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Garlic (Allium sativum) is a bulbousplant of the family of genus Allium.It can be produced everywhere inFrance.

The garlic production is done byvegetative multiplication: a bulbgives several cloves. A plant of garliccorresponds to a clove.

We divide the garlic in two types ofvarieties:- The autumn varieties, includingpurple garlic (PRIMOR andGERMIDOUR) and white garlic(MESSIDROME,THERMIDROME, MESSIDOR).- The alternative varieties, or thespring varieties (CLEDOR,FLAVOR).

GarlicTechnical Sheet

� Crop rotation

The previous crop on the field must not be of the same type: Allium are to be avoided toprevent fungal problems (white rot in particular) and nematodes (Ditylenchus dipsaci). We shallwait if possible 5 years between two cultures of garlic.Moreover, oat, pea and corn are to be avoided as previous crops on the field, because they maybe favourable to the development of nematodes (Ditylenchus dipsaci). Wheat, barley andsunflower are the best choices, and they give the advantage to release the ground early.

� Choice of the land

The garlic culture does not require a very specific soil. It needs to be healthy and well-drained.argilo-calcareous and limono-clayey grounds suit particularly well.Garlic likes to grow in well exposed land and rather aerated (avoid wet zones or basins).

� Preparation of the ground

A deep plowing must be done to allow a goodaeration of the ground throughout thevegetative cycle of the garlic.The preparation should be done just beforethe plantation to obtain a soft ground withoutclods (rotating harrow or vibrocultivators), ata minimum of 10 cm to allow a good setting-up of the cloves. The ground preparationmust be at least as deep as the planting depth.

Technical information

Technical information

� Plantation

• Certification of seeds

It is essential to plant certified seeds,which obtained the blue label from theSOC (French Official Inspection andCertification Department for seeds). Thisplanting material is obtained from selectedvarieties free of diseases, virus and ofnematodes (Ditylenchus dipsaci). They aremore productive and more resistant.To obtain a high quality level garlic, theprofessionals of the sector set up a verystrict system for the plant’s production.The first generations are multiplied underinsect-proof tunnels to avoid any viralcontamination (aphids are vector ofvirus).

Throughout the vegetation cycle, technicians licenced by the SOC (French Official Inspection andCertification Department for seeds) visit and note the cultures. The absence of nematodes(Ditylenchus dipsaci, a quarantine parasite) is verified by sample analysis in laboratory. These analysesof plants lots in laboratory rather than the ground are a will of our specialists to obtain plantswith a highest standard quality. Moreover, the certification standards used in France are moresevere than European certification standards.

The garlic plants certification has adouble purpose: it guarantees thequality of plants for the producers,and thus a potentially very high yield,moreover it helps the work done ongenetic research.

� Plantation

• Period of plantation

- The autumn varieties are planted from October until the beginning of December.- The spring varieties are planted from January until March.

Technical information

• Densities of plantation and spaces

The plantation is realized with mechanical or pneumaticplanters, in 3, 6 or 9 rows. Garlic may also be plantedmanually.The garlic is planted in boards from 2 to 4 rows (usually 3rows), with a minimum of 45 cm between rows (consider 60cm in Organic production to be able to work with hoes).According to the equipment, boards measure from 150 to190 cm.The distances between the cloves on the row are from 8 to 10cm, this means from 8 to 12 plants on a linear meter.For autumn garlic, with traditional varieties such asGERMIDOUR or MESSIDRÔME with 8 plants on a linearmeter, we consider that we need 160 000 cloves / ha orapproximately 1 200 kg of seeds. With the new varieties suchas MESSIDOR or SABAGOLD, more productive varieties,with 11 plants on a linear meter, we consider that we need220 000 cloves / ha or approximately 1 500 kg of seeds.For spring garlic, with 10-12 plants on a linear meter, weconsider that we rather need 190 000 cloves / ha orapproximately 1000 kg of seeds.The depth of plantation must be homogeneous, around 6-7cm.

• Preparation and treatment of the seeds

The splitting of the garlic head, done manually or mechanically, has to be as close as possible to themoment of plantation.To fight against various fungi among which the white rot (Sclerotium cepivorum), the cloves can betreated with some products such as prochloraze (OCTAVE) or iprodione (ROVRAL AQUA FLO).In France, the use of the product called SIGNUM (boscalid + pyraclostrobine) is allowed untilJanuary 17th, 2017.

� Fertilization

The needs in fertilizer for a garlic culture in a ground normally provided in mineral elements are:- N: from 120 to 150 units- P: from 100 to 150 units- K: from 200 to 250 units.Besides, a soil analysis should help to define the precise needs in fertilizer.The basic phospho-potassium fertilisation will be brought on the ploughed land before all othersuperficial works. According to the results of the soil analysis it might be relevant to use afertilizer containing magnesia and sulphur.The addition of nitrogen will be split in 2 or even 3 times (between February until the end ofApril, according to weather conditions). It is important to choose fertilizers as sulphate whichbring some sulphur.

� Weeding

In order to keep the ground clean as long as possible during the culture we advise to spread somePROWL 400 = pendiméthaline 3,3 l / ha and some CENT 7 = isoxaben, in 2 times (twice 1 l /ha, just after plantation and then another one in January), on a wet ground.During the culture, we can use products such as FUSILADE MAX (fluazifop-p-butyl) in 1,5 l /ha or CENTURION 240 EC (cléthodime) in 0,75 l / ha to fight against monocotyledon.For the fight against dicotyledon, it is better to choose “clean” lands because very few weed-killers are authorised. The STARANE 200 = fluroxypyr split in 2 steps 0,2 l / ha is interesting, inparticular on bistort bindweed.

In organic as in conventional culture, the mechanical weeding allows to limit thedevelopment of weeds. Working several times with finger-weeder machines andspiked harrow can give very interesting results.

� Irrigation

In the garlic culture, irrigation is important during the plantation stage if the ground is dry andwith clods, it will help the ground to stick around the cloves and so it limits the risks ofdevelopment of Penicillium.Then, during the growing stage, water is needed from March to April (according to the rainfall)and particularly during the bulbing stage (period of development of bulbs). The irrigation will bepursued until maturity and stopped 10-15 days before the harvest.

Technical information

� Rust

The rust is one of the main diseases of the garlic. Due to afungus (Puccinia allii), the symptoms are orange blister onleaves. Hot and wet weather conditions are favourable to itsdevelopment. The first symptoms appear in spring, and canend with a total drying of the foliage and as a consequence aloss of yield.The fight against the rust has to be done in vegetation, withfungicides containing mancozeb (DITHANE), ortebuconazole (TESON) or even azoxystrobine (ORTIVA).

Phytosanitary protection

� White rot

The white rot is due to a fungus of the ground (Sclerotium cepivorum) which affects the bulbs. Theresult is a yellowing and a withering of the foliage. We observe on roots the presence ofmycelium as well as sclerota, organs of preservation of the fungus which will remain for yearsin the ground. In the case of a strong attack, we observe "circles" of sick plants in the field. Ifpossible, it is better to irrigate in order to maintain humidity in the ground.The only way to get rid of them is a treatment of the cloves with fungicides like prochloraze(OCTAVE) or iprodione (ROVRAL AQUA FLO).In France we are allowed to use the product called SIGNUM (boscalid + pyraclostrobine)thanks to an authorisation until January 17th, 2017.

The CONTANS is a preparation containing spores of a competing fungus(Coniothyrium minitans). It may be used as a treatment of the ground. Theobjective is to limit the inoculum of Sclerotinia. Both are sensitive to the same

agents of destruction. This product is authorized in Organic production.

In organic production, several products containing copper are approved: hydroxidecopper (HELIOCUIVRE), sulphate copper (BORDEAUX MIXTURE) …It is also possible to apply foliar fertilizers or biotonics containing lithotamne,

wetting agent, or decoctions of plants like horsetail and nettle.

� The disease "café-au-lait" (light brown) marks

This disease is due to a bacterium, Pseudomonas fluorescens. We observe on the bulbs a brown tintof the skins which depreciates the visual aspect of the product. For the moment, we do notknow the way for fighting this disease. The only preventive method is a judicious use of thenitrogenous fertilization. We can also work on the density of plantation, and on the date ofharvest to hide the brownish skins.

Harvest and storage

� Harvest

In our region, the Drôme, the harvest often takes place aroundmid-June for autumn varieties, and in July for spring varieties.The stage of harvest is controlled visually, when 2/3 of theleaves are flabby and begin to turn yellow. We can also considerthe number of skins recovering the cloves (4 are needed).Nowadays, the harvest is mechanized. Most of the machines areharvesters toppers: the stems are cut and remain on the field,while bulbs are sent to boxes which can directly be put in thedrying system. In some places, people still harvest the garlicwith the tops. The garlic remains a few days on the field to dry,the piles are usually elongated in a windrow style this way theheads do have direct sunlight on them. After that, the garlic canbe stored under a shed to finish drying.

� Drying

The garlic must be very quickly ventilated after harvest to avoid therisk of becoming too warm and spoilt.In most of the situations the drying is done by dynamic ventilation,and this is a necessity for the garlic without tops. For the garlic withthe tops it is essential to make sure there is a good circulation of airbetween bunches.The objective of the drying is to extract approximately 30 % ofwater to ensure a good storage. 3 weeks are needed to complete theprocess of drying. The garlic is then sorted out and calibrated.

� Storage

A good preservation depends largely on the quality of the drying. The garlic is stored into bigwooden boxes (palox) or in packing cases, under a ventilated shelter.It may be kept at room temperature (= 15°C) to sell it during autumn. For a longer conservation, itis necessary to organise the storage in cold room with a temperature slightly lower than 0°C (-2°C)and with permanent air renewal.Kept in good conditions (without diseases and humidity), the garlic can be stored several months.

� Average values of yield

The average yield varies between 7 to 10 tons / ha of dry garlic (between 4 to 6 tons / ha of drygarlic in Organic production). It also varies according to the variety, the number of plants perhectare, the type of ground and the climate.

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