Abstract

Many orchard sprayers used in Swedish fruit production are rather old. The interest from growers or industry to improve and modernize the sprayer stock would be stimulated by solid and undeniable arguments. Modern spray application technology that results in a possible dose reduction is an example of such an argument. Equipment to reduce wind borne spray drift has been introduced on the market. We have encountered contradictory data about how biological efficiency, with possible dose reduction interactions, are influenced by modern application technology. Dose-response experiments could be one way to verify these relationships, but traditional methods are expensive and require large acreage. The objectives of this project are to develop knowledge on how the dose could be reduced by use of modern spray technology. An important part of the project is about development of experimental procedures, aiming at more reliable and inexpensive plant protection experiments in orchards. The project was carried out in close cooperation with the Royal Research Station of Gorsem (PCF), Gorsem, Belgium. Experiments were made with a modified method where the dose was linearly changed along the plot; a method known from traditional agricultural field experiments. A “semi-field”-method was developed, implying that the experimental field area could be radically reduced. Small (pot plant sized) apple plants were hung into the canopies of a row of about 25 apple trees. Spraying was done with a linear dose, starting with clean water and ending with full dose of an adequate pesticide. The small plants could be infected with pests either before or after the spray application. Experiments were made with aphids, apple scab or different types of mites. Larger field experiments, with full canopies as targets, were also carried out in both Belgium and Sweden. The result showed that the new experimental procedure using linear dosing could give new information on the effect of different technical contributions. At the same time these experiments revealed additional questions and possibilities for further developments. For the grower, a useful project result concerned air inclusion (AI) nozzles, used to reduce wind drift. AI nozzles have to be used with caution, because they showed less reliability in pest control when reduced doses are used, compared to traditional hollow cone nozzles

Keywords

orchard spraying; application technology; plant protection; methodology; spray quality

Published in

Rapport (Sveriges lantbruksuniversitet, Institutionen för landskaps- och trädgårdsteknik)
2004, number: 4
Publisher: Institutionen för landskaps- och trädgårdsteknik

SLU Authors

• Svensson, Sven Axel

  • Department of Landscape Management and Horticultural Technology, Swedish University of Agricultural Sciences
    

• Björkholm, Anna-Mia

  • Department of Landscape Management and Horticultural Technology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Environmental Sciences related to Agriculture and Land-use
Horticulture


Permanent link to this page (URI)

https://res.slu.se/id/publ/3991