Issue link: http://winesandvines.uberflip.com/i/101495
GRAPEGROWING SOUR shrivel r r andall andall SOUR shrivel tagg tagg Furthermore, the shoots adjoining the shoot with SOUR shrivel on the same cordon may either develop healthy or afflicted clusters. Also, the vines adjacent to the afflicted vine are either free of SOUR shrivel clusters or get affected to a varying degree depending upon the severity of incidence. Irrespective of spatial variation in occurrence, all SOUR shrivel berries are flaccid and soft, their skin wrinkled and pulled away from the receptacle forming deep grooves in the flesh reminiscent of a deflated soccer ball. This is the most characteristic feature of SOUR shrivel, which can be used to distinguish it from other disorders such as bunch stem necrosis. Another interesting feature is that the whole bunch stem appears to be healthy(see photos at right.) The collapsed flesh is responsible for the flaccidity of the berries; despite this breakdown the seeds remain healthy, indicating that SOUR shrivel initiates after veraison. These modifications do not alter the wax (bloom) structure. Even though SOUR shrivel berries have viable seeds, they cannot be used for making wine or any other product due to low sugars. The bunch stem appears healthy (left), but berries with SOUR shrivel resemble deflated soccer balls. Management: Sour shrivel afflicts grape clusters to varying degrees of severity during every growing season. In a given block, yield loss can be up to 50%. A lack of knowledge about causal factors makes it very difficult to manage SOUR shrivel through cultural practices. Since the clusters afflicted with SOUR shrivel are not ever salvageable, the rational course of action to optimally achieve desired fruit and wine quality is to drop the clusters prior to harvest. Bhaskar Bondada is a grapevine physiologist on the faculty of Washington State University, Tri-Cities, with interests in both basic and applied research geared to address industry goals. His particular area of research is integrative plant physiology and plant anatomy, utilizing the knowledge of structure-function relationships to improve vine health and fruit quality. www.atmbl.net 413 St. Andrews Dr. Napa, CA 94558 T: 707.257.3757 F: 707.224.4641 ���Let us take the stress out of your BottLing��� Self Contained Nitrogen Generator (No dewars needed) Touch Dry Ink Case Printing (Saves a person and saves a label) Screw Caps, Corks or ZORKS Nitrodose Easy Dose liquid nitrogen Steam Sterilization���The Four Big ���E���s��� Economy, Efficiency, Effectiveness, Environmental Laser Bottling Coding for Time and Date 98 W in e s & V i ne s JANUARY 20 13 SEE US AT UNIFIED, BOOTH #2610 SEE US AT UNIFIED, BOOTH #917 u