Showing posts with label How to Grow. Show all posts
Showing posts with label How to Grow. Show all posts

Oct 18, 2016

Planting Beans in Zimbabwe: Tips for Growing, Harvesting and Marketing Beans

Growing, Harvesting and Marketing Beans in Zimbabwe


As a farmer you don't get a lot of shots at making a profit in a growing season. You have to be very thoughtful about what you choose to grow. It is after all your livelihood. Edible beans ( fabaceae) can help diversify your farm income and make your farm more sustainable. They can be interplanted with other crops such as maize, and also grown as cover crops. They are a wide variety of beans to choose from making it likely for you to find a type that is best suited for your farm.

Let's get started...


Why beans? 

Before we get into the actionable growing stuff it is important to understand why to grow beans. Here are some reasons:

1. Quick growing

Beans are a short season crop (+/- 70 days), relatively easy to grow, and can produce high yields in a small space. They are also adaptable to different cropping systems.

2. Improve soil health

They are nitrogen fixing and can improve your overall soil health. Building good soils can help you grow healthier, more resilient crops and improve your crop yields. Beans such as cowpeas use less water to grow (they are water-efficient) making them drought tolerant.

3. Increased consumer demand

Consumer demand for low cost staple foods is making beans more important than ever. Beans can help reduce household food costs, which is very important in these difficult economic times.  While Zimbabwean consumers have not traditionally enjoyed eating most beans (they are slow to cook, cause flatulence, and are often cooked badly in boarding schools etc) rising meat prices are making beans an important meat substitute.

They are also a versatile source of protein that is an important source of nutrition. The United Nations declared 2016 The International Year of Pulses to celebrate the growing importance of beans.

4. Potentially profitable

The price of beans on the local market has been trending upwards while production is still relatively low compared to other countries.  Current production levels are much lower than countries such as Tanzania and Malawi. Most local beans are still being imported into the country from those higher producing countries.

The margins for growing beans (e.g. cowpeas, and sugar beans) is larger than that of growing most other food crops such as maize. The key to getting profitable with bean farming is choosing a bean variety that does not have high input costs such as costly seed, crop protection and high labour costs. Shop around for good input prices to help reduce your overall production costs.

Bean Varieties

There are a number of factors to consider when choosing which bean variety to grow. (we are not covering soybeans in this guide!) You should consider the following: space, growing habit, days to maturity, market, costs, available capital and yields.

All these factors are important for determining your profitability. Seed is a big part of your costs, so buy it carefully!

Space: climber beans because they are staked (supported) do not need a lot of space. You can pick to grow climber or bush beans based on your available space.

Growing habits: Beans can be determinate or indeterminate. Determinate (bush or dwarf bean varieties such as Kidney, Lima or snap beans) require less maintenance and are self-supporting. Indeterminate (climbing / pole varieties) grow taller and need staking (support).

Growing season (days to maturity): short (85-94 days), medium (95 to 104 days) and long (105 to 115 days)

Market: consider the preferred bean variety for your target market. Are you supplying a canner, open-market or exporting? Different beans are good for different markets.

Costs: if you have limited capital look at growing beans that don't require much labour for staking (bush varieties), grow on a smaller scale and don't require much inputs e.g cowpeas.

Yield potential: read the seed details on the yield potential of the seed variety. You can ask around for seed that does well in your area and soil type.

Cowpeas (Black-eyed peas)

They are also known as black-eyed peas. They have the shape of a kidney bean, white flesh and a small black eye. They cook quickly and do not require soaking overnight.

This fast-growing bean making it a great cover crop. It is the best bean for fixing nitrogen and reducing soil erosion and compaction. It does well in a variety of soils including poor soils and is largely drought-tolerant. It has a vining habit.

Good choices: Seed Co's IT 18 ; CB2; CB3 ( potential yields for 2500 - 4000 kg/ ha)

Sugar Beans

Also know as the common bean. This is a nutritious bean. It has green pods. It's crop residues are good for livestock. It however has high input costs (seed, fertiliser and pesticides).

Good choices of  sugar beans: include high-yielding varieties such as Speckled Ice, Bonus, Cardinal, SC Bounty , GLORIA,  NUA 45.

Navy Beans 

They are commonly known as the white pea beans. They are small, white oval beans. These white pea beans are primarily used by processors to make baked beans.

Navy beans can be bush type or vining, indeterminate plant type depending on the cultivar. Used in soups and stews and for baked beans.

Kidney Beans

Come in red or white known locally as Canadian Wonder. These are large, kidney shaped beans that are reddish-brown in colour. They are high in iron. Easy to grow.

Nyimo Beans

Also known as Bambara nuts, groundnuts and groundnuts.

Fava Beans

Also known as broad, English Windsor or cattle beans are the oldest cultivated ban.  They have a fresh, distinctive flavour. Grow well in a variety of soils, as long as they are not too wet or dry. They have a green pod, light green to whitish flesh. Firm bean with thick, slightly leathery skin. They are a hardy bean.

French Beans 

Known as fine beans or  snap beans. Can either be dwarf ( bush) or climbing bean varieties. Pod colours vary. Seeds may be black, white, red, brown or a combination of colours. They are a fast growing, cash crop usually grown for export.They are planted 5 cm deep, 5-7 cm apart, with 45 cm between rows. Self-pollinating, high yielding beans.

Pinto Beans

Medium sized, oval-shaped bean with beige and brown skin.

Buying seed

It is important to buy blemish free, clean seed from a good and certified seed breeder to get high yields. Calculate your seed needs as accurately as possible before buying them. Some recommended seed suppliers: National Tested Seeds, Prime Seeds, Pioneer, Pannar and Seed Co.

You can also save your harvested seed to replant. When you using saved seed especially if its old (over 1 year old), do a germination test with some of the seed before you plant all of it.

Growing Process

Site selection & soil: Bean plants require an open, sunny site that is protected from wind. Choose a site that gets at least 6 hours of sunlight. Beans like fertile to moderately fertile, well-drained soils. Beans do not tolerate acidic soils well. They prefer a soil pH of about 5.8 to 6.

You can check your soil pH by doing a soil test using your own soil test kit or by sending a sample of your soil to a lab. The soil test will tell you the pH value of your soil and give you an idea of any deficiencies in your soil. You can increase your soil pH by liming your soil with dolomitic lime. Follow the liming directions carefully.

Beans need soil temperature of about 16 degrees C. They do not like cold weather or frost and need warm temperatures to germinate. If your soil is too cold you can cover your beds with row covers or wait until your soil warms up. The best temperatures for beans is between 20 - 25 degrees C.  The best time to plant your beans is usually from October to December.

Crop rotation: don't grow your beans in the same site year after year. Rotate your beans (legumes) with other crops such as maize.

Companion planting: You can intercrop or companion plant your beans with maize but be careful because beans don't grow well when they are shaded. To reduce the shading effect you can grow multiple rows of beans after two rows of maize.  Don't plant beans with alliums (onions).

Windbreaks: Beans need protection from strong winds. You can plant a hedgerow or use an artificial windbreaker to protect your beans from strong winds.

Land Preparation

Clear the site of any weeds. We outlined land preparation in our growing maize guide, check it out for more details.  Well prepared land helps with good germination and reduce weed competition.

If you choosing to till, don't plough too deeply and follow ploughing with harrowing your fields. Incorporate organic matter such as compost into your fields to improve your soil structure. If you don't produce your own compost on-farm you can buy compost from commercial compost producers such as Zimbabwe Earthworm Farms.

Sowing and Planting

Start with good quality seed. If you plant beans where they have not grown before dust them with an inoculant for the specific bean type e.g Thiram (a seed protectant fungicide) for sugar beans or a relevant rhizobium  for the specific bean. You can buy inoculants from a farm supply store.

Succession planting: You may want to practice succession planting your beans. Succession planting means to plant once, then plant again ( e.g. two weeks later).  This helps with getting a continuous bean harvest and with averting crop failure.

Seeders: You can use a hand bean precision seeder or tractor seeder to direct seed your beans for faster planting (seeding). Some farmers use seeders just for beans. You calibrate your seeder for proper spacing.  Beans do not transplant well, so better to plant them directly into your fields.

If you don't have a seeder you can use string and stick to make holes and place seed, it's slower but still works just fine. Cover the planting holes with soil using a rake.

Plant your beans in rows to make it easier for correct density, weeding and harvesting. Plant when soil is moist. The spacing and density for your beans varies by the bean type:

Sugar Beans:

Plant 20 to 50 cm centimeters inter-row spacing. You need about 80- 100 kg/ ha of seed. Refer to your seed pack for specific spacing for your seed type. Plant 1 seed per station at depth of about 5 cm deep.

Cowpeas:

Refer to the information provided by the seed supplier for information on spacing and density.

Germination

Uniform germination depends on soil moisture and temperature. Always keep your soil moist  up until the seeds emerge.

Wait for the soil has warmed up before planting. Beans need warm soils. Bush beans typically germinate in about 7 days, while pole beans germinate in about 14 days.  Fill in gaps after seeds emergence (one or two weeks after planting.).

Staking

Climbing beans can grow as tall as 4 m tall, so therefore need support to lift them off the ground. Staking your pole and runner beans helps produce a clean, high-yielding crop in a small space. You can use a single, string and stake trellis, tripod stake or rope stake to support your beans. 

For more on staking plants check out our post "How to Grow Tomatoes outdoors." 

Fertilising

Beans are light feeders that produce nitrogen so do not need much fertiliser. Incorporate a lot of organic matter (well-rotted manure and compost) in your soil to improve your soil fertility.

While beans may not need a lot of fertiliser they may need some depending on your soil condition. You can apply some phosphorous (P) at planting. Use SSP or Compound L for phosphorus. You will need about 150 kg/ ha of compound L. Your soil test results can better determine the right fertilization needed for your specific field.

Weeding

Remove annuals and perennial weeds prior to planting by ploughing and cleaning your fields. Weeds compete with your beans for nutrients, sunlight and space. You can weed using mechanical or chemical means. Limit use of chemicals (herbicides) to remove weeds, and only use them in extreme cases. You can apply mulch (straw, cut grasses or compost) around your beans to suppress weeds.

Mechanical weeding: Weed two weeks after planting. Then five or six weeks after planting. Do not mechanically weed after that point.

Chemical Weeding: You can apply chemical weeding depending on type of weeds in extreme cases. Chemical (herbicides) are divided into pre-emergence or post-emergence herbicides. Pre-emergence herbicides: Dual Magnum, Sencor, Lasso. Post-emergence herbicides:  Fusilade Super, and Classic.
Herbicides are available from places like Windmill and ZFC.

Watering and Irrigation

Most of your water will come from rainwater. But you may need to set up irrigation (drip, sprinkler etc) or harvest rainwater for times of prolonged dry spells. This is the best way of keeping your plants healthy. Companies such as Driptech  provide irrigation services.

To conserve water, you should water early in the morning or evening so water doesn't immediately evaporate. Your plants need consistent soil moisture of about 1 inch of water per week from rain or by watering.

Beans have shallow roots and can easily dry out. If your soil dries out you will reduce your overall yield potential. Make sure to water your beans deeply and evenly every week. You can use a rain gauge and soil sensors to monitor how much water your plants are getting.

Do not leave the soil around your plants bare, cover it with mulch. Mulches help conserve water and prevent weeds! Mulch is a twofer (two for one!).

You can learn more about accessing water for your farm in a post we published titled "How to Run a Water Wise Farm."

Pests and Disease

They is a long list of common pests and diseases that can affect beans. They best method of preventing disease is by practicing good agronomic practices ( planting at right time, proper spacing, watering, removing diseased plants etc). It is important to keep your bean plants healthy so they don't succumb to pests and disease.

Practice regularly checking your plants for pests so that you discover them early to prevent them from destroying your entire crop.

Common Pests

Cutworm: can completely sever the stems of your seedlings. They are larvae that curl up when undisturbed.

Aphids: sap-sucking pests, that are rarely cause serious problems. Signs of aphids are plants that are curled, yellow and stunted. You can control them using lady bugs, insecticidal soap or by blasting them with water.

Red Spider Mites: are tiny red or yellow creatures that generally live on the undersides of leaves; their feeding causes yellow stippling on leaf surfaces.

Semi-Loopers: common pest especially during the flowing and pod filling stage. Eat leaves and pods.

Stem maggots: causes wilted bean stems. They can be prevented by choosing a resistant seed variety. You can control them using neem, applying mulch and planting at the onset of rains when populations are low.

Other common pests are root knot nematodes, and CMR beetle (blister beetle). Not all pests are harmful, and can be easily removed.

Common Diseases

Anthracnose: a fungal disease that causes back, egg-shaped, sunken cankers on pods, stems, and seeds and black marks on leaf veins. You can avoid it by not working wet fields which causes disease to spread. You can use fungicides to control it.

Angular Leaf Spot: a bacterial disease usually visible at the flowering stage. Signs of leafspots are lesions on leaves. Caused by late planting and extended wet periods.

Rhizoctonia root: signs appear on stems or roots as reddish lines or circular lesions. Can cause stem rot, seedling death and wilting.

Powdery Mildew: a fungal disease that affects beans when there is warm, wet and overcast weather. Signs are small, round whitish spots on upper part of leaves. Can be controlled using a fungicide with sulphur and aerating your soil before planting.

Common Bacterial Blight: bacterial disease spread by warm wet weathers. Signs are large, brown blotches on the leaves; the foliage may fall off the and the plant will die. Remove and destroy diseased plants.

Bean Common Mosaic Virus: signs include yellow leaves, stunted growth and lower yields. It is spread by aphids.

Bean Rust: fungal disease that attacks beans causing reddish brown spots on leaves, stems, and pods. To avoid rust, don't work wet plants.  Apply a sulphur spray every 7 to 10 days until the disease is under control.

Fusarium Wilt: fungal disease that cause yellowing of the lower leaves.

Integrated Pest Management (IPM)
  • Check your crops regularly. Use insect traps to monitor pests
  • Use beneficial insects such as ladybugs, lacewings and hoverflies
  • Use clean, certified seed
  • Use disease-resistant varieties
  • Practice crop rotation every one or two year to avoid disease build up in the soil
  • Space your beans far enough apart to provide air flow
  • Use clean surface to process your harvested beans
  • Use biopesticides e.g pyrethium
  • Remove weeds before planting and weed regularly
  • Don't harvest beans when foliage is wet

Chemical pesticides: if all else fails you may need to apply chemical pesticides. Use recommended insecticides with caution.

The insectides for beans are Malathion (aphids, spider mites, cucumber beetles, leaf miner), Dursban (diamondback moth, cutworms, bollworms) , Diazinon ( bean flies, bean caterpillar) and decis (red spider mite.

Harvesting, Post-Harvesting  & Processing

Harvest when your bean plants are mature and ready to pick.

Pick green beans when the pods are as wide as a pencil, tender, bright green and before the seeds inside form bumps on the pod. Pick them every 2 to 4 days or grow too big, lose flavour and tenderness. The more you pick, the more they produce. Don't wash freshly harvested beans can form mold. Place in a cooler, not freezer to preserve flavour.

Bush varieties are ready to harvest about 2 to 3 weeks after they bloom. Pods will be long, slender and velvety. Pole beans mature slowly can be harvested right through the season.

To dry beans harvest the beans when they have turned yellow-brown.  You can also check that the seeds rattle in the pod. Seeds should be very hard

If its forecast to rain and pods are yellow pull them down and hang them upside down off the ground in a shed to dry. It important to protect your harvest from the rain.

Pull up the whole (entire) plant by hand. Beans produce the majority of their crop during a two to three week period. Place the beans on clean tarp for sorting and grading. Remove any damaged beans and separate beans by variety.

 Fresh beans should be marketed quickly before they lose their sweetness. The alternative is to dry your beans.You can dry your beans in the sun or using a heated-air dryer. Process using a thresher

You can treat beans with Actellic Super before storing.Store the shelled beans in a dry, clean, well-ventilated storage room. Place in clean bags (wash used bags). Make sure bags do not have any holes and are airtight. Good, airtight, hermitically sealed bags such as Purdue Improved Cowpea Storage (PICS) bags.Beans can store for up to a year if they are kept cool.

Marketing

Beans are cost competitive and can be sold on the local or export market depending on available quantities and the varieties. Make sure though that you do some research to see if a market exists for your selected bean variety in your target market.

Informal markets: You can sell your beans by the bucket at local informal markets such as Mbare Musika or Sakubva. The prices vary depending on supply and demand.

Processors: White pea beans and sugar beans can be sold for canning to a processing companies such as Cairns Foods and Harvest Fresh. Cairns has been working on increasing is production of baked beans. Sugar beans can also canned so they are quick and ready to cook and eat (convenience foods) such as these KOO Canned Speckled Beans.

Contract farming: You can sign a contract to supply beans such as sugar beans and white pea beans with processors. Read your contract carefully and make sure it has a clause for challenges like pests and climate risks that might affect your crop. Review the payment terms and price before deciding on a buyer. Avoid side-selling if you are not happy with a contract, choose instead to agree on terms before hand.

The Grain Marketing Board (GMB) is a buyer of dried sugar beans. Other bean contractors and buyers are companies like Sidella Trading (cowpeas) and Reapers.

Other Markets: explore other high value local markets such as schools, hospitals and supermarkets to supply your fresh or dried beans. Just make sure they are making payments!

Record Keeping and Budget

Keep track of what seeds you used, the supplier, number of seeds, dates planted, your soil type, the weather, yield etc. Keeping good records can help explain a challenges that happened in the field and help with better future decision making. Try to make decisions based on real numbers not on guessing.

Budget includes:

* Seed
* Fertiliser (SSP and Compound L)
* Insecticides
* Land Preparation
* Transport
* Labour
* Packaging

Have you grown beans? Are you planning on growing beans? We would love to hear your take in the comments.



May 12, 2016

How to Grow, Harvest and Market Onion in Zimbabwe

Growing_Onion_in_Zimbabwe

Winter is coming that means it's time to pick cool-weather crops to grow, harvest and market.

A good option to pick to grow commercially is the onion. Onions are one of the most useful, versatile and popular vegetables. They are used widely in all types of local cooking and are a staple in every household. They also store well which helps reduce post-harvest losses, while giving you extra time to market them. 

Local market demand for onions in Zimbabwe is currently not met by domestic production and is usually supplemented by imports from South Africa. There is clearly room to consider adding onions as your main or supplemental winter crop.

We are going to breakdown how to select the right onion type for your climate and location, plant on time, improve your soil and practice good farming practices to get a good and profitable onion crop.

Ready to start onion farming? Let's get started...

Types and Varieties

Fresh-market onions (Allium cepa) come in different bulb shapes (globe, top or spindle-shaped), sizes (small to large) and skin colours (red, white and yellow).

The number one key to growing a good onion crop is selecting the right onion cultivar for your geographic area. Onions are grouped by the number of daylight hours they need to form bulbs.Onion varieties are classified according to their day length requirement: short-day, intermediate-day or long-day length.

Short-day varieties: form bulbs when they receive 10-12 hours of daylight. These varieties are best suited to Zimbabwe because of the short summer days and low latitude of the country.  Short-day varieties are usually Grano or Granex types. An example of a short-day variety is 'Texas Early Grano'.

Intermediate-day varieties: form bulbs with 12-14 hours of daylight. They are also known as day-neutral. They need a long growing season but not long days. An example of an intermediate-day variety is 'Candy'.

Long-day varieties: need 14-16 hours of daylight to form bulbs. An example of a long-day variety is 'Walla Walla'.

Onions can also be grouped based on their sulfur content. Pungent varieties contain more sulfur, which makes them keep longer in storage and produce more tears when you cut them. Sweet varieties don't have as much sulfur and need to be used sooner after harvest.

Some recommended varieties for Zimbabwe are:

Short-Day Onions
  • Texas Early Grano
  • Yellow Granax (sweet)
  • Bombay Red (red onion)
  • Red Creole
  • Giant Red
Greenleaf Onion
  • White Lisbon
Site Selection and Soil

Onions prefer an open site with full sun for 6-8 hours a day. They are cool-season plants, whose growth is dependent on the temperature. They like cool weather in the early part of their growth and then warm weather when forming their bulbs.  In most areas with mild winters, onions are grown as a winter crop. If you are in a colder area, plant later to stop bolting.Onions typically take from 18-42 weeks from sowing to harvest depending on whether you plant seed or sets.

Soil is another important element for a good onion crop. The ideal soil to grow onions is reasonably fertile, well-drained, rich, loose soil. Onions prefer a soil pH of about 6.0 - 6.8, and will not grow well in acidic or waterlogged soil.

Know your soil pH: before you begin production do a soil test. To do a soil test, first, collect a representative soil sample. See here how to properly collect a soil sample. Send the sample off to your test lab or a local research centre such as Kutsaga Research Board.  You will get back an analysis of your soil: its nutrients and pH level: alkaline (high pH), acidic (low pH) or neutral (just right).

To amend your soil pH: After you get your test results you can work on amending or adjusting your soil pH in line with the soil test results. If your soil is too acidic (low pH) you will  need to add the recommended lime such as dolomitic limestone to bring it closer to the optimum pH. If it is too alkaline (high pH) you can make it more neutral by adding peat moss, or compost on a regular basis.

Land Preparation

It is best not to grow onions or plants in the onion family (allium) in the same site year after year.The onion family includes garlic, leeks, shallots, scallions, cucumbers, zucchini, summer and winter squashes. Growing plants in the allium family in the same site year after year will cause a disease build up such as nematodes.  Plan to rotate your crops to avoid this.

Begin land preparation about a month before planting. To prepare your beds for onion production remove weeds and stones from the fields. Prepare the soil to a fine tilth. Add and dig in a 5-10cm layer of organic matter such as good-quality compost or well-aged manure (4 or more months old) in the last plough. Organic matter will help the soil retain nutrients and moisture.

Make raised beds for planting 100cm wide (standard size), some bed sizes vary. You will be planting multiple rows in the bed. Before planting rake in fertilizer (Compound S) into your beds, at a rate recommended on the package to help encourage root growth and early bulb formation. Cover with 5cm of fresh soil.

Sowing and Planting

Onions can be planted in three ways:  as seed, small bulbs called sets, or transplants. Seeds  give you a greater  selection of varieties, but they take long.

Sets are useful when the growing season is short and are easier to grow.

Sowing onion seeds in trays: Sow seeds in flats or cell packs in February-March, then transplant seedling into the field at least 6-8 weeks before transplanting.

Sowing seed in seedbeds outdoors: To sow seed directly into the ground in areas with long and warm growing seasons. Make sure that you have added well-rotted compost, then an all-purpose fertilizer.

Let's outline the general seed planting steps:
  1. Make seed bed 1m width and 5m in length. Rake soil level to create a smooth layer
  2. To sow onion seeds in place use a string held taut by two pegs knocked into the ground to mark a straight line
  3. Then drag a stake or broom handle and press into the soil to mark out drills (groove) between the pegs into which to sow. Planting in a straight line makes watering and weeding easier after germination
  4. If the bottom of the drill is dry water lightly
  5. Then sprinkle the seed thinly in drills, the seed packet to tell you how deep the drills will be {onion seed are planted shallow approximately 1.2cm deep}.
  6. Cover by carefully drawing soil back to fill the drill, and firm down the soil gently with the back of your rake. 
  7. Water well, using a fine spray to avoid dislodging the seed. Sprinkle seed bed with water whenever the surface is dry.
  8. Cover seed bed with a floating row cover (light, woven fabric), this prevents insects getting to your young seedlings.
You can buy unexpired seeds from a reputable supplier like National Tested Seeds.

Sowing onion sets: an onion set is a small onion bulb that is too small to form flowers if subjected to the cold. It has already gone through one bulbing process. Sets produce  bulbs faster than starting from seed.  They are sold simply as a red, white or yellow onion.

Here are the steps for planting sets:
  1. Make a drill 2cm deep into the ground. To help keep it straight run the edge of a hoe along a length of string held taut by two pegs knocked into the ground.
  2. Plant sets 10cm apart in rows about 30cm apart.
  3. Push each bulb firmly into the soil, burying so only the tip is visible above the soil. Cover with a row cover to deter birds and warm the soil.
  4. Water plants during dry spells, they don't need much water at other times. 
  5. Onions take about 18-42 weeks from sowing/planting to harvest using this method.
Onion transplants: transplant is a small plant usually between 8 to 10 weeks old from seeding, that has not yet formed a bulb.  They give you a head start on the long onion growing season.Select transplants that look healthy, disease-free and have a neck  that has a pencil size in diameter. Pre-irrigate fields before transplanting.

Plant transplants about 2.5 cm deep in wet soil and 8-10cm apart within rows on raised beds 100cm wide, some bed sizes vary. Plant in multiple rows. The number of rows you choose is dependent on your choice of irrigation.

You can buy transplants from a reputable nursery like Emerald Seedlings or Seedridge

Fertilising

Onions are heavy feeders and need constant nourishment to develop big bulbs. Fertiliser application should be based on your soil test. Supplement missing nutrients based on the test.  Use fertiliser at the time of planting and add side dressings (extra ration of nutrients) of nitrogen every 2-3 weeks once bulbs start forming. An acre needs about 113kg of nitrogen.

Take care to keep fertiliser away from the foliage and bulbs. Apply near the onion rows, and cover with soil.Water immediately after feeding.

Fertiliser is not needed late into the season especially when  necks are soft and tops start to fall over.

You can add organic material to the soil on a regular basis. This can be well-rotted compost or animal manure, both of which contain a good range of nutrients.

Watering

Onion seeds must be kept moist during germination and should not be left to dry out. Watering is critical during the early stages of plant growth when establishing transplants, and when bulbs are forming.

Drip irrigation can help get moisture directly to roots after germination without wetting foliage which can cause powdery mildew.

Keep onions moist with consistent water at a rate of about 1"of water per week. If using drip you will likely water about 2-3 times a week.The rate may vary dependent on your soil, weather, rainfall and plant growth stage.

Onion plants need to be thoroughly watered  during dry spells because they have limited root systems. Don't let plants dry out or they may split.

Also don't overwater your onion plants or it will reduce their shelf life. If leaves start to yellow, you may be overwatering.

Stop watering once tops start to fall over and brown and let dry before harvesting. You can use timers and sensors to determine the water needs for your onions.

Weeding

Onions can become easily swamped by weeds especially in their early weeks when the plants are young. Their long growing seasons means they are more opportunities for weed growth. Weed control is important to prevent competition for water, nutrient, and light which reduce bulb formation. Weeds can also harbour pests and disease.

Plan to weed when the weeds are small. Hand-weed while being careful not to cause bulb damage or loosen the bulbs in the soil. Mulch around plants with a thin layer of straw or wood chips to control weeds and retain moisture.

You can also look into registered herbicides to control pre-emergent weeds before you start planting.

{For more on how to control weeds read our 7 tips here}

Problems, Pests, and Disease


Watch out for these problems which may affect your  onion leafs and bulbs:

Insects:

Onion thrips: barely visible small insects that appear as tiny yellow or dark specks during hot, dry weather. They cut out the life out of leaves, turning leaves grey and then curling. You can prevent thrips by planting resistant cultivars and keeping beds well-weeded.

Onion maggots: worst onion disease feeding on onion roots and bulbs. Mulching, crop rotation and row covers over newly planted onions can help reduce the risks from these pests.

Nematodes: a variety of nematodes attack onions. Nematodes live in the soil and feed on the root, stems and bulbs of onions. You can prevent nematodes by crop rotation.

Onion Disease: 

White onion rot: all in the onion family which includes garlic, leeks and shallots are susceptible to onion rot. Onion rot doesn't occur until the bulbs have been harvested. Practice crop rotation to prevent it.

Downey mildew: a fungal disease that causes yellow spots on the upper part of leaves that eventually show up as mold. It can impair bulb development. Remove and destroy affected leaves, improve air circulation and water at the base to avoid spreading it.  It can be prevented by planting in well-drained soil, keeping foliage dry and providing enough space for good circulation.

Purple Blotch: foliar disease. You can use drip irrigation to keep foliage dry.

Bolting: this is the process of premature flowering in onions is called bolting. To prevent bolting choose onion varieties that are suited for your region and planting at the recommended time. Onions bolt when they are planted in the summer in Zimbabwe.

Preventing problems:

If you practice good crop practices you can avoid a lot of diseases and problems.

Here are some good crop husbandry tips:
  • Choose an onion variety that is well suited to your location. All farming is local! 
  • Practice crop rotation: move onions every year to prevent a build-up of fungal spores.
  • Buy seeds that are disease resistant from a reputable supplier.  If you are buying sets make sure that they are not diseased. Problems can also be reduced by ensuring a good flow of air round your plants by wide spacing.
  • Pull up and remove infected or problem plants. This will help prevent disease spread.
  • Maintain weed-free beds. Hand weeding and mulching effectively control most weed species.
  • Use row covers to push seedlings to produce the most robust plants possible before lengthening days trigger bulb formation.
  • Keep plants watered and avoid overwatering.
  • Plant onions in well-drained soil, and avoid overcrowding plants.
  • Practice good sanitation such as cleaning tools (planting, weeding and harvesting) and washing clothing after use
  • Use chemical controls only as a last resort.
Harvesting & Storing Onions

When to harvest onions: harvest onions when they reach optimum maturity. You can determine maturity by pinching the onion neck. Immature onions have stiff necks, whereas mature necks are soft and limber.

Another way to tell that onions plants are ready for harvesting is when 50% of plant leaves fall over and die back. Stop irrigation at this point. Harvest before the foliage dries completely. To harvest carefully loosen the bulbs from the soil using a garden fork or by hand and pull the bulb out by its neck. Be careful to avoid bruising or damaging bulbs.

Lay the bulbs on top of the ground for a few days to dry out in the sun. Keep the onions from getting sunscald by placing the tops of one row over the bulbs of another row. Onions are cured when their tops are thoroughly dry. Once the outer skins are thoroughly dry gently knock off any loose soil and remove the tops.

If rain is expected cure under cover. Place onion bulbs with tops in a cool, dry well-ventilated shed to 2-3 weeks to cure. After curing cut the tops about 1 inch from the bulbs and store the bulbs in a cold, dry, and airy place. Handle with care to avoid bruising.

Short-day varieties, when harvested carefully, can keep for several weeks or longer, this depends on the storage conditions.

Storing: Store dried bulbs in netting or orange mesh bags to permit airflow. Place the onions in a cool, dry shed or area with good ventilation. Handle them with care and avoid dropping them or you can cause bruising and damage. The optimal temperature for onion storage is 0 degrees C and 60-70% humidity. Maintain good sanitation, cool temperatures and humidity in the storage room to prevent or reduce post-harvest losses.

Marketing

You can sell fresh onions at a fresh market like Mbare Musika. Market prices fresh markets fluctuate based on the supply and demand on the market.

Monitor the market prices for the current price to avoid selling your onions too low at the market or to middlemen.

You can also sell your onions wholesale or to retail supermarkets such as Pick n Pay for fresh consumption.Other marketing avenues: restaurants, food service, schools, and hospitals. Start talking to buyers to see their buying needs.

Other buyers of onions are processors. They buy onions for processing into seasonings, sauces, and soup. You may need to meet their volume requirements, but this can be met by pooling your supply with other onion farmers.You can also sell your onions directly to customers out of the back of a pickup truck at a roadside. Other options are selling on classifieds. Be creative!

Recordkeeping

Record what you planted and when, and how your onions performed and yields. Also, make a note of the inputs you used: how much and when you applied them. These include seed, fertiliser, labour, irrigation, crop protection, harvesting and storing costs. Keep track of any problems you faced and what solutions you applied. This will help with next year's crop and with deciding whether to plant onions again. You can use a simple notebook or a free app like Evernote to keep tracks of your farm records.

At the end of the season spend some time reviewing your notes. Consider what you could have done slightly differently. Also, think about what went right. It's not always about the negative!

Conclusion

A good onion cultivar for your region, loose, well-drained soil, fertilising and watering are all important things for a good onion crop.

If you build your soil and practice good crop husbandry you will likely benefit from giving onion growing a try. Happy farming!

If you have any questions, tips or feedback add them in the comments.

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