RHEA airblast sprayer: dose calibration indexes related to canopy and foliage characteristics.

In recent years, the pest control treatments have become central stages of the agricultural production processes. The reasons are related to climate change, which are gradually varying the types of pathogens and parasites and their development trends, but also for the forthcoming rules imposed by Legislative Decree 150/2012 Italian transposition of Directive 2009/128/EC on sustainable use of agrochemicals. The sustainable use of PPP (Plant Protection Products) focus the designing of the EU FP7 RHEA Project (Robot fleets Highly for Effective Agriculture and forestry management). To this end, the research unit has designed and developed an innovative sprayer that allows a variable rate spraying. However, this technique requires studies to define the relationships between the characteristics of the target and the volume distributed. In fact, tree crops pesticide spraying three variables of GAP good agricultural practices need to be considered: the drops type, the unit dose, the air flow intensity. Based on these considerations, a study to assess the most appropriate dose in relation to the canopy features variation, was conducted. The tests were carried out in an experimental vineyard in central Italy (Arezzo) employing a tunnel sprayer in order to quantify the doses distributed/recovered during the green management stages. In so doing a geo-referenced measurement system for monitoring the level of mixture in the tank, made by ultrasonic sensor was built. The results showed percentages of recoverable doses from 17,8% to 30,6% during the green management. This study represents a first stage of the research, which is also focused on the assessment of the potential correlations between vigour (e.g. NDVI vigor index) and the required dose.