GARLIC PRODUCTION

1. Introduction

Figure 1 Photos of garlic just after harvest

Garlic is an annual bulbous herbaceous plant in the family Amaryllidaceae, which is grown for its pungent, edible bulb. Garlic is an herb that is grown around the worldin Rwanda garlic (part of Allium sativum species) or tungurusumu in Kinyarwanda is one of the significant spices related to onion, leeks, and chives. It is thought that garlic is native to Siberia, but spread to other parts of the world over 5000 years ago. It is mostly white with the characteristic cloves that form bulbs in allium members. The crop thrives on a pseudo-stem or sheath with beautiful flower heads. It features a pinkish white flower cluster with some whitish petals. Garlic is most commonly used for conditions related to the heart and blood system. These conditions include high blood pressure, high levels of cholesterol or other fats (lipids) in the blood (hyperlipidemia), and hardening of the arteries (atherosclerosis).In foods and beverages, fresh garlic, garlic powder, and garlic oil are used to add flavor.Garlic is majorly used for flavoring food and can be dried, ground or powdered for this purpose.

2. Varieties

One of the main varieties is the single-clove type while the other is multiple-cloves. China is home to the single-clove type with some 80% of production levels worldwideThe plant can either have a short, woody central stem (hard neck) or a softer pseudo stem made up of overlapping leaf sheaths (soft neck).Hard neck varieties produce a false flower stock which is known as a scape and produce larger garlic cloves

but in smaller numbers while soft neck garlic produces relatively smaller cloves and has a stem

Figure 2Hard neck variety and soft variety differentiated by the cloves numbers and the hard neck at the bottom of garlic.

which is very short and flattened and gives way to a pseudo stem. The garlic plant can have 6–12 flat, blade-like leaves, which can stretch up to 50 cm long, and it can reach 60 cm in height. Softneck garlic, like artichoke, do not normally produce flower stalks; however, climate can be a factor as to whether or not this actually happens. Although some types of Softneck garlic are suitable for cool climates, most do better in warmer environments. Your best chance for garlic seed propagation to be successful is to grow several varieties.

3. Agro-ecological requirement

Garlic is a hardy perennial, which can be grown in a variety of soil types. The plant performs best in a light, well-draining, organic soil with an optimum pH of between 6-7. It grows well in cool weather but can tolerate a temperature range of from 9–28 degrees centigrade. Garlic should be planted in an area that receives full sun for most of the day because it requires a period of cold followed by a period of light and heat in order to develop properly.

4. Seedling and nursery establishment

It is very important to prepare the soil properly for growing great, large, good-tasting bulbs of garlic. First, you need to know what kind of soil you have–and conducting a soil test is perfect for that. It can help you determine if you have the best soil for garlic–and if not, how to make it better. Fertilizing with organic fertilizers like manure and alfalfa and using cover crops to build fertility can help poor soil, so do not let it stop you from growing garlic. Garlic grows best in loose, good-draining soil. Sandy loam is the ideal type of soil for growing garlic, but plenty of small farmers do well with clay soils. If you have too much clay, there are several issues to deal with such as rotting of the cloves if it stands in water too long or dirty bulbs when it’s time to harvest since the clay clings to the outer paper garlic skins. This will be cumbersome to remove and may stain the outer wrappers. It can also make harvesting garlic more difficult, especially if the ground is dry and the clay has hardened.

5. Seed multiplication and certification requirements

Although you may see or hear it referred to as seed, seed garlic or even seed stock, the truth is garlic does not usually set true seed, and on those rare occasions when it does, garlic seed resembles the small, black seeds of onions. The flowers of garlic plants usually fade long before producing any seed. Of course, plants produced using garlic seed propagation are not likely to grow anyway and those few that do will take years to produce any garlic. Occasionally, top sets (or flower stalks) can be removed and used to increase seed stock, as some varieties may stimulate seed production. However, for the most part, garlic is reproduced and grown from cloves. Garlic seed propagation depends mainly on the variety used and the climate where it is grown. Garlic can be grown easily, and again, it is typically grown from cloves, not garlic seed. Youcan plant garlic cloves between March to June; provided it is early, enough for them to build strong roots systems and the soil is still manageable. Separate the cloves just prior to planting and locate a sunny area to grow them. Plant the cloves with the point facing upward about 2 to 3 inches deep and spacing about 6 inches.

Integrated soil fertility management

Garlic is more like potatoes than onions in terms of how it responds to pH and nutrient balance. Here is a general idea for basic soil composition for optimum growing
PH: Between 6.0 and 7.5 is the ideal pH for growing garlic.
Nitrogen: Garlic needs more nitrogen than most farmer’s think, mostly during its initial growth phase as it emerges and spreads its leaves. Adding organic manures, such as cow and poultry, are a great way to add nitrogen
Phosphorus: Phosphorus is needed for optimal root development.
Potassium: Enough potassium is critical for leaf growth and healthy bulb formation.
Sulfur: Sulfur compounds are directly related to garlic unique healing benefits and flavors. To add sulfur, sprinkle gypsum over your beds in the spring, after the plants have emerged and begun to leaf out.
Amending with manure when adding manure, use caution. You do not want to add manure too close to harvest time. Organic certification usually requires applying it no sooner than 120 days before harvest. Antibiotics, drugs, and GMO residue from animal feed take time to break down in the manure. Use of cow, poultry manure would be great improvement by mixing into the soil thoroughly before planting since that is when nitrogen concentrations high

6. Regenerative agriculture

Regenerative agriculture is a system of farming principles and practices that seeks to rehabilitate and enhance the entire ecosystem of the farm by placing a heavy premium on soil health with attention also paid to water management, fertilizer use, and more. It is a method of farming that “improves the resources it uses, rather than destroying or depleting them.”

Generally, garlic is one of the most beneficial of companion plants in the permaculture garden. Its chemical makeup means it repels a large number of potential pests, not only insects such as aphids but also larger mammals such as moles, squirrels and deer. Its pungent scent seems to be a primary reason for this, and its strong taste puts animals off trying garlic a second time. However, garlic also protects plants around it by accumulating sulfur in the soil. Sulfur is a naturally occurring fungicide, and its presence helps protect plants from soil diseases. Plants that particularly benefit from companion planting with garlic include fruit trees, cabbage, broccoli, kale, tomatoes, and cane fruits, such as blackberries and raspberries. Really, the only plants to avoid planting in proximity to garlic are peas and beans, as it appears to have a detrimental effect on their growth.

7. Land preparation

Garlic needs room to spread its feet, so you need to loosen your soil before planting. We are not huge fans of conventional tilling, but we find it necessary to prepare to plant cloves. We use it as little as needed; just two times immediately prior to planting. Since we use a three-year rotation for our fields, we till any given bit of land once (well, twice, but within 3 weeks) every three years.

Figure 3 Small plot prepared for garlic clove planting

The reasons we have been able to minimize tilling are the following Impamvu twabashije kugabanya inshuro zo kurima ni izi zikurikira:

Compost tea: A healthy soil is simply teeming with microorganisms – bacteria, fungi, yeasts and more – that create an intricate, living web. Traditional cultivation and fertilization damages this web. Compost tea helps restore it. We have a 1,100-liter tea to our fields at least twice each year to help rejuvenate the soil microbiology.

Cover crops: Also known as “green manure,” cover crops can add nutrients to your soil as well as help loosen the soil with their powerful root system. See which cover crops are ideal for loosening soil.

8. Fertilizer application

Garlic requires frequent applications of fertilizer in order to produce the highest yields and the largest, best quality bulbs.A proper nutrition should be ensured by supplying the crop with both macro and micronutrient elements which is achieved by application of basal and foliar fertilizers.Basal fertilizers e.g. DAP and CAN, are absorbed by the crop through the roots while foliar feeds e.g. OPTIMIZER and GATIT are taken up through the foliage of the crop. Soil analysis should be done in order to determine the amount of nutrients present before planting and manure can be added, depending on the organic matter levels of the soil.The crop needs different nutrients levels and composition at different growth stages. Proper timing is very critical for best results.

Early growth stage

This is the period between planting about 2-3 weeks after the sprouting of the cloves.The planting site should be drenched with OPTIMIZER 20ml/20l that helps in breaking dormancy and ensuring uniform sprouting.In order to promote strong early growth, maximize root development, ensure good shoot growth and supply food reserves to the young crop, spray it with GATIT SUPER START 50g/20l or LAVENDER 20ml/20l or VITABOR GOLD 30ml/20l or PLANT SOUL 20ml/20l.Use of DAP is critical

Vegetative growth

During this time the crop is actively growing and making food in order to accumulate enough resources for utilization during bulbing.To ensure continued growth and development, maintain vigorous, healthy leaf growth and to ensure that photosynthetic growth is not limited, spray the crop with GATIT SUPER GROWTH 50g/20l or LEGENDARY 40ml/20l or LAVENDER 20ml/20l.

The size of the bulb is majorly dependent upon the health level of the green leaves or tops at the time of bulb maturity. Top dressing is mostly done using CAN, although other basal fertilizers like NPK 23:23:0 could also be applied at this stage.

Reproduction stage

This entails bulb formation, development and maturity. The crop should be supplied with adequate nutrients during this stage in order to achieve the best.Spraying it with GATIT SUPER FLOWERS & FRUITS 50g/20l or LEGENDARY 40ml/20l or DIMIPHITE 20ml/20l or GREENPHITE 50ml/20l or VITABOR GOLD helps in;

Maintaining leaf growth
Maintaining early growth and bulb development
Maximizing dry matter and general quality of the bulbs
Maintaining bulb firmness and size
Ensuring ripening and early maturity
Improving the storage quality of the bulbs
Potassium-rich basal fertilizers like NPK 17:17:17 should be applied during this stage

9. Planting

Most garlic varieties do not produce fertile seed and therefore, the plant is mostly propagated from the cloves. The individual cloves are obtained by breaking apart the bulb. Cloves should be planted 5–8 cm deep, leaving 8–10 cm between individual plants and 15–20 cm between rows. They should be planted with the pointed side up and the basal plate positioned downwards. Roots grow from the basal plate.

Each clove produces a whole head of garlic.Although the bulbils produced at the top of the hard neck stalk can be used to produce bulbs, the process usually takes two years. In general, the size and weight of the clove planted will affect the ultimate size of the bulb formed. In a given planting of a single cultivar, bigger cloves usually make bigger bulbs. Use 30 kgs of cloves to plant 0.25 acre. The yield from this land should be approximately 1 ton, depending on soil type, local conditions, etc. Sandy soil makes for easier weeding, growth and harvesting, but any type will produce a good crop should the right additives, manure fertilizer, etc. be employed. Buri gapande gakora umutwe wa tungurusumu wuzuye.

10. Crop management

Various practices are adhered when managing a crop of garlic and they include:

Irrigation– the plant requires additional irrigation during dry periods but watering should be ceased a few weeks prior to harvesting, in order to allow the papery skin around the bulb to dry and to prevent the development of disease.

Pruning– the hard neck garlic should be pruned when the flowering stalks/scapes begin to straighten. Removal of the flower head directs the plant’s energy to bulb production. Softneck garlic does not require pruning.

Weeding– weeds compete with the crop for growth factors and harbor pathogens. Garlic is a poor competitor with weeds and therefore the garden should be kept weed free.

Mulching- this helps in retention of moisture and suppression of weeds. When the mulch decomposes, it releases nutrients into the soil that are absorbed by the plans.

11. Pests and disease

Pests

Figure 4 Onion Maggot

1. Onion maggot– infestation causes stunting or wilting of seedlings and plants commonly break at soil line if an attempt is made to pull it up. If infestation occurs when plants are bulbing, bulbs become deformed and susceptible to storage rots after harvest. Drench soil with PROFILE 440EC 60ml/20l or PENTAGON 50EC 20ml/20l

2. Thrips– these cause significant economic losses. They cut the epidermis of the leaves or stem and suck the plant sap creating white silvery patches on the deformed leaves.Spray ALONZE 50EC 5ml/20l or PROFILE 440EC 30ml/20l or DEFENDER 25EC 40ml/20l

Figure 5 Garlic Thrips

3. Nematodes– the common symptoms due to infestation include an erratic plant stand developing in the field, stunting of plants, yellowing, deformed bulbs, and stem swelling. Root system lacks fine roots and round or irregular lesions form on roots.Drench soil with ALONZE 50EC 10ml/20l or mix fertilizer 50kg with ADVENTURE 0.5GR 2kg whenever doing basal application of fertilizer.

Figure 6 Garlic infested with nematodes

Diseases

1.Garlic mosaic virus (GarMV) – infection causes formation of mosaic patterns on leaves, chlorotic mottling or streaks on leaves, stunted plant growth and reduced bulb size. Aphids transmit it.

Treatment: Control aphids with KINGCODE ELITE 50EC 10ml/20l or LEXUS 247SC 8ml/20l or PRESENTO 200SP 5g/20l

2. Damping off– these results in seed and seedling rot before they emerge out of the soil. The pathogen can als o attack the collar region of seedlings on the surface of soil, which rots and ultimately the seedlings collapse and die.

Treatment: Drenchsoil with PYRAMID 700WP 100g/20 Spray CHANCETYL ELITE 800WDG 50g/20l or MILLIONAIRE 690WDG 40g/20l

3. Bacterial soft rot– this is mainly a problem on mature bulbs. Affected scales first appear water-soaked and pale yellow to light brown. As the disease progresses, invaded fleshy scales become soft and sticky with the interior of the bulb breaking-down. A watery, foul-smelling thick liquid can be squeezed from the neck of diseased bulbs.

Treatment: Drench soil with GREENCOP 500WP 100g/20l or COLONIZER 440WP 100g/20l or TRINITY GOLD 425WP 100g/20l.

4. Purple blotch-the symptoms occur on leaves and flower stalks as small, sunken, whitish flecks with purple colored centres. These lesions may girdle leaves/stalk and cause their drooping. Infected plants fail to develop bulbs

Treatment: Spray COLONIZER 440WP 50g/20l or ABSOLUTE 375SC 10ml/20l or TRINITY GOLD 425WP 50g/20l

5. Colletotrichum blight/anthracnose/twister disease– symptoms due to infection appear initially on the leaves as water soaked pale yellow spots, which spread lengthwise covering entire leaf blade. Affected leaves shrivel and droop down.

Treatment: Spray RANSOM 600WP 15g/20l or DUCASSE 250EC 20ml/20l or PROVIDENCE 400WP 50g/20l

6. Fusarium basal rot/basal rot– Initially yellowing of leaves and stunted growth of plant is observed, which later on dry from tip downwards. In early stage of infection, the roots of the plants become pink in color and rotting takes place later while in advanced stage, the bulb starts decaying from lower ends and ultimately whole plant dies.

Treatment: Drench soil with PYRAMID 700WP 100g/20l or GEARLOCK TURBO 250WP 50g/20l

7. White Rot– the initial symptoms are yellowing and dieback of leaf tips. Later, scales stem plate and roots are destroyed. The bulbs become soft and water soaked, and as infection progresses, white fluffy or cottony growth of mycelium with abundant black sclerotia resembling mustard grain develops on the infected bulbs yellow discoloration. Infection can kill younger plants and stunt the growth of older ones. Diseased leaf tips and other tissues eventually collapse. Bulbs in storage develop a blackened neck, become shriveled, and outer scales become water-soaked. Some bulbs may sprout prematurely.

Treatment: Spray GEARLOCK TURBO 250WP 25g/20l or FORTRESS GOLD 720WP 40g/20l or TRINITY GOLD 425WP 50g/20l

8. Botrytis Rot– infection causes the stems to develop water-soaked and gray fuzzy fungal growth. This disease is also called “neckrot.”

Treatment: Spray EXEMPO CURVE 250SC ml15/l20 cyangwa IPRODE 500SC ml10/l20 or EXPLORER 3SL ml10/l20

9. Penicillium Decay– infection causes seed clove decay often resulting in stunted, wilted, and yellowing plants. Disease can also reduce growth. The fungus may sporulate on diseased cloves, appearing as a bluish-green mass.

Treatment: Spray ABSOLUTE 375SC 10ml/20l or TRINITY GOLD 425WP 50g/20l

10. Black mould – infection usually is through neck tissues as foliage dies down at maturity. The infected bulbs become discolored black around the neck, and affected scales shrivel. Masses of powdery black spores develop as streaks along veins on and between outer dry scales. Infection may advance from the neck into the central fleshy scales.

Treatment: Spray EXEMPO CURVE 250SC 15ml/20l or EXPLORER 3SL 10ml/20l or ABSOLUTE 375SC 10ml/20l.

12.Harvesting and post harvesting of garlic

Figure 7 Garlic harvested and in the process of being cured.

Garlic is ready for harvesting when the plants begin to turn yellow or brown and begin to fall over. Knowing when to harvest has always been tricky.Different varieties will often mature at different times.Harvesting too early will result in small bulbs that do not store well.Harvesting too late will force the cloves to pop out of the skins, making them susceptible to disease and resulting in unmarketable bulbs.To harvest, the bulbs should be dug with the shoots and roots still attached.The bulbs are harvested by digging the plant carefully and lifting the bulbs using a fork.In large scale, onion/potato lifters can be used to lift the bulbs.This should be done while there are still some green leaves remaining on the plant.After digging the plants, they should be tied in bundles of 10 to 15 and allowed to dry in a well-ventilated room.After about three to four weeks of curing, the shoots and roots should have dried down. The tops should then be cut about one-half to one inch above the main bulb and roots should be trimmed close to the base of the bulb. The harvested garlic can be used straight away or it can be cured for longer storage. Curing garlic can be achieved by hanging the plants in bunches or by spreading them out on a rack or screen. Clean bulbs by removing the outermost skins, being careful not to expose any cloves. Any remaining soil should be brushed away. The plants should be kept intact while they cure; the tops should not be removed until the garlic is dry. This should be carried out in a cool, dry place with good ventilation. Bulbs are then graded for market.

13. Storage

Fruit and vegetable storage is helpful to extend product marketability, avoid price drops, keep produce for processing, and reduce losses during long-term storage. While storage provides many benefits for farmers, several issues can arise that lead to reduced quality or increased losses. Certain types of fruits and vegetables may not be suitable for storage. Poor storage conditions and packaging can also reduce produce quality.

At higher temperatures of (26 –30°C) garlic can be stored for 1 month

Intermediate temperatures (4.4 –18°C) favors rapid sprouting and high relative humidity cause molding

At 0°C and 65% relative humidity, garlic stores for 28-36 weeks

a) Points to be considered when constructing storage structures for garlic

It should be constructed in such a manner so that it can maintain the required temperature and relative humidity.

There are two type of storage structures i.e. one row and two row storage structures. Hence, direction of erecting storage structure is more important. One row structure should be erected against the flow of wind whereas; two-row structure should be erected along the direction of wind. Therefore, single row should be constructed in North-South direction while double row structure should be constructed in East-West direction.

The width of one stake should not be more than 4 feet. The maximum height at the sides should be 5 feet and at the centre, it should be 8 feet. Length of two-row structure should not be beyond 40-60 feet whereas in one row it can be according to requirement. There should be minimum 4 feet working space in between two-row structure.

Bottom ventilation of I tool 7u feet should be provided for proper aeration.

The floor and sidewall should be constructed with wooden bantam or bamboos.

The roof should be constructed with asbestos sheet or mangaloro tiles or thatches. Galvanized iron sheets are not suitable for roofing material for storage structures. In case asbestos sheet or if galvanized sheets are used it should be thatched with dry sugarcane leaves or grasses during hot periods.

The structures should be construction at an elevated place. There should not be any waterbody or water stagnation around the storage.

b) How to reduces Losses

The leaves and roots of the bulb should be trimmed off in order to remove soil in order to prevent the movement of pathogens into storage

Selection of good varieties.

Judicious use of nitrogenous fertilizers and irrigation water

Timely harvesting and proper curing bulbs

Proper drying of leaves and shade curing

Fumigation and use of ventilated store reduces the storage losses •

Avoid storing the bulbs in bags

The storage room should be kept dry with a relative humidity of 70% or lower and the temperature should be 0-1°C. Under these conditions, the garlic can be stored for 6 to 7 months. Garlic that is intended to be planted as seed should be stored at 10°C and a relative humidity of 60% to 70%.

16. Marketing

Garlic is a high value horticultural crop in the onion family.Farmers in most parts of the country can be able to grow it and considerably increase their income because garlic has a good local market.It is mainly used as food flavoring and for medicinal purposes. Garlic has anti-feedant, insect stop feeding, bacterial, fungicidal, insecticidal, nematicidal and repellent properties.Garlic can be marketed as cloves or even as seedlings for establishment of garlic enterprises by youth.Once harvested before taking to the market,prepare the garlic plants for curing out of the sun and store in a shaded, dry place, preferably one that receives a draft.Tie bundles of 8-10 plants together, or use a mesh bag, and hang the garlic up for four to six weeks.This allows the bulbs to ‘cure’, developing the distinctive papery skinsOnce formed, trim off the roots and the stalks to around 1 inch above the bulb.Store in a light, dry location (but not in direct sunlight); it should keep for between six and eight months. Garlic is stored in net bags, crates, in pallet boxes, or in bulk bins.When stored in bins or boxes, there should be at least some vent space.Bags of garlic are usually stored on pallets and should be stacked to allow proper air circulation.Once completely dry, the bulbs can store for up to a year.