Cordon System Research Articles

Comparative Economic Efficiency of Four Peach Production Systems in California

A clingstone peach (Prunus persica L. Batsch `Ross' on `Nemaguard' rootstock) orchard was established at the Univ. of California Kearney Agricultural Center, Parlier, for evaluating the economic efficiency of three high-density planting systems in comparison with the conventional Open Vase system. The orchard contained four replicate plots (0.80 ha/plot), each containing four different planting systems. The four planting/training systems (in-row spacing given first) were: the “KAC-V” (a perpendicular V system spaced 2.0 × 5.5 m, 919 trees/ha); the “HiD KAC V” (spaced 1.8 × 4.6 m, 1196 trees/ha); the “Cordon” (spaced 2.4 × 4.0 m, with perpendicular harvest drives 4.8 m every 22 m and tree height limited to 2.5 m, 919 trees/ha); and the “Open Vase” (spaced 6.1 × 5.5 m, 299 trees/ha). All system-specific costs and crop yields were recorded annually on each subplot for the first 5 years. Although the Cordon system had the highest yields in the second year, the V systems had the highest returns after 5 years. Cumulative costs were: HiD KAC-V system > KAC-V ≥ Cordon > Open Vase. The system that was designed to maintain tree height <2.5 m (Cordon) tended to be less profitable than the V systems because of modest crop yields and high pruning costs that were not offset by increased harvest efficiency. In the last 3 years of the study, pruning, thinning, and harvesting accounted for the majority of the system-specific costs.

Training and Pruning System Effects on Vegetative Growth Potential, Light Interception, and Cropping Efficiency in Peach Trees

Plant dry matter production is proportional to light interception, but fruit production does not always increase with increased light interception. Vegetative growth potential, the effect of cropping on vegetative growth, light interception and cropping efficiency of a clingstone peach [Prunus persica (L.) Batsch `Ross' on `Nemaguard' rootstock] were assessed in four production systems differing in tree density and training system. The four systems were a perpendicular V (KAC-V) system, a high-density perpendicular V (HiD KAC-V) system, a cordon system, and an open vase system. Vegetative growth potential, assessed on defruited trees, was higher in the cordon system and lower in the open vase system compared to the V systems. Cropping reduced leaf growth on the V and cordon systems and stem growth on the KAC-V and cordon systems. On a ground area basis, the HiD KAC-V system had the highest crop yields and the open vase system had the lowest. The cordon and HiD KAC-V systems intercepted more light and produced more fruit, stem, and leaf biomass than the open vase system. However, the modified harvest increment, the ratio of fruit dry mass to the sum of fruit, leaf, and stem dry mass, was lower in the cordon system than in the other systems. Thus, on this basis, the cordon system was the least efficient. On a trunk cross-sectional area basis, there were no significant differences in fruit production among any of the four training systems. For current year production, crop production per unit ground area is the best measure of economic efficiency. However, when planning the spacing, training and pruning of orchard trees, the most appropriate goal seems to be a system that increases light interception without increasing vegetative growth potential, such as the HiD KAC-V system.

Effect of Fruit Zone Leaf Removal on Total Glycoconjugates and Conjugate Fraction Concentration of Riesling and Chardonnay (Vitis viniferaL.) Grapes

Grape glycosides are, in part, important aroma and flavor precursors. Their quantification may offer a means of determining the impact of viticultural practices, such as leaf removal, on potential wine quality. Fruit zone leaf removal of Riesling and Chardonnay grapevines grown at two sites for two seasons was evaluated for its influence on total and phenol-free grape glycosides at harvest. Vines were trained to a low bilateral cordon system at one vineyard and a high bilateral cordon at the other. The concentrations of total and phenol-free glycosides were higher in Riesling and Chardonnay fruit from leaf-pulled <i>vs</i> control vines at three of four harvest dates. Phenol-free glycosides averaged 80% of the total in Riesling juice and 66% of the total in Chardonnay. Grapevine canopy microclimate plays an important role in determining fruit composition, although knowledge about the relationship between microclimate and aroma/flavor development is limited. This study illustrates the affect of microclimate manipulation on grape glycosides, important components of fruit quality.

Comparative study of juvenility resulting from &lt;em&gt;in vitro&lt;/em&gt; propagated &lt;em&gt;Vitis vinifera&lt;/em&gt; L., cv. Albari&amp;ntilde;o vines when subjected to different pruning systems

&lt;p style="text-align: justify;"&gt;Plants of &lt;em&gt;Vitis vinifera&lt;/em&gt; L., cv. Albariño propagated &lt;em&gt;in vitro&lt;/em&gt; were planted on their own roots and subjected to three different pruning systems, one at high level (Crosstree cordon system), one at middle level (Sylvoz system) and one at low level (Royat cordon system). Ampelographic and ampelometric characters were studied in different organs of these vines at several periods of the vegetative cycle during the 4th and 5th year.&lt;/p&gt;&lt;p style="text-align: justify;"&gt;ln the 4th year, although the vines from the Crosstree cordon system were slightly different, all of them showed very similar characteristics, such as: leaves with deep lateral sinuses, anthocyanin pigmentation of buds, and of the dorsal face of the nodes and internodes, presence of erect hairs on the young and adult leaves and, above all, on the margin of the dentation. These features were less noticeable in leaves on the Crosstree cordon system. Flowering during the 4th year was limited resulting in the production of a low number of small grape clusters. In the high cordon system, the level of f1owering was slightly better.&lt;/p&gt;&lt;p style="text-align: justify;"&gt;During the 5th year, a very marked difference was observed between the vines subjected to the Crosstree high cordon pruning system and those subjected to the other two systems. In the first case, the leaves show an almost total absence of erect hairs and lateral sinuses, and the number and the size of grape clusters increase significantly. The vines from Sylvoz and cordon Royat continued practically to appear the same as the previous year and flowering continued to be almost absent.&lt;/p&gt;

An empirical model for the simulation of leaf appearance and leaf area development of primary shoots of several grapevine ( Vitis vinifera L.) canopy-systems

A simple empirical model for leaf appearance and leaf area formation of primary grapevine shoots with different growth orientation is presented. The growth orientations characterize two groups of canopy-systems; one group with upright-growing shoots, represented by the Espalier-type system and the Vertical cordon system; and one group with hanging shoots, represented by the Geneva-Double-Curtain and unilateral cordon systems. Thermal time in degree days (°C day, > 10°C) was used as the driving variable starting at bud burst. Leaf appearance and leaf area expansion were linked to thermal time via the plastochron concept. A subroutine was devised to model hedging effects on shoot leaf area. Canopy-systems with hanging shoots exhibited fewer leaves per shoot and smaller individual leaf areas. Simulation runs on datasets from 2 years showed that the model closely describes leaf area development of whole shoots throughout the growing season for both groups of canopy-systems under cool climate conditions (Geisenheim, Rheingau, Germany). The model underestimated leaf number and leaf area of shoots during the latter part of the season when tested on a dataset from a hot climate (Davis, CA).

Influence of Training System and Pruning Severity on Yield, Vine Size, and Fruit Composition of Vignoles Grapevines

Vignoles grapevines were trained to four training systems: (1) high cordon - a bilateral cordon at the top wire (1.8 m); (2) low cordon - a bilateral cordon at the bottom wire (1.0 m); (3) high head - a head with the trunk maintained at or just below the top wire; and (4) low head - a low head with the trunk maintained at or just above the bottom wire. In addition, three pruning severities were applied (15 + 15, 20 + 20, and 25 + 25). Data were collected over a seven-year period from 1983 through 989. The vines were evaluated for yield, vine size maintenance, fruit quality, winter damage, and vine canopy characteristics. Vines trained to the high cordon system were superior to other training systems in yield and the equivalent or better than other systems with relation to vine size and fruit maturity indices. Tentatively, we propose that crop may be controlled via a linear pruning severity of 15 + 15.

Effects of Mechanical Pruning on the Yield and Quality of Muscadine Grapes

Dixie muscadine grapes (<i>Vitis rotundifolia</i> Michx.) were mechanically pruned and then either adjusted to 800 or 400 nodes per vine or not hand pruned following trimming for three consecutive years. Vines were trained to a quadrilateral cordon system and mechanical pruning cuts were made 15 to 20 cm from the cordon. Mechanical pruning with no touch-up resulted in much higher yields during the first and second year, but not the third. Vines hand pruned to 400 nodes had the lowest yield during all three years. Increasing pruning severity increased berry weight and generally increased soluble solids and pH. Wine produced from the mechanically pruned vines with no touch-up had a weaker muscadine aroma intensity and a lighter color in the first year, but wines produced from this treatment in subsequent years were similiar in muscadine character and color to wines from the other treatments.

Influence of Training System, Pruning Severity, and Spur Length on Yield and Quality of Six French-American Hybrid Grape Cultivars

A four-year study was conducted on three red and three white commercially important French-American hybrid grape cultivars to determine their responses to training systems, pruning severities, and spur lengths. Chelois and Chancellor, both red, were the highest yielding cultivars, and Chelois was the most vigorous. Verdelet and Aurore, both white, were the lowest yielding cultivars, but had higher percent soluble solids and lower acidity at harvest than the higher yielding red cultivars. Regression analysis showed that the Verdelet and Aurore cultivars had a higher pH at a given percent soluble solids than did Seyval (white), Villard Noir (red), Chelois, and Chancellor cultivars. All cultivars except Aurore had higher yields on the Geneva Double Curtain (GDC) training system than on the single-wire, bilateral cordon system. Training system had no effect on pH or acidity, but the GDC training system produced lower percent soluble solids. There were no differences between the 10 + 10 and 20 + 10 pruning severities on yield, pruning weight or quality parameters, probably due to the productivity of non-count nodes. No differences occurred between the two-node spurs and the four-node spurs on yield, pruning weight, or quality parameters.