Classification and formation features of grapevines in viticulture

Forms (lat. forma — appearance, shape), known throughout the world, are represented by a specific combination of perennial (trunk, head, and arms of various sizes and quantities) and annual parts (fruiting shoots or fruit-bearing units), pruned to different lengths and arranged in space in various ways. They differ in appearance, the structure of the skeletal part, and the type of fruit-bearing units and shoots.

All existing forms can be classified into 6 types.

Head-trained forms are characterized by the presence of a well-developed head and often the absence of arms, as the fruiting shoots are pruned to spurs and are located directly on the head. They can be non-trunked or trunked with various heights. These are used in rootstock nurseries in northern viticulture regions, where it is difficult to form arms with fruit-bearing units, as well as in areas where trellis installation is difficult due to the lack of supports, but plants can be grown without winter cover. The bushes are short-lived (no more than 20 years) and relatively low-productive.

Goblet-shaped forms have 3 or more growing arms radiating from the center of the bush. They can be non-trunked (Don, Moldavian) and trunked (Gobelet, Turkmen, etc.). The arm ends in a spur or a fruit-bearing unit. They are classified by size: small — with three to four arms 20–40 cm long (Crimean, Gobelet); medium — with four to eight growing arms 40–70 cm long (Ukrainian, Taman); and large — with eight to ten arms or more, over 80 cm long (Don, Moldavian, Turkmen). They can be single- or multi-tiered (pyramid).

Fig. 47. Goblet-shaped forms:

/ — small; a — Crimean; b — Gobelet (France); 2 — large—a — Moldavian, Don; b — Turkmen; 3 — multi-tiered (pyramid).

The small goblet-shaped form is characterized by low productivity, dense foliage, and poor use of PAR (if shoots are tied to a single stake). Medium and large goblet-shaped forms are more productive. Mechanization of work in vineyards with ground-level forms is difficult. In the USSR, they have been preserved in household plots.

Trellis forms (the old name is single-arm or double-arm Guyot, after their author) have 1, 2, or more (umbrella, radial) vertical trunks 10–200 cm high (the slanted trunk is only found in the slanted trellis form by Kipen), and one to two growing arms located along the plane of the trellis horizontally or at an angle (pergola), ending in one or rarely two fruit-bearing units. They can be single- or double-sided (by the number of arms), and single- or two-tiered. There are many varieties of trellis forms: in the USSR — single- and double-sided trellis, slanted trellis by Kipen, Kakhetian (Georgian); umbrella, or umbrella (Yugoslavia, Italy, etc.); Kniffen umbrella, Keuka (USA); Nižnik double-sided two-tiered (Bulgaria and Yugoslavia); Rheinhessen heart-shaped (FRG); Parronal (Argentina, Chile); Faget (France); pergola, radial, or Regino (Italy), etc.

These forms are medium to low in volume and are characterized by good leaf illumination. Yield depends on the structure of the bush and the plantation; mechanization of all work is possible. They have become widespread in non-covering culture zones on low-fertility soil and for low- to medium-vigor cultivars in Europe and America. In recent years, the most voluminous forms (umbrella, pergola, radial) have been used when introducing wide-row high-trunk culture. They are more productive, and the harvest quality is high.

Fan-shaped forms have 3 to 12 growing arms with spurs or fruit-bearing units, arranged in a fan shape in the plane of the trellis. They can be without a trunk or with a trunk. These forms are distinguished by the size and number of arms. The small one has 3–4 arms 20–40 cm long and is used on low-fertility soils and low-vigor cultivars; the medium fan (also called multi-arm) — with 4–8 arms 40–80 cm long, is used in Moldavia, the Ukrainian SSR, and other regions; the large one — with 8–12 arms over 1 m long, with several fruit-bearing units or shoots on each of them, is used in Central Asia on vigorous table cultivars under irrigation.

Fig. 48. Trellis forms:

/ — single-sided (after Guyot); 2 — double-sided; 3 — umbrella: a — single-trunk and b — double-trunk; 4 — radial (Regino); 5 — pergolas: a — single-sided, b — double-sided, c — Californian; 6 — Kakhetian, or Georgian (dimensions in centimeters).

There are also some modifications of fan-shaped forms. In rootstock nurseries, a short-arm fan form is used. The ground-level fan form (after Altman) has many short arms with fruit-bearing units. This form without a trunk is found in the Krasnodar Territory, where the bushes are hilled up in autumn and pruned afterwards.

The fan-shaped training system with a rejuvenating base, according to Potapenko et al., has 2 renewal spurs at the base of the vine (rejuvenating bases). Shoots developing from the buds on these are used to form the permanent arms. It is used in the Rostov region, where winter weather is unstable, and permanent arms are susceptible to spot necrosis, thus requiring frequent renewal.

The Moldavian espalier form, based on the number of permanent arms with fruiting units (4–8), can be classified as fan-shaped. It differs in that the permanent arms branch out, and from two to four, four to eight are formed, each ending in a Moldavian fruiting unit.

The high-trunk fan-shaped form has a high trunk and 4–6 permanent arms. It is common in non-covering zones under wide-row cultivation.

Fig. 49. Fan-shaped forms:

1 — small; 2 — medium; 3 — large; 4 — ground-level (after Altman); 5 — Moldavian espalier; 6 — high-trunk; 7 — short-armed for rootstocks. Semi-fan (one-sided) forms: 8 — Moldavian; 9 — <Magarach — Ilcher>; 10 — Samarkand-style; II — long-armed after Guseinov (dimensions in centimeters).

Fan-shaped and semi-fan forms: frost protection and mechanization

Fan-shaped and semi-fan (one-sided) grape training systems are excellent for regions with cold climates. Their main practical advantage lies in the ability to fully mechanize covering the vines for the winter. For the convenience of tractor unit passage in the field, it is recommended to alternate the direction of the permanent arms every 10 rows. This allows protecting the plantings from freezing without unnecessary manual labor.

Agronomists value fan-shaped constructions for their high productivity, especially in long-armed variants. In this case, semi-fan forms are trained with 2–4 permanent arms on a rejuvenating base only on one side of the vine. In viticulture practice, five main types of such training are used. They differ in the length of the permanent arms and the structure of the fruiting units for specific farm tasks.

• Semi-fan with short permanent arms 40–60 cm long, on each of which one simple fruiting unit is formed.
• Moldavian semi-fan with permanent arms 50–90 cm long, bearing Moldavian fruiting units.
• Semi-fan with two branched permanent arms 100–160 cm long on offshoots (reinforced fruiting units).
• Long-armed fan-shaped with three permanent arms up to 90 cm long and a Z-shaped bend.
• Semi-fan with several shoots on the permanent arms.

• Change of permanent arm direction — every 10 rows
• Length of short permanent arms — 40–60 cm
• Length of medium permanent arms — 50–90 cm
• Length of long permanent arms — 100–160 cm

Cordon forms: classification and schemes for non-covering zones

Cordon forms consist of a trunk and one or two (rarely four) permanent arms. At specific intervals, they feature spurs (up to 2–4) with fruiting units, buds, or fruiting shoots. The structures are divided according to several characteristics depending on their spatial arrangement. The choice of a specific type depends on the climatic conditions of the region and the adopted cultivation technology.

• By tier: single-, double-, triple-, and multi-tier.
• By number of sides: one-sided and two-sided (formerly called one-armed and two-armed).
• By direction of permanent arms: horizontal, inclined, and vertical.

Horizontal cordons are used in the non-covering zone of viticulture. They ensure good ventilation of the vines and uniform lighting of the clusters. Several proven schemes for forming such cordons are used in practice.

Based on the hanging cordon, modified designs have been developed for special conditions. For example, for the Black Sea coast, a scheme is suitable where green shoots are guided behind two parallel wires, after which they hang downwards. Pruning in this case is also performed short.

In regions with mild winters, the two-trunk bush form shows high productivity. On two trunks over 120 cm high, arms are formed along the row, directing the spurs alternately in opposite directions of the inter-row. To hold the growth at the height of the trunk, crossbars 25–30 cm wide with two parallel wires are installed.

For intensive plantings, the Moldavian trunk form with a low trunk up to 30 cm is suitable. From it, two parallel arms go vertically upwards, which are spread horizontally to the sides at a height of 80–100 cm. On each arm, 3–4 spurs with a Moldavian fruiting unit are formed. On high-fertility soils, the number of arms can be increased to four, and the number of fruiting units can be brought up to 80.

The Geneva Double Curtain (GDC) is widely used in the USA and Western Europe. It is characterized by a combination of two bushes. One of them is on a medium trunk, the other on a high trunk with the placement of permanent arms on two parallel rows of wire of a vertical trellis. The shoots hang downwards.

Fig. 50. Cordon forms:

1 — Cazenave; 2 — Royat 1; 3 — Sylvoz; 4 — Moser; 5 — ground cordon (per double-sided curtain; 9 — inclined Merzhanian; 10 — vertical Merzhanian; protected ground (dimensions in centimeters).

Melnik); 6 — hanging 7 — Moldavian trunk; 8 — Geneva double-tiered. 10 — mixed (umbrella); 12 — vertical; 13 — horizontal for protected ground

A horizontal cordon for protected ground has a trunk 1.2–1.5 m high, 1 or 2 permanent arms up to 4 m long (to the center of the greenhouse). On them, alternating in different directions, there are spurs every 20 cm. Fruiting shoots are pruned to 2 buds.

The Thomery cordon is also used, combining several cordons with trunks of different heights.

The mixed umbrella cordon is used in Bulgaria and other countries for high-trunk grape cultivation with hanging

Among vertical cordons, the following are used: the Merzhanian cordon, characterized by a low trunk and one vertically positioned permanent arm, from which spurs with fruiting units extend evenly in both directions along the row every 30–40 cm; it is used in the non-covering zone — such cordons are known in Bulgaria as the Thomery cordon, in the CSSR, France, and others as "Vertiko"; a cordon for protected ground, characterized by a low, up to 40 cm, trunk and a long permanent arm (up to the ridge of the greenhouse); spurs develop on both sides of it every 20 cm; fruiting shoots are pruned to 2 buds; the Thomery cordon with several trunks of different heights, widely used in the warm countries of Europe.

Among inclined cordons, the following are especially common: the Merzhanian cordon, having a 45° arrangement, a trunk, and a permanent arm, on which there are spurs with fruiting units every 35–40 cm; it is used in zones of conditionally covering (on combined forms) and covering cultures, but it is more difficult to rejuvenate when perennial parts are damaged than fan forms; a cordon on a trunk up to 101 cm, known in Germany in the non-covering zone.

Cordon forms are common in zones of non-covering and rarely covering viticulture on vigorous and medium-growth cultivars characterized by high productivity. They are especially widely introduced in high-trunk cultivation with free positioning of shoots in space.

They are distinguished by lower labor costs, primarily with large feeding areas (up to 10 m²). On them, it is possible to use mechanization of pruning and harvesting">harvesting.

Combined forms are used in regions with unstable snow cover and sharp temperature fluctuations, when in warm winters, buds may suffer from dampness (damping off), and in cold winters, the uncovered part of the bushes may be damaged (Kazakhstan, Kuban, Crimea, Transcarpathia, Chechen-Ingush ASSR, northern part of the Dagestani ASSR, etc.). In these forms, the lower tier of the bush is covered for the winter, and the upper one is left uncovered.

Several such forms are known:

• Semi-covering form of the Kuban Agricultural Institute (according to Gukasov) — can be attributed to the fan type. It has two arms ending in knots and two in fruiting canes. Every other year, their arrangement changes.
• KSKhI-I, KSKhI-II, KSKhI-III forms of the Crimean Agricultural Institute, Bolgarev, etc. — combine in different variations double-sided trellis forms and horizontal cordons with two to four spurs.
• Merzhanian–Bagrintsev form — represented by the Cazenave cordon and the inclined Merzhanian.
• AZOS form — consists of a single-sided Cazenave cordon and an inclined trellis (according to Kipen).
• Bravich form — where the medium fan and Moldavian trellis forms are combined, recommended in Moldova.

All the variety of forms existing in the world are modifications of the types considered above. The creation and development of new forms aim to give the canopy structure such a look that would allow for minimizing manual labor costs, mechanizing plant and soil care processes, and making the plantations highly productive, profitable, and with good harvest quality.

Fig. 51. Combined forms:

1 — semi-covered bilateral cordon of the Kuban Agricultural Institute (according to Gusakov); 2 — of the Crimean Agricultural Institute; 3 — of Merzhanian-Bagrintsev; 4 — AZOS.