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Thomas J. Zabadal

, Gene Pierce and Eastman Beers for making grapevines available. and the Michigan Agricultural Experiment Station and Cornell Univ. Cooperative Extension Service for their support of this work. The cost of publishing this paper was defrayed in part by the

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Sadanand A. Dhekney, Zhijian T. Li, Michael E. Compton, and Dennis J. Gray

Genetic engineering of Vitis has emerged as an alternative to conventional breeding for the introduction of desirable traits into elite varieties. The routine use of embryogenic cultures for grapevine transformation ( Gray et al., 2005

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Xiaoxu Yang, Yinshan Guo, Junchi Zhu, Zaozhu Niu, Guangli Shi, Zhendong Liu, Kun Li, and Xiuwu Guo

Flavor and aroma compounds belong to the large group of secondary metabolites in grapevine berries ( Lund and Bohlmann, 2006 ). Monoterpenoids are also responsible for aroma development in these berries, with the amount of monoterpenoids present

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Yi Zhang and Imed Dami

). Furthermore, ABA treatment has increased freezing tolerance by reduced intracellular water content to avoid ice formation. Exogenous ABA application to potted grapevines has delayed budburst for spring frost protection but was not effective on field

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Uri Yermiyahu, Alon Ben-Gal, and Pinchas Sarig

Table grape production has recently become popular in arid and semiarid regions where conditions of salinity and excess boron (B) can be prevalent. This study addresses B toxicity in grapevine to define toxicity symptoms and evaluate growth, production, and B accumulation. The effect of excess B on grapevines (Vitis vinifera L. cv. Sugraone) was evaluated in a 4-year study in Israel's Jordan Valley. Vines were grown in 60-L perlite-filled containers and irrigated with complete nutrient solutions with four B concentrations: 0.03, 0.12, 0.21, and 0.31 mm. Vines were monitored for growth, yield, and B accumulation. Boron accumulation in leaves correlated with B toxicity symptoms that materialized as chlorosis and necrosis of leaves beginning at their margins, reduced leaf size, and reduced internodal distance between adjacent leaves. Boron accumulated in grapevine leaves linearly as a function of increased B in irrigation solution with time and with age of leaves. The highest B levels were found at the end of each season and in the oldest leaves. No long-term (multiyear) effect of exposure to B was observed because similar accumulation patterns and levels were found in each year of the experiment. Hence, consistently sampled diagnostic leaves and time of sampling for B analysis is seen to be critical to provide valid comparisons between vines or over time. Boron supply influenced vine growth. At low levels of B (0.03 mm), canopy development was restricted but trunk size was not. At high levels of B (0.21 and 0.31 mm), substantial visual symptoms of B toxicity were observed, and the rate of trunk growth was reduced, but pruning biomass was not influenced. Despite severe visual toxicity damage and reduced overall growth rates, commercial fruit yield of the vines remained unaffected by high environmental B levels.

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N.K. Dokoozlian, N.C. Ebisuda, and R.A. Neja

The effects of surfactants on the efficacy of hydrogen cyanamide (H2CN2) applied to `Perlette' grapevines (Vitis vinifera L.) grown in the Coachella Valley of California were examined in 1994 and 1995. Vines were pruned in mid-December in both years and treatments applied at 1000 L·ha-1 the following day to dormant spurs and cordons using a hand-held spray wand. In 1994, H2CN2 was applied at 0.5%, 1%, or 2% by volume in combination with 0%, 0.5%, 1%, 2%, or 3% by volume of the amine-based surfactant Armobreak. In 1995, H2CN2 was applied at 0.5%, 1%, or 2% by volume in combination with Armobreak at 0% or 2% by volume. In 1994, budbreak rate was highly dependent upon H2CN2 concentration when 0% to 1% Armobreak was used; budbreak was generally most rapid for vines treated with 2% H2CN2 and slowest for vines treated with 0.5% H2CN2. When 2% or 3% Armobreak was used, however, little effect of H2CN2 concentration was observed. Results were similar in 1995, but the budbreak of vines treated with 2% H2CN2 + 2% Armobreak lagged behind that of vines treated with 1% H2CN2 + 2% Armobreak. The number of days after treatment required for 70% bud-break generally declined as the concentrations of H2CN2 and Armobreak were increased. A separate experiment conducted in 1995 revealed that several surfactants varying in chemical composition, Armobreak, Activator 90 and Agridex, had similar effects on H2CN2 efficacy. The results indicate that the addition of surfactants to H2CN2 solutions can significantly reduce the amount of active ingredient necessary for maximum efficacy on grapevines. Chemical names used: hydroxypolyoxyethylene polyoxypropylene ethyl alkylamine (Armobreak); alkyl polyoxyethylene ether (Activator 90); paraffin petroleum oil (Agridex).

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Kang Hee Cho, Jung Ho Noh, Seo Jun Park, Se Hee Kim, Dae-Hyun Kim, and Jae An Chun

Grapevine ( Vitis spp.) belongs to the Vitaceae family and is one of the most economically important perennial crops in the world. The number of global cultivars has been estimated to be between 5000 and 8000 and many have been cultured for several

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Ulrike C.M. Anhalt, Katharina Martini, Ernst-Heinrich Ruehl, and Astrid Forneck

environmental changes quicker than plants carrying only homozygote alleles ( Hansson and Westerberg, 2002 ). Many loci in a continuously asexually reproducing genome such as the vegetatively propagated cultivated grapevine display a high level of heterozygosity

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Nagehan D. Köycü, John E. Stenger, and Harlene M. Hatterman-Valenti

needed for cultivation under these relatively new conditions and with nontraditional grapevine cultivars ( Hatterman-Valenti et al., 2016 ). If left uncontrolled, powdery mildew has been shown to cause premature leaf drop, stop the growth of berry

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Yi Zhang, Tracey Mechlin, and Imed Dami

short growing season. This impacts not only the quality of the fruit and wine, but also the cold acclimation process and ultimately the winter hardiness of grapevines ( Zabadal et al., 2007 ). Freeze protection methods have been developed for grapevines