The classic American juice-grape cultivar Concord was developed in the mid-1800s in Massachusetts ( Cahoon, 1986 ; Schofield, 1988 ). Its parentage is predominantly the wild northern fox grape ( Vitis labrusca ), but one male grandparent was the
Markus Keller and Lynn J. Mills
James N. Moore, Justin R. Morris, and John R. Clark
Terence R. Bates, Richard M. Dunst, and Paula Joy
Three-year-old field-grown 'Concord' (Vitis labruscana Bailey) grapevines were destructively harvested at eight growth stages during 1998 to quantify growth, carbohydrate distribution, and nutrient concentrations of different organs. The roots were the major storage organ for carbohydrates and nutrients, accounting for 84% of the starch and 75% of nitrogen stored in the vines at the beginning of the season. About 78% of the reserve starch in the vine was used for prebloom root and shoot growth. Early-season fine-root growth was a sink for stored vine nitrogen; however, the fine roots quickly became a nitrogen uptake source, providing at least 84% of the spring growth nitrogen. Total root biomass increased from bloom to leaf fall, but reserve carbohydrates and nutrients lost in the prebloom period did not begin to recover in roots until the end of rapid shoot development in late July. Crop removal at harvest, and a late-season root flush, further increased vegetative carbohydrate and nutrient reserves in the short postharvest period.
Jason E. Stout, Joan R. Davenport, and R. Troy Peters
International Inc., Concord, CA Cuykendall, C.H. White, G.B. Schaffer, B.E. Lasko, A.N. Dunst, R.M. 1999 Economics of drip irrigation for juice grape vineyards in New York State. R. B. 99-01, Cornell University, Ithaca, NY Davenport, J.R. Stevens, R.G. Whitley
J.N. Moore, John R. Clark, and Justin R. Morris
The impending release of a new blackberry cultivar and a new grape cultivar by the University of Arkansas Agricultural Experiment station will be discussed. The blackberry, tested as A-1536, is an erect, thornless type ripening two weeks before 'Navaho'. It produces very firm, highly flavored fruit similar to 'Navaho'. The grape, tested as A-1335, is a blue-seeded juice grape with good adaptation to areas with high summer temperatures where 'Concord' does not ripen evenly. Fresh fruit and processed juice quality has been rated equal to or better than 'Concord' juice for quality attributes.
Justin R. Morris
Interest in grape juice has risen as the public becomes more aware of natural foods and the specific evidence of healthful benefits of grapes. Among major preharvest conditions that influence quality of grape juice are climate, soil, cultivar, vineyard management, and maturity. Each of these factors exerts its own influence, but complex interactions among these factors must be recognized. For mechanically harvested juice grapes, cultivar takes on special importance to quality and yield as do the production system, harvest machines, postharvest handling systems, and processing method. Grape juice composition has been extensively studied, and production and processing methods have improved over the years. The following discussion deals with developments in grape juice production.
R. Keith Striegler, Justin R. Morris, Gary L. Main, Chris B. Lake, Simon R. Graves, Renee T. Threlfall, and Janice M. Blevins
`Sunbelt' is a juice grape cultivar developed by the Univ. of Arkansas. This cultivar produces `Concord'-type juice and is adapted to climatic conditions of the southern United States. Preliminary evaluation showed that `Sunbelt' has potential to produce high-quality juice under the hot climatic conditions of the San Joaquin Valley. A study was conducted during the 1998 and 1999 seasons to further evaluate the adaptation of `Sunbelt' to San Joaquin Valley conditions and determine the response of this cultivar to selected pruning methods. Vines of uniform vine size and vigor were subjected to four pruning treatments: severe hand-pruning (60 to 80 nodes retained/vine); moderate hand-pruning (120 to 160 nodes retained/vine); machine-pruning (160 to 180 nodes retained/vine); and minimal pruning (200 to 400 nodes retained/vine). Vines were trained to a Geneva Double Curtain trellis system. Yield and components of yield were significantly impacted by pruning treatment. In both seasons, mechanized systems of pruning (machine or minimal) produced higher yield than hand pruning. Minimal pruning resulted in the highest yield in 1998, while yield from machine-pruned vines was highest in 1999. Minimally pruned vines had the highest clusters/vine, lowest cluster weight, and lowest berry weight among the treatments. Fruit composition was also affected by pruning treatment. Minimal pruning produced fruit which was less mature than fruit from the other treatments in 1998. This result was likely due to the high yield obtained. Few differences in fruit composition were observed among treatments in 1999. The effect of pruning method on processed juice quality will be presented. Acceptable juice quality was obtained for most treatments.
Kyle E. Bair, Robert G. Stevens, and Joan R. Davenport
Concord grape (Vitis labrusca L.) accounts for a majority of juice grapes produced in Washington State. Because synthetic nutrients are not permissible in USDA organically-certified production systems, legume cover crops are used to supply nitrogen (N) to the crop. In order to supply a sufficient amount of N, the cover crop must successfully establish and produce large quantities of biomass. This study evaluates how the planting date influences emergence and biomass production of hairy vetch (Vicia villosa subsp. villosa L.) and yellow sweet clover [Melilotus officinalis (L.) Lam.] when used as legume green manures. The research was conducted on a commercial vineyard and a research vineyard from 2003–05. Treatments for the study consisted of yellow sweet clover and hairy vetch planted in both the spring and fall. Plots receiving soluble N sources were planted with wheat (Triticum aestivum L.) or rye (Secale cereale L.). Because of the large relative seed sizes of rye, wheat, and hairy vetch compared to yellow sweet clover, these treatments established faster with good stands in 2004. In 2005, clover plots had high emergence and biomass production because of water management modifications. Biomass data from the commercial vineyard in May 2005 indicates that fall-planted vetch produced more biomass than spring-planted vetch. Fall-planted hairy vetch and yellow sweet clover in the research vineyard showed higher biomass production than spring- and fall-planted hairy vetch and yellow sweet clover. When hairy vetch and yellow sweet clover are planted in the fall, they generally have better seedling emergence and biomass production due to the heightened aggressiveness exhibited by competing weed species during late spring and summer.
R. Keith Striegler, Chris B. Lake, Justin R. Morris, Renee T. Threlfall, Gary L. Main, and Simon G. Graves
'Sunbelt' is a juice grape cultivar developed by the Univ. of Arkansas. This cultivar produces 'Concord'-type juice and is adapted to warm climatic conditions of the southern United States. Preliminary evaluation showed that 'Sunbelt' has potential to produce high-quality juice under the hot climatic conditions of the San Joaquin Valley. A study was conducted during the 1998 and 1999 growing seasons to further evaluate the adaptation of 'Sunbelt' to the San Joaquin Valley and determine the response of this cultivar to selected pruning methods. Vines were grown for two seasons without use of insecticides, fungicides, or herbicides. Vines were subjected to four pruning treatments: severe hand pruning (60-80 nodes retained/vine); moderate hand pruning (120-160 nodes retained/vine); machine pruning with hand follow-up (160-180 nodes retained/vine); and minimal pruning (200-400 nodes retained/vine). Vines were trained to a Geneva Double Curtain trellis system. Yield, components of yield, and juice quality were significantly impacted by pruning treatment. In both seasons, mechanized systems of pruning (machine and minimal) produced higher yield than hand pruning. Minimal pruning resulted in the highest yield (42 t·ha-1) in 1998, while yield from the machine-pruned vines was highest (29 t·ha-1) in 1999. Minimally pruned vines had the highest clusters/vine and lowest cluster weight among the treatments. The extremely high yields obtained for the minimal pruning treatments produced fruit that was less mature resulting in juice with lower soluble solids than the other treatments in 1998. However, in 1999 the juice from minimally pruned vines had the highest soluble solids. Sensory analysis of juice produced in 1999 showed that the juice from the machine-pruned treatment had the least color intensity. Sensory analysis showed that minimal and severe hand pruning were ranked higher for sweetness than machine and moderate hand pruning. In the second year of the study, the juice from the minimal-pruned and severe hand-pruned treatment were preferred over the moderate hand-pruned treatment or the machine-pruned treatment.
efforts are needed and potentially could be a worthwhile investment in helping to manage invasive species. American Juice Grapes in a Warming World Increasing growing-season temperatures are challenging for color production by ‘Concord’ juice grapes. In a