Rick Dunst, Viticulturist, Double A Vineyards, Inc.   Winter injury caused by low winter temperatures is an important limiting factor to grape production in many regions the United States. Our Grapevine Characteristics Chart lists grape varieties by their winter hardiness according to USDA hardiness zone. Hardiness is determined by using a number of sources, including university publications, v...

Rick Dunst, Viticulturist, Double A Vineyards, Inc. After successfully managing a crop to within weeks or even days of harvest, few things can be as frustrating as fruit damaged by birds and other pests.  In addition to direct loss of fruit, bird-damaged fruit is also more susceptible to various fruit rots that can cause off-flavors and other defects in wine.  This article will summarize a few ...

Entire textbooks (or chapters of textbooks, anyway) have been devoted to the topic of pruning, training, and trellising grapevines.  This article will provide a brief overview of the main concepts of pruning grapevines, with emphasis on pruning during vineyard establishment. Dormant grapevine pruning during vineyard establishment is performed annually with two main goals in mind – training the ...

Top Photo Left: ‘Concord’ on TWC; Top Photo Right: ‘Vidal’ on TWC; Bottom Photo Left: ‘Pinot Gris’ on VSP, prior to leaf pulling; Bottom Photo Right: ‘Pinot Gris’ on VSP, after leaf pulling Rick Dunst, Viticulturist, Double A Vineyards, Inc. The production of large crops of high quality fruit requires that grapevines be pruned and trained to produce a large area of healthy leaves exposed to sun...

Rick Dunst, Viticulturist, Double A Vineyards, Inc. This month’s article is inspired by several e-mails and phone calls received over the past few weeks from all over the country regarding yellow jackets in vineyards and how to control them.  Unfortunately, there are no easy solutions to this group of insects, and they can pose a stinging hazard, especially to workers harvesting ripe fruit in t...

Rick Dunst, Viticulturist, Double A Vineyards, Inc. With Jim Kamas, Assistant Professor & ExtensionSpecialist – Pomology & Viticulture, Texas A&M AgriLife Extension Service, Fredericksburg, Texas Grape growers in southern regions of the United States face a potential problem not encountered by growers in more northern regions–Pierce’s disease (PD) of grape.  An excellent resource, P...

Rick Dunst, Viticulturist, Double A Vineyards, Inc. Most grape growers recognize the need to determine the nutritional status of their soil prior to planting, but it is also important to monitor the nutritional status of the vineyard on a regular basis once it is bearing fruit. Ideally, soil and petiole testing are used together to monitor the nutritional status of the vineyard in order to anti...

Rick Dunst, Viticulturist, Double A Vineyards, Inc. Managing disease is a key component to successful grape production. Cultural practices and variety selection can have a large impact on disease pressure and susceptibility, but most grape growers rely, to some extent, on chemical fungicide applications in order to produce disease-free fruit and foliage for the production of high quality fruit ...

Rick Dunst, Viticulturist, Double A Vineyards, Inc. Part I provided an introduction to the major diseases that affect grapes and some options for early season disease control in vineyards. Please refer to that article for links to fact sheets for five major grape diseases – anthracnose, Phomopsis, black rot, downy mildew, and powdery mildew. This article will focus on disease management conside...