Progress 10/01/98 to 09/30/04
Outputs
This project has included a wide range of research designed to provide answers regarding adaptation of vinifera grape varieties to NY, identification of best management practices for vinifera grape production and wine quality, and the effect of rootstock on vine growth production and survival. Results will be highlighted. Variety and clone: this project has demonstrated significant differences among clones of Pinot noir and Chardonnay in terms of cold hardiness, disease resistance and wine quality. The research also identified additional vinifera varieties well or marginally adapted to NY. These include Auxerois, Merlot, Sirah, Cabernet Franc, Gamay noir, Dornfelder, Rkatistelli, Rotberger, Lemberger and Viognier. Rootstock: The effect of 23 rootstocks on growth, suvival, yield and wine quality of Chardonnay grapevines was explored. Growers are very anxious to understand the potential of rootstock to control growth vigor. We divided the stocks into 3 vigor categories.
High vigor vines had more than 0.38 kg cane prunings/M of row and included 1202 C, Harmony, 3309 C, MgT 101-14, 125AA, AxR1 and 5BB. Medium vigor vines averaged less than 0.38 and greater than 0.24 kg cane prunings/M of row and included MgT 18-815, Riparia gloire, 44-53, 420A, 333EM, 5A and SO4. Low vigor vines averaged no more than 0.24 kg cane prunings/M or row and included 1616E, Own, 41B, 110R, Sonona, 99R, Riparia Montreal and Shakoka. As a class, vines grafted to high or medium rootstocks had better growth, production and quality than vines grafted to low vigor vines. There were not significant differences in vine or bud hardiness among the classes. In general in years of winter cold injury, larger vines produced more fruit because they produced more buds/vine. However, a high vigor rootstock, 125AA produced vines with greatest winter injury. Once yield effects were eliminated, no rootstock associated differences in wine quality were observed. Training and pruning systems:
Comparisons were made between cane and spur pruning for non-divided, vertically divided (Scott Henry) and horizontally divided (Lyre) trained vines vertically shoot positioned vines. Spur pruned, cordon trained unpositioned vines were also tested. Three varieties, Chardonnay, Cabernet Sauvignon and Cabernet Franc were tested. Greatest yield and cold tolerance was found with Lyre training. Cane pruning tended to produce higher crops than spur pruning, but cordon trained vines had higher yields following winters with bud injury. Scott Henry vines produced high crops in years without cold stress, but had greater injury in cold winters. Non-shoot positioned vines had lowest production cost and almost highest yield. For red wine varieties highest wine quality was associated with Lyre training and from non-positioned vines.
Impacts
Vitis vinifera varieties command the highest prices and are in most demand in New York. Because the number of wineries has increased 5 fold during this project, there is intense interest in methods to grow these varieties. These data are helping growes make the best decision as they plant vinifera varieties.
Publications
- Pool, R., G. Howard, S. Lerch, T. Johnson and D. Weiman. 2005. Relationship between rootstock and growth, yield and cold hardiness of chardonna grapeines growing in finger lakes vineyard with somewhat poorly drained soil and with no initial phylloxer population. Proceeding Finger Lakes Grape Growers Association.
- Pool, R.M. 2004. Vineayrd balance - whtat is it? Can it be achieved? ISHS Acta Horticulturae 640.
- David W. Wolfe*, Mark D. Schwartz, Alan N. Lakso, Yuka Otsuki, Robert M. Pool, Nelson J. Shaulis. 2005. Climate change and shifts in spring phenology of three horticultural woody perennials in the northeastern United States. Journal of Biometeorology. in press
|
Progress 01/01/03 to 12/31/03
Outputs
Our vineyards experienced low temperatures of 25 degrees below zero or more in late winter, 2003. Widespread cold injury caused us to shift cultural practices to maximize crop and minimize future retraining cost. We were able to assess the impact of experimental variables on bud survival and ability to survive cold damage. The following conclusions were obtained: 1. Retaining more than 100 buds/vine resulted in substantial crop in vines with up to 80% bud kill. 2. Pencil diameter canes were not the most cold hardy. Percent bud survival increased with cane diameter, but the vineyard did not contain very vigorous canes. 3. Cane bud break was reduced when a persistent lateral was present. When laterals were spurred, almost twice as many shoots were obtained in comparison to nodes without persistent laterals. 4. Percent bud survival was least at the base of the cane and tended to increase at higher nodes. However, because there were more short canes, hedge spurring to 4
buds or so would result in as many shoots as pruning to a small number of long canes. 5. Low vigor vines and vines growing on low vigor rootstocks had no better survival and lower yield and quality than moderate and high vigor vines. 6. Mid-wire cordon trained vines had relatively good bud survival and yield. Possibly because the buds were higher from the ground and so avoided the very low, near ground temperatures. 7. Lyre training produced highest yield, but the extra costs may not justify its use. 8. Cordons had higher yields than cane pruned vines, but the vines may require more extensive retraining in future years. 9. Gamay noir and the Dijon Pinot noir clones were among the least damaged red wine varieties. 10. Auxerois and the Dijon Chardonnay clones were among the least damaged white wine varieties.
Impacts
This is the first time substantial winter injury has been observed in these experimental vineyards. The observations made were very important. They first demonstrated that normal or near normal crops could be obtained on vines with up to 80% cold, killed primary buds. Secondly they demonstrated a method to handle winter injured Vertical Shoot Positioned (VSP) trained vines which have recently dominated NY premium wine grape culture so as to maximize yield and minimize retraining cost of cold damaged grapevines. We were also able to provide growers with ways to predict which buds or canes are most likely to survive winter cold. There was widespread cold injury in NY vineyards in January, 2004, so these results will find immediate usefulness
Publications
- No publications reported this period
|
Progress 01/01/02 to 12/31/02
Outputs
Data from a trial evaluating impact of rootstock on Chardonnay allowed a vigor rating on impact of rootstock on vines growing in NE soils and climate. Average cane pruning weight (CPW) values, classified stocks as vigorous (CPW greater than 0.4 kg/meter of row); medium (CPW greater than 0.3 and LTE 0.4 kg/meter of row) and low (CPW less than 0.3 kg/meter of row). Vigorous stocks were: MgT 101-14, Harmony, C. 3309, C. 1202, AxR 1, 5BB and 125AA. Medium vigor rootstocks were: SO4, Riparia gloire, MgT 18-815, 5A, 44-53, 420A and 333EM. Low vigor stocks included: Sonona, Shakoka, Riparia Montreal, Own roots, 99R, 41B, C1616E and 110R. Own rooted, Shakoka roots and 41B were unproductive and damaged by Phylloxera (P. vasatrix). Combined effects of high bud fertility, drought stress and insufficient heat reduced vine size after the 2000 growing season. The subsequent season had lower than average crop size and excellent growing conditions leading to dramatic increases in
vine size. The increase was generally related to vigor classification with a few exceptions. Of high vigor stocks, C. 3309, MgT 101-14, AxR 1, and Harmony were less inclined to overvigor. SO4 and 44-53 were most stable of the medium vigor stocks and 110R was most stable of low vigor stocks. High vigor vines were able to recover full productivity more quickly than the other rootstocks following severe winter damage. High vigor vines produced more fruit than low vigor vines, but not more than moderate vigor vines. This was because fruitfulness per node was lower in high vigor vines. Low vigor vines not only had reduced yield, but also delayed maturity. There was no evidence that vigor was related to dormant bud cold hardiness. Investigations into impact of crop adjustment on grape and wine quality of Pinot noir and White Riesling grapes were continued. For Pinot Noir in 2002, crop ranged from 5.7 to 9.5 Tonne/ha. Early post-fruit-set adjustment had less impact on final crop weight than
post-veraison adjustment, but did not further increase fruit soluble solids at harvest. Tasting results from 2000 and 2001 wines indicated that crop adjustment had a very favorable impact on wine quality in the very cool year, 2000, but little impact in the warm 2001 season. White Riesling yield ranged from 7 to 14.4 Tonnes/ha. Maturity was advanced only by the most severe thinning (1 cluster/shoot). Wines were made, but will not be evaluated until later. Because wines are sold at a range of price points, an understanding of the quantity/quality relationship is critical. These data suggest that severe crop adjustment is only justified for super premium Pinot noir wines. Previous studies showed that the primary difference between cluster rot susceptible and resistant Pinot noir clones is cluster compactness. We have been evaluating cultural practices which might impact flower or berry set. Retaining extra nodes or clusters until after berry-set did not reduce final compactness, nor did
reducing leaf area before bloom. Brush thinning of flower clusters as is done with table grapes was the only non-chemical method which affected cluster compactness. The economics of this treatment should be evaluated.
Impacts
Primary expansion of north-east vineyards is premium, European grapes. There has been little information available on the relative impact of grape rootstock on vine growth in the soils and climate of the north-east. This data will allow growers to make better decisions when planting new vineyards. Bunch rot is a very serious problem with Pinot noir, making the wine unmarketable. The development of a non-chemical strategy to reduce incidence will be very valuable.
Publications
- Pool, R.M. 2002. Vineyard Balance - What is it? Can it be Achieved? Proc. World Hort. Cong. Toronto, Acta Hort. in press.
|
Progress 01/01/01 to 12/31/01
Outputs
Rootstock Research. Data for 12 years regarding impact of rootstock on Chardonnay was summarized. Impact on vigor was determined by mean cane pruning weight. Stocks producing large vines were: 125AA, A x R 1, C. 1202, C. 3309, Harmony, and MgT 101-14. Medium vine size was associated with: 333EM, 420A, 44.53, 5BB, MgT18-815, R. Gloire and SO4. Small vines were produced by: 41B, 5A, 99R, Own, R. Vine size category averages showed no significant relationship between category and live nodes/vine. Small vines had fewer clusters, smaller berries, lower yield and lower soluble solids than medium or large vines. Except for juice soluble solids, there has been no consitent effect of vine size on fruit composition. Training system: Impact of training system components on bud hardiness of Chardonnay and Cabernet Franc was measured using DTA. No differences in bud freezing temperature were observed between buds formed on VSP, Scott Henry, Lyre or Tee Trellises. No consitent
impact of spur vs. cane pruing was observed. Red wine quality was more affected by training system than was white wine quality. Wines from Scott Henry and Lyre trained vines were most appreciated. Effect of time of crop adjustment on cluster compactness of Pinot Noir. It has been suggested that post-fruit-set crop adjustment will reduce flower-set, cluster compactness and bunch rot. Our data did not support that concept. Effect of time and amount of crop adjustment on wine quality of Pinot noir. Best wines were obtained when vines were thinned to 1 cluster/shoot after fruit-set or after veraison. Selective and variable post-veraison thinning based on cluster appearance also resulted in substantial wine improvement with less cost and greater vine yield. Crop prediction of intensly manged Pinot noir vines using historical yield and cluster size data was able to predict final crop size within 2%. Vinifera cultivar and clone testing. New plantings included 26 red cvs. and clones.
Impacts
Premium wine grape acreage is increasing rapidly in New York. Data on impact of rootstock, variety, clone and appropriate training system is vital to continued succes of the premium wine industry. Use of non-chemical methods to decrease disease incidence is highly desired. Entry into the super-premium wine market will depend on improved fruit and wine quality.
Publications
- Pool, R. M. 2001. Grape Production in New York State. Academie Suisse du Vin. 39:67-72
- Lakso A.N. and R.M. Pool. 2001. The effects of water stress on vineyards and wine quality in eastern vineyards. Wine East, Nov-Dec;12-20.
|
Progress 01/01/00 to 12/31/00
Outputs
Regional Tests of V. vinifera clones were initiated with grower/cooperators in NY, PA, and OH. Coordinated evaluation with other experiment stations were established in PA, OH, MI and Ontario, Canada. First plantings emphasized Pinot noir and Chardonnay clones. Training Systems for V. vinifera wine production using Chardonnay, Cabernet Sauvignon and Cabernet Franc showed that: 1. Cordon vines have higher pruning weights than cane pruned vines. 2. Divided canopies had higher percent bud kill, but greater total bud survival than non-divided canopies. 3. Cluster weight is lighter and percent fruit rot is higher on the Tee than on the other trellises. 4. Lyre trained vines had more clusters per vine and higher yield than other vines. 5. Preliminary results indicate profound training system impact on red wines and lesser impact for Chardonnay. Wines from Lyre trained vines were most appreciated; those from Tee least. Effect of crop load on Pinot noir wine quality was
investigated by imposing three crop levels at two fruit development periods using two selection strategies. Yield in 2000 was 2.2 to 4.1 tons/acre. There were few differences in the standard fruit quality parameters. Wines have been made and will be evaluated after one, 2 and 3 years of age. Effect of rootstock on Chardonnay Consecutive summers of below average rainfall demonstrated that different rootstocks react to drought differently. Vegetative growth, crop size and crop maturity are all affected by drought. Drought tolerance was estimated based on degree to which an individual stock was able to sustain these three yield components. Highly drought tolerant stocks included: 5 BB, 99R, Shakoka and 420. Stocks with moderately high tolerance were Riparia Montreal, C. 1202 and SO4. Moderately resistant ratings were given to C. 3309, 125AA, MGT 101-14, 333EM and Harmony. One stock, 110R was rated moderately low, and A x R 1, C1616E, 41B, MGT 18-815, Own roots and Riparia Gloire had a
low tolerance rating. Sonona was rated as having very low drought tolerance. Remote sensing. Multi-spectral images of commercial vineyards were used to detect vine stress. Riesling grapes harvested in 1999 from stressed vineyard sections made wines which developed the stress related wine disorder, Atypical Aging (ATA). Those from non-stressed symptoms had no ATA character. Chardonnay wines did not demonstrate ATA symptoms by the end of 2000. Images were also used to separate vineyards into regions of high and low water content. Soil and petiole analysis showed that uniform application of K resulted in uniform soil K, and sufficient K in all vine petioles. However, vines in higher water content vineyard sections developed Mg deficiency as a result of high K availability.
Impacts
Our long term research evaluating the vineyard and winery potential for Pinot noir clones has motivated commercial planting of desirable clones. As a result a new association of wineries, The Finger Lakes Pinot Noir Alliance, was formed by 19 wineries. The Alliance has the goal of identifying vineyard and cellar practices required to produce ultra-premium Pinot noir wines. The Alliance invited a group of wine makers from Burgundy, France, to evaluate our Pinot noir wines. They indicated that wines made from the best clones produced wines in the Finger Lakes whose quality is comparable to the best from France. Because of the introduction of superior varieties and improved cultural practices wine quality from farm wineries has greatly improved. In turn the number of wineries in New York has increased 10 fold. Essentially all new vineyard plantings are of varieties and clones which were identified from our research program. The vineyards are using production methods
based on our research results. A side benefit is the increased economic viability of small (less than 50 acre) farms, and the development of important tourist related business in the wine districts.
Publications
- No publications reported this period
|
Progress 01/01/99 to 12/31/99
Outputs
In spite of successive seasons of water stress, vine size of `Chardonnay' increased for all but 4 of 23 rootstocks. Rootstock effect on mid-winter primary bud freezing temperature was evaluated. Median freezing temperature ranged from -21.0 C. to -23.2 C. In general, lower vigor was associated with greater bud cold hardiness, but there were several major exceptions. Buds from `Chardonnay' grafted to `Sonona' and `110 R' had low cold hardiness in spite of low vigor. Buds from `125AA' grafted vines were among the most cold hardy although vine size was second largest. There was no relationship between vine size and yield. There was less variation in yield than vigor. Wines made from differently trained `Chardonnay' vines revealed a relationship between fruit sun exposure and wine quality. VSP and Lyre training produced superior fruit to California Tee training. Eight clones (3 `Chardonnay', 5 `Pinot noir') and 3 other varieties were selected for expanded commercial
testing throughout the north-east region. There was relatively little variation in bud hardiness of `Chardonnay' clones (-21.1 C to -23.2 C) and much more for `Pinot noir' clones (-20.8 C to -24.2 C). Variety tests identified several as or more cold hardy than `Cabernet Franc'. Two of these (`Viognier' and `Syrah') also produced superior wines and will be included in regional commercial trials. Image analysis and remote sensing was used to classify vine stress. Separate wines of `Chardonnay', `Cabernet Sauvignon' and `White Riesling' were made using fruit from stressed or non-stressed vines. The relationship between vineyard stress and the development of the ATA (atypical aging) disorder will be investigated.
Impacts
New and expanding wineries are among the few growth areas in NE agriculture. Continued growth is dependent upon learning which premium varieties can be grown in the region and determining culture methods to optimize wine quality potential.
Publications
- Keller, M., R. M. Pool and T. Henick-Kling. 1999. Excessive nitrogen supply and shoot trimming can impair colour development in Pinot Noir grapes and wine. Australian J. Grape and Wine Research 5;45-55.
|
Progress 01/01/98 to 12/31/98
Outputs
Irregular grape (Vitis) flower set has been a New York industry problem, especially in machine pruned vineyards. In a multi-year test of stress factors, crop, irrigation, thinning, mulch and defoliation did not interrupt the yearly alteration in set. Only reducing shoot number was effective. Thus it appears that competition between developing flowers and shoot growing points for a nutrient or growth regulator is responsible for poor flower development. A long term study evaluating the effect of different levels of between-the-row grass cover and irrigation on Concord grapevine growth and yield was terminated. There was a negative linear relationship between vine vegetative growth and percentage grass cover. This resulted in reduced crop size. Irrigation increased vegetative growth and crop size, but there was no interaction between the two factors. In a year where there was neither cold nor crop stress, training system still had a major impact on yield and maturity of
V. vinifera grapevines. Well adapted varieties produce satisfactory crop and quality with simple cordon systems, but winter tender varieties require divided canopies and cane pruning. Differences in vine size among rootstocks is declining, except for own rooted vine where phylloxera is causing stress. Important quality differences in wine quality and character were noted among Chardonnay clones. Recently imported clones from Burgundy produced very distinctive wines.
Impacts
(N/A)
Publications
- No publications reported this period
|
Progress 01/01/97 to 12/31/97
Outputs
Irregular grape (Vitis) flower set has been a New York industry problem, especially in machine pruned vineyards. Two on-going experiments clarified causation. In a test of stress factors, crop, irrigation, thinning, mulch and defoliation did not interrupt the yearly alteration in set. Only reducing shoot number was effective. Thus it appears that competition between developing flowers and shoot growing points for a nutrient or growth regulator is responsible for poor flower development. Studies of cereal rye and ryegrasses did not reveal any direct effect on vine growth, and these two weed suppressants appear to be suitable for use in vineyard cover crops as an adjunct or replacement for herbicides. Maximum short and long term vinifera yield has been obtained with vertically divided vine training systems. This is due to increased light interception, more total vine growth and a greater number of nodes produced. The last item means that although percent winter cold
damage is the same, divided canopies have more surviving nodes. Differences between vine size of Chardonnay grafted to different rootstocks were less in 1997. The industry standard, Courderc 3309, was as vigorous as any of the 23 rootstocks being evaluated. New York industry has reviewed performance records of Pinot noir clones and selected the following for cooperative testing: Dijon 113, FPMS 29, Clone 7, Mariafeld.
Impacts
(N/A)
Publications
- Smith, R.L., R.M. Pool, A.D. Fendinger, J. Barnard and T.E. Acree. 1997. Effects of crop load on the flavor character of Concord grape juice determined by descriptive sensory analysis. Proc. 4th. In. Symp. Cool Climate Viticulture & Enology. IV-24-28.
- Wantanabe, J., R.M. Pool, K.N. Wantanabe. 1997. The evaluation of an optical method to estimate leaf area of grapevines. J. Japan Soc. Hort. Sci. 66: 235-244.
- Fendinger, A.G., R.M. Pool, R.M. Dunst and R.L. Smith. 1997. Effect of mechanically thinning 'Concord' grapevines on fruit composition. Proc. 4th Int. Symp. Cool Climate Viticulture & Enology. IV-218-223.
|
Progress 01/01/96 to 12/30/96
Outputs
Sunny 1995 weather resulted above average bud fruitfulness in 1996, challenged traditional experiment methods in crop prediction and adjustment. Balance pruning and mid-season crop estimated plus machine thinning produce lg. crops which matured. Pruning to set node or cane no. results in severe over crop and failure to ripen fruit. Close canopy space increased vine capacity. Canopies separated by 2.7,1.8 and 1.4m ripen to 34,42 and 48 T/ha respectively. No effect if 1.4m space canopies were created by reducing distance between rows or trained to Geneva Double Curtain. Alternatives to soil active herbicides for vineyard floor mgt. were explored. New labels allow control weeds using shortlived postemergent herbicides w/results equal or better than conventional reliance on diruon and simazine. 2nd exper. explored the extent cover crops compete w/vines and how much competition is for water rather than vine need. 1st year was inverse yield relationship between percent
cover and yield. Only component affected-berry size. Irrigation provides growers w/alternatives to herbicides and reduce their vulnerability to variation in rainfall. Wine evaluation of vinifera varieties and clones resumed. 1st wines made from new Chardonnay clones, untested V. vinifera varieties and Pinot noir clones. Rootstock research did not demonstrate any rootstocks superior to C.3309. Lyre training increased yield of Chardonnay, Cabernet Sauvignon and Merlot due to node number, not enhanced node survival.
Impacts
(N/A)
Publications
- Dunst, R.M., Pool, R.M., Kamas, J.S. and Fendinger, A.G. 1995. Development of a postemergence vineyard weed management program. Proc. NEWSS 49:121-125.
|
Progress 01/01/95 to 12/30/95
Outputs
Close row spacing increased yield, effective LAI and light interception of Concord grapevines, but only with lighter pruning. Low 1995 yield of minimal pruned vines was due to high 1994 water use. Yield/quality relationships show increased vine capacity with close row spacing. GDC training also produced high yield. A companion experiment was terminated because equipment was unable to control disease; yield potential was limited by disease rather than light. Crop load impact on fruit color, soluble solids and acidity was the same for minimal/machine thinning and conventional pruning. Demon LAI meter predictions of vine capacity at thinning time combined with cluster number predicted total fruit soluble solids/vine production with an r-squared of 0.89. Killed rye cover crops reduced competition and water use between bloom and veraison resulting in increased yield of no-till vines. Chardonnay vine size varied from 20 to 180% of that of own rooted Chardonnay in an
comparison of 23 rootstocks. Small vine size hastened leaf senescence and periderm initiation, but not fruit maturity. Only vines grafted to a Vitis riparia selection from Quebec, Canada, induced early Dec. cold hardiness, but small vine size, Nov. hardiness and node survival following -27 C in January were correlated for 15 of the 23 stocks. Lyre training produced largest, but not excessive crop size for Chardonnay, Merlot and Cabernet Sauvignon grapes. A test winter validated differences in cold hardiness of Pinot noir clones; FPMS 29 c.
Impacts
(N/A)
Publications
|
Progress 01/01/94 to 12/30/94
Outputs
Cold survival, acclimation and rootstocks. Rootstock did not significantly affect winter cold acclimation, but early acclimation resulted in greater survival of Chardonnay grafted to rootstocks. Survival on two late acclimating stocks was high indicating at least two hardiness mechanisms. Following -27 degrees Centrigrade in Jan. highest Chardonnay survival was on C.#3309, Mgt 101-14, C. 1202 and Sonona rootstocks (>50% normal crop). Lyre trained vines had highest yield because of more nodes not greater hardiness. Mechanization and crop control. For the 15th consecutive year minimal pruned vines produced high crops of commercial quality fruit. Concord berry development curves confirmed their validity as a basis for mechanized crop prediction and adjustment. Following preliminary commercial evaluation in 1993, crop estimation protocols were widely and successfully commercially applied in 1994. Narrow row spacing. Narrow rows produced higher crops and more total soluble
solids, but only with light pruning. Machine thinning resulted in the same fruit soluble solids and color as hand thinning or severe pruning. Organic viticulture - A five year project showed that fruit can be commercially produced with organic methods in New York's climate, but yields are lower and cost of production higher compared to standard techniques. Reduced yields reflect poor weed management.
Impacts
(N/A)
Publications
|
Progress 01/01/93 to 12/30/93
Outputs
Mechanization - Poor 1992 weather allowed evaluation of minimal pruning as a wayto achieve proper crop. Both minimal and balance pruned vine yield was down 30 percent in 1992, but minimal pruning produced twice the fruit. Berry development curves were used to predict and adjust final crop in mid-season with a high degree of accuracy. Spacing - Small scale experiment showed that narrow rows out yielded both conventional and GDC vines in the third year. No benefit was observed with large scale plantings, probably due to poor disease control because of lack of suitable spray equipment. Two optical methods of leaf area development were tested and shown to reliably estimate leaf area index of grapevines. Floor management - It was observed that chemical and non-chemical control methods achieve similar levels of season long competition. Period of competition during the season differs among systems. Non- chemical methods provided minimal competition during fruit
ripening and chemical methods during berry development. Clones - Winter injury associated with poor 1992 growing conditions confirmed differences in cold hardiness among clones of Pinot noir. Jackson (FPMS 29) and Geneva were the most cold hardy clones tested. Cold Hardiness - Acquisition of cold hardiness by accessions of V. riparia originating throughout its natural range and growing at Geneva was evaluated. Accessions from extreme northern range were first to achieve maximum hardiness.
Impacts
(N/A)
Publications
|
Progress 01/01/92 to 12/30/92
Outputs
COMPETITIVE PRODUCTION: Narrow row/mechanized production plots showed crop related reduced quality and return yield. Mechanical thinning was added to the test, and showed 20-30 days after bloom suitable. Minimal pruning does not alter shape of berry growth curve, just final size. Hence can be used as part of machine thinning decision. Optical estimations of leaf area index were as good as components of yield in predicting best crop. Mepiquat-Cl response was independent of pruning wt and node number. Continued use did not reduce capacity of Concord vines. COLD HARDINESS: Rate of hardiness acquisition is critical. With National Grape Repository at Geneva, we evaluated fall phenology and monitored acclimation with DTA of clinal V. riparia and rootstocks. Northern accessions had early senescence, periderm, growth termination and hardiness. Best acclimation rate of V. riparia was north central>north-east = south>mid-central. Rootstocks were late acclimates. Rate was
related to known rootstock field hardiness; no correlation between rootstock acclimation rate and scion hardiness was established in first year. LISA: Third organically managed crops were harvested at a profit. Production cost was higher for organic grapes. Success with non-chemical weed burner encouraged field testing as replacement for paraquat. Floor management systems (10) were successfully established and will be used to evaluate impact on growth, yield and water consumption by a Concord vineyard.
Impacts
(N/A)
Publications
|
Progress 01/01/91 to 12/30/91
Outputs
Mechanization: Experimentation with minimal and hedge pruned systems have showed minimal pruned vines gave greatest overall yields. Greatest combined impact was the use of cloe horizontal top cuts on non shoot-positioned vines. Minimal pruned, non-thinned systems on inter-row layered high density vineyards gave excessive yields, emphasizing the need for identifying thinning requirements on high density plantings. Cold hardiness: The wintr tolerance of 2 Vitis vinifera varieties grafted on 5 rootstocks and 5 clones of Pinot Noir grafted on 1 rootstock; all of the Clonal Repository for Apples and Grapes were evaluated at various winter time periods using differential thermal analysis (DTA). In late January the range of median LTE temperature for the pinot accessions were: Portugeeser Blauer (-25.0 C), Clevener Mariafield (-23.8 C), Blauer Spate Burgunder (-23.8 C), Gamay Beaujolais (-23.0 C), Pinot Meunier (-24.9 C). In late January there were no differences between
treatments in LTE temperatures in either the variety Riesling or Chardonnay grafted to 5 different rootstocks. Lisa: In 1990 a project to assess the impact of conversion to organic viticulture was begun. In the second year, early indications of nitrogen deficiency were corrected by a heavy application of a pelleted chicken-manure product in early May. The lower yield levels of the organic plots suggest that the increased competition from weeds between the rows emphasize the need for less competitive cover crops.
Impacts
(N/A)
Publications
|
Progress 01/01/90 to 12/30/90
Outputs
MECHANIZATION: Five years experimentation with minimal and hedge pruning systemsshowed minimal pruned vines gave greatest overall yields and fruit reached commercial maturity in each year. Drought had equal impact on yield of conventional and hedge pruned vines, but stress was expressed one year later with conventional vines. Various hedging systems combined with shoot positioning were tested in an attempt to decrease crop and increased fruit soluble solids to levels similar to balance pruning. Greatest combined impact was the use of close, horizontal top cuts on non-shoot positioned vines. Mechanical thinning was as effective as pruning in enhancing soluble solids, but greatest need is for variable thinning. Immediate emphasis will be on image technology capable of identifying thinning need. COLD HARDINESS: The USDA survey of mid-winter hardiness was completed. Species (39), rootstocks, American wine and table, V. vinifera and interspecific wine accessions of
the Clonal Repository for Apples and Grapes were evaluated using DTA. A total of 251 accessions were evaluated. Greatly fluctuating temperatures during Jan, Feb and Mar allowed assessment of de- hardening. In Jan there was little de-hardening, but it increased as winter progressed. Even in late spring de-hardened buds were able to re-gain hardiness upon exposure to sub-freezing temps. LISA: A 5 year project to assess impact of conversion to organic viticulture was begun.
Impacts
(N/A)
Publications
|
Progress 01/01/89 to 12/30/89
Outputs
MECHANIZATION: Two years of drought challenged the ability of minimal pruned grapevines. Sites with deep soils provided sufficient moisture to maintain productivity. Minimal pruned, non-thinned vines on sites with shallow, non-uniform soil did not mature fruit and had reduced vine and root size after stress year 1. They showed low return crops and reduced vegetative growth in year 2, but increased vine size in spite of continued stress. Machine thinning allowed maintenance of productivity of minimal pruned vines. Number of periderm covered nodes measures capacity of minimal pruned vines. Use of inter-row layers to create a high density vineyards successful. Two new, experiments were created to investigate the potential for commercial conversion of existing vineyards. COLD HARDINESS: Efficacy of differential thermal analysis (DTA) to assess cold hardiness of grape buds was established when the technique accurately forecast damage following an early December 1988
cold event. DTA is being used to assess hardiness of the germplasm collection. Field injury to 200 accessions were made and DTA done on those with less than 50% injury. The 95 tested accessions included vinifera, French- American hybrid and American wine, table and rootstock cultivars as well as 14 species. Range of observed median LTE temperature were: rootstocks, Sonona (-31.2!C) to Millardet 219A ( -24.3!C); species, V. riparia (Pulliat) (-31.9 C) to V.
Impacts
(N/A)
Publications
|
Progress 01/01/88 to 12/30/88
Outputs
Shoot topping increases set and berry number while reducing vine size. On undercropped balance pruned vines, topping also increases yield. With hedged vines shoot topping with increases set but not yield. Topping may be useful for Concord table grape production. Niagara vines are more severely impacted than Concord by first year overcropping. Applying alternate crop control techniques allows high crops, high quality and good node survival on hedged vines. Thinning is beneficial for minimal pruned Concords in years when water and ozone stress are high. Minimal pruned Geneva Double Curtain trained Concord vines require cuts made on and inside the cordons and shoot positioning. Machine pruning without follow-up is suitable for vigorous, but not low vigor French-American vines which must have follow up node or crop adjustment to maintain productivity. Machine thinning does not increase berry damage and decreases incidence of bunch rot. The exception is Cayuga
White. Fruit quality and composition is similar between hand and machine thinned vines at the same crop stress. The improved mechanical shoot positioner produced damage and layers of leaves values similar to hand positioned vines. Clonal evaluations of Pinot noir showed significant differences between clones in terms of bud survival, crop, bunch rot and fruit maturity. To date best performance has come from Swiss selections. Leaf removal was as effective as botrytis fungicide treatment to prevent bunch rot of Chardonnay.
Impacts
(N/A)
Publications
|
Progress 01/01/87 to 12/30/87
Outputs
MECHANIZATION: Minimal pruned and machine thinned Concord grapevines entered their second year. Return bloom indicates desirability of 2 rather than 1 pruning cut, but satisfactory crop potential was retained on all treatments. Machine thinning soon after set does not control crop. Very late thinning reduces crop, but does not result in increased fruit maturity. Comparison of vine separation at 2.4 vs 7.3 m significantly altered nodes and clusters/vine but, because of cluster wt. compensation, did not alter yield. Dormant hedge pruning was able to produce crops similar in yield and brix to balance pruned vines. Both bloomtime summer pruning and daminozide treatment altered berries/cluster but not yield. Machine pruning alone produced acceptable crop size of Aurore and Cayuga White, but not Seyval. Combinations of hand or machine thinning produced acceptable sugar levels on machine pruned hybrid vines. Machine thinning hybrid grapes produced increased sugar,
bruising and botrytis. Except with Cayuga White, unacceptable damage was only obtained with excessive thinning speeds. Close in-the-row vine spacing decreases wt. prunings/vine but increases wt. pruning/m canopy and so does not reduce vigor. Summer pruning or basal leaf removal did not alter crop or cold hardiness, bird damage was increased and botrytis reduced on leaf removed vines.
Impacts
(N/A)
Publications
|
Progress 01/01/86 to 12/30/86
Outputs
Mechanical Pruning: American grapes: Attempts were made to use mechanical means to thin the buds, shoots, flowers, berries or clusters of minimal pruned Concord vineyards. Horizontal and vertical stroke harvesters were evaluated for efficacy and vine damage. Controlled thinning of shoots, berries and cluster pieces, but not of buds or flowers was obtained. Greatest crop control and lowest vine damage was obtained with early berry thinning. Excessive machine speed resulted in low crop and reduced vine growth. Properly timed thinning gave good crops of well matured fruit. French-American grapes: Three mowing heights were used on Seyval and Cayuga White vines. Crop was controlled by mowing height alone with cordon trained Cayuga White but not with Seyval vines. Mowing combined with limited hand flower cluster thinning gives satisfactory crop control for Seyval. Mechanical thinning: Machines were used to berry thin De Chaunac, Foch, Baco noir, Seyval and Vidal
vines. They differed in sensitivity to harvestor aggressiveness. De Chaunac was sensitive and Seyval and Vidal resisted damage. Crop was reduced and maturity increased on machine thinned vines. Most damaged berries mummied or abscissed, but a few were bruised and failed to mature normally. Wounding berries at different times showed that pre-veraison berries only became Botrytis infected when inoculated with spores. The data encourage further experiments, but long term effects on vine size, productivity and cold hardiness must be assessed.
Impacts
(N/A)
Publications
|
Progress 01/01/85 to 12/30/85
Outputs
Shoot positioning Concord grapes: Successful positioning involves 3 factors. 1) Shoots must be positioned before tendrils become attached. 2) Shoots should be strong enough to withstand stress of positioning, and 3) They must be long enough to remain positioned once moved. Shoot characteristics (detachment force, length, leaf area, base area, node and internode diameter, divergence angle and plastochron index) were followed for a 6 wk period around bloom and compared to internal anatomical changes. All except divergence angle were highly related to attachment. Secondary vascular development in the cane and shoot were related to attachment. Lignification in the former bud gap was a late and important event. Near bloom positioning is needed to avoid tendril attachments, but should not be before bloom-10 days. Shoots do not stay positioned until 20 days after bloom. Thus at least two positionings must be done at bloom and 20 days later. Weak shoot attachment at
bloom restricts ability to machine position them. Alar & mepiquat-Cl: Efficacy in increasing set and yield was compared over a 2-year period on large and small, balance pruned Concord grapevines. In year 1 both increased set and yield regardless of vine size. In the year 2, vine size changed and simple treatment comparisons did not reveal yield increases. There were significant linear relationships between yield (and set) and concentration both years. Pix is effective both at bloom and fruit-set while Alar timing must be precise.
Impacts
(N/A)
Publications
|
Progress 01/01/84 to 12/30/84
Outputs
Summer pruning: Ethephon or shoot tip removal primarily influenced vegetativegrowth, basal leaf senescence and cluster exposure. Lateral shoot removal impacted cluster exposure, canopy density and leaf senescence. Basal leaf removal greatly reduced bunch rot. Yield and node survival were not altered. Cold injury was lowest on the sparse canopy produced by combined lateral and shoot tip removal. Mechanical shoot positioning works well on small but not on large vines. Yields were 2.5 tons/acre and 36 g/node higher on hand than on machine positioned large vines. Shoot breakage in the renewal zone occurs at the bloom positioning, because lignification through the former leaf gap is not yet complete. Attachment strengths are not exceeded when force is applied later than first bloom plus 3 days or applied beyond node 2. Renewal zone shoot bases are within or below 10 centimeters of the cordon. We have been using incorrect timing. Layers of leaves above the cordon
measure renewal zone shading. Hand as opposed to machine positioning reduced layers (2.7 vs 4.2 layers) but the value after proper hand positioning was 0.8 layers. Altering machine placement at time 1 and improving timing may lead to satisfactory machine shoot positioning of large Concord grapevines. Alar registration may be lost and mepiquat-Cl (Pix) is a potential replacement. In comparisons on 2 vine sizes, Alar gave highest yields but timing was critical. Pix increased yield at all times and vine sizes. Pix may substitute for Alar.
Impacts
(N/A)
Publications
|
Progress 01/01/83 to 12/30/83
Outputs
Preliminary experiments which showed that summer pruning in combination with ethephon treatment resulted in a cessation of shoot growth and a slight increase in cold hardiness encouraged expansion of that work. In 1983, summer pruning resulted in less bunch rot and higher brix of young White Riesling vines. Hardiness and yield effects will be monitored. The role of N nutrition in growth and yield of cold tender varieties is being studied as is the rootstock interaction with N. First results indicate a possible delay in stage 1 hardiness as a result of enhanced N status. Studies on factors associated with breakage during mechanical shoot positioning of Concord shoots revealed a relationship between phenology, shoot length, area of shoot base and detachment force. Also important was site of force application. It appears that breakage is associated with delayed secondary cambial activity and lignification in the leaf gap of the previous year. The results help
explain the excess breakage encountered on large vines and suggest alternative strategies for the obligatory early bloom positioning. Mepiquat-Cl continued to enhance fruit set. In light of the RPAR status of Alar, this may be important. Post-veraison enhancement of rate of Concord sugar accumulation in response to Mp-Cl was not confirmed with whole vine treatments or cluster dipping experiments on 8 other varieties.
Impacts
(N/A)
Publications
|
Progress 01/01/82 to 12/30/82
Outputs
The differential propensity for and sensitivity to overcrops of wine varieties was evaluated. It appears that crop of Aurore vines can be controlled by pruning level alone. Satisfactory crops, survival and quality can only be obtained on De Chaunac with cluster thinning to 1/shoot. With Seyval, thinning to less than 1 cluster/shoot is necessary. Studies on the leaf area requirement of Seyval in relation to crop load indicate that at least 4 shoots/30 cm of row are required to obtain reasonable trellis fill. Proper crop is obtained with about 17 clusters per 0.5 kg prunings (8 clusters per 30 cm of row). Second crop and bunch rot is reduced by cluster as opposed to flower cluster thinning. Cluster exposure to the sun results in higher soluble solids and lower acidity. Low renewal zone training systems such as Kniffen, Moselle, Guyot or low cordons result in less sun exposed Seyval clusters. The relationship between vine size as influenced by rootstock and winter
cold injury was assessed in a non-stress year and shown to be less important than in a year of severe cold stress. The use of growth contolling agents in preventing excessive sucker elongation and poor winter survival of replacement trunks was tested. The use of bloom-time ethephon increased trunk survival, but the viticultural significance is doubtful. Application of Pix to Concord gave as good response as did the standard Alar treatment, but offered more flexibility in terms of timing.
Impacts
(N/A)
Publications
|
Progress 01/01/81 to 12/30/81
Outputs
Severe winter injury allowed evaluation of experimental parameters on survival. The relationship between vine size and cold hardiness confirmed that small vines are hardier. With a vine size range 0.1 to 2.3 kg/vine on differing stocks, there was a highly significant negative correlation between size and percent bud survival. However, because large vines had so many buds, large vines (White Riesling on Baco rootstock, 10.6% live nodes) averaged 4.5 kg/vine fruit while small (White Riesling on Elvira stock, 20.2% live nodes) vines averaged only 2.9 kg/vine. The vine size-survival relationship was constant among stocks, but vines that are small because of nutrient or pathogen limitations have a lower survival rate than vines from healthy but equivalent size vines. Following three years of "hedging" (minimal pruning) there were no significant differences in yield or fruit maturity in comparison with balance pruned Concord vines. When powdery mildew diseased were
compared with healthy vines of Rosette, yield was reduced by 65% and bud injury was increased by 100%. Wine from infected vines had off flavors. Winter injured trunks may die or partially or wholly recover. Partially recovered trunks of De Chaunac still showed reduced vine size and yield three years after being winter injured. Delaware showed a similar response. Thus, although trunks may appear to recover from winter injury and persist, they should be replaced with new trunks.
Impacts
(N/A)
Publications
|
Progress 01/01/80 to 12/30/80
Outputs
Mechanization: A three-year study comparing normal pruning with the Cornell machine pruning system in a commerical Concord vineyard showed a doubling of labor efficiency coupled with no loss in vine capacity, productivity or fruit quality. Simulation experiments to study the adaptability of the Cornell pruning system to non-Concord labruscana varieties were initiated on Niagara and Delaware vines. results with simulation experiments showed that top wine cordon machine pruning with the Cornell system is not feasible on French-American varieties even with extensive follow-up manipulations. Results with mid-wire cordon trained French-American varieties were more promising. Studies to document the effects of long term "hedging" indicate unacceptable re-conversion costs on umbrella trained Concords and that hedged vines fail to respond favorably to mechanica shoot thinning or shoot positioning. A study to evaluate machine shoot positioners showed that, on moderate vine
sizes, at least two machine operations with one hand follow-up are necessary to adequately position the canopy. All machines resulted in decreased cluster number. Growth Regulators: Ethephon's growth retardant effect was demonstrated on Concord, Baco noir, White Riesling and Chardonnay, but attempts to demonstrate the conversion of vegetative growth potential into increased wood maturity or conversion to economic yield were not positive.
Impacts
(N/A)
Publications
|
Progress 01/01/79 to 12/30/79
Outputs
The effects of the potassium deficiency noted in the report for 1978 on winter survival during 1978-1979 were studied in 1979. For Delaware vines grafted to own, C 1616, Sori, C 3309, 5A, 5BB, G1 and 5C respectively, the percentage leaf area with -K deficiency symptoms in 1978 were 5, 25, 30, 5, 5, 10, 12 and 7. Delaware trunk injury in 1979 in the same order of rootstock was 1.6, 26, 69, 3, 0, 10, 8 and 16%. There was a direct relationship between 1978 crop/vine, crop/node or crop/wt, prunings and 1979 trunk injury, but the primary relationship was between trunk injury and percent leaf area with -K symptoms in 1978. Powdery mildew infection in 1979 was shown to drastically reduce crop and vine size of Rosette and White Riesling but had minimal 1979 effect on Concord productivity or vine size.
Impacts
(N/A)
Publications
|
Progress 01/01/78 to 12/30/78
Outputs
The 1978 advances in this project are listed. (1) The effect of a 3-week advance on 'Concord' harvest was to accelerate the green leaf destruction by senescence with roots by 'Concord' and of phylloxera resistant stocks. The early harvested vines, especially those on '3309' roots, also showed less leaf destruction by oxidant stipple and black leaf (K-deficiency) maximum greenness of leaves in mid-October was with own-rooted vines whose harvest was late. (2) Leaf area soundness was severely reduced by potassium deficiency by the combination of 1978 summer drought, 1978 large crops (as 10 to 15 tons per acre), and inadequate potassium. Drought tends to reduce potassium availability and higher yields withdraw more potash, and both occurred in 1978 on 'Delawares' and 'Concord' in Fredonia and on 'Concord' and 'Elvira' in Geneva. (3) In a few instances, leaf soundness was also reduced by excess heat during the drought by directly damaging the leaves. Leaf area
production was generally reduced as a result of both the drought and the large crop. Plots with varying degrees of weed control and with widely varying yields afford the treatment comparisons for this observation on less growth of shoots in 1978. (4) In years prior to 1978, the management of 'De Chaunac' (15 x 10 pruning of GDC-trained vines with defruiting of base shoots and secondary shoots) afforded high yields of ripe grapes.
Impacts
(N/A)
Publications
|
Progress 01/01/77 to 12/30/77
Outputs
The amount of leaf area in the light crop year, 1977, was generally excessive leading to inadequate leaf exposure and inadequate maturity of the crop. There were numerous instances of leaf area that were inadequate: in White Riesling and Chardonnay on American rootstocks, caused by soil calcareousness, in White Riesling and Delaware on own roots, caused by soil phylloxera, in Aurore and Pinot noir caused by crop stress, in Ives caused by oxidant stipple, in seven varieties of V. vinifera caused by winter cold, and in Concord by nitrogen stress. The cause is indicated because there is proof by that cause and to suggest remedial action. The leaf area inadequacy was indicated by a % trellis fill, of green leaves near harvest, of less than 60% or by a very delayed development of leaf area as in above. The restrictions of leaf exposure in 1976 and 1977 and grape composition on grape yield were serious and widespread. In several experiments on grapevine canopies, the
yield reductions due to shade were up to 4 metric tons/ha; and were accompanied by 1 degree to 2 degrees lower Brix and by greater damage to Concord buds by winter cold. This shade caused early senescence and abscission of leaves, and delayed and less completematuration of canes.
Impacts
(N/A)
Publications
|
Progress 01/01/76 to 12/30/76
Outputs
In July-Oct. 1976, mean daily max. temp. were much lower than normal. The delayin sugar accumulation was zero to more than 30 days - zero, where shoot spacing was wide; more than 30 days where the canopy was crowded, even at the same crop/acre. The high Brix of grapes depended on having a proximal leaf area that was: (1) adequate in area; (b) sound, as low in chlorosis by oxidant stipple or deficiencies or excesses; (c) exposed to the sky. The combination of(a), (b) and (c) was superior in minimizing the sub-normal temperatures on Brixas well as on the weight of fruit soluble solids per unit length of row. When (a) or (b) or (c) was sub-optimal, the Brix was reduced importantly. The canopy characteristics affording the highest Brix in Fall, 1976 were similar with those increasing fruitfulness, by severalfold over the minimum of fruitfulness.
Impacts
(N/A)
Publications
|
Progress 01/01/75 to 12/30/75
Outputs
1975 was a year of much progress. At Hector, research showed that the fruitfulness at a 'Concord' cane node in year #2 was highly associated with the exposure to the sky of the leaf at the node in year #1. The effect of year #1 exposure on year #2 fruitfulness was highly local within the cane. At Hammondsport, N.Y., experiments were conducted with 'Aurore'. They showed that the amount of sound leaf area per shoot was profoundly affected by the severity of the stress of cropping. As that stress increased there was: (1) chlorosis ofleaves opposite the clusters, (2) reduction in primary shoot length and leaf area and (3) reduction in length and leaf area of lateral shoots. This dependence of amount of leaf area on the amount of grapes, when considered with the leaf area requirement to mature a gram of grapes shows that vegetative development and the fruiting development of the vine are mutually dependent.
Impacts
(N/A)
Publications
|
Progress 01/01/74 to 12/30/74
Outputs
This has been a very active effort in 1973-74. In the experimental vineyard of Concord grapevines at Hector, N.Y., two Ph.D. researches have been completed anda third is almost completed. In addition, a 6-months investigation, by a visiting (Australia) Professor of Viticulture, was conducted in that vineyard. All of this was in collaboration with the U.S.D.A. Microclimatic Investigations at Cornell University. The results at Hector indicate that normally occurring differences in light flux density were far more important than those of moistureor turbulence in affecting photosynthesis and fruitfulness of grapevines. At Fredonia, N.Y. The effect of 3 nitrogen levels and resistant rootstock was to profoundly affect the amount of leaf area produced by Concord grapevines, and hence their grape production.
Impacts
(N/A)
Publications
|
Progress 01/01/73 to 12/30/73
Outputs
Collaborative work with the USDA Microclimatology Investigations in making meteorological definitions of vine canopies continues; vititultural evaluations of those canopies proceeds. The mechanical pruning studies (Project 27317) emphasize that the extent of leaf exposure, on a localized basis, is a major feature in those efforts. Many viticultural techniques, old and new, have theirimpact on vine productivity via the leaf exposure route; examples are 6-arm Kniffin vs Geneva Double Curtain training, vine spacing in the row, vertical cordons, and position of renewal spurs. There is a vine variety interaction with leaf exposure primarily in the vine growth characteristics which affect shading. Vine site selection studies are now being summarized; they afford a guide to sites in which the amount of leaf area is likely to be adequate and at which the temperature will be less restrictive than at randomly selected sites. This project continues to be the keystone of our
viticultural research.
Impacts
(N/A)
Publications
|
Progress 01/01/72 to 12/30/72
Outputs
The three emphases in 1972 were: leaf soundness, localization of leaf effects and measurement of canopy climate. The widespread brown leaf symptoms of grapevines in grape growing regions near the Great Lakes were identical to thoseobtained by exposing 2-year old potted Concord and Ives grapevines to 30 or 60 pphm ozone for 6 hours, indicating that the brown leaf disorder of grapevines isoxidant stipple, a manifestation of O(3) injury. High incidence of oxidant stipple was associated with grafted vines and low nitrogen fertilization. Injury was reduced to varying degrees by fungicide trt. Detailed evaluation, byshoot and cluster count and by crop weights of many vines in several experimentsshow that localization within the vine or canopy did occur. This should afford an analysis of yield and the sources of its variation. The question, with regard to this project, is the relation of between-vine variation to within-vinevariation; and this is being clarified. The
implications of this effort with respect to vine training and pruning, seem to be important. Canopy climate studies are in progress.
Impacts
(N/A)
Publications
|
Progress 01/01/71 to 12/30/71
Outputs
In spring 1970, at the beginning of bud break, 36 vines were started on levels of light intensity. The effect on the 1970 crop was huge, varying from no crop to a normal crop. At 30 days after bloom the vines were moved to a full sunlight position until the end of 1971. The 1971 crop was as much affected by the 1970 range of intensities as was the 1970 crop. Analyses of Concord grapes at 4 different canopy positions on each of 22 different canopies showed that grapes in exterior position had more soluble solids and less acid, particularly malates. This project has customarily dealt with quantity of leaf area; in 1966-1971, leaf area quality has come to the fore because of "brown leaf" which may be caused by ozone. The severity of this varies by scion variety, rootstock, and nitrogen supply, and is always more serious on the basal 6 leaves. Concord, Catawba and Ives are the most susceptible. Mechanical pruningefforts bring an examination of cane quality. The
largest size canes are more productive than average canes, and the difference varies but is likely about 20 to 30%.
Impacts
(N/A)
Publications
|
Progress 01/01/70 to 12/30/70
Outputs
A major experiment on the effect of light intensity (50 fc to 4,000 fc) at one temperature on Concord growth and fruiting was conducted in 1970. Although not completed until the 1971 fruiting of those vines has been observed, the 1970 responses were large as a function of light intensity and of the growth stage atwhich the treatments were applied. Cane selection of Concords on the basis of shoot exposure to light was followed by a definition of cane color, by detailed records of shoot and fruit production per node, and by chemical analyses of the canes. There are major within-vine differences. This is a cooperative experiment. Leaf area studies on potted Concords included a range in leaf area/berry, in position of retained leaf area and in growth stage but not calendar date of treatment. Each of the three variables affected the time of leaf senescence, especially at minimum leaf area. In a cooperative experiment, the study of the effects of leaf exposure on the
malic and total acid content and concentration in the fruit was continued because it is productive.
Impacts
(N/A)
Publications
|
Progress 01/01/69 to 12/30/69
Outputs
Daytime leaf temperature for a three-week period starting at first bloom, in therange 15C to 30C increased shoot growth and leaf area but had no clear effect on fruit set of Concords; the light intensity was 2,000 f-c. In the period fromtwo weeks before bloom to one week after, solar radiation was subnormal, and fruit set was subnormal; particularly with vines whose canopy was dense. The association of nodes/ft of canopy, as an index of leaf exposure, with fruitfulness was very close; it suggests that spacing is really a matter of exposure to above-saturation light intensity. The amount of leaf area per vine,per shoot, or per pound of fruit was inadequate only when exposure was adequate or excessive. The productivity of leaf area arrayed over the usual 5,000 ft. ofcanopy per acre is more likely to be restricted by inadequate exposure; at 10,000 feet of canopy per acre, additional leaf area would more likely increase productivity. Fruit soluble solids was
dependent on exposure of leaves; fruit acid was affected by exposure of berries.
Impacts
(N/A)
Publications
|
Progress 01/01/68 to 12/30/68
Outputs
Potted Concord vines were used to study an array of 3 amounts of leaf area per vine at 3 crop loads per vine and each of these 9 treatments at two light intensities (full exposure and 1 to 3% of full exposure). The exposure difference, of course, caused a major change in time of veraison and solids accumulation; but it also determined if crop load affected time of veraison, which means it profoundly affects the fruit maturity response to thinning of fruit. Sub-optimum leaf area, on the basis of fruit maturity, was associated with delayed leaf senescence and partial maturity of the shoots. The conclusionis that leaf area requirements depend on leaf exposure (and leaf temperature). Vine size (and leaf area) optimum could not be expressed on a vine unit basis but best with respect to the number of nodes retained per linear foot of canopy.Work on Sultana in Australia showed that many vines had excess leaves for the canopy, and that canopy extension or contraction had
a substantial effect on production of mature fruit. Concord grape acid concentration was affected by the density of foliage in the canopy.
Impacts
(N/A)
Publications
|
Progress 01/01/67 to 12/30/67
Outputs
85 In New York, Concord vines were grown for 27 days during fruit maturation in chambers having controlled temperature (15 o to 25 C) and light intensity (500 ft-c to 6,000 ft-c). The net assimilation fate was affected about 3-fold; primarily and positively by light intensity. Fruit solids increase was affectedmore than 2-fold; positively and equally by light intensity and temperature. Acid concentration of the fruit was affected more than 2-fold; negatively, and only, by temperature. Optical density of the fruit juice was affected 10-fold; positively and by both light intensity and temperature. The range of light intensity caused leaf heating (above ambient) of 1 o to 8 o C. Vine responses to temperature was more consistently related to leaf temperature than to ambienttemperature. For fruit solids increase, 6000 ft-c was 26% superior to 2000 ft-cat 28 o C ambient, but was less than 10% superior on the basis of similar (28 o C) leaf temperature. In Australia, when
ambient temperature was 36 o C and leaf temperature above 40 o C, heat injury to Sultana can occur. There, maximum exposure of leaves is not necessarily optimum exposure as it is so frequently with Concords in New York.
Impacts
(N/A)
Publications
|
|