Do High Saving Rates of Plant Protection Products Imply Sufficient Leaf Coverages and a High Biological Efficiency

As part of the three-year project (OLSVA), the main focus was to precise the use of plant protection products in intensive horticultural production systems by using sensors, where savings result in an ecological and economical optimization. Therefore, three sprayer prototypes were equipped with different fans, improved sensors, associated electronics and magnetic valves and then transferred to practical testing. The field trials were carried out at different field sites with different existing intensive pest occurrence. This publication shows an overview of the results from field tests of a sprayer with cross-flow fan conducted at a grower’s field site in Brunswick. The results show that the amount of the savings of plant protection products (15–70%) depended on the age of an orchard, the foliage during vegetation and the number of gaps. Currently, it is not possible to make a final conclusion on the biological efficiency due to time delays and ongoing technical developments. In general, the use of this sensor technique has not shown negative impacts on the appearance of powdery mildew and apple scab at the location Brunswick.In sum, before market maturity will be reached, a reduction of the costs of the system and a statistical back-up of the biological efficiency is necessary.