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Fruit, vegetables and potted plants bursting with health

Pesticide consumption in the horticultural sector in Denmark is low compared to other countries, but there is still room for improvement with the aid of new methods that are being developed in collaboration between researchers and the horticultural industry.

[Translate to English:] Forskere fra Aarhus Universitet undersøger forskellige alternative strategier til at beskytte afgrøder mod sygdomme, skadedyr og ukrudt, så pesticidforbruget kan reduceres eller udelades. Foto: Colourbox

On the one hand we consumers want the strawberries, apples and other fruits and vegetables that we place in our shopping cart to look good and not have any spots, mould or wormholes. On the other hand, we also like to see that the products are produced with a low level of pesticides or even none at all. 

This is a difficult dilemma for Danish horticulturalists but help is on the way. A project lead by Aarhus University will develop novel methods for protecting fruit, vegetables and potted plants so that pesticide use can be reduced or even avoided altogether – and thus increase profits in the Danish horticultural industry. 

- Efficient plant protection is crucial to profitability in the horticultural industry – both the organic and conventional sectors – but it is not always so easy, says the leader of the new project Professor Per Kudsk from the Department of Agroecology at Aarhus University. 

Fewer pesticides available

In recent years a range of pesticides have disappeared from the market due to restrictive approval policy in the EU and Denmark. One of the greatest challenges facing organic crop farming is the lack of efficient plant protection methods. In recent years this development has contributed to a fall in production in some of the sectors of the horticultural industry, including potted plants and berry production. 

However, pesticides are not the only way to go. 

- There is a need for more integrated solutions that also comprise other solutions than pesticides, says Per Kudsk. This is where the new project enters the scene. In collaboration with researchers from the University of Copenhagen as well as the horticultural advisory service Gartnerirådgivningen and companies that develop new technologies, the researchers from Aarhus University will find and hone new methods for protecting horticultural crops.    

- Our goal is to develop integrated solutions that are not only interesting for conventional production but can also in some cases be put to use in organic production, says Per Kudsk. 

Danish means environmentally friendly

In Denmark the horticultural industry is characterised by having a low level of pesticide use and rare findings of pesticide residues compared to horticultural industries in other countries. Many consumers prefer Danish-produced fruit and vegetables because of the generally low level of pesticides. 

Continuing focus on pesticide residues and environmentally friendly production methods will promote Danish-produced products on the domestic market and also make them attractive on the foreign market. This can help insure the future of the Danish horticultural industry.   

- Our focus is on developing methods that can supplant the use of  pesticides in conventional production and increase the efficiency of plant protection in organic production and thus promote the shift to organic farming that in certain sectors is the shortest route to increased profits, says Per Kudsk. 

A range of alternatives will be investigated

Which sorts of alternative methods can be used? The project partners will investigate and develop several methods. 

To protect against weeds in vegetables, strawberries and fruit, the researchers will, among other things, test and develop direct drilling and strip tillage. With this method the seeds are sown directly in a cover crop that has previously been established. The advantage of this method is avoidance of weed germination due to no tillage, cover crop competition, and a potential chemical-biological (allelopathic) effect of the cover crop on the weeds.  

Another possibility is to develop various strategies and technologies for treating crop rows and between rows, respectively. This can be relevant if, for example, there are different times at which mechanical weeding is optimal in the rows and between the rows. 

In order to prevent pesticide resistance and avoid pesticide residues one of the things the researchers will investigate is to what extent it is possible to include biological protection of strawberries against mould. The scientists will also survey and optimize the effect of microbiological agents in greenhouses and outdoor vegetables as well as investigate the effect of crop rotation, catch crops and bare fallow on the occurrence of nematodes in outdoor vegetables. 

In collaboration with GartneriRådgivningen researchers from the University of Copenhagen will investigate the possibilities for reducing nematode problems, which have been posing a growing threat in the horticultural industry in recent years.    

The four-year HORTPROTECT has been granted 6.0 mill. DKK from the Green Development and Demonstration Programme (GUDP) under the Ministry of Environment and Food of Denmark. It is led by Aarhus University and is a collaboration between Aarhus University, University of Copenhagen, Gartnerirådgivningen, and companies that develop new technologies. 

For more information please contact: Professor Per Kudsk, Department of Agroecology, e-mail: per.kudsk@agro.au.dk, telephone: +45 8715 8096, mobile: +45 2228 3382 

Sustainable Pest Management is one of the research areas in which the Department of Agroecology is particularly strong and from which results are delivered in line with national and global societal challenges and goals.