Issue link: http://read.dmtmag.com/i/51841
VINEYARD ent applications. Explaining another application, Battany said, "Vineyards tend to lose growth and produc- tivity with age, so this is a way to monitor overall canopy loss over time, and potentially identify and assess vineyard vigor or canker disease problems that reduce canopy size." IRRIGATION ISSUES AND CALCULATION METHODS Tools and sensors to monitor water status for vineyard irriga- tion can be grouped into three major categories: plant-based, soil moisture-based and climate-based. Plant-based tools measure leaf or vine water status with tools such as a pressure chamber or porom- eter. Soil moisture-based sen- sors measure available water for roots and plant uptake with tools such as a tensiometer or neutron probe. Climate-based systems use weather stations to monitor local atmospheric conditions and use ref- erence ET and crop coefficient cal- culations. The Paso Panel is a tool for a climate-based system. "Some people tend to use one of these methods, but I suggest using more than one," Battany said. The American Vineyard Founda- tion provided funding for research using the Paso Panel. In 2010, Bat- tany evaluated 84 vineyards east of Paso Robles to determine crop coefficients within an area des- ignated as a "groundwater basin area of concern" due to declining groundwater levels. Mid-summer measurements were taken dur- ing the peak irrigation water-use period that indicated an average Kc of 0.53, with a range from 0.27 to 1.03. This variability indicates the wide disparity in irrigation water requirements for vineyards. In Paso Robles, as in other areas of California, water availability and use are issues that will con- tinue to become more critical in the future. "If we can save just 5% in irrigation water use, that will really be important in California," Battany said. "And if we can cal- culate needs more accurately using measurements like these, it WWW.VWM-ONLINE.COM could be very important, if not man- datory, at some point." COMPONENTS A Paso Panel can be assembled at a cost of about $300 to $400. "This is a free and open design, so anyone who wants to build one can do so," Battany explained. Details – including a field demon- stration video, photos of the panel under construction and downloads of spreadsheets for calculating Kc values – can be found at Bat- tany's website: http://cesanlu- isobispo.ucdavis.edu/Viticulture/ Paso_Panel/. The Paso Panel is made of three main components: with an operating voltage of 15.4 volts, and weighs 2 pounds. Products can be ordered through the company website – www. powerfilmsolar.com – or pur- chased from local vendors. 2. A lightweight frame made of extruded aluminum materi- als, available at most hardware stores. It is designed with carrying handles on one end. A bubble level is built into the frame near the handles to ensure the panel is level when readings are taken. 3. A digital multi-meter (available at hardware stores, Radio Shack, etc.) rated up to 10 amps, which The Paso Panel can be constructed from materials found at most hardware stores, along with a PowerFilm solar panel. Photo: Mark Battany 1. A PowerFilm brand solar panel – thin, lightweight and rollable. PowerFilm is the Iowa-based developer and manufacturer of thin, flexible solar photovoltaic (PV) panels commonly used as portable devices for charging batteries and for remote power applications. Battany commonly uses the R15-200 model, a 12-inch by 73-inch panel that produces 15 watts of power reads the electrical output from two output wires connected to the solar panel. A push-button switch located near the carrying handles is depressed momen- tarily to complete the electrical circuit; this provides a reading in amps of the output generated from the solar panel correspond- ing to the amount of light it receives. JAN - FEB 2012 VINEYARD & WINERY MANAGEMENT 85