You must demonstrate the 'need' for the requested use and provide supporting information. Information may come from field trials, laboratory trials, grower information, independent consultants (eg ADAS, AICC), the public domain and, where appropriate, from UK research laboratories. You are encouraged to liaise with the authorisation holder of the product before making your application.
Your application must include the specific identity of the target pest(s) and crop(s) and the nature and importance of the damage, eg for some high value horticultural crops a pest may occur that, whilst causing only superficial damage, would result in high economic loss through reduced quality and marketability.
Occasionally situations arise where pests and diseases, which are considered to be of minor importance and for which no on-label authorisations exist, can give rise to significant economic damage. For example when weather conditions either allows the development of a disease to seriously damaging proportions,or enables a pest to enter the country in large numbers and rapidly invade crops.
Applications for Extensions of Use may be accepted if evidence is provided of the species of organism involved and the level of damage that it is causing is significant.
Applications for Extensions of Use for the eradication or control of outbreaks of non-indigenous organisms (which can be from imported plant produce) are the responsibility of Defra's Food and Environment Research Agency (Fera).
Economic damage can occur if, the damaging organism overcomes host resistance. An application for an extension of use may be appropriate in the absence of a suitable approved plant protection product or extrapolation under the LTAEU. Grower evidence and assessments by independent consultants (eg ADAS, AICC) of such breakdown should be submitted with the application.
The repeated use of single plant protection products or a number of closely related products can result in reduced effectiveness for reasons other than resistance in the target organism. Where such loss of activity has been shown to occur, there may be grounds for granting extension of use for suitable alternative products. Evidence must be presented demonstrating the loss of activity of the product and that effective control cannot be maintained with its continued use.
The development of resistance to an active substance in a target organism can render products ineffective,and may also confer cross-resistance to other active substances approved for controlling that organism.
Where control of the target organism is often dependent on a single active substance growers may wish, in the interests of reducing resistance risk, to have use of another product with a different mode of action; an accepted strategy for delaying resistance. You may submit an application for an extension of use authorisation if you can show either:
Where resistance has previously been identified reference to the relevant Resistance Action Group advice may be sufficient.
Where new instances of resistance are suspected, it can often be difficult to practically demonstrate the existence of resistance and in such cases you should first send a copy of your case to the relevant Resistance Action Group who will give an opinion on the merits of the case. You must then enclose a copy of the Groups conclusions with your application along with your detailed case.
Where there are one or more active substances available with differing modes of action (MOA) with current authorised use for that target, and a further active substance is sought, or if there is little or no information to substantiate the case that resistance is present in a species, you will need to contact the relevant Resistance Action Group for their opinion.
Where there is one or more active substances with a single mode of action and the situation leads to an increase in the resistance risk to an unsustainable level for a specified target(s), a resistance risk assessment conducted in line with CRD Efficacy guideline '606 - Resistance risk analysis and use of resistance management strategies', EPPO guideline 'PP 1/213 - Resistance risk analysis' or relevant Resistance Action Committee guidance must be submitted with the application as part of the reasoned agronomic case.
Where this case identifies a significant risk of resistance and the product requested contains an active substance (either solo or in co-formulation) which is from a different MOA to any existing on-label use for that target, then there is no need for any additional specific justification from the applicant.
. You must submit an opinion of the need for the extension of use from the current product authorisation holder.
You must submit information to confirm the basis on which the case has been made You must submit full details to support your case for 'need' which fully considers the range of alternatives available, the nature of the target organism and, where appropriate, knowledge of how this target organism has evolved resistance elsewhere outside the UK.
Ideally, any information from available field trials, laboratory studies or growers should be provided. You should be aware that a case based solely on a statement from a grower expressing knowledge of failure to control due to resistance is unlikely to be accepted as a basis for accepting an application on resistance grounds.
In all cases where an extension of use is required in response to a resistance issue, you must consider the potential impact of the use of the pesticide both in exacerbating the resistance issue and in conflicting with established resistance strategies which may have been developed.
Newly introduced or rarely-treated varieties may be found to be particularly sensitive to a pesticide, leading to unacceptable levels of phytotoxicity. Where a suitable alternative product with on-label use is not available, an application for an Extension of Use may be made. Evidence of phytotoxicity from correct use of the existing product must be submitted. We also require such incidents to be reported to us by the authorisation holder in line with their legal obligation to report all adverse data.