Issue link: http://winesandvines.uberflip.com/i/116287
grapegrowing Determining patterns The pattern of symptom expression is often a key to understanding the nature of the disorder. Growers should try to answer these questions: TANK AND BARREL • re leaf symptoms on basal, middle or A apical leaves on a shoot? • re symptoms on exterior or interior A leaves only? • re symptoms on some individual A shoots or on all shoots of a vine? • re leaf symptoms on leaf margins or A some other distinct pattern? • re vines with symptoms clustered A together or scattered throughout the vineyard, or are they just on the edge rows or vines? • re vines associated with any topoA graphic character of the site, such as a swale or hilltop? • hat is the time of year or growth W stage when symptoms appear: spring as shoots are beginning to grow, early summer around flowering time, late summer as clusters begin ripening or fall at or after harvest? CLEANING MACHINES CUSTOMER-DRIVEN SOLUTIONS FOR WINE TANK AND BARRELS • Spend Less Time Cleaning Fritz Westover, Texas A&M University • Use Less Water & Chemicals Environmental disorders include shoot tip dieback caused by drought (top) and oxidant stipple (bottom) caused by ozone. Growers should document their observations with written notes and photographs, especially close-up photos of symptoms. Summary Grapevine disorders can be the result of both biological and abiotic factors. When determining the cause of a disorder symptom in the vineyard, all factors that could contribute to the problem must be • Preserve Product Quality 70 p r acti c al w i ne ry & v i n e yard APRIL 20 13 Fritz Westover, Texas A&M University 604 Jeffers Circle Exton, PA 19341 Tel: 610.408.9940 Web: www.gamajet.com Email: sales@gamajet.com Nutrient toxicities and deficiencies (clockwise from top left): Iron chlorosis on high-pH soil in wet conditions, boron spray toxicity and sulfur burn (bottom two).