Ohio State University Extension Bulletin

Midwest Grape Production Guide

Bulletin 919-05


Glossary

Arm

A short branch of old wood extending from the trunk or cordon on which canes or spurs are borne.

Arthropod

Any invertebrate animal (including insects, mites, spiders, and crustaceans) that has a jointed body and limbs.

Ascospore

The sexual spore of an ascomycete fungus.

Balanced Pruning

Pruning the vine based on its growth and number of nodes the previous growing season. A method of determining the potential fruiting capacity of a vine at pruning time.

Base Shoot

A shoot arising from a bud at the base of a cane.

Bleeding

Flow of plant sap from wounds.

Brix

A scale used to indicate soluble solids content: ºBrix = grams of sucrose per 100 grams of liquid at 68ºF.

Bud

The compound bud or eye in the axil of a leaf, at the node.

Callus

Parenchyma tissue that grows over a wound or graft and protects it from drying or injury.

Calyptra

The petals of a grape flower.

Cane

A mature woody, brown shoot that develops after leaf fall.

Canker

A necrotic, localized disease area with a sharp line of demarcation between healthy and diseased tissue. Usually on trunks or canes.

Canopy

The entire foliage of a grapevine as it is positioned on the trellis.

Chlorosis

Yellowing of normally green parts of the plant, especially shoots and leaves.

Cleistothecium

The sexual fruiting body of a powdery mildew fungus.

Conidia

Asexual spores formed by several types of fungi.

Cordon

An extension of the grapevine trunk, usually horizontally oriented and trained along the trellis wire.

Crop Load

The ratio of crop size/vine size.

Crop Size

The fruit weight per vine (in pounds) measured at harvest.

Curtain

A portion of the canopy composed of the current season’s shoot growth that is normally oriented downward.

Dormancy

That stage when the plant is not actively growing.

Escapes

Weeds in a treated area that have been missed or that have survived the treatment.

Floret

The individual flower of a cluster.

Fragipans

Impermeable soil layers or texture changes that prevent free downward movement of water.

Fruiting Wood

One-year-old wood (cane) that produces the current season’s crop.

Fungicide

A chemical or physical agent that kills fungi or inhibits its growth.

Gall

An abnormal growth of plant tissue caused by stimuli external to the plant itself, generally caused by insects or parasitic bacteria. Example: Phylloxera gall.

Germ Tube

The initial hyphae strand from a germinating fungus spore.

Head

The top of the vine where canes are selected to produce the current season’s crop.

Hedging

Trimming ends of shoots in a vertically shoot-positioned traning system, such as VSP.

Herbicides:

Infection

The process in which a pathogen enters, invades, or penetrates a host plant and establishes a parasitic relationship with it.

Infection Period

The time required for a plant pathogen to penetrate host plant tissue and establish a parasitic relationship. Length of the infection period depends on environmental factors such as wetness duration and temperature, and host susceptibility.

Internode

That portion of the cane or shoot between nodes.

Lateral

Side branches of a shoot or cane.

Lesion

A wound or delimited disease area.

Life Cycle

The period of time between fertilization of an insect egg and the death of the individual that proceeds from that egg. In most insects, includes the stages of egg, larva (grub), pupa, and adult.

Mummy

A dried and shriveled grape berry resulting from attack by a fungus.

Necrosis

The localized death of plant tissue, generally brown or black in color.

Node

The thickened portion of a shoot or cane where the leaf and its compound bud are attached.

Oospore

A thick-walled, sexually derived resting spore of oomycete (downy mildew) fungi.

Pedicel

The stem of an individual flower or berry.

Peduncle

That portion of the rachis extending from the shoot to the first branch of the cluster.

Petiole

The stem end of a leaf.

Pheromone

A chemical substance (i.e., sex attractant) produced by an animal that serves as a stimulus to other individuals of the same species for a behavioral response.

Pruning

Physical removal of portions of the vine for the purpose of maintaining size and productivity.

Pycnidia

An asexual, globose, or flask-shaped fruiting body of a fungus that produces conidia. See Conidia.

Rachis

The main stem or axis of a cluster. The framework of the cluster to which the pedicels are attached.

Renewal Spur

A cane pruned to one or two nodes, generally on an arm or cordon. Its primary purpose is to position a cane for fruiting the following season.

Rest

That period of nonvisible growth controlled by internal factors. Visible growth will not occur even under favorable environmental conditions.

Sclerotia

Hard, dark, and rounded mass of fungal tissue that permits survival in adverse environments.

Shatter

That physiological stage following bloom when impotent flowers and small green berries begin to drop from the cluster.

Shoot

The green, leafy growth developing from a cane, spur, cordon, or trunk. The developing growth is the source of leaves, stems, tendrils, flowers, and fruit.

Skirting

Trimming ends of shoots in a downward shoot-positioned training system, such as High Cordon.

Slip-Skinned

The grape flesh separates readily from the skin.

Sporangiophore

A sporangium-bearing body of the downy mildew fungus.

Sporangium

A fungal structure producing asexual spores, usually zoospores.

Spore

A reproductive body of a fungus.

Spur

A cane pruned to one or two nodes. A fruiting spur is chosen to produce shoots with fruit. See Renewal Spur.

Stomate

An opening or pore usually in the lower surface of a leaf that functions in gas exchange.

Sucker

A shoot arising from a bud below ground.

Summer Lateral

A weak shoot produced in the axil of the leaf adjacent to the bud.

Tendril

A curled structure arising from some nodes of the shoot and capable of attaching itself to other portions of the vine or trellis.

Trunk

The main, upright structure of the vine from which arms, cordons, shoots, and canes arise. Vines may have more than one trunk.

Veraison

That physiological stage in the development of a grape berry when it begins to ripen as indicated by color change and fruit softening.

Vine Size

Weight of cane prunings on a vine. Measured by weighing cane pruning per vine (in pounds) during the dormant season.

Water Sprout

An unwanted shoot arising from buds on the trunk.

Weed Shift

The build up of tolerant weed species.

Zoospore

A fungal spore with flagella, capable of locomotion in water.


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