Applied Engineering in Agriculture Vol. 25(2): 145‐151 E 2009 American Society of Agricultural and Biological Engineers ISSN 0883-8542 145 DESIGN OF A DECISION SUPPORT METHOD TO DETERMINE VOLUME RATE FOR VINEYARD SPRAYING E. Gil, A. Escolà ABSTRACT. Dose determination in crops such as grapevine, which develops a large canopy within a relatively short period of time, becomes a key factor on the final success of plant protection product (PPP) application. Efficacy of PPP applications depends on many factors. Based on multiple data obtained over several years in real working conditions using different types of sprayers in vineyards, and by adding a complete data base about crop characteristics (structure, crop stage, leaf area, LAI, etc.), the objective of this work has been to develop an easy and useful tool, DOSAVIÑA, able to determine the optimal volume rate in spray applications in vineyards. DOSAVIÑA, based on a spreadsheet (Microsoft Excel R ), allows quantifying all the parameters involved in the application process (sprayer type, crop characteristics, working conditions, weather, etc.), and to determine the efficiency of the application. By selecting and choosing the different options for each parameter (crop, pesticide, working conditions, weather conditions, sprayer, and droplet characteristics) the program calculates the theoretical volume rate (L ha ‐1 ) based on two different methods, the Optimal Coverage Method and the Tree‐Row‐Volume method. Results obtained with DOSAVIÑA allow reducing the recommended volume rate in comparison with traditional application rate selection managed for farmers. In order to make a complete and useful tool, the program includes the possibility to calculate the final working parameters (pressure, nozzle type, and size) according to the recommendations on volume rate (L ha ‐1 ) obtained. Keywords. Vineyard, Spray application, DOSAVIÑA, Tree‐row‐volume, Coverage, Volume rate, Dose, Efficiency. he recently published proposal of Directive of the European Parliament and Council establishing a framework for Community action to achieve a sustainable use of pesticides states: “This Directive establishes a framework for achieving a more sustainable use of pesticides by reducing the risks and impacts of pesticide use on human health and the environment in a way that is consistent with the necessary crop protection” (COM, 2006). Moreover, in article 13, part 1 establishes: “Member States shall take all necessary measures to promote low pesticide‐input farming, including integrated pest management (IPM), and to ensure that professional users of pesticides and other Plant Protection Products (PPP) shift towards a more environmentally‐friendly use of all available crop protection measures, giving priority to low‐risk alternatives when possible, and otherwise to the products with minimum impact on human health and the environment among the ones available for the same pest problem.” Submitted for review in October 2007 as manuscript number PM 7221; approved for publication by the Power & Machinery Division of ASABE in January 2009. The authors are Emilio Gil, ASABE Member Engineer, Associated Professor, Department of Agri Food Engineering and Biotechnology, Universitat Politecnica de Catalunya, Campus del Baix Llobregat – Edificio ESAB, Avda. Canal Olimpic, 15, 08860 – Castelldefels, Barcelona, Spain; and Alexandre Escolà, Assistant Professor, Department of Agro Forestry Engineering, Universitat de Lleida, Escola Tècnica Superior d'Enginyeria Agraria, Avda. Rovira Roure, 191 25198 Lleida ‐ Spain. Corresponding author: Emilio Gil, Department of Agri Food Engineering and Biotechnology, Universitat Politecnica de Catalunya, Campus del Baix Llobregat – Edificio ESAB, Avda. Canal Olimpic, 15 08860 – Castelldefels, Barcelona, Spain; phone: +34‐935‐521‐099; fax: +34‐935‐5210‐121; e‐mail: Emilio.Gil@upc.edu. A well‐defined method to establish the most suitable working parameters is a key factor to obtain an environmentally friendly application system, reducing drift, improving the sustainability and decreasing the total amount of PPP, directly complying with the main objective of the Directive. The European Plant Protection Organization (EPPO) has widely promoted and encouraged the absolute need to have at one's disposal a harmonized methodology to determine the optimal volume rate during the spray application process, specially focused in orchards and vine crops, due to its inherent difficulty and influence of crop characteristics on the final success of the operation. Determination of the amount of liquid to be sprayed is a difficult aspect (a great number of parameters influence the process) with a certain amount of subjectivity. There are many and very variable factors affecting efficacy and efficiency in pesticide applications in vineyard. Most of them can be classified as controllable (depending on sprayer type, working conditions, pesticide characteristics, etc.). Another group of factors is made up of all those that are uncontrollable, on which it is impossible to act but with high influence on the final success of the process such as weather conditions, pest and/or disease requirements, crop development and structure, and others. Taking all those aspects into account or not will turn into important variations in the final selected volume to be sprayed. The absolute need to improve both quality and profit of PPP applications requires a coordinated action in all the involved aspects of the process: characteristics of pesticide, target (pest, disease or weed), specific crop conditions, and selected application technology for distribution. A good interrelation between all of those aspects will lead to improved control during the PPP application process, T