Vine production process
Preparation before graftingTo produce bench grafted vines, raw
material is needed, namely cuttings and buds.Cuttings : mother
vines of rootstock are trained in single pollard head or tte de
saule formed at ground level. They produce wood that will serve for
bench grafting. Cuttings measure 3 feet with a 1/4 to 1/2 inch
diameter and packaged in 200-bunch. Then, they are chopped in one
feet fractions with heel cut and disbudding to prevent new growth
of rootstock in the vineyard. About 10 varieties of rootstocks are
available to suit the different soil types.3 Feet cuttings
Cutting up in fractions
Buds : mother vines of bud wood are generally fruit-bearing
vines. Lignified vine shoots are collected, packaged in 200-bunch.
Their diameter must be below 1/2 inch. They are cut in one-bud
buds. In California, about 30 varieties are routinely multiplied.
The improvement of this stock by clonal selection has been
developed since 1960 in France in order to provide grapegrowers
with virus-free vines (fanleaf and leafroll viruses) presenting
cultural and production characteristics meeting their
needs.One-bud
Buds
Cutting Buds
Woods are stored in a cold storage (34 to 36F). Cuttings and
buds are cut and soaking (half a day to 2 days in water depending
on batches and nurseries) is done later. However, some people
prefer soaking the wood prior to cutting. Wood treatment is usually
done on buds, more rarely on rootstocks. After rinsing, buds and
rootstock fractions are stored in a cold room in plastic bags or
protected by a polyane to prevent their
desiccation.GraftingGrafting is the assembling of a one-bud with a
cutting. The cutting will form the underground part of the
grapevine.Omega grafting is usually practiced. This technique
requires no particular aptitude and a good yield is rapidly
achieved by workers even inexperienced. The cutting of the buds has
to be done as close as possible to the bud. Grafting is done
mechanically. Bench grafting
Grafting machine
A graft
Waxing and case fillingOnce the graft is done, a special wax is
used to replace the tie with raffia. This is done to consolidate
the graft and also to prevent the tissues from desiccation. The wax
contains hormones. The waxed grafts are set up horizontally in
plastic bin by 3000. They are sealed with nylon plastic so as to
incorporate one third of the volume with water. Water acts as a
moistening agent to prevent desiccation during the callussing
process.Callussing ProcessThe objectives of the callussing process
or forcing are :- getting a callus with a contour ridge between the
bud and the cutting- preparing the basis of the rootstock to the
production of the future roots- making the bud to develop along
with the first two or three leaves.
Cases are emptied from their water and placed in a hot room at
83 F and a hygrometry of 70 to 80 %. To prevent the buds from
desiccation, a P17 film and pine saw dust are placed on the bins.
At the end of callussing, grafts are waxed again and their heels
are soaked in a bath of growth hormone.
Greenhouse stratification
Cases in stratification process after 14 days
Grafts in stratification process after 9 days
After 8 days
PlantationPlantation is the final stage of grafted vine
production.First solution :
- Plantation in a greenhouse in little fertil pots.- 20 % are
planted this way.
The grafted vines are planted in a fertil pot. Forcing under
greenhouse aims at obtaining a shoot from the bud and roots from
the basis of the rootstock. This period lasts five to six weeks.
Regular watering and pest control treatments are required. At the
end of this stage, the plants are sorted to be delivered to
grapegrowers.Sorting is done following those criterions :- A normal
vegetative state with an enough developed shoot (20 cm)- A
sufficient root development, well spread in the pot.- A regular
callus at the graft point.
Second solution :- Plantation open-fields.- 80 % are planted
this way.- Plantation in nursery in May. About 100 000 grafted
vines are planted manually per acre.- Care by watering, hoeing and
pest control treatments.- The objectives are to obtain a vegetative
shoot and a good root system.- Pulling-up of the nursery around
November the 15th after leaf fall.Plantation
Field nursery
Sorting is carried out according to strict regulation
standards:- Lignified stem with a 8 inches minimum length.- Regular
and strong callus.- At least three well-developed and well-spread
roots.- A 7 inches minimum length from roots to graft
point.Trimming :- Pruning of the vine-shoot to two buds.- Pruning
of the roots at 3 inches- Waxing of the graft pointWrapping first
in a plastic film and then in a cardboard.Storage in a cold room at
34 - 36 F.Wrapped bare-rooted vines
