Seed imidacloprid

The LD50 values for bobwhite quail and Japanese quail are 152 and 31 mg kg respectively. Redwinged blackbirds and brown-headed cowbirds have been observed to avoid imidacloprid-treated seeds after experiencing transient gastrointestinal distress (retching) and ataxia (loss of coordination). And so, it was concluded that treated seeds represent a minimal risk to birds. 

Imidacloprid is highly toxic to bees if used as a foliar application, especially during flowering, but is not considered a hazard to bees when used as a seed treatment. 

Concerning the test methods, some development is required. Questions encountered recently in France with imidacloprid, a systemic seed treatment applied to sunflowers, have shown the limitations of the existing methods. In fact, the suspected sublethal effects (changes in bee behavior) involve extremely low doses and are difficult to demonstrate with currently available methods. 

Bayer CropScience sells triazoxide as seed dressing in mixtures with DMI inhibitors such as triadimenol (trade name Brio ) or tebuconazole (trade name Raxil S ), the latter also in mixture with the insecticide imidacloprid (trade name Gaucho Orge ). 

The EU ban on neonicotinoids from December 2013 means that seed dressings containing clothianadin, imidacloprid and thiomethoxam can no longer be used for the control of cabbage stem hea beetle (CSFB) or the peach-potato aphid, a vector of turnip yellows virus. Fohar apphed pyrethroids ate now the only control for CSFB, but resistance is now widespread. 

Viras yellows can be very serious in some years, particularly if an early attack by aphids occms (Table 6.2). In the absence of imidacloprid seed treatment a spray of cypermethrin may be necessaiy. Powdery mildew, appearing as a white powdeiy growth on the leaves in early autumn, is not usually considered serious enough to treat with a fungicide. 

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