity (PAA) and weed biomass at heading, Means from two years organic field trials at Alnarp

The participants appreciated the field trip very much and I think it was a good reminder of the positive effects of mixtures and populations and that there are possibilities by breeders to improve weed competitive ability.  

Eleven of the 29 participants at the field tour in the organic fields of the camopus in Alnarp the 15th of June 2015

Eleven of the 29 participants at the field tour in the organic fields of the camopus in Alnarp the 15th of June 2015

 

Nils-Ove Bertholdsson
Department of Plant Breeding
SLU, Alnarp, Sweden
nils-ove.bertholdsson@slu.se

 

 

 

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