3 research outputs found

    Predicting crop injury caused by flea beetles in spring oilseed rape through pest monitoring in the autumn

    Get PDF
    1. Reliably predicting pest damage would allow farmers to reduce insecticide use without incurring economic losses and thus contribute to agricultural sustainability. However, means to predict pest severity are lacking.2. We assessed whether crop feeding injury caused by flea beetles in spring oilseed rape can be predicted from flea beetle pest densities in the previous season using 22 years of suction trap catches of flea beetles in combination with crop feeding injury data from 293 fields.3. We found a strong positive relationship between the densities of flea beetles of the genus Phyllotreta in the summer and autumn activity period of the previous year and crop feeding injury caused by flea beetles in spring oilseed rape the following year. Autumn weather or the total cover of spring oilseed rape in the study region did not improve the prediction further.4. Pest monitoring using suction traps is thus a promising tool to predict crop feeding injury and can reduce insecticide use in years with low pest pressures

    Pest management and yield in spring oilseed rape without neonicotinoid seed treatments

    Get PDF
    Use of neonicotinoid insecticides as seed treatments has been prohibited in the EU. As a consequence, concerns of lost production have been raised among producers. It remains, however, unclear to what extent the ban has increased pest attacks and crop damage, and reduced yield and farm profit. It is also unclear to what extent alternative, non-chemical options can protect crops. Flea beetles (Chrysomelidae: Alticini) are the main pests targeted by insecticide seed treatments in spring oilseed rape (Brassica napus L.). Over three years, we conducted 23 field experiments in which we compared seeds treated with neonicotinoids with untreated seeds, grown at normal or doubled sowing rates. The experiments were established during a range of sowing times at the same time as the hosting farmer sowed, which also allowed us to assess the impact of sowing date. We measured flea beetle activity density, crop plant density, cotyledon damage, crop yield and relative economic performance. Flea beetle activity density was eight times higher in 2014 than in 2016, with intermediate activity in 2015. Neonicotinoid seed treatment, increased sowing rate and an earlier sowing date all reduced crop damage. Seed treatment decreased crop yield loss by 521 kg ha(-1) and relative profit loss by 144 Euro ha(-1) in 2014, but had no effect on yield or profit in 2015-2016. Increased sowing rate did not affect yield, but decreased profit in 2015 (-138 Eum ha(-1)) and 2016 (-114 Euro ha(-1)), mainly due to higher costs for seed. Earlier sowing date was consistently associated with higher yield and profit. Our results put prophylactic seed treatments in question, as they gave lower yield losses in only one year out of three. Earlier sowing and somewhat higher sowing rate emerge as viable alternative pest management practices. Because management outcomes depended on pest pressure, which varied from year to year, crop damage prognosis tools are needed based on improved understanding of the population ecology of crop pests, to support the growers' decisions and avoid unnecessary use of insecticides
    corecore