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Marlee A. Trandel, Penelope Perkins-Veazie, and Jonathan Schultheis

may contribute to inadequate pollination. Previous studies have reported that watermelon fruit from plantings with lower diploid-to-triploid ratios have a higher incidence of HH ( Fiacchino and Walters, 2003 ; Freeman et al., 2007 ). Generally, any

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D.R. Bergdahl and H.B. Teillon

White pine blister rust (WPBR) (Cronartium ribicola J. C. Fischer) has been present in Vermont and other northeastern states since the early 1900s. The fungus is commonly observed on currants and gooseberries (Ribes L.) every year, but incidence varies on eastern white pine (Pinus strobus L.). Our general impression has been that Vermont has had a relatively low level of infection on eastern white pines; however, we recently found rust incidence in Christmas tree plantings in northern Vermont to range from 10 to 42% (average 20%) based on 721 trees surveyed. Also, in pole-sized stands in southern Vermont, incidence ranged from 12 to 46% (average 32%) and 76% of these trees had main stem infections. In the southern survey, 98% of wild ribes plants had varied amounts of both urediniospores and teliospores. These preliminary survey data suggest that incidence of WPBR may be more significant than previously thought and therefore, additional survey work is needed. We screened cultivars of Ribes for susceptibility to WPBR. Eighteen cultivars were inoculated in the field with a mass collection of aeciospores of C. ribicola. The percentages of leaf area infected ranged from 0 to 49 for the urediniospore stage and from 0 to 55 for teliospores. The gooseberry (Ribes uva-crispa L.) `Welcome' had the highest percentage of leaf area with urediniospores, while black currants (R. nigrum L.) `Coronet,' `Consort,' and `Crusader' had no visible infection. Presently, Vermont has no WPBR regulations. However, previous federal laws did restrict black currant cultivation. Little is known about the genetic diversity of WPBR or its potential for change. Caution must be used when considering any cultivation of Ribes for the purpose of producing fruit because our valued white pine resources could be negatively impacted.

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Mary Ruth McDonald and Sean M. Westerveld

) the effect of seeding date on the incidence and severity of clubroot; 2) the effect of air temperatures, soil temperatures, and rainfall during the growth period on clubroot incidence and severity; and 3) the critical periods for determining potential

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Ed Stover and Greg McCollum

conducted to detect differences in HLB severity and incidence as well as CLas titer among diverse citrus cultivars in extant field plantings known to be affected by HLB to provide guidance in selection of cultivars for long-term field tests. Materials and

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Omar Carrillo-Mendoza, José X. Chaparro, and Jeffrey Williamson

in peach ( Wert et al., 2007 ). A wide range of blind node frequency (0% to 90%) has been reported for the University of Florida peach germplasm, demonstrating that there is genetic variability for blind node incidence, and breeding against this

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Ramón A. Arancibia, Jeffrey L. Main, and Christopher A. Clark

suggested. Ethylene is produced in plants under stress/injury and a previous study has indicated that preharvest foliar applications of ethephon enhance the incidence of a similar disorder in North Carolina ( Dittmar et al., 2010 ). This suggests that

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Corina Serban and Lee Kalcsits

length extension via the application of GA 3 (ProGibb ® ) decreases or increases bitter pit incidence, respectively. This work will provide a greater understanding of the association between shoot extension and bitter pit incidence in ‘Honeycrisp’ apple

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Maude Lachapelle, Gaétan Bourgeois, Jennifer R. DeEll, Katrine A. Stewart, and Philippe Séguin

and Silsby, 1992 ). At harvest, subsamples were analyzed for maturity. After 3 to 4 months in storage, 20 apples per site were evaluated for fruit quality, including incidence of soggy breakdown, whereas the remaining fruit (≈30 per location) were

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Martin M. Williams II, Carl A. Bradley, Stephen O. Duke, Jude E. Maul, and Krishna N. Reddy

Nebraska, Goss’s wilt was observed in additional states across the Plains and the Midwest, which included Colorado, Illinois, and South Dakota ( Wysong et al., 1981 ). Incidence of Goss’s wilt in midwestern states, such as Illinois, continued to be very low

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E. Vanessa Campoverde, Georgina Sanahuja, and Aaron J. Palmateer

weather conditions in high intense production areas of ornamental crops in Florida. This study addresses the incidence of Pythium and Phytophthora affecting ornamental crops and the relationship with environmental conditions such as rainfall, solar