Reduction in water use or increased water use efficiency are important concerns for wine grape growers. However, conservation of water must not reduce productivity, wine quality, or increase production costs. Targeted systems have been used in tree fruit and citrus production to provide frost protection while reducing the amount of water used. Potential benefits of a targeted system, such as microsprayers, for frost protection in vineyards include: reduced water use; less reservoir capacity is required; lower equipment costs for installation (smaller pumps and pipe); and less energy use. The purpose of this experiment was to investigate the use of microsprayers for frost protection in a commercial vineyard. The experimental site was a Chardonnay vineyard located near Los Alamos, CA. Plots were established during early March 1993 and data was collected from March 11, 1993 through May 20, 1993. The objectives of this experiment are to determine if an alternate method of frost protection (targeted microsprayer system) for California grapes is feasible and to determine if this method is less water consumptive than current practices demand. The microsprayer (Wade Pulsator?) being evaluated uses a pulsing action that produces larger diameter droplet sizes, while maintaining lower application rates than those found with conventional microsprayer design. This microsprayer produces a narrow band of water (approximately 0.6 meters wide) directed over the cordon of the vine. Microsprayers were installed in every vine row and mounted 0.56 meters above the cordon on every other stake, approximately 3.6 meters apart. A 2 ha block of microsprayers was compared to an adjacent sprinkler block. The sprinkler block is a typical design and installation for a commercial coastal vineyard. Sprinkler spacing is 15.6 meters X 12.8 meters, using a conventional impact type head and a 2.78 mm nozzle. The water source for both systems was an above ground reservoir filled by pumping ground water. Water was passed through a perforated tube filter for the sprinklers and a sand media filter for the microsprayer system. Water use was measured by a Rockwell sealed register meter. 30 Data collected for the microsprayer and sprinkler blocks were bud temperature, air temperature, and relative humidity. Environmental conditions monitored outside the vineyard were air temperature, wind speed and direction, and relative humidity. Environmental data was collected with Omnidata data loggers using a series of thermocouples for bud temperatures(attached at bud locations) and Psychem RH sensors for air temperature and relative humidity. A data logger and associated sensors were located within the microsprayer and sprinkler blocks and outside the vineyard. Radiational freezing events occurred on 28 April and 14 May 1993. Data collected on these dates suggests that microsprayers were as effective as overhead sprinklers for frost protection. A second year of data was collected during the spring of 1994 to further quantify the level of frost protection provided by microsprayers and the amount of water savings.
/wp-content/uploads/2017/09/AFV-Header-Logo.png 0 0 AVF /wp-content/uploads/2017/09/AFV-Header-Logo.png AVF1993-11-22 15:20:402017-11-22 15:21:44Evaluation of Microsprayers for Frost Protection in California Vineyards