Controlling Animal Depredation in Table Grapes
It can be very frustrating to bring a wonderful table grape crop through its stages of development and then lose it to critters at the moment of harvest. Birds and raccoons are often the culprits, but skunks or deer can also be a problem. Control measures for these problems range from slightly to totally effective and inexpensive to costly. Fig. 19 - A cluster in full bloom on the right and a cluster that has not begun to bloom on the left . Fig. 19 - A cluster in full bloom on the right and a...
Shoots Laterals Trunks Arms and Cordons
The structure of a grapevine is really quite simple. Trunks and arms are the rough-barked, semi-permanent woody parts of the vine. A trunk is easy to identify because it originates at or near the ground like the trunks on other woody plants Fig. 1a . There can be one, two or several trunks on a grapevine. When a trunk divides into branches, these branches are called arms. Arms are rough-barked portions of the vine other than the trunk s . Sometimes a trunk is bent so a horizontal arm runs along...
Selecting Grape Varieties to Plant
More bad table grape varieties are available for purchase than good ones. Don't rush this decision. Though numerous high quality seeded table grape varieties are available for temperate-climate vineyards, the commercial grower should be mindful that the American consumer now has a 90 preference for seedless table grapes. That's the future, even though a few growers in the eastern United States still fresh-market significant quantities of 'Concord' and 'Niagara'. Hardiness is an important...
Quality Table Grapes
Any grapes that pass the taste test are often considered acceptable fruit quality by backyard growers. Commercial growers must use a more complex consumer definition of acceptable fruit quality that involves not only taste but also appearance, including compactness of the cluster, berry color, berry size, and freedom from visible defects such as cracking, rot and spray residue. Numerous vine practices can influence these aspects of table grape quality Table 2 . Grape growers must decide how...
The Complete Grape Growers Guide
Bordelon, B.P. 1995. Grape Varieties for Indiana. Bull. HO-221. Lafayette, Ind. Purdue University. Cahoon, G., M. Ellis, R. Williams and L. Lockshin. 1991. Grape Production Management and Marketing. Bull. 815. Columbus, Ohio Ohio State University. Eichenlaub, V.L., J.R. Harman, F.V. Nurnberger and H.J. Stolle. 1990. The Climatic Atlas of Michigan. Notre Dame, Ind. University of Notre Dame Press. Ellis, M.A. 1995. Integrated Pest Management IPM Disease Management Guidelines for Grapes in Ohio....
Shoot Topping
Too many berries per cluster and excessive cluster compactness are common concerns of table grape growers. Occasionally, however, a grower may desire to increase berry set on straggly, loose clusters. Flower cluster thinning and berry thinning Table 2 are good strategies for increasing cluster compactness. Shoot topping is another method for increasing fruit set. When grapevines are going through bloom, the clusters and rapidly growing shoots are competing for the sugars and other substances...
Modified Arm Kniffiii Growers who do not
Wish to construct trellis cross arms for the modified Munson training system can obtain many of the benefits of that system by utilizing a more simple two-dimensional training system called 4-arm Kniffin. William Kniffin developed this training system for grapevines in the Hudson Valley region of New York in the 1850s. He utilized four long fruiting canes for each vine. These canes were tied to two trellis wires at varying heights on the trellis Fig. 3a . In later years, as vines developed a...
Pruning Vines for Table Grape Production
Pruning is the removal of unwanted parts of a vine. A manageable growth form of a vine is the most visible result of pruning, but the most important reason for pruning is to control crop level. Unpruned vines will at first overbear to produce large crops of poor quality fruit. Vines left unpruned for several years develop alternating cycles of large and small crops. New grape growers often fear that pruning will injure a grapevine. The reverse is true. The more severely a vine is pruned, the...
Insect and Disease Control
Most consumers have no tolerance for imperfections in table grapes, so the table grape grower must control grape insects and diseases. The first step is to recognize the principal insects affecting table grape production in a temperate climate grape berry moth, leafhoppers, rose chafer and Japanese beetle as well as the principal grape diseases powdery mildew, downy mildew, black rot, Phomopsis cane and leaf spot, and Botrytis bunch rot. Several excellent publications are available to assist...
Suckers and Trunk Renewals
The trunk of a grapevine may remain healthy for decades or become diseased or winter-injured after just one or two years. Therefore, the trunks of vines Fig. 2b - The cross-section of a node indicating a dead primary bud in the middle with live secondary and tertiary buds on either side. Fig. 2b - The cross-section of a node indicating a dead primary bud in the middle with live secondary and tertiary buds on either side. need to be managed for the specific conditions of a vineyard. Even under...
Harvesting Table Grapes
The balance between sugar and acid in a grape berry determines its palatability. Though the timing of commercial table grape harvests may be guided by measurements of sugar and acid levels in the fruit, often the start of harvest of table grapes will simply be a matter of deciding when the grapes taste good. Grapes do not ripen off the vine, so their quality can only go down after picking. Picking too early may jeopardize your market. Picking too late may cause a loss of early market...
Planting and Care of Young Vines
Plant vines as early as possible in the spring. Keep vines cool and moist from the time you obtain them until planting. If the vineyard site has been adequately prepared Zabadal and Andresen, 1997 , then the steps in planting Zabadal, 1997 should proceed in rapid succession. The hobbyist grower with a small number of vines should take the time to plant each vine so the root system is well distributed in the soil volume. Do not merely shove roots down a hole made with a posthole digger. Dig a...
Crop Adjustment
Pruning a dormant grapevine is the principal method for controlling the size of its crop. However, even when the same vine is pruned identically each year, its crop level will vary considerably from year to year. This variability occurs because the weather during both the previous and the current growing seasons greatly influences the number of shoots that develop per node, the number of clusters that develop on each shoot, the number of florets that develop on each cluster, the percentage of...
Girdling
The benefits of girdling grapevines were documented more than 250 years ago through a fortuitous accident. A donkey had been tied to the trunk of a grapevine. It was observed that this vine matured fruit earlier and of higher quality than fruit on surrounding vines. Inspection of the vine revealed that the donkey's rope had worn away the bark and a portion of the trunk just below the bark. Girdling has the same effect by cutting through the phloem tissues below the bark so that the downward...
Gibberellic Acid Sprays
Gibberellic acid GA is a naturally occurring compound in a group of plant hormones called gib-berellins. GA application to table grape clusters may produce several responses. When it is applied to clusters early in their development, it may lengthen the cluster stem rachis to reduce cluster compactness. However, this response to GA application is often negated by the natural elongation of the cluster in a later stage of cluster development. Therefore, there is seldom a true cluster-loosening...
Section III Cultural Practices for Managing Mature Grapevines
All cultural practices applied to grapevines are aimed at achieving the goals of acceptable yield and acceptable fruit quality. The intensity of a grower's vine management will reflect what he considers acceptable yield and fruit quality. Modest crops of imperfect fruit may be quite acceptable to a backyard grower, but such standards would put a commercial grower out of business. Several good vine management options for table grape production are presented below. Growers need to choose among...
