Applying "vine row volume" (plant row volume or PRV) principles to rate selection and spray machinery operations

ASVO Seminar • Canopy Management Background The concept of Plant Row Volume (PRV) as a standardisation technique in the spraying of horticultural crops was developed because so many plants are grown in so many different ways. The authors became interested in this approach in the early 1980s after a series of seminars with fruitgrowers when it became evident that while the concept of spray volume (amount of water and chemical mixture applied per hectare) was familiar to most growers, there was a large variation in what was considered a dilute or high volume application. This meant that there were similar disparities in what was considered ‘concentrate’ or low volume spraying. At this stage there was no common method of describing or comparing spray applications. The other reason for developing PRV was that most research on agricultural chemicals and other foliar sprays was done with high-pressure hand guns while all fruitgrowers were using airblast sprayers of various sizes and configurations. We needed to relate the hand gun work to the various types of airblast spraying. In the last ten years the PRV concept has been used to standardise agricultural spraying of varied techniques from hand gun and boom through high volume and low volume airblast spraying and even to aerial application. This paper summarizes our findings and practical experience and relates these to the spraying of grapevines. This should be a starting point for those who are interested in being able to better analyse their operations and in improving their spray efficiency.