American Foundation

California Competitive Grant Program for Research in and Enology

Viticulture Consortium Program

Annual Progress Report January 2001

Project Title: Trellising and Vine Spacing Studies

Principal Investigators: Nick Dokoozlian* Department of Viticulture and Enology UC Kearney Agricultural Center 9240 South Riverbend Avenue Parlier, CA 93648 Phone: 559/646-6587 Fax: 559/646-6593 E-mail: [email protected]

Paul Verdegaal University of California Cooperative Extension - San Joaquin County

Steven Vasquez University of California Cooperative Extension - Fresno County

*PI to whom correspondence should be directed

SUMMARY

Three separate studies were conducted in 2000 to examine the effects of trellis/training system and in-row spacing on the yield, growth and fruit composition of wine in the San Joaquin Valley. This progress report summarizes data collected during the second year of evaluation.

In the first experiment, grapevines (Clone 4 grafted to 5C ) were trained to six different systems trellis/training systems (Sprawl, VSP, Wye, Lyre, Smart-Henry and Smart- Dyson) at the Kearney Agricultural Center in Parlier. The horizontally divided Wye and Lyre systems produced the most clusters per vine, the Sprawl was intermediate, while the VSP, Smart- Dyson and Smart-Henry produced the fewest. However, when fruitfulness was expressed per foot cordon length, vines trellised to the Sprawl, VSP and Smart-Dyson were more fruitful than the remaining systems. Total yield per vine was generally similar among the trellising treatments, except that vines trained to the Lyre and Wye produced significantly greater yields than VSP vines. Based on standard industry row spacing for each treatment, estimated yields per acre ranged from 12.4 tons per acre for the Smart-Henry to 10.5 tons per acre for the California Sprawl. Sprawl and Smart-Dyson vines produced larger berries than the other treatments, while soluble solids, titratable acidity and juice pH were similar. Sprawl vines produced the greatest pruning weights per vine and per foot cordon length, the greatest mean cane weight, and the lowest yield:pruning weight ratio in the trial. In contrast, Wye and Smart-Henry vines had the lowest pruning weights per vine and per foot cordon length, as well as the greatest yield:pruning weight ratios in the trial.

A separate experiment at the Kearney Agricultural Center examined the effects of in-row spacing and training system on vine performance and characteristics. Syrah grapevines (UC Clone 7 grafted to 5C rootstock) were planted either 4, 6, 8, 10 or 12 feet between vines in the row and trained to two training systems (bilateral vs. quadrilateral cordon). Nearly all bilateral cordon trained vines were trained fully in 1999, while the portion of fully trained quadrilateral cordon vines dropped linearly as in-row spacing increased. About 80% of the cordon wire was filled when quadrilateral vines were spaced 4 feet in the row, but this dropped to less than 40% when in-row spacing was 12 feet. Cordon and trunk diameters revealed that 4 and 6 foot in-row spacing reduced initial vine size compared to wider spacing, while canopy density (leaf layer number or LLN) also decreased as in-row spacing increased. Productivity per acre was maximized when in-row spacing was 6 to 8 feet for bilateral cordon vines. Maximum productivity per acre for quadrilateral vines was obtained with an in-row spacing of 4 feet, and tons per acre declined steadily as in-row spacing increased. No significant differences in berry size and fruit composition were observed among the treatments at

A trial was also established near Lodi in a commercial vineyard to examine the effects of in-row spacing on vine performance and canopy characteristics. Syrah grapevines (UC Clone 7 grafted to 5C rootstock) were planted either 5, 7, 9, 11 or 13 feet apart in the row. Clusters per vine and total yield increased linearly with in-row spacing, while both parameters declined with increased in-row spacing when expressed per foot row or cordon length. Point quadrant parameters indicated that canopy density declined as in-row spacing increased. Total tons per acre were greatest when the space between vines ranged between 7 and 9 feet. No significant differences in berry size or fruit composition were observed among the treatments at harvest.

Wines from all three trials will be evaluated in the spring of 2001.

OBJECTIVES

1. Compare the yield, fruit quality and canopy characteristics of Chardonnay grapevines grown under six modern wine grape trellis/training systems commonly used in California.

2. Determine the effects of in-row spacing and training system on the yield, fruit quality and canopy characteristics of Syrah grapevines.

EXPERIMENTS CONDUCTED Vineyard Sites, Treatments and Experimental Designs

Trellis Study The trial is located at the Kearney Agricultural Center in Parlier, CA. Chardonnay grapevines (UC Clone 4) grafted to '5C' rootstock were planted in 1996 on sandy loam soil and oriented in east-west rows. The vines were trained to six different systems (Sprawl, VSP, Wye, Lyre, Smart-Henry and Smart-Dyson) in 1997 and 1998. Each system was replicated six times using seven vine plots arranged in a randomized complete block design. The middle three vines in each plot is used for data collection. All vines are spur pruned and cordon trained (bilateral and quadrilateral cordons for single curtains, quadrilateral cordons for double curtains). In-row vine spacing is 6' in all treatments, while between row spacing is 10'. All treatments were pruned to approximately 2, 2-3 bud spurs per foot cordon length, with 16 and 32 spurs retained per vine, respectively, on the single (Sprawl, VSP, Smart-Dyson) and divided (Wye, Lyre, Smart-Henry) curtain systems. Shoot positioning and hedging will be performed per standard industry practice for each system. Trellis dimensions and wiring configurations are shown in Figure 1.

Syrah Spacing Studies Parlier Experiment - the trial is located at the Kearney Agricultural Center in Parlier, CA. Syrah grapevines (UC Clone 7) grafted to 5C rootstock were planted in 1997 on sandy loam soil and oriented in east-west rows. The experiment was designed as a 5 x 2 factorial consisting of in- row spacing (4, 6, 8, 10 or 12 feet between vines within the row) and training system (bilateral vs. quadrilateral cordon) arranged in a randomized complete block, split plot design. Each treatment is replicated six times using six vine plots. The middle two vines in each replication are used for data collection. The cordon height of both training treatments is 54". A single catch wire was placed 12" above the cordon on bilateral cordon trained vines. Fruiting curtains of the quadrilateral cordon vines are separated 22". A 30" crossarm, with 2 foliage support wires, was placed 12" above the cordons in this treatment. All treatments are pruned to approximately 2, 2- 3 bud spurs per foot cordon length. Between-row spacing is 11' for all treatments.

Lodi Experiment - the trial is located in a commercial vineyard near Lodi, CA. Syrah grapevines (UC Clone 7) grafted to 5C rootstock were planted in 1997 on clay loam soil and oriented in east-west rows. The experiment was designed as a 5 x 3 factorial to analyze the effects of in-row spacing (5, 7, 9, 11 or 13 feet between vines within the row) and pruning level (5, 10 or 15 buds retained per pound dormant pruning weight). Data collection on the pruning level portion of the experiment will be initiated in 2001. The 10 bud per pound pruning weight treatment approximates the industry standard pruning level (approximately 2, 2-bud spurs per foot cordon length). The treatments are arranged in a randomized complete block, split plot design. Each spacing treatment (main plot) is replicated six times using 10 vine plots. Subplots (pruning treatments) are replicated 6 times using 2 vine plots. All vines are cordon trained, spur pruned and trellised to the vertically shoot positioned (VSP) system. Between-row spacing is 8' for all treatments.

Light and Canopy Density Measurements

The light environment along a vertical profile of the fruit zone in each replicate was determined with a sunfleck ceptometer (Decagon Devices, Inc, Pullman, WA) calibrated to measure average PPF. Measurements were taken near harvest between 11:00 and 13:00 Pacific Daylight Time (PDT). Point quadrant measurements were performed on data vines simultaneously to PPF measurements. The sharpened tip of a 1-m rod (3-mm diameter) was positioned perpendicularly to the canopy surface at the height of the fruit zone. The rod was inserted into the canopy at an angle of 90º with respect to the canopy exterior, and the number of leaves, clusters and gaps intercepted by the tip of the rod recorded. Readings were taken through the entire width of the canopy. Twenty insertions per replicate were made at 5-cm intervals. Leaf layer number was calculated as the mean number of leaf contacts per insertion.

Vine Performance Evaluations Vine yield components (shoots/vine, clusters/shoot, berries/cluster, berry weight and total fresh weight, bunch rot incidence) were determined in each experiment. One-hundred berries were collected per replicate at harvest to determine berry weight, soluble solids, titratable acidity, juice pH, and skin anthocyanins (Syrah only). Yield components and fruit composition from upward and downward positioned shoots in the Smart Henry and Smart Dyson systems were recorded separately (Chardonnay only). Pruning weights, shoot numbers per vine and individual shoot weights were determined in each plot at dormancy.

Fruit ripening was monitored in all experiments to allow treatments to be harvested at similar soluble solids levels (23.5 to 24.5 oBrix). Combined wine lots (250 pounds of fruit per treatment) from each trellis treatment in the Chardonnay experiment, as well as from main plot treatments in each Syrah experiment, were made and evaluated at the University of California, Davis Experimental Winery.

Statistical analyses All data were analyzed using appropriate SAS software. Performance parameters (yield and growth) were expressed and analyzed using vine, cordon length and canopy row-length indices as appropriate.

RESULTS AND ACCOMPLISHMENTS

Chardonnay Trellis Study

Trellis system had a significant effect on cluster number per vine and per foot cordon length, as well as clusters per bud retained at pruning (Table 1). The horizontally divided Wye and Lyre systems produced the most clusters per vine, the Sprawl was intermediate, while the VSP, Smart- Dyson and Smart-Henry produced the fewest. However, when fruitfulness was expressed per foot cordon length, vines trellised to the Sprawl, VSP and Smart-Dyson were more fruitful than the remaining systems. This was also reflected in the bud fruitfulness of the individual treatments; Sprawl vines produced the greatest cluster numbers per node retained at pruning and Wye, Lyre and Smart-Henry vines produced the least. This indicates that canopy division in this trial did not improve bud and individual bud productivity, but simply increased the total number of buds per plant and thus total cluster number per vine. Mean cluster weight did not differ significantly among the treatments. Total yields per vine were generally similar among the treatments, although Lyre and Wye vines produced significantly greater yields VSP vines. However, Wye and Lyre vines had lower yields per foot cordon length compared to the remaining treatments. Based on industry standard row spacings for each treatment, estimated yields per acre ranged from 12.4 tons per acre for the Smart-Henry to 10.5 tons per acre for the California Sprawl. Sprawl and Smart-Dyson vines produced larger berries than the other treatments (Table 2). Few differences in soluble solids, titratable acidity and juice pH were found among the treatments.

Horizontally divided Wye and Lyre vines produced more total shoots than single curtain Sprawl, VSP and Smart- Dyson vines (Table 3). However, when shoot number was expressed per foot cordon length Wye, Lyre and Smart-Henry (vertically divided) vines had lower shoot densities than the remaining treatments. Sprawl vines produced the greatest pruning weights per vine and per foot cordon length, the greatest mean cane weight, and the lowest yield:pruning weight ratio in the trial. In contrast, Wye and Smart-Henry vines had the lowest pruning weights per vine and per foot cordon length, as well as the largest yield:pruning weight ratios in the trial.

Leaf layer number (LLN) in the fruiting zone was greatest for Sprawl vines, and these canopies had the smallest percentage of exterior leaves (sunlight exposed leaves) among the treatments (Table 4). The number of canopy gaps in all treatments were quite low, and this parameter did not differ significantly among the treatments. Mid-day PAR in the fruit zone was lowest for the VSP and Lyre, and greatest for the Wye.

One of our major objectives when establishing this trial was to evaluate the wine grape trellis systems currently used in California under conditions of moderate vine growth or vigor. Based on mature vine pruning weights ranging from 3 pounds (VSP) to 5 pounds (Sprawl), the initial objective appears to have been met. This was considered critical in order to allow experimental results to be applied to as many different growing regions as possible.

Although horizontally divided systems (Wye and Lyre) generally produced the highest cluster and shoot counts per vine. Total yield per vine varied little among the systems, except that the Lyre and Wye produced significantly more fruit per vine than the VSP. However, single curtain, vertically shot positioned systems (VSP, Smart-Dyson and Smart-Henry) were estimated to produce slightly more per acre than horizontally divided systems due to their higher density. Based on commonly used spacings for each system as summarized in Table 1, estimated total yield per acre ranged from 12.4 tons for the Smart-Henry to 10.5 tons for the California Sprawl. Significant yield and growth differences are beginning to appear between the upper and lower tiers of the Smart-Henry system (data not presented). While the upper tier is producing more fruit and vegetative growth than the lower tier, the overall productivity of this system remains high. Based on yield:pruning weight ratios, the Wye was the most physiologically efficient system in the experiment (yield:pruning weight ratio = 10.7) while the Sprawl was the least (yield:pruning weight ratio = 5.5). These values indicate that none of the systems were severely overcropped or undercropped for this cultivar or region. Few differences in fruit composition at harvest were observed in 2000. Wine lots will be evaluated in the spring of 2001.

Wines of each treatment will be evaluated in the spring of 2001.

Syrah In-row Spacing x Training Study (Parlier)

Measurements taken prior to budbreak in the spring of 2000 (prior to the beginning of the 4th leaf) reveal differences in the percentage of allocated space filled by cordons due to both in-row spacing and training system (Figure 2, upper graph). While nearly all bilateral cordon trained vines were fully trained, the portion of fully trained quadrilateral cordon vines dropped linearly as in-row spacing increased. Approximately 80% of the allotted fruiting area was filled when quadrilateral vines were spaced 4 feet apart, but this dropped to less than 40% when in-row spacing was 12 feet. Cordon and trunk diameter measurements from both training systems indicate that 4 and 6 foot in-row spacings reduced initial vine size compared to wider spacing (Figure 2, middle and lower graphs). Cordon and trunk diameters were significantly greater for bilateral trained vines compared to quadrilateral trained vines.

Clusters per vine increased linearly for vines of both training systems as in-row spacing increased (Figure 3). At the same in-row spacing, quadrilateral vines had greater cluster numbers than bilateral vines in both years. Note that total vine fruitfulness increased dramatically from 1999 (3rd leaf) to 2000 (4th leaf). Changes in mean cluster weight and total yield per vine due to in-row spacing followed similar patterns in both training systems, increasing linearly with in-row spacing (Figures 4 and 5). However, yield per foot row length was generally similar for bilateral cordon trained vines regardless of in-row spacing (Figure 6, upper graph). In contrast, yield per foot row length declined slightly for quadrilateral cordon vines as in-row spacing increased (Figure 6, lower graph). On bilateral cordon vines, productivity per acre was maximized when in-row spacing was 6 to 8 feet (Figure 7, upper graph). Maximum productivity per acre was obtained with an in-row spacing of 4feet for quadrilateral trained vines, and tons per acre declined steadily as in-row spacing increased (Figure 7, lower graph). At similar spacings, quadrilateral cordon vines produced nearly twice the yield of bilateral cordon trained vines. Despite these large differences, fruit composition was similar among the treatments at harvest (Table 5). Wine lots produced from each treatment will be evaluated in the spring of 2001.

Point quadrant analysis revealed that leaf layer number (LLN) in the canopy generally declined with in-row spacing for both training systems (Table 6). The portion of total leaf area on the canopy exterior increased with in-row spacing, while differences in the percentage of canopy gaps and exterior clusters were not observed. Mid-day PAR in the fruit zone also increased with in-row spacing for both systems.

Pruning weights and dormant shoot counts will be collected in late January, 2001.

Syrah In-row Spacing Study (Lodi)

Clusters per vine increased linearly as in-row spacing increased in both seasons (Figure 8, upper graph). However, clusters per foot row length declined as in-row spacing increased (Figure 8, middle graph), while mean cluster weight increased with in-row spacing (Figure 8, lower graph). Total yield per vine increased linearly with in-row spacing (Figure 9, upper graph), however yield per foot row length and total tons per acre generally reached their highest levels when in- row spacing was between 7 and 9 feet (Figure 9, middle and lower graphs). These trends were similar in both 1999 and 2000.

No significant differences in fruit composition were observed among the treatments at harvest (Table 7). Wine lots from each treatment will be evaluated in the spring of 2001.

Leaf layer number in the canopy generally declined with in-row spacing (Table 8). The portion of total leaf area on the canopy exterior, as well as the percentage of exterior or exposed clusters per vine, increased with in-row spacing. Mid-day PAR in the fruit zone also increased with in- row spacing, while no differences in the percentage of canopy gaps were found.

Dormant pruning weights, shoot counts and trunk and cordon diameters will be collected in late January, 2001.

OUTSIDE PRESENTATIONS

The results of these studies were presented at the UC Canopy Management Short Course (August 2000) and the UC Winegrape Production Short Course (2000 and 2001). Written summaries of the work were included the proceedings of these meetings.

SUCCESS STATEMENTS

This study provides a detailed comparison of the modern trellis systems used for winegrape production in California. The study will also provide basic information regarding the effects of in-row spacing on vine productivity and canopy characteristics of several training/trellis systems commonly used in the San Joaquin Valley. The information developed by this study will be used by growers to aid in their trellis selection, as well as to compare the relative merits and/or disadvantages of the systems. The study will also illustrate the effects of in-row spacing on vine productivity and canopy characteristics, allowing growers to make more informed decisions when designing new .

STATUS OF FUNDING

Approximately $4,200 remains in this project account as of November 1, 2000. These funds will be used to perform pruning weight measurements and wine sensory analyses for the 2001 .

Table 1. Influence of trellis system on the yield components of Chardonnay grapevines. Parlier, CA. 2000.

Clusters per Clusters per Mean Yield per Clusters per bud Yield per *Estimated Trellis system foot cordon cluster wt. foot cordon vine retained at vine (lbs) tons per acre length (lbs) length (lbs) pruning

California 109 bc1 18.1 a 2.3 a 0.26 29.0 ab 4.8 a 10.5 Sprawl

Wye 124 a 10.3 b 1.3 c 0.27 33.1 a 2.8 b 10.9

Lyre 128 a 10.6 b 1.3 c 0.26 32.9 a 2.7 b 10.8

VSP 95 c 15.8 a 1.9 b 0.30 24.8 b 4.1 a 11.2

Smart-Dyson 99 c 16.5 a 2.0 b 0.27 26.9 ab 4.5 a 12.1

Smart-Henry 96 c 8.0 b 1.1 c 0.26 27.6 ab 4.6 a 12.4

p 0.001 0.001 0.002 0.321 0.001 0.002

1 Mean separation within columns by DMRT (p=0.05).

* Based on the following plant spacing (row x vine spacing) and densities per treatment: Sprawl = 10’ x 6’ (716 vines per acre) Wye. Lyre = 11’ x 6’ (656 vines per acre) VSP, Smart-Dyson, Smart-Henry = 8’ x 6’ (907 vines per acre)

Table 2. Influence of trellis system on the fruit composition of Chardonnay grapevines. Parlier, CA. 2000.

Soluble solids Titratable acidity Trellis system Berry wt. (g) pH (oBrix) (g/L)

California Sprawl 1.60 a1 23.9 b 5.8 bc 3.68

Wye 1.40 c 24.3 ab 5.9 ab 3.67

Lyre 1.46 bc 24.8 a 5.7 c 3.64

VSP 1.46 bc 24.1 ab 6.1 a 3.64

Smart Dyson 1.58 a 24.3 ab 5.9 ab 3.65

Smart-Henry 1.47 bc 24.1 ab 5.7 c 3.68

p 0.042 0.001 0.031 0.158

1 Mean separation within columns by DMRT (p=0.05). Table 3. Influence of trellis system on some vegetative growth parameters of Chardonnay grapevines. Parlier, CA. 2000.

Shoots per Pruning wt. per Shoots per Mean shoot Pruning wt. Yield pruning Trellis system foot cordon foot cordon vine wt. (g) per vine (lbs) wt. ratio length length (lbs)

California 51 c1 8.5 a 47.2 a 5.3 a 0.88 a 5.5 c Sprawl

Wye 67 ab 5.6 b 20.3 d 3.1 c 0.26 c 10.7 a

Lyre 70 a 5.8 b 23.9 cd 3.7 b 0.31 c 8.9 ab

VSP 50 c 8.3 a 29.0 c 3.2 c 0.53 b 7.8 b

Smart Dyson 54 c 8.5 a 31.0 c 4.0 b 0.66 b 6.7 b

Smart-Henry 61 b 5.1 b 22.3 cd 3.0 c 0.25 c 9.2 a

p 0.001 0.001 0.012 0.001 0.001 0.001

1 Mean separation within columns by DMRT (p=0.05). Table 4. Influence of trellis system on some canopy characteristics of Chardonnay grapevines. Parlier, CA. 2000.

Canopy Mid-day PAR in the Leaf layer Exterior Exterior Trellis system gaps fruit zone (µmol m-2sec- number leaves (%) clusters (%) (%) 1)

California Sprawl 5.1 a1 1.1 37 c 23 a 37.6 b

Wye 2.8 b 1.8 78 a 22 a 78.4 a

Lyre 2.7 b 1.6 71 ab 29 ab 15.6 c

VSP 2.9 b 0 62 b 28 ab 9.4 c

Smart-Dyson 2.2 c 1.1 72 ab 51 c 37.8 b

Smart-Henry 2.6 bc 1.5 69 b 35 b 28.4 b

p 0.001 0.731 0.022 0.011 0.031

1 Mean separation within columns by DMRT (p=0.05).

Table 5. Influence of in-row spacing and training system on the berry weight and composition of Syrah grapevines. Kearney Agricultural Center. 2000.

Soluble Titratable In-row spacing Training system Berry wt. (g) solids acidity (g/100 pH (feet) (oBrix) ml)

Bilateral 4 1.5 24.8 3.9 3.9 cordon 6 1.5 24.1 3.8 3.9 8 1.5 24.7 3.8 3.9 10 1.6 24.5 3.8 3.9 12 1.6 23.7 3.8 3.8

Quadrilateral 4 1.4 24.5 3.6 3.9 cordon 6 1.3 24.4 3.6 3.8 8 1.5 24.6 3.6 3.8 10 1.4 24.4 3.6 3.8 12 1.5 24.2 3.7 3.7

p 0.447 0.387 0.266 0.288

Table 6. Influence of in-row spacing and training system on some canopy characteristics of Syrah grapevines. Kearney Agricultural Center. 2000.

In-row Canopy Exterior Mid-day PAR in the Leaf layer Exterior Training system spacing gaps (%) leaves (%) fruit zone (µmol m- number clusters (feet) 2sec-1)

Bilateral 4 2.4 a1 1.2 55 a 10 35 a cordon 6 2.5 a 1.3 64 bc 11 33 a 8 2.5 a 1.4 65 bcd 12 48 b 10 2.1 b 1.6 72 de 9 51 b 12 2.1 b 1.5 71 d 8 96 c

Quadrilateral 4 2.1 b 1.3 57 ab 9 35 a cordon 6 2.0 bc 1.4 60 b 10 39 a 8 1.8 cd 1.3 68 d 11 68 b 10 1.8 cd 1.2 72 de 12 120 c 12 1.6 d 1.4 74 de 11 160 d

p 0.001 0.432 0.015 0.485 0.001

1 Mean separation within columns by DMRT (p<0.05).

Table 7. Influence of in-row spacing on the berry weight and composition of Syrah grapevines. Lodi-Woodbridge. 2000.

Soluble Titratable acidity In-row spacing Berry wt. (g) solids (g/100 ml) pH (feet) (oBrix)

5 1.4 23.7 5.4 3.6

7 1.5 23.4 5.2 3.6

9 1.6 23.8 4.9 3.6

11 1.5 23.6 4.8 3.7

13 1.5 24.3 4.9 3.6

p 0.076 0.505 0.302 0.560

Table 8. Influence of in-row spacing on some canopy characteristics of Syrah grapevines. Lodi-Woodbridge. 2000.

Canopy gaps Exterior leaves Mid-day PAR in the In-row spacing Leaf layer Exterior (%) (%) fruit zone (µmol m-2sec- (feet) number clusters 1)

5 2.5 a1 0.8 71 a 19.1 a 12.1 a

7 2.1 b 1.7 69 a 19.4 a 10.3 a

9 2.0 bc 2.5 74 b 36.7 b 17.0 a

11 2.0 bc 2.7 76 bc 47.9 c 33.3 b

13 1.8 bc 1.9 78 c 49.3 c 35.7 b

p 0.036 0.521 0.025 0.001 0.001

1 Mean separation within columns by DMRT (p<0.05).

Cordon length Trunk diameter (mm) Cordon diameter (mm) (% alloted space) 100 10 11 12 13 14 15 15 16 17 18 19 20 21 30 40 50 60 70 80 90 7 8 9 012 10 8 6 4 Bilateral Bilateral In-row (ft) spacing Quadrilateral Bilateral Quadrilateral Quadrilateral Figure 2. Figure 120 Bilateral 1999 2000 100

80

60

40

20

0 250 Quadrilateral

200 Clusters per vine

150

100

50

0 4681012 In-row spacing (ft)

Figure 3. 0.85 Bilateral 1999 0.80 2000

0.75

0.70

0.65

0.60

0.55

0.50

0.45 0.58 Quadrilateral 0.56 Cluster (lbs) wt 0.54

0.52

0.50

0.48

0.46

0.44

0.42 4 6 8 10 12 In-row spacing (ft)

Figure 4.

100 Bilateral 1999 2000

80

60

40

20

0 120 Quadrilateral

100 Yield per vine (lbs) Yield per vine

80

60

40

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0 4 6 8 10 12 In-row spacing (ft)

Figure 5.

4 Bilateral 1999 2000

3

2

1

0 6 Quadrilateral

5

4 Yield per ft length row (lbs) 3

2

1

0 4 6 8 10 12 In-row spacing (ft)

Figure 6. 16 Bilateral 1999 2000 14

12

10

8

6

4 22 Quadrilateral 20

18 Tons per acre 16

14

12

10

8

6

4

2 4 6 8 10 12 In-row spacing (ft) Figure 7. Cluster weight (lbs) Clusters/ft row length Cluster number per vine 0.30 0.35 0.40 0.45 0.50 0.55 100 120 140 10 11 12 20 40 60 80 6 7 8 9 113 11 9 7 5 2000 1999 In-row (ft) spacing Figure 8. 45 1999 2000 40

35

30

25

20 Yield per vine (lbs)

15

10 3.8

3.6

3.4

3.2

Yield/ft row length (lbs) Yield/ft row 3.0

2.8 11

10

9 Tons per acre 8

7 5 7 9 11 13

In-row spacing (ft) Figure 9.