It is essential that registration and product development is co-ordinated. The correct trials programme has to be designed to optimise the performance of a candidate product, reduce the lead-time to a minimum and keep costs within budget. OAC have a wealth of expertise in this field over a considerable period of time.

• Initial screening is a quick and cost effective way of getting basic product information from which rates, crops, situations and timings can be gauged. • Glasshouse screens can help give answers, dose response, growth stage response and many ancillary questions e.g. formulation efficacy, tank mix compatibility and soil type interractions.

• Field trials should encompass all aspects of the potential label recommendations in as wide a range of circumstances all possible. • Trials design must reflect the defined purpose. Screening trials need small plots and low replication. Compatibility, field trials and variety screens normally have low numbers of sites, low replication, but high treatment numbers. Efficacy trials need to be high in number of sites with moderate replication. Crop safety trials can be moderate in site number but have wide dose rates and high replication.

• When recommendations are at the label stage yield must be determined both in crop safety trials and efficacy trials. • Quality effects of the test compound must also be determined in any trials programme. This can include everything from grain quality to taint in processed crops.

• The ultimate test is on commercial crops with applications by farm scale spraying machines. This is often the point at which any fine tuning to the proposed recommendations can be made.