Alternatives to herbicides in apple orchards
Abstract
Cover materials or cover crops can be an alterative to herbicides, without affecting fruit yield and quality. Earthworms thrives under rape straw but not under black polypropylene or by mechanical weeding. A questionaire showed that consumers are ready to pay more for apples produced witout herbicides.Mouse is a major problem where cover materials are used.
Description of the substitution
Herbicides are used to control weed in the tree row in apple orchards. Some alternatives to herbicides have been developed, but their effects on the fruit yield, quality and tree growth have not been studied so far. The aim of the present project was to study possible alternatives to herbicides and their potentials in relation to effect on yield and quality, and on natural flora and earthworms. A trial with the cultivar ‘Elshof’ was established as a traditional orchard comparing herbicide treatment with 9 alternative methods, including untreated control, mechanical weeding with rotor harrow in the row, weed cutting by a lawn mower, cover crops as: grass, Tagetes erecta or hop medick (Medicago lupulina), or cover material as: black polypropylene (MyPex), paper wool or rape straw. The effects of the 9 methods on fruit yield and quality, flora and earthworms were determined in comparison to herbicide treatment in a two-year study, applying daily or weekly irrigation.
The results show that alternative methods as covering the soil with rape straw or black polypropylene (mulching) may be used without negative effects on quality and yield under the optimal conditions as in the present trial. Mechanical harrowing, cover crops as Tagetes, Medicago or grass reduced yield when irrigation was performed daily, but no negative effects were found when irrigating weekly with the same total amount of water. The weed cutting could not reduce the competition from the weed at the frequency and method used in the trial, and yield was reduced. Yield was reduced when covering with paper wool, independently of irrigation schedule. Probably competition for nitrogen could be the reason and furthermore the material decayed, thus becoming less efficient the second year.
The air temperature was never below 0° C during the flowering period, and hence, no frost damage on the flowers was observed. Rodent damage (e.g. mice) on trees was a major problem in some treatments, especially with Tagetes and polypropylene cover. Earthworms thrived under the rape straw contrary to under black polypropylene and in treatment with harrowing. In the second year of the trial more plant species were found in plot irrigated weekly than in plot receiving daily irrigation. Coverage was highest in untreated control and in the Medicago treatment and lowest in herbicide treated plots.
Consumer willingness to pay extra for the apples grown without herbicide was tested in a valuation of non-marketed goods by using a questionnaire. The investigation showed, that the consumers were prepared to pay an additional charge between 2,9 Dkr. and 4,14 Dkr. per kilo of apple, where no herbicides have been used. Estimates showed that some of the alternative methods would not cost more than the use of herbicide, based on calculations from agriculture and if the conditions in the calculations were right.
The example includes
Safety and health at work:
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Environment:
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Technical requirements the product must fulfil
What problems made you look for a substitution?
What substance or product did you use before?
What solution did you find?
Assessment of the solution
What other solutions did you try/assess?
Breakdown into industries
Others
Who entered the example?
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Company:
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Environmental Protection Agency
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Name:
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project
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Address 1: |
Strandgade 29
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Address 2: |
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Zip code: |
1401
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City: |
København K
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E-mail: |
mst@mst.dk
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Type: |
Project
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Created by:
Lone Wibroe
Thursday, June 12, 2008
Last edited by:
Lone Wibroe
Friday, June 13, 2008
565
lw@alectia.com
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