Cultural activities led throughout onion cycle Farmers’ practicesResearch recommendations or Standard recommendationUPL-SPF cropping solutions
Soil, climate requirement Onions can be grown under wide range of soil types but free draining fertile light loam soil with a pH of 6.0-6.8 (although alkaline soils are also suitable) is the best. A cool weather is required during the early stages of vegetative growth (13-240c), while warm drier period is necessary during the latter period of bulb growth and maturity (20-250c)
Crop Season (sowing window) The dry season experienced in the northern part of Nigeria is suitable for onion production because it is cool between November and February and warm in March.
Variety/hybridThere are different varieties of onions based on day length and bulb colour. a. Based on day length: i. Short day onions (12-13 hour threshold) e.g. Bermuda and Granex types ii. Intermediate day onions (13.5-14.5 hours threshold) e.g. Brown moderate cochise, yellow moderate Rialto iii. Long day onions (over 14.5 hour threshold) e.g. White pungent, Downing Yellow Globe. b. Based on bulb colour i. Red cultivars e.g. Kano Red, Wuyan Bijimi, Ex- Hunkuyi, Maiduguri Improved, Ex- Dala ii. Brown cultivars (e.g. Australian Brown, Cape Flat, Born Accord) and Yellow types (e.g. Yellow Sweet Fiesta, Ebenezer, Yellow Pungent Autumn Spice) iii. White cultivars e.g. White sweet, White Granex, White Creole, White Pungent. The red is the popular one in the country and it is of great commercial value for farmers that cultivate it.
Pre-sowing activities

-preparation of land
Land clearance which involves bush burning as opposed to chemical herbicides (pre-emergence) application is an aspect of land preparation. Ploughing, harrowing, and bed preparation (to facilitate moisture retention in irrigated tomatoes) are carried out after the land clearance, but ridges are made for rain fed tomato production to minimize contact with water.The land can be prepared by ploughing and harrowing thoroughly into fine tilth. The land is either ridged or made into 1.0-1.5 m wide beds
-sowing method, seed rateOnion is majorly propagated from seeds by method of transplanting the seedlings from the nursery.The planting of onions is done with seeds or setts. The planting is done on ridges; and furrows should be created to ensure ease when carrying out post planting activities. An advantage of raised beds over flatbed is that it prevents water logging. Usually excessive rain can cause water logging, and onions tend to do poorly on waterlogged soil. The raised beds along with a network of furrows will ensure that there are channels of exit for the water and this can help to prevent waterlogging.
-plant population, spacingSpacing of 5-10 cm is utilized for onion production.In spacing of plants, 15cm by 10 cm is ideal.
Seedling (Nursery) and transplantingOnion seeds are broadcasted in sunken beds and mulching materials are used to cover the seedlings, the mulch is removed some days after sowing in the nursery. Afterwards the seedlings are transplanted to the main field at 1-2 weeks after sowing. The spacing between plants is around 5-10cm.Another strategy in onion farming is to plant your seeds in the nursery, then after 45 days, you can move them to the farm. The seedlings are transplanted early in the morning or late evening, in 2 rows per ridge with the plants spaced at 15-20 cm within each row.
Irrigation Onion is irrigated from the surface by the method of flooding. The water is applied from a nearby well (using pump) or from a canal.It is important you water your onion plant adequately. This can be done by drip irrigation. Generally, irrigation should be done weekly for at least 2 months after planting or 3 weeks before the plant attains full maturity. Irrigation is very essential during the bulb forming stage, however if the watering doesn’t stop at the right time, it may delay maturation. Ideally, the best irrigation system for onion farming is drip irrigation
Fertilization Organic fertilizer of different sources are applied and incorporated during land preparation. Mineral fertilizer is applied at 1-2 week after transplanting and after every weeding operation.Where available in low fertile soils, 20-25 t/ha of farm yard manure should be incorporated in the soil during land preparation. NPK should be applied at the rate of 250 kg/ha. In addition, 250 kg/ha CAN could be applied as side dressing in 2 equal split doses at 2 and 6-8 WAT.
Weed Management Manual hoe and hand weeding is employed in small scale farming 2-3 times throughout the growth life cycle of the plant.One of the important activities after planting is weed control. Weeds have the capacity to decrease your yield hence it is important they are taken care of. Weeding is most important in the early growth phase. However, weeding is generally done 2 to 3 times within the onion planting season. Use of Pre emergence herbicide after transplantation and soil incorporation chemicals by irrigation
Pest and disease management
* Thrips
Farmers have little knowledge regarding the identification and differentiation of insect pests; although neem seed extracts, wood ash and detergent solutions are used in managing insect pests. Traps, poisoned food are used in controlling rodents. Farmers have zero to little knowledge on identification of diseases of onion. Thus finding it difficult in controlling diseases.Management practices Cultural control - Removal of infested bulbs and shoots of onion at regular intervals and prompt destruction - Remove crop debris, weeds and other sources of thrips at the end of each crop - Plough and keep fields fallow for 3–4 weeks to allow thrips to emerge and disperse - Reduce cultivation within the field to avoid movement of thrips from infected plants Chemical control - Chemicals with Acetamipride or Chlorpiryphosetyl or Lambdacyhalothrine as active principle which are ratified in vegetable protection are also recommended against thrips, and flyers.
Beet Armyworm (Spodoptera exigua)
Beet Armyworm: (Spodoptera exigua) Damage is mainly caused by larvae They damage the vegetative (leaf) stage Symptoms - Presence of skeletonized leaves - Holes on onion leave and bulbs Management practices Cultural control - crop rotation with non-host plants should be practiced - Use of nucleopolyhedrovirus (NPV) as biological pest control.
Chemical control - Neem seed extracts have been found to be effective in controlling army worm. - pesticides such as dieldrin have been used to control armyworms effectively in the past
Leaf miners

Leaf miners They attack leaf, stem and fruit Damage is caused by the larvae Symptoms * Thin silvery trails (tunnels) on leaves which may join together to form white blotches * Green larvae with black heads, and their black frass, inside the tunnels * Tiny holes on stems * Silky webs produced by larvae to fold leaf * Holes in fruit, possibly surrounded by black frass * Larvae and galleries inside fruit * Sunscald of fruit due to leaves prematurely falling Identification Adults: is small, grey-brown, thin ; hide between leaves during the day Larvae: is small, yellow-green with black heads, turning pinkishgreen with age. Found in tunnels on leaves, stem and fruit Management Cultural practices * Crop rotation * Use of resistance varieties * Remove and destroy infested plants
Root knot nematodes
Onion is ready for harvest at about 3-4 months. Drying of the leaves signifies that the onion bulbs are ready for harvest. The bulbs are pulled from the ground after which the bulbs are cured by sun drying. The bulbs can also be harvested before the leaves dry off.- Rootknot nematode: They cause damage to plant roots Sypmtoms * Wilting and yellowing of plants * Stunted growth Management
Cultural practices * Rogue and burn affected plants * Remove galled roots * Application of poultry manure or cow dung at a rate of 5t/ha can boost crop vigour and reduce nematode infestation on the crop - French marigold (Tagetes patula) or African marigold (T. erecta) are very effective trap crops in lowering the rootknot nematode density in soil - African lettuce (Launeae taraxacifolia) in rotation with tomato or pepper reduce the rootknot nematode density in soil.
Bacterial soft rot
Bacterial soft rot Caused by bacteria ectobacterium carotovorum ssp. carotovorum) They damage plant vegetative stage (leaf) reproductive stage (bulb) Symptoms * Bacterial soft rot symptoms often appear as a soft, watery rot of individual scales that may advance and rot the entire bulb. * A foul-smelling viscous fluid oozes from the neck when infected bulbs are squeezed. * In the field, the youngest leaves or the entire foliage of affected plants appear bleached and wilted. Management Cultural practices * use resistant varieties * Control alternate weed hosts * Practice crop rotation with non-host plants * Rogue infected plants and debris Chemical control Apply copper based pesticides to manage the disease such as: * Champ DP(Copper hydroxide 57.6%) * Cuprofix Dipress (200 g/kg COPPER)
Downy mildew
Downy mildew: Caused by fungus Peronospora destructor They damaged thevegetative plant stage Symptoms * Pale–green, yellowish to brownish areas of irregular size and shape (oval to cylindrical) on infected leaves or seed stalks. * Infected leaves become girdled in the region where mildew develops and they eventually collapse. * The dead leaf tissue is rapidly colonized by purple blotch, which is dark in color and obscures Downy mildew. * Bulb tissue, especially the neck, may become spongy and the bulb may lack storage quality. Management Strategy Cultural method * Remove alternate plant hosts * Spray seedlings with sulphur based fungicides * Choose planting time/site to avoid favorable environmental condition for disease * Minimize leaf wetness to prevent fungal infestations
* Use resistant/ tolerant varieties Chemical method:The following fungicides are fit for use in both prevention and eradication of Downy mildew disease; * FORTRESS GOLD 720WP 40g/20l * GEARLOCK TURBO 250WP 25g/20l * KATERINA 720SC 50ml/20l * PROPELLER 722SL 50ml/20l * SACRIFIDO 125EC 20ml/20l * TOWER 720WP 50g/20l * TRINITY GOLD 425WP 50g/20l * COMRADE 450SC 20ml/20l * PYRAMID 700WP 50g/20l * ABSOLUTE 375SC 10ml/20l * CADILAC 800WP 50g/20l (as prophylaxyl)
Botrytis Leaf Blight Caused by fungus Botrytis squamosa They cause damage mainly to the vegetative stage Symptoms - Small (1 to 5 mm) grayish-white oval shaped lesions
- Spots often surrounded by slivery-white ‘halo’ - Active lesions are grayish-white colour - Older lesions tend to be brownish-white and desiccated (dehydrated or dried out) - When numerous lesions are present the leaf tips begin to dieback eventually affecting the entire lea Management Strategy Cultural method * Monitor timing and amount of nitrogen fertilizer applications to reduce the amount of rot * Biochar can be applied as soil ameliorant to reduce severity of the disease by stimulating defense pathways. * Well timed fungicide applications are recommended.
HarvestIt takes the bulb onions about 3 to 4 months to reach maturity. The ideal time for harvest is the dry season. They can be harvested in January or February.
The plant is harvested when 50% of the neck falls. Another indicator is the formation of a shiny membranous cover around the bulbs or when the foliage of the plant begins to wither. Usually, harvesting is done by pulling the bulbs of the onion plant then cutting it off from the leaves. After harvesting, it is important you dry the bulbs in the sun before storage. This is because moisture can trigger fungal disease infestation. After adequate drying, the bulbs can then be stored in the storehouse ready to be transported to the market.