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Single-orchard experiments showed a significant effect on field populations of the leafroller species complex. While promising, in light of the variability of the result, field scouting may be required to enable practitioners to estimate the density of the pests and avoid possible unexpected attacks. Additional experiments are needed to evaluate the efficacy of the product against C. pomonella.

Low impact alternatives to synthetic insecticides for the control of apple sawfly (Hoplocampa testudinea Klug) are scarce encumbering pest management in organic apple orchards. We investigated the soil persistence and field efficacy of the entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin (BotaniGard) against apple sawfly under common organic orchard practices. We also assessed the efficacy of B. bassiana GHA and Metarhizium brunneum Petch (indigenous strain) against sawfly in the laboratory. Larvae treated with either fungus in the laboratory died faster than control larvae and displayed 49.4%-68.4% mycosis. In the field, B. bassiana density remained high in the week after application, during larval descent to the soil. Fungal density decreased to 25% at 49 d after application and to 0.4% after 55 weeks. Molecular markers revealed that the majority of fungal isolates recovered comprised the applied B. bassiana strain GHA. Larvae pupating in soil cages in the orchard for 49 d displayed 17% mycosis. The high efficacy under laboratory conditions was not seen in the field. B. bassiana application resulted in densities above the upper natural background level during the growing season, but reversion to background levels occurred within a year. It remains to be investigated whether this has a detrimental effect on nontarget organisms. Additional work is needed to bridge the knowledge gap between laboratory and field efficacy in orchards.

Apple sawfly (Hoplocampa testudinea Klug) is a serious pest in European organic apple production. They hatch during a short period only, making correct timing of control measures crucial. Swedish organic growers have requested a strategy for optimal timing of the Quassia amara (Simaroubaceae) extract against the apple sawfly. The aim of this study was, therefore, to develop methods to predict the timing of Q. amara control in Sweden. A temperature sum model for timely placement of monitoring or mass-trapping sticky traps was validated for Swedish conditions. The average emergence of sawflies occurred at 169 degree days (SD = 20) counted from March 15 (threshold temperature 4 °C). The difference in emergence from existing first flight model of average and maximum 9 and 39 degree days (1 and 9 calendar days) was found acceptable. Accumulated oviposition of 85 % at full bloom (BBCH 65) suggests that mass trapping and monitoring could stop at this time. This is supported by a tendency of decreased trap catches during that period. Three application times for Q. amara were compared: (A) at petal fall (BBCH 67), (B) at a date calculated using female trap catch numbers and temperature sums, and (C) prior to peak egg hatch observed in the field. All treatments resulted in significantly lower percentage of damaged apples compared to the unsprayed control, with significantly less damage (1.3 %) in plots treated according to method (B). The results provide information on adult phenology and methods that could be used to determine timing of mass trapping and insecticide application against the apple sawfly.

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There is a growing interest among farmers and consumers in increasing production and consumption of grain legumes in Sweden. This requires better knowledge among farmers and advisors about suitable species, varieties and management practices for different conditions. Since cultivar suitability and management practices are highly site-specific, farmers need to gain their own experience of new crops and practices. This paper describes a farmer–researcher collaboration in which cultivation of grain legumes for food was investigated in on-farm experiments designed, managed and evaluated jointly by a group of farmers and researchers. Farmers tested innovative practices using within-field species diversity, comparative performance of varieties and methods for weed control. Post-harvest steps such as cleaning and selling the crops were considered by farmers to be integral components of the experiments. The process generated different types of knowledge, including practical knowledge on crop management, strategic knowledge on economic sustainability and knowledge about joint learning through collaboration. The on-farm experiments combined advantages of ‘pure’ farmer experiments (i.e., context specificity) and ‘pure’ researcher experiments (i.e., scientific inquiry), facilitating deeper analysis and understanding of outcomes. This enabled efficient knowledge building, adoption of new crops and innovative practices and stimulated further experimentation. The outcomes of this study are that farmer–researcher collaborations using on-farm experiments can stimulate collective learning by stimulating the exchange between participants and combining complementary perspectives throughout the experimentation process. The study also provides recommendations for facilitating on-farm experiments in future work, for instance using collective settings to evaluate the results.

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