feasibility and technical report on onion cultivation in conakry-jravishanker-2005

Feasibility & Technical Report on Onion Cultivation in Conakry. West Africa.

Submitted to

TOPAZ INDUSTRIES S. A. R. L. New Guinea. By Ravi Shanker Consultant. Jove Agro Sciences. India. October 2005.

Feasibility & Technical Report on Onion Cultivation in Conakry. West Africa. By - Ravi Shanker. 2005.

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Contents: Page No. Summary 3 Cost Break up for 5 year project on Onions in 50 hectares 3 Geophysical conditions of the site 4 Climate 5 Potential Crops 6 Introduction to Onions 7 Cultivars 7 Indian Cultivars suitable to Conakry 8 Soils and Climate 8 Land Preparation 9 Planting systems 9 Sowing 10 Direct seeding 10 Transplantation 10 Nutrient management 11 Water management 12 Bulbing 13 Bolting 14 Weed control 14 Insect Pest and Disease control 15 Cultivation 17 Harvesting 17 Curing 18 Short storage 18 Cleaning 19 Packaging 19 Long duration storage 20 Marketing 22 Soil Fertility Analysis Chart 23 Storage structure 24 Land topography and physical condition 25 Farmland map and tentative crops 26 Fertilizer requirement map 27


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Summary: Location: Koteya Farm Land . around 100km from Main City. Land available for Onion cultivation: 50 hectares. For other crops: 48 Hectares Feasibility: farming operations re feasible. Water: Excess in Monsoon. However bore well needed to maintain controlled supply through out the year. Labor availability: Farming should be semi-mechanized at the beginning. Economics: Cost is ‘estimated’. Actual costs may vary. Establishment costs are same for all vegetable crops/fruit crops.

8 Initial investment: Minimum USD 75,000 to 200,000

8 Gross Returns in first year: USD 100,000 to 450,000 Cost breakup1: Establishment Cost: for 50-100 hectares

Units Cost in USD

Water pump 1 460 Drip /sprinkler systems 50 35000 Generator 1 460 Transplanter 1 3000 Tractor 1 10250 Tractor attachments like plough, earth tiller, extractor, weeder, sprayer,

6 5000

Tractor Trolley 1 2700 Hand tools like plough, weeder, 30 3000 Spray pumps 10 500 Onion Storage Structure 1 12000 De Humidifiers 6 2100 Blowers 4 250 Storage bags 50000 5800 Staff quarters Renovation 5000 Kitchen 365 days 17000 Material store 1 2000 Overseas travel cost 5 24000 Cost of land One time 20000 Total fixed expenses 148520

1 The costs are worked out on tentative market value plus cost of shipment from India. However they are purely indicative and local currency and market rates should be considered while taking decision.


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Recurring costs specifically for Onions and similar rooters (vegetables) Recurring costs: Seeds Per year 4500 Fertilisers Per year 5000 FYM Per year 3000 Pesticides (50 hectare x 2 times) Per year 1200 Diesel (tractor + pump) Per year 10000 Transportation 250 truck loads Per year 15000 Local Wages Per year 15000 53700 Human resource: Manager (1) Per year 6000 Supervisor(1) Per year 4000 Watchmen(2) Per year 1000 Field Technicians(3) Per year 6000 17000 Total working expenses per year 70700

Returns on Capital Invested: Establishment Cost: for 50 hectares Units Cost in USD Working expenses for 5 years @ 5% inflation

367640

Fixed costs 148520 Miscellaneous expenses @ of 10% 51616 Total expenses 567776 Return on production at 50 tons/Hec./year At 180 per ton for 50 hectares

450000

Total Returns in 5 years 2250000 Net Returns in 5 years 1682224 Net average returns per year 296% 336445 Net average returns per year on single crop basis

148% 168222

Add Stevia crop in another 48 hectares

Establishment cost of Stevia 820000 Working expenses for 5 years 700000 Total 1520000 Returns on production at 6tons/hec/year @ of 2280 per ton for 48 hectares

656640

Total returns in 5 years 3283200 Net returns in 5 years on Stevia 2626560 Net average returns per year 173% 525312


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Total returns from 98 hectares 5533200 Average annual investment (Onion+Stevia)

417555

Average net Returns per year (Onion+Stevia)

206% 861757

Geophysical conditions of site:

Topography: The site is located around 100km from the main city. Undulating topography with couple of rivulets crisscrossing the site totaling around 100 hectares. Out of this about 50 hectares is located on low laying areas and remaining half is on slopes. The low laying areas are water logged in monsoon. There is need to develop drainage systems to maintain permeable soil moisture levels in high rainfall season.

As the land is virgin it has good potential for agriculture practice. However the initial land clearance costs could be incurred to make it cultivable. Clearance of bushes, trees and weeds could be done mechanically.

There is approach road. However at couple of points the turnings need to be straightened for the convenience of heavy vehicles. The farm house with little modifications could be sued for storing onions for shorter duration. Other rooms could also be used for store tools and machines.

Soils: There are tow types of chiefly available in this site. One is with high amount of organic matters and second is medium to moderate levels of nutrition. Soils are medium black with sandy to loam. Rubbles are found in parts of higher elevation. The level of phosphorous is less and hence the onions don’t grow to proper size. Application of required amounts of phosphorous is recommended.

Water availability: Due to heavy rainfall and existence of couple of rivulets and sufficient ground water levels the risk of water scarcity doesn’t exist. There is a bore in the farm. However its depth and water availability need to be measured. Installation of drip or sprinkler systems could help in better crop and water management.

Climate:

Sunshine: The sunshine levels are too low in the months of August and September. Overall the day lengths are small in monsoon period. This could be deterrence in onion bulb formation that is established in pre monsoon period.

Rainfall: Monsoon period should be avoided for any king of cropping activity. Heavy down pore adversely affects plant growth and survival. Over all the region receives highest rainfall and the crisis for water is not there.

Relative Humidity: Humidity levels are also very high at 70 to 85 in monsoon. This adversely impact storage of goods. De-humidifiers should be used for better storage life of product. In rest of the season the humidity levels are optimum for storage.


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Potential crops: Following are some of the vegetable crops.

Vegetables:

Onions Potatoes Cauliflower

Cabbage Carrot Brinjal /Egg Plant

Spices

Ginger Garlic Chilies/Pepper

Fruits:

Banana Papaya Orange


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Introduction to Onions:

Onion (Allium cepa) is a popular vegetable grown for its pungent bulbs and flavorful leaves. It is widely grown throughout the world.

The bulb is composed of concentric, fleshy, enlarged leaf bases or scales. The outer leaf bases lose moisture and become scaly and the inner leaves generally thicken as bulbs develop.

The green leaves above the bulb are hollow and arise sequentially from the meristem at the innermost point at the base of the bulb. The stem remains very small and insignificant during vegetative growth. Long days do not induce reproductive growth but tend to accelerate development of

the seed stalk once it has been initiated by vernalization. Temperature has a major role in inducing bolting.

The onion root system is fibrous, spreading just beneath the soil surface to a distance of 30 to 46 cm. There are few laterals, and total root growth is sparse and not especially aggressive. Therefore, in monoculture, onions tolerate crowding, particularly in loose, friable soils such as peat and muck. Competition from aggressive root systems (as from weed growth) severely limits onion growth.

Cultivars differ substantially with respect to the threshold day length required for bulbing. Other factors such as temperature may interact with day length to modify the bulbing response. In all cultivars, bulbing is accelerated with increasing temperature. Cultivars In Onions male sterility is a genic-cytoplasmic factor and male fertility can be restored in plants carrying the sterility factor by introducing a single dominant allele. Any line carrying the sterile trait must be cross-pollinated, and seeds harvested from male sterile plants isolated with a normal pollen-bearing parent will be hybrid seed. Hybrids have higher yield, larger and more uniform bulb sizes than open-pollinated cultivars. Hence we should go for Hybrid variety and labels on pack should be checked for details.

Suitable type of cultivars:

The bulb onion cultivars are grouped into short, intermediate, and long-day types. Short-day onions (12 to 13 hour threshold) are generally mild, soft fleshed, and suitable for storage. For Conakry these types are suitable.

Long-day onions (over 14.5-hour threshold) if grown in the lower latitudes, will not form bulbs, and only green onions would be produced. In contrast, short-day types grown in the higher latitudes will bulb very quickly and will be little more than sets in size.

The intermediate-day cultivars (13.5 to 14.5-hour threshold) are relatively soft-fleshed and used primarily for fresh trade. They are grown in areas of mild temperatures lying between 32 and 38° latitudes.


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Daylength Color Pungency

Short Brown Sweet Red Sweet Red Pungent White Sweet Yellow Sweet Yellow Pungent

Intermediate Brown Moderate Red Moderate White Moderate Yellow Moderate

Long Brown Pungent Red Pungent White Pungent Yellow Sweet Yellow Pungent

Indian Cultivars suitable to Conakry: (subject to field trials) Red Onions: N-53 (Niphed53) and Agrifound Dark Red are cultivated during monsoon Season; Pusa Red and Arka Niketan during winter season. Pest or disease resistance varieties: Punjab Red Round, Punjab Narroya. Good varieties for Storage: N 2-4-1, Agrifound light red, Arka niketan Soils and climate Onions can be grown successfully on any fertile, well-drained, non-crusting soil. The optimum pH range, regardless of soil type, is 6.0 to 6.8, although alkaline soils are also suitable. Onions do not thrive in soils below pH 6.0 because of trace element deficiencies, or occasionally, aluminum or manganese toxicity. Clay soils often produce a hotter onion, while sandy soils require more fertilizer and water than loamy soils. It is best to avoid heavy clay or course sandy soils.

Optimum temperatures for plant development are between 13 and 24°C, although the range for seedling growth is narrow, 20-25°C. High temperatures favor bulbing and curing. In India the temperatures rise up to 380C also.

Land Preparation Prior to planting, soils should be plowed and disked sufficiently to eliminate debris and soil clods. In most commercial areas, beds 0.9 to 1.0 m wide are formed, and two to six rows are seeded or planted on the bed. If two rows, they may be two-line (twin) rows with plants staggered to achieve proper spacing and high population density.


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8 Shred litter from previous crops or other weeds or roots with a rotary mower and disc into top few inches of soil as soon as possible.

8 Deep-turn soil at least three to four weeks prior to planting using a moldboard

low.

8 Adjust equipment so that all litter will be buried at least eight inches deep.

8 Form beds with a roto-tiller or other bed-shaping device as soon after turning as possible. Apply broadcast fertilizer and insecticides during this operation. Do not use a disc-harrow because this will re-compact the soil.

8 Beds should be 6 or more inches high to allow good drainage. If rain doesn’t

occur, irrigate to firm beds a couple of days before planting or setting plants. This is essential for direct-seeding to allow planting at a uniform depth.

8 Plant seed 1/4 to 1/2 inch deep and set transplants one to two inches deep.

Some growers cultivate shallowly after transplanting to throw soil to the plants. If this is done, pre-emergence herbicides need to be applied after plowing.

8 Do not plant too deeply as this could cause disease problems.

Planting systems Three systems of planting may be employed:

8 Direct seedling is preferred and gives excellent results where the season is sufficiently long to provide early pre-bulbing growth. (in Conakry we do not have enough time for this. However this could be experimented)

8 Transplants normally have three to five well-formed leaves at transplant time. Transplant leaves are pruned during growth prior to field setting, facilitating handling and increasing plant hardiness. (Transplants could be prepared on a plot for desired hectares. But these transplants should be manually planted)

8 Sets are used in some areas to ensure large bulb size and uniform maturity. Sets are small dry bulbs, approximately 12 mm in diameter, produced the previous season by seeding thickly or growing under conditions favoring rapid bulbing. (this is most suitable and can be done mechanically)

Sowing Ultimate yield of onion is determined by the number of leaves that are formed prior to bulbing. Since bulbing in each cultivar is triggered by a specific day length, early planting is the most effective method of improving bulb size and is a primary factor contributing toward yield. However cool air temperature or cool wet soils could influence the stand and crop maturity. Seeds are sown 6 to 18 mm deep in heavy mineral soils, deeper in light mineral soils and mucks. Excessively thick seedlings of bulb onions may delay maturity, however necks tend to be thinner than in sparse seedlings, and bulbs are somewhat more globular in shape.


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Direct seeding Using coated seed (shown) and precision seeding, the seeding rate can be adjusted easily for projected bulb size. For normal storage onions, seeds are spaced 7.5 cm apart. When small boiling, pickling or pearl onions are desired, spacing would be reduced to 2.5 cm in the row. Large bulb size is promoted by spacing of 10 cm or more. Use four or six rows on a bed, with those rows being 9 to 18 inches apart. Increasing the number of rows on the bed makes it harder to control diseases due to decreased air drainage and the difficulty of getting good spray coverage. Precision planters are available for accurate seed placement in direct seeding operations. Grade uncoated seed to a fairly uniform size for more efficient direct seeding. Direct-seeded onions can be planted at various in-row and between-row spacing. Generally, they are planted on six-foot wide beds with in-the-row spacing varying from four to six inches and between row spacing of 10 to 18 inches. A seeding depth of ¼ to 1/2 inch is adequate. Plant in a moist seed bed (irrigate, if necessary, a day or two before planting) and keep beds moist until plants emerge. Planting in a dry bed and trying to “irrigate seedlings up” usually results in poor stands and uneven growth. Irrigation must be light and frequent until plants are established. Transplants For seed bed production, space rows nine to 14 inches apart and plant 20 to 30 pounds of seed per acre depending on row width. The seeding rate should be about 60 to 70 seed per linear foot. Plant from July 15 to August 5 to have transplants ready for the field in mid September. If plants are set four inches apart in the row (with four rows per six foot bed) approximately 90,000 plants will be needed to set an acre. Many of the seeding considerations mentioned in the direct seeding section also apply to transplant beds. Prepare transplants in green house to ensure timely supply. After transplants are pulled from the seed beds, clip the tops and roots. Clip tops to allow about four inches of foliage to remain. Clip roots leaving only 1/4 to 1/2 inch. Use only strong, disease-free transplants. Plants should be healthy, vigorous and a minimum of 1/4

inch in diameter. Set plants one to two inches deep and surround them with soil. Irrigate immediately after setting to further firm the soil around roots, reduce air pockets that dry out young roots, and ensure good soil moisture for new root growth. Nutrient management Onion responds very well to organic manure. Organic manure at 25 to 40 t/ha is recommended to obtain high bulb yield. Onions require more fertilizer than is used in most vegetable production and respond well to additional fertilizer applied 40 to 60 days after seeding or transplanting. Apply 64kg of Urea after 30 days of sowing. Apply only small mounts of nitrogen at one time. No more than 30 pounds of actual nitrogen should be applied in one application. Initial nitrogen applications can be reduced by 20 to 30 pounds when onions follow peanuts, soybeans, or other legume crops. Phosphorus (P) is essential for rapid root development. It is not very much available at low soil temperatures. It is best to band at least part of the phosphorus about two inches to the side and two inches below the seed at seeding or three inches below and to the


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side of the transplant at setting. Always use a starter fertilizer DAP at the rate of 109kg per acre at planting. Nitrogen (N), if too little nitrogen is available, onions can be severely stunted and more susceptible to diseases. High nitrogen application rates produce a succulent plant that is more susceptible to winter injury disease and to the production of flower stalks. Onions highly fertilized with nitrogen do not store well. Excess nitrogen late in the growing season delays maturity and causes doubling. Fertilizers containing ammonia are mildly toxic to onions, so exercise caution when using ammonium-based fertilizers. Potassium (K), if applied in a concentrated band near the seed or transplant, can result in damage and stand reduction. Potassium is also subject to leaching from heavy rainfall or irrigation. A low potassium level makes plants more susceptible to cold injury. Apply 134kg Murate of Potash in small amounts throughout the growth of onions. Sulfur (S) is an essential element for plant growth. Early applications of sulfur are advisable in both direct-seeded and seedling transplant beds. To minimize pungency, fertilizers that contain sulfur should not be applied after bulbing begins. But do not completely eliminate sulfur from the fertility program. Present recommendations call for 40 to 60 pounds in the seed beds and 35 to 55 pounds for crops grown to maturity. Apply sulfur as a split application to avoid deficiency. Boron (B) is required by transplants grown in plant beds as well as for direct-seeded or transplanted onions in the field. If the soil test shows boron levels are low, apply one pound of boron per acre. Boron can also be applied foliarly. Zinc (Zn) levels determined to be low by soil testing can be corrected by applying 2.56 kg zinc sulfate per acre. Excessive amounts of zinc can be toxic, so apply only if needed. Zinc is usually added in the general fertilizer in the early part of the crop year. Magnesium (Mg) If soil pH is adequate and the soil-test magnesium level is low, apply 10kg of magnesium sulfate per acre in the fertilizer. Onion plants utilize substantial amounts of nutrients. Based on a yield of 18 t/ha of bulbs, the plants remove an average of 66, 11, and 70 kg of N, P, and K respectively. Soils differ widely in fertilizer needs, depending on production history, soil type, and analysis. Hence go for regular soil tests and apply needed dosage of NPK. Mineral soils on average contain 90 to 112 kg/ha of N and 56 to 168 kg/ha of P2O5 and K. N, P, and K application of about 160, 90, and 40 kg/ha, respectively, is recommended. One or two side dressings of nitrogen are applied during a season through the irrigation system. Onions require only P2O5 before seeding and require N when active growth starts and twice thereafter. Insufficient N will induce early maturity and reduce bulb size; high N may increase bulb size and cause large nicks and soft bulbs with poor storage quality.

Minor element deficiencies, particularly zinc and copper, may be encountered. Suggested corrective rates are 11 kg/ha of zinc or 17 to 28 kg/ha of copper, applied every two to three years. Relatively high levels of sulfur are utilized by onions, but corrective applications vary widely, according to soils, leaching losses, and presence of sulfur contaminants in the atmosphere. If applied, sulfur will acidify the soil, and therefore, liming rates should be adjusted accordingly.


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Water management Onions require uniform moisture throughout the growing season. Fields that suffer growth retardation may produce excessive numbers of doubles or splits, reducing the number of Grade 1 bulbs. Furrow irrigation is generally used. Light sandy soils are irrigated with overhead systems or by subsurface seep irrigation where the soil profile allows. Onions at the bulbing stage utilizing substantial amounts of water, although excessive moisture must be avoided during the growing season. Cost of Drip irrigation system in Onions that could control water requirement, fertigation and pesticide application. Inline drippers are applied. Sr. No.

Description (Row spacing 1.5mts.)

Rate Unit Qty. Amount

(A) Fixed cost 1. Screen Filter 25 cum/hr 55.00 Nos. 1 55.00 2. Ventury assembly complete 16.50 Nos. 1 16.50 3. Ventury Manifold 2” Metal 37.70 Nos. 1 37.70 Total USD 109.20 (B) Variable cost for drippers 4. RPVC pipe 63mm-4kg/cm2 0.75 Mtrs. 36 27 5. RPVC pipe 50mm-6kg/cm2 0.72 Mtrs. 66 47.50 6. Lateral line 16mm-2.5 kg/cm2 0.12 Mtr --- 0 7. Turbo drippers 8 lph 0.05 Nos. --- 0 8. Turbo line 12mm-4lph 30cmc/c 0.18 Mtrs. 2904 522.70 9. PVC control Valves 50mm 5.45 Nos. 2 10.9 10. Flush Valve 50mm 1.77 Nos. 1 1.77 11. Fittings and Accessories L.S. --- --- 50.00 12. Installation Charges 20.00 679.87 TOTAL USD 789.00 OR (C) Variable cost for sprinklers 4. RPVC pipe 63mm-4kg/cm2 0.72 Mtrs. 36 25.92 5. RPVC pipe 50mm-6kg/cm2 0.72 Mtrs. 66 47.52 6. Lateral line 20mm-cl-2 0.19 Mtr 600 114.00 7. Sprinkler head complete 2.73 Nos. 60 163.80 8. PVC control Valves 50mm 5.45 Nos. 2 10.90 9. Flush Valve 50mm 1.77 Nos. 1 1.77 10. Fittings and Accessories L.S. 50.00 11. Installation Charges 20.00 464.00

TOTAL USD 573.00 The onion has a shallow root system, with most of its roots in the top 12 inches of soil. Onion continues to produce new roots (three or four per week) throughout the growing season as older roots die. Root growth is most active during early plant growth. Proper soil moisture is critical for continuous root growth and for supplying the needs of the foliage and bulb.


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Prior to emergence and during the first three weeks of seedling growth, it is essential that adequate moisture be maintained in the top three to four inches of the soil. Depending on the soil type, temperature, wind velocity and rainfall, this may require daily applications of 1/10 to 1/4 inch of water. The largest amounts of water are required during the period from bulbing through maturity. 11/2 inches of water per week are required to satisfy these needs. Over-watering just before harvest can increase disease, splits and doubles. A week before harvest, discontinue watering. This makes undercutting easier and encourages the onion to form protective scales. Bulbing Bulbing in short-day cultivars occurs when a critical day length longer than 101/2 to 11 hours is reached. Onion plants require a certain amount of leaf tissue before they respond to day length and until that time, they behave as immature plants and produce only leaves. Once sufficient leaf tissue has developed, onion plants can perceive the bulbing stimulus and will bulb if the day length is long enough.

Bolting Bolting occurs when the onion produces a flower and it results in a seed head. Bolting is also referred to as hard stems, seed stems, or buttoning. The process is influenced mainly by temperature, plant size and variety. Once onion plants reach a certain size, (usually 7 to 10 leaves), exposure to night temperatures below 50 degrees F for a period of two to three weeks usually causes some bolting. High temperatures in early growth also encourages bolting. This is primarily due to the effect of warm temperatures that produce large plants. Transplants about 1/4 inch in diameter do not bolt because they are not large enough to perceive the bolting stimulus. Early planting and high dose of fertilizer application can also lead to bolting. Weed control Onions are not good competitors with weeds. Cultivation, if used, must be shallow to avoid root damage. Chemical weed control is the most cost-effective method. Crop rotation is important to maintain land free from troublesome weeds. During rotation, avoid lands treated with herbicides to which onions are sensitive. Many of the herbicides used for weed control in agronomic crops (peanuts, soybeans, corn, cotton, grain sorghum) have not been thoroughly tested for onion sensitivity. The residual soil life, particularly of the newer compounds, has not been fully established. It is important to keep a record of the herbicides used on fields and to check herbicide labels for crop rotation guidelines. Herbicides that have the potential to carry over and cause problems in onions include Diuron, Pursuit, Cadre, Zorial, Broadstrike, Grazon P+D, Reflex and Command.


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Pre-emergence herbicides - Apply pre-emergence herbicides within three days of seeding or transplanting and before weeds begin to germinate. Once the weeds have germinated, they will not be killed by pre-emergence herbicides. Pre-emergence herbicides require moisture for activation, so if rainfall does not occur within five days of application, apply 1/2 inch of irrigation. Most pre-emergence herbicides begin to lose their weed control ability about 60 days after application. Post-emergence herbicides - Application of a post-emergence herbicide is critical to onions. Apply a post-emergence herbicide only after the onions have acquired three to four fully developed leaves, and do not apply after onions begin to bulb. Apply a post-emergence herbicide when weeds are at the smallest size that coincides with the proper onion growth stage. Weeds exceeding the four-leaf stage might not be killed. Never use a non-ionic surfactant, a crop oil concentrate or any additive in combination with a post-emergence herbicide. These materials have the potential of breaking down the waxes on the onion leaves and severe onion damage can occur. Apply a post-emergence herbicide with a well-calibrated sprayer using appropriate nozzle tips, pressure and water volume. Pre-transplant herbicides - All pre-transplant herbicides must be applied to a well-prepared, weed-free soil. When transplanting into treated soil, minimize disturbance of treated soil. Delay cultivation as long as possible. Insect, Pest & Disease control Field and storage diseases reduce profitability in Onions. Field diseases include purple blotch, Stemphylium blight, anthracnose, downy mildew, Botrytis leaf blight, pink root, smut, smudge, and several basal rots. Storage diseases include some of the common field rots, black mold, botrytis neck rot, and bacterial soft rot. Downy Mildew is indicated by pale green, oval, slightly sunken spots on leaves. Bands of yellowish and greenish tissue may be evident, and a fuzzy, purplish mold may appear in diseased spots. Blast or Tip Blight is indicated by numerous white to light tan flecks or spots on leaves. Affected leaf tips may die back. The foliage in the entire field may turn tan, then brown, and collapse and die within a week. Cloudy, humid weather with temperatures of 60 degrees F or above encourages leaf diseases. The use of fungicides for the control of these diseases is highly beneficial. Purple blotch Small white sunken spots develop on the leaves. These enlarge, become

zonate and under moist conditions, turn purple. Infection can cause a semi-watery rot on necks of bulbs that turn yellow-red in color. Infected bulb tissues eventually become papery. This pathogen is widespread. The optimum temperature for disease development is 21 to 30°C. Therefore, it is most serious in hot, humid climates.


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The fungus is seed-borne. Infected onion debris has been implicated as an infection source. Red Creole. Taliana Red varieties of Hungary is reported to be resistant to this fungus. Nitrogen fertilizer at low and high rates will incrase the prevalence of disease.

Stemphylium leaf blight (Stemphylium vesicarium) has been reported from Europe, Africa, North and South America, and Asia. Foliage losses of 80 to 90 percent have been reported. Disease symptoms are very similar to purple blotch. Lesions are light yellow to brown, watersoaked and progress from the tip to the base of leaves. The conidia have up to six transverse septa, besides several vertical septa. Wet and warm conditions favor the disease spread.

8 Long rotations with unrelated crops and good drainage system should be employed to avoid this fungus. Application of high rates of calcium superphosphate and potassium fertilizer will reduce infection.

8 Routine (weekly interval) field sprays with dithiocarbamate fungicides, particularly mancozeb and chlorothalonil reported to be effective.

Anthracnose (Colletotrichum gloeosporioides) favors hot (24 to 29°C) and wet conditions. The disease over winters in sets and soil, and spores are spread by wind, splashing water, and tools. The leaves become twisted due to infection.

Downy mildew (Peronospora destructor) attacks young plants, appearing as white specks, usually confined to the oldest leaves of young plants. A white mold develops rapidly in cool damp weather and progresses down the sheath, and plants eventually fall over and dry up. Spores are carried long distances by air currents.

Botrytis leaf blight, commonly termed blast, is caused by several Botrytis species. The disease first appears as white specks on leaves, expanding to cause a dieback from the leaf tips. Tops may be killed completely within a week, and entire fields may be affected. Frequently, blight follows previous damage from insects, disease, mechanical damage, or air pollution.

8 For control, young plants can be treated with mancozeb at weekly intervals until bulbing begins.

Basal rot, caused by Fusarium species, results in a breakdown of inner scales. Outwardly, the bulb may appear normal. It eventually becomes soft, however, and will develop a watery rot under moist conditions or a dry shriveled bulb in a dry environment. The disease is most severe in warm areas with poor soil drainage.

Thrips (Thrips tabaci) are minute insects that cut or "rasp" the epidermis of leaves or stems and suck the plant sap resulting in white blotches on leaves. Severe infestations result in leaf blasting and collapse. Bulbs become distorted and undersized. Infestations are more severe in dry seasons than in moist, and entire fields may be destroyed. The insect has many host plants. Adults and nymphs overwinter on plants or plant debris, or in

weeds bordering the field. Most of the insects are female, which can reproduce without a male. Eggs are thrust into the leaves and will hatch in 5 to 10 days.


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8 Diazinon sprays at 7-10 day intervals are recommended to control thrips. Up to six applications may be necessary and good coverage is essential.

Nematodes Onions are sensitive to nematode injury. Both rootknot and sting nematodes can cause damage to onions. Potential onion growing sites should be sampled to determine what nematodes are present. The presence of either of these nematodes should justify a treatment for nematodes.

Onion Maggots Onion Maggots are attracted to soil that has a high level of decomposing organic matter. Before direct seeding or transplanting onions, deep-turn crop residue to help avoid this problem. Wet years favor onion maggot infestations. The maggots attack weak plants and early plantings. Small white maggots up to 1/3 inch long bore through the underground portion of the leaves and into the bulbs, causing the plants to become flabby and turn yellow. Large bulbs that are not completely destroyed will rot in storage. The adult onion maggot is a fly similar to the common housefly. However, the adult onion maggot is smaller with straighter, longer wings. Good land sanitation is necessary. The onion maggot fly is attracted to fields where post-emergence herbicides are used for weed control because of the decaying plant matter. Where several applications of Post-emergence herbicides are used, expect a continuous maggot problem.

Cultivation Cultivate shallowly as often as needed to control weeds, but do not put excessive soil around the plants. Cultivations are often beneficial when used with side dressings or to improve root aeration after successive heavy rains. Once onion roots have begun to extend into the row middles, discontinue cultivations. Late cultivations can cause root pruning, damage which often leads to water stress and possibly to invasion by diseases.

Harvesting Onions are ready for harvest when the leaves collapse. For storage, onion tops should have broken over before harvest and the necks should collapse and dry. Storage bulb maturity can be accelerated by withholding irrigation water or by pruning the root system.

Conduct sample counts on the number of bulbs, which has fallen over in a field; and when the percentage of bulbs, which have fallen over, reaches about 70-80% then the entire crop should be harvested. Harvesting could commence earlier when 50-80% of the tops have gone over, before it is possible to see split skins exposing onion flesh

Bulbs generally mature within 100-120 days from sowing, depending on the cultivar and the weather. Spring onions mature for harvesting after 35-45 days from sowing.

Manual harvesting is the most common practice. Leverage the bulbs with a fork to loosen them and pulling the tops by hand. In large scale farms, mechanical harvesting is commonly used. In wetter, temperate regions, mechanical harvesting and artificial heating and ventilation for drying are essential for reliable production of high quality bulbs on a large scale.


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The following steps are followed during two-phase harvesting of onions: (a) mowing the leaves (if necessary); (b) stubbing, undercutting and sieving the onions to remove stones and clods; (c) roll the soil in the row to get a plane surface; (d) drying the bulbs (windrowing) 8 to 10 days in the field; (e) turning the bulbs 1 to 2 times; (f) harvesting, sieving and hand-grading, overloading into a trailer or in crates; and (g) transport. For one phase harvesting usually commercial potato harvesters have been adapted. After mowing the leaves the crop is immediately harvested, sieved, hand graded and loaded onto the trailer.

Because of the additional operations involved, labour costs for two-phase harvesting are about 30 to 100 % higher than for one phase harvesting. The main disadvantage of one-phase harvesting is the high energy consumption required for mechanical drying.

Bulbs for storage may be harvested when 50 percent of more of the tops have broken over, but the bulbs must be cured and dried thoroughly before being placed in storage. Bulbs intended for immediate use can be undercut when 15 to 25 percent of the tops are down.

To harvest a knife or lifter is drawn under a bed or row, cutting roots and loosening the soil. Then the bulbs may be dug or allowed to cure further before digging. To avoid damage from direct sunlight, however, onions normally are placed in field containers and moved to a dry shady location for subsequent curing.

Curing Both curing and drying remove excess moisture from the outer layers of the bulb. The dried skin provides a surface barrier to water loss and microbial infection, thereby preserving the main edible tissue in a fresh state. Drying also reduces shrinkage during subsequent handling, reduces the occurrence of sprouting, and allows the crop to ripen before fresh consumption or long-term storage (Opara and Geyer, 1999).

Weight losses of 3-5% are normal under ambient drying conditions and up to 10 % with artificial drying.

In traditional small-scale operations, onion drying is carried out in the field in a process commonly called ‘windrowing’. It involves harvesting the mature bulbs and laying them on their sides (in windrows) on the surface of the soil to dry for 1 or 2 weeks. Successful windrowing is weather dependent and therefore cannot be relied upon for large scale commercial onion production business. Immediately after harvest let the onion should get dried for about 8 to 10 days which helps to remove the excess heat giving better color to onion.

The purpose of a curing period is to allow natural dormancy to develop and to dry the onion sufficiently. A properly cured onion will have a dry shrunken neck and dry outer scales. The respiration rate of a cured bulb is lower than that of an uncured bulb.

The tops and roots are removed during harvest. When this is not possible, they should be removed after curing, before storage or sale.


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Fully mature bulbs are harvested and cured by exposure to temperatures up to 35° in low (less than 50 percent) relative humidity.

Short Storage:

Air movement must be provided at the rate of 1 cubic foot/minute/cubic foot of onions (60 cubic meters/hour/cubic meters of onions). Immature onions require twice the rate of air exchange.

The temperature of stored onions is lowered gradually to 0°C, or slightly higher, with the relative humidity at 60 to 70 percent. Air exchange in the storage facility is important to prevent any condensation on the bulbs. Also, when the bulbs are removed from the storage, they should be conditioned for several days at 20 and 50 percent relative humidity.

Before and after storage stabilization of the storage structure can be done by spraying 10g Bavistin + 15ml neuocron in 10 liters of water which helps in controlling the pest.

1ft3 area can store 20kg of onion.

Storage structure should be constructed 30cm from the ground level giving base that avoids contact with soil moisture. Roof could be of good temperature control. About 10000sq.ft space is needed for 50 hectare farm to store the onions for short duration. For good aeration central height of piling should be optimum (120cm) sloppy.

Harvested bulbs can also be taken straight from the field and dried artificially either in a store, shed, barns, or in a purpose-built drier. This method is commonly used when crops are stored in bulk but it can also be applied to bags, boxed or bins. Under this method, bulbs are laid on racks and heated air is rapidly passed across the surface of the bulbs night and day [O’Connor, 1979; Brice et al., 1997].

Drying may take 7-10 days and is considered complete when the necks of the bulbs have dried out and are tight and the skins shriek when held in the hand. The control of humidity level in the store is critical. Under very high humidity, drying is delayed and fungal infection can increase. However, if relative humidity is too low (below 60%), excessive water loss and splitting of the bulb outer skins can occur, resulting in storage losses and reduction of bulb value.

Placing onions on wire mesh in well ventilated conditions and using air at about 30°C, 60-75% rh and 150 m³.h-1.m-3 is generally recommended for mechanical drying of onions.

Cleaning:

Freedom from any impurity, which may materially alter the appearance or eating quality, is essential. Soil and other foreign materials must be removed and badly affected produce must be discarded. Cleaning may be carried out using air or by manually


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removing unwanted materials on the bulb surface. Care should be taken to avoid physical injury on the bulb during these operations.

Packaging:

Both packaging and transport systems must be selected to ensure minimum handling damage to produce. Hard surfaces should be cushioned with leaves, foam or other appropriate force decelerators.

Good packaging for onions must meet the following criteria: (Brice et al., 1999).

(a) strong enough to retain the required weight of onions under the conditions of transport and storage,

(b) allow sufficient ventilation for the air around the bulbs to maintain relative humidity in the required range, and

(c) in many circumstances, provide a means of displaying legally required and commercially necessary information.

Onions can be packaged and stored in a variety of containers such as boxes, cartons, bags, bulk bins, pre-packs, plastic film bags, and stretch-wrapped trays.

Packages typically contain 25 kg and above, especially for transporting crop from field to store and/or during storage. The same 25 kg bags or smaller bags may be used from store to market place. Decision on type of packaging to use depends on crop size, length of storage and marketing requirements.

A problem with packaging onions in boxes, net bags and bulk bins is that if they are too large, and airflow pattern tends to be around rather than through them. Under this condition, the respiration heat of the bulb results in a warm, humid environment in the centre of the package, which can result in decay or sprouting.

Onion Bags

Sacks and nets used for onion packaging fall into three groups: (i) general-purpose jute sacks, as used for many agricultural commodities, (ii) open-weave sacks of sisal-like fibre, (iii) open-mesh nets, normally of plastic materials and (iv) big bags, used alternatively to crates, containing up to 1000 kg . Jute sacks are readily available in most developing countries, but their disadvantages include: (i) generally too large - may contain 100 kg onions, hence difficult to handle and an increased risk of mechanical damage; (ii) bulbs are not visible through the fabric, and it is difficult to monitor condition during storage; (iii) there is some resistance to airflow if they are used in an aerated store; (iv) difficult to label effectively; and (v) recycled sacks may encourage spread of post harvest diseases.

Sisal sacks are made from sisal-like hard fibres and have an open weave, with thick threads spaced between about 10 and 15 cm apart. The rough nature of the fibre


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provides a sufficiently stable weave. These sacks are similar to jute sacks, but will allow limited visibility of the onions and impedance to airflow is less.

Packaging bags:

Open-mesh nets are the most widely used package for onions, and they are normally red or orange in colour. The slippery nature of plastics can result in the movement of the threads allowing large holes to open up. To overcome this problem, alternative nets are industrially produced to give fully stable mesh and stronger bag. The principal techniques include: (i) using extruded net from high-density PVC, (ii) knitted (warp-knitted) and asymmetric construction, and (iii) special weave in which weft threads are double, and twisted.

They are also slowly degraded by sunlight, and should not be left outdoors for long period before use. In comparison with the other types of bags, they offer several advantages, including: (i) light weight, small bulk when empty, (ii) usually available in 12.5 and 25 kg sizes, (iii) fairly good visibility of bulbs, (iv) excellent ventilation, (v) hygienic, (vi) easy closing (draw-string types only), (vii) and crop brand and marketing information may be printed around the middle of the bag for easy identification.

Rigid Packages

A range of rigid containers is used to package onions for transportation, marketing, and/or storage (Opara and Geyer, 1999). The principal rigid containers are trays (10-15 kg of onions each), boxes (up to 25 kg), and bulk bins (up to 1000 kg). These types of packaging enable segregation of onions into different cultivars or sources. Choice of packaging material is important as wooden bins, for example, are liable to termite attack, and weathering during off-season. Rigid containers are also expensive, need regular maintenance and a forklift is required for handling larger containers. Where rigid containers are used for onion storage, building design is simpler than that for large-scale loose bulk storage as reinforcement of retaining walls are not required to support the bulbs. Handling damage of bulbs during filling and emptying can be high, but damage is reduced during store loading and unloading operations in comparison with loose bulk handling and storage.

Onion Pre-packs

Onions are commonly sold in retail outlets in pre-packs with a capacity of 0.5-1.5 kg. Pre-packing offers the following advantages over single bulbs in heaps or bags: (i) price can be attached to produce, (ii) the collation of a number of pieces into one unit of sale may promote sale of a larger quantity than would be purchased otherwise, (iii) provides a clean odourless unit for the customer to handle, and (iv) reduces time spent at the check-out. The use of weight/price labelling machines and bar-coding has reduced the need to pack to fixed nominal weights. During preparation for retail, the quantity of produce is measured by hand or machine and filled into the pack. Then the actual weight and price and/or bar-code are automatically calculated and printed on a label, which is attached to the package. This mechanised weighing and labelling system assists the packer in accurate record keeping and avoids losses due to inaccurate pack weights. The three main types of onion pre-packs are nets, plastic film bags, and stretch-wrapped trays


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Long duration storage Freshly harvested onions are dormant and will not sprout for a variable period of time (depending on cultivar). Storage will prolong this dormancy. Sprouting will increase in storage temperatures above 4.4°C, decreasing again as temperatures exceed 25°C. To reduce the frequency of sprouting after the rest period, onions may be field treated with maleic hydrazide (MH-30) at 2.2 to 3.4 kg/ha when the tops are still green but beginning to senesce.

Bulbs selected for storage should be firm and the neck dry and thin. Discard thick-necked bulbs because they are most likely to have high moisture content than optimum for storage, and therefore would have short storage life. Careful harvest and pre-storage treatments with minimal mechanical loads are important to achieve a long storage period. Both store room temperature, relative humidity, and atmospheric composition affect the length of storage that can be achieved.

Shelves for onion handling and storage are made from either wooden slats or metal mesh on a wooden or metal frame, and are usually fixed in position with the bulbs loaded and unloaded in the store. Ventilation (natural or forced) is usually achieved by passing air over the shelves. To achieve adequate aeration of the bulbs, the depth of bulbs on the shelves should be limited to 10 cm.

Temperature (°C)

Relative humidity(%)

Length of storage

-3-0 70-75 6 months -3 85-90 5-7 months -2 75-85 300 days

(-2) - (-0.6) 75-80 6 months& -1-0 70-80 6-8 months -0.6 78-81 6-7 months

0 75-85 6 months 0 65-75 - 0 70-75 20-24 weeks* 0 70-75 - 0 65-70 1-2 months# 0 65-70 6-8 months† 0 - 230 days 0 70-75 or 90-

95 up to 120 days

0 80-85 30-35 weeks§ 1-2 80-85 30-35 weeks¥ 1 87 -

1.1 70-75 16-20 weeks‡ 4 - 170 days 8 - 120 days 12 - about 90 days 20 - 25 days


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*= With 16.3% loss (red onion); #= Bermuda cultivar; †= Globe cultivar; ‡= With 14.2% loss (red onion); &= Superba cultivar; §= Optimum storage conditions, 7% maximum water loss before becoming unsaleable; ¥ = Probable practical storage conditions, 7-10

days shelf-life (approx.) at 20°C after storage, 7% maximum water loss before becoming unsaleable. Compiled from (Thompson, 1996; Thompson, 1982).

Bulk storage permits maximum utilisation of store space, and uniform aeration is easier to achieve than in stacks of bags or other rigid packaging. However, where bulk storage is to implemented, the retaining walls must be strengthened when storing larger quantities of bulbs, and arrangements need to be made for rebagging before subsequent marketing. It is also difficult to inspect bulbs regularly under these storage conditions. Loose bulk handling of onion is most suitable for large-scale operations where forced ventilation can be provided during long-term storage.

Cultivars intended for long-term storage should be firm with a thick dry neck; free from greening, root growth, sunburn, or freeze damage; and well covered with dry scales. Bulbs with fleshy, soft necks are susceptible to persistent rot, especially if storage humidity exceeds 70 percent.

Flavor in onion is associated with pungency (propyl disulfides and other disulfides) and with sugars (glucose, fructose, and sucrose). Both sugar content and pungency are related to percentage dry matter. Short-day and long-day types differ in their flavors. Pungency and dry matter content are important quality attributes in onions for processing.

Marketing

Onions normally are shipped in 22.7-kg mesh bags. The bulbs are graded by size, with jumbo and pearl sizes frequently used by processors. Those intended for international trade are packed in 25-kg bags.

Green onions are pulled before bulbing, when the basal diameter exceeds 6 mm, and the roots are trimmed near the base. They should be washed free of soil. Discolored stalks are discarded. Storage life of green onions is limited to approximately one week at 0°C and 90 to 95 percent relative humidity.

(A)Tractor Sr. No.

Capacity Price in Rs.Lakhs

Tractor Attachments.

Rate

1. 25 HP 2.83 Tractor trolley Up to Rs.70,000.00 2. 39 HP 3.70 Ploughing attachment Up to Rs. 10,000.00 3. 45HP 3.85 Seeder Up to Rs. 20,000.00 4. 50 HP 4.00 Fumigation Up to Rs. 15,000.00 5. 60 HP 4.75 Weeding equipments N.A.


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Soil Fertility Analysis Charat: Based on GSFC lab test results and recommendations. % Kg./Ac Kg./Ac 1;2 1;2 ppm ppm ppm ppm Ppm P.no. OC P2O5 K2O pH EC S Zn Fe Mn Cu

3 0.92 6.00 50.00 6.90 0.23 6.30 0.88 10.78 0.52 0.84 6 0.89 3.00 45.00 6.80 0.25 5.10 1.06 22.32 0.44 0.58 7 0.95 3.00 50.00 6.90 0.28 4.60 0.56 29.88 0.68 0.66 8 0.88 5.00 35.00 6.73 0.35 4.80 0.34 25.20 0.18 0.48 2 0.89 3.00 50.00 6.80 0.28 10.60 0.44 28.00 0.68 0.62 4 0.90 3.00 73.00 6.90 0.32 4.80 1.60 29.72 0.76 0.92 9 0.84 4.00 73.00 6.75 0.27 7.60 0.84 27.20 0.58 0.56

10 0.78 3.00 58.00 6.50 0.34 6.30 0.90 26.80 0.88 0.70 12 0.73 6.00 60.00 6.83 0.28 5.10 0.46 17.40 0.30 0.44 13 0.78 5.00 38.00 6.94 0.32 2.60 1.38 13.20 0.94 0.66

Avg. 0.86 4.10 53.20 6.81 0.29 5.78 0.85 23.05 0.60 0.65 Less Medium More V.less

Recommendation Base Nutrients

Recommendation Fertilizers Additional Nutrients Requirement

Kg/Ac Kg/Ac Kg/Ac Kg/Ac Kg/Ac Kg/Ac Kg/Ac Kg/Ac Kg/Ac/Y Kg/Ac/Y Kg/Ac/Y P.no. N P K Urea+ AS DAP* ASP MoP Zinc

Sulfate Manganese

Sulfate Gypsum or Sulfur base

3 12.00 30.00 26.00 26.00 0.00 65.00 0.00 43.00 2.40 10.00 50.00 6 12.00 32.00 26.00 26.00 0.00 69.00 0.00 43.00 0.00 10.00 50.00 7 11.00 32.00 26.00 22.00 0.00 69.00 0.00 43.00 3.20 10.00 50.00 8 12.00 30.00 30.00 26.00 0.00 65.00 0.00 50.00 4.00 10.00 50.00 2 12.00 32.00 120.0 87.00 75.00 139 0.00 199 3.20 10.00 0.00 4 12.00 32.00 110.0 87.00 75.00 139 0.00 183 2.40 10.00 50.00 9 12.00 32.00 110.0 91.00 85.00 139 0.00 183 2.40 10.00 50.00

10 12.00 32.00 120.0 91.00 85.00 139 0.00 199 2.40 10.00 50.00 12 13.00 30.00 120.0 98.00 105 135 0.00 199 3.20 10.00 50.00 13 12.00 62.00 120.0 91.00 90.00 135 0.00 199 2.40 10.00 50.00

12.00 34.40 80.80 64.50 51.50 109 0.00 134 2.56 10.00 45.00 • * Gypsum or Ammonium sulfate, Ammonium Phosphate Sulfate. • +Applied after 30 days of plantation


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Notional Storage + dryer structure for Onions.

The above one is a structural design. This type of structure could be developed for drying and storage. The temperatures are very conducive except August and September where dehumidifiers should be used to maintain humidity levels at 60 to70. Rest of the year the temperatures and humidity levels are ok. This structure could either be built with Wood / Asbestos/ RCC / Tin. Depending on the local availability of materials these structures could be developed. We need large storage PVC or any Plastic frames (porous) to store Onions either for short term or long term. The exact dimensions are given under subtitle ‘storage’. All the costs are considered while calculating summary table given at the beginning of the report.


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Land Topography and physical condition: Soil Sample

Soil texture

Soil Type Pre-cultivation Measures

Water requirement

Area in Hectares (+/- 5 %)

1 Up land Morum/Gravel

Medium black soils

Clear trees Grasses

Irrigation 5

2 Up land Morum/Gravel

Medium black soils

Clear bushes/grasses

Irrigation 5

3 Low land

Black loam

Remove grasses

Winter Irrigation

6

4 Up land loam

Medium black- loam

Remove grasses

Irrigation. 5

5 Up land Hard morum

Remove trees

Irrigation 5

6 Sloppy Black loam

Remove grasses

Winter Irrigation

6

7 Low Black loam

Remove grasses

Winter Irrigation

15

8 Sloppy Medium black to morum

Trees and grasses

Irrigation 6

9 Low land

Black Loam

Trees Winter Irrigation

6

10 Up land Morum

Medium black

Trees and grasses

Irrigation 5

11 Upland Morum

Medium black

Trees and grasses

Irrigation 6

12 Sloppy Medium black

Grasses Winter Irrigation

7

13 Up land Gravel Trees and grasses

Irrigation 5

14 Up land Gravel Trees and grasses

Irrigation 5

15 Sloppy Medium black

Grasses Winter irrigation

6

95


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feasibility and technical report on onion cultivation in conakry-jravishanker-2005

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