Living Without Neonicotinoids
Will Foss – Regional Technical Advisor
In spring 2013 the European Commission decided to ban the use of the neonicotinoid insecticide active ingredients clothianidin, imidacloprid and thiamethoxam for seed treatment, soil application and foliar treatment on those plants and crops attractive to bees. The period of the ban started on 1st December 2013 and is due to run for 2 years during which time it will be reviewed. Neonicotinoid seed treatments have been an extremely useful part of integrated agronomy, providing targeted use of relatively small amounts of active ingredient helping to protect seedlings and young plants from insect pests. Note that Deter can continue to be used on cereals in the autumn I.e. must be drilled by 31st December.
In the absence of neonicotinoid seed treatments a number of issues will need managing by adapting agronomic practices to deal with common pests in oilseed rape and linseed crops.
Select the right variety and drilling date – go for good early vigour
In the case of spring oilseed rape, delaying drilling until late March/ early April into favourable seedbeds with warm soil is the best defence against early flea beetle, so that the plant emerges and grows away quickly. The faster developing spring rapes, such as Dodger from Bayer and Docktrin from DSV, are ideal candidates for this early development.Choice of Winter Oilseed Rape varieties can help in the defence of the damage caused by Flea beetle and the prevention of TuYV spread. Generally the hybrid varieties are faster in their leaf development especially DK Expower and DK Excellium.
Achieve good establishment
Rapid emergence and early growth will be important for all crops to help them grow away from early pest pressure. Fine seedbeds and consolidation with the rolls will also help prevent flea beetle damage which can occur in loose seedbeds before the crop even emerges.
Use TakeOff seed treatment
This can improve rooting and crop establishment, helping the “germinative vigour” mentioned above. This is true for both Oilseed rape and Linseed and the cost/ha in these crops is minimal, making it a very useful component of the overall strategy.
Consider increasing seed rates
In high risk locations / situations this should be considered to allow for a percentage loss due to early pest attack, especially in spring crops which have less opportunity to compensate compared to winter crops.
Agrii trials are assessing comparative starter and placement fertiliser products in WOSR in autumn 2013 and this will also be looked at in spring 2014 trials. Nitrogen and phosphate will be the most important nutrients for rapid establishment and early growth particularly in situations of comparatively low N & P availability.
Apply foliar insecticides EARLY and monitor regularly
Timeliness of insecticide applications is essential – crops can disappear very rapidly. In spring OSR there are a number of approved pyrethroids (for early flea beetle control) plus non-pyrethroid options (targeted mainly at pollen beetle). Timing for flea beetle will need to be early (i.e. as soon as the crop just starts to emerge) and repeat applications should be planned whilst pest pressure remains. Once Oilseed rape gets to the 4 leaf stage the plants are more tolerant of damage.
Managing without neonicotinoids will not be easy. It is important to seek the advice of a qualified agronomist who has access to the latest agri-intelligence and to pay careful attention to product labels for details on maximum total dosage and number of applications.
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