FRENCH BEANS PRODUCTION

1. Introduction

French bean growing Source: http://www.nafis.go.ke/vegetables/french-beans/french-beans/

Rwanda French bean (one of several tender varieties of Phaseolus vulgaris) or imiteja in Kinyarwanda is the edible pod of the immature runner or hyacinth bean. Its other names include green bean and snap bean. French beans are the immature green pods grown for local consumption and export. Due to high labour requirements, it is recommended that it be grown on a small scale, possibly with staggered planting. It is grown for both fresh consumption and processing. Canning and freezing are the main processing done on French Beans. The terms apply to the fact that unlike shelled types, the legume undergoes harvesting while still tender and undried. . Interest in French beans farming is fast-growing for both fresh consumption and processing (mainly canning and freezing). The crop is one of the major vegetable exports of Rwanda. It is a frequent inclusion in dishes, side dishes, and salads in restaurants, especially in Europe. There is diversity within Rwanda French bean in that it can grow by strings that run along the midriff of the pod or have no such strand. Most modern varieties lack strings, which makes them tender at meals. Though its protein content is low at 3 percent in each meal, the vitamin content of the green bean more than compensates. The vitamin C proportion is 5% in each serving. That of B-6, which aids in metabolism stands at 5%. Iron is in equal concentration at 5% of the daily value, a good enough margin for anemia control. The volume of bone-strengthening magnesium is 6%. The proportion of calcium goes to 3%, just enough to give teeth enamel an outstanding sheen. Vitamin A, which improves eyesight, is available in the legume at 2% of the daily needs.

2. Varieties of Dwarf / Bush French Bean Varieties

Variety	Varietal traits
Vanilla	Vanilla variety is very popular among most buyers for french beans in Rwanda Indeterminate growth up to 2.5m-3m high and are normally supported they grow to 60cm / 2ft high and produce masses of thin, straight bean pods which are best harvested when 10cm to 12cm (4in to 5in) long Vanilla grows well even in heavy ground. It produces a crop slightly later in the year when many other varieties are past their peak.
Annabel	Annabel produces rounded pods 8cm to 10cm (4in) long. They are slightly thicker than the average fine French bean. The plants are small at around 30cm high and ideal for growing in containers. The flowers are white and the first pods are normally ready for picking in late July. Expect about an average yield of beans.
The Prince	Flavor is delicious with tender and juicy pods. The cropping period is longer than most and of course, this is a stringless variety. This variety of French Bean is widely available.
Teepee French Bean	Delicious French Beans that are deep purple when growing, pods produced at the top of the plant for easy picking. The overall plant is attractive because of not only the purple pods but also the magenta colored flowers that appear from late July. Not only are the beans a "fun" color but they taste good as well.
Samantha variety	Samantha High yielding super-extra ne bean Excellent variety with super extra ne pods. Light green straight pods which ts in most markets. Features and benefits. Early maturity 50-58 days. High yielding variety -10 tons per hectare. Excellent grade out disease Resistance Resistant to Bean Common Mosaic Virus Anthracnose (Race Lambda). Excellent light straight light green pods.
Ferrari variety	'Ferrari' _ 'Ferrari' is a half-hardy, dwarf, climbing annual with white, pink or red flowers followed by flat green pods in summer. . This is a fast-growing variety producing stringless pods.
Climbing / Pole French Bean Varieties.
Variety	Varietal traits
Cobra	Cobra is a climbing French bean that is a classic, modern pencil shape Cobra; this is the way to grow a huge crop of delicious beans in a small area. Completely stringless, Cobra will crop through to early autumn.
Purple Cascade	Purple Cascade is a climbing French Bean which has very vibrant (some might say "over vibrant"!) purple pods. If they are lightly cooked or steamed the pods retain most of this purple color. They grow as well as any other variety so if you want a novelty plant this year then give these a try.
Hunter	Hunter French Beans have flatter pods compared to average French Bean and they almost stringless, certainly so when young. The pods grow to around 25cm / 10in long although we suggest harvesting them at 20cm / 8in to get the freshest flavor and best texture.

3. Agro-ecological requirements

Soil: French beans can grow in different soil types, ranging from sandy, loam to clay, which are high in organic matter with optimum pH. The beans are sown directly into the seedbed and take 60 days to mature in warm areas. The optimum soil pH is 6.5 to 7.5, but the beans can tolerate a low pH of up to 4.5. Below a pH of 4.5, plant growth is impaired through limitation of development of the rhizobium bacteria that are responsible for the nitrogen fixation in the galls formed on the bean roots.

Rainfall: Rain-fed cultivation is possible in areas with well-distributed, medium to high annual rainfall of 900-1,200mm per annum. However, to maintain continuous supply especially during the off-season, irrigation is essential. Up to 50mm of water per week is required.

Temperature : The optimum temperature for production is 20-25°C. However, the beans survive in temperature ranging from 14-32°C depending on the variety. Seedlings will not tolerate temperature lower than 10°C. They, however, grow well on friable (easily crumbled), silty loam to heavy clay soils which are well drained and high in organic matter.

Altitude : French beans grow well in lower midland to lower highland zones of altitudes ranging from 1500-2100 metres above sea level.

4. Seed multiplication and certification requirement

French beans are sown directly into the seedbed. The land should be ploughed and harrowed properly just before planting. With irrigation, French beans can be grown all-year round but the main export season is from October to May. Spacing should be single rows of 30x15cm (a seed per hole) or double rows of 60x30cm. The spacing will depend on the variety, soil fertility, water availability as well as climate. It is advisable to plant in blocks of about four rows separated by a path of about 50cm. The optimum soil pH is 6.5 to 7.5, but the beans can tolerate a low pH of up to 4.5. Below a pH of 4.5, plant growth is impaired through limitation of development of the rhizobium bacteria that are responsible for the nitrogen fixation in the galls formed on the bean roots. It’s advisable to carry out a soil test before planting. Various varieties are grown mainly for export, and they are determined by the market preference.

5. Integrated soil fertility management

In areas with low rainfall, it is advisable to practice irrigation. A farmer is advised to carry out a soil test before planting. They thrive in a temperature of 20 to 25 degrees Celsius. Farmyard manure is highly recommended to increase the soil fertility. French beans are grown from seeds. Spacing should be single rows of 30x15cm (a seed per hole) or double rows of 60x30cm. They do well in a wide range of well-drained soils from loam, clay and sandy soils that is rich in organic matter and has a PH scale level of 6.5 to 7.5.

It takes one and a half to two months for French beans to grow to maturity. The farmer should practice farm maintenance practices such as weeding to minimize competition of soil nutrients, sunlight, space and water and to keep away pests causing diseases.

6. Regenerative Agriculture

Staking should be done for the climbing French beans to ensure maximum production.

Mulching is also important as it reduces soil erosion, conserves moisture, keeps of pests causing diseases and adds soil fertility on decomposition.

Mulched French beans Source https://steemit.com/life/@holisticmom/excited-newbie-grower-sees-first-seeds-pop

Crop rotation: should be done from time to time as it helps control weeds, diseases and improves soil fertility by adding nitrogen into the soil. This should be done with crops that do not belong to the Fabaceae family. It helps in weed control, pests and disease management, reduction of soil erosion, and rejuvenation of soil organic matter.

7. Land Preparation

Site preparation for french beans

https://www.pinterest.cl/pin/365354588490892005/

Site selection and soil preparation: To get beans off to a good start, till or spade a sunny section of your garden to a depth of six to eight inches, making sure the soil is as free as possible of clumps of earth or sod. A seedbed of deep, loose soil allows bean roots to stretch rapidly and to take in water, food and oxygen easily. To get a jump on the weeds, work the soil two or three times over a period of several days before planting (the more, the better). Each time you do this, you will kill many weeds that have just begun to germinate. Till one last time just before planting. Working the soil this way takes care half your weeding chores before you even plant! Most beans are not too choosy about where they will sink their roots. They will give you a good crop in soil that is loamy, sandy, rocky, rich or poor and even in clay. However, avoid planting beans in the shade or in soil that stays wet and does not drain well. Bean diseases thrive in wet conditions, and the roots may not get enough oxygen with water and mud clogging their air channels.

Sowing French beans are sown directly into the seedbed. The land should be ploughed and harrowed properly just before planting. With irrigation, French beans can be grown all-year round but the main export season is from October to May. Spacing should be single rows of 30x15cm (a seed per hole) or double rows of 60x30cm. The spacing will depend on the variety, soil fertility, water availability as well as climate. It is advisable to plant in blocks of about four rows separated by a path of about 50cm.

Field selection, preparation and layout in general, common bean requires deep, fertile soil, from loose to slightly compact, with good physical properties, a pH of 5.5–6.5, and flat or rolling topography with good drainage. Prepare the seedbed carefully then irrigate before planting so that the soil is uniformly moist. The altitude of the planting area should be the same as, or very similar to, the altitude of the origin of each material to ensure flowering. To avoid disease problems, do not grow beans in the same field in consecutive year.

8. Crop management

Manure and fertilizers

To achieve optimum yields, timely application of basal and foliar fertilizers is essential. Manure should be added specially to soils with little or no organic matter.

At planting apply 100Kg of DAP per hectare and thoroughly mix it with the soil before planting. DAP is preferred because it contains considerably higher levels of phosphorus which helps the crop with root development. Other phosphatic fertilizers like TSP can be used. A week after germination, the young plants should be sprayed with lavender super starter® 20ml/20l or gatit super start® 50g/20L which promote early crop establishment besides other benefits.

Topdressing apply 50kg can per hectare at the first 3-leaf stage and 50kg per hectare when the crop begins to flower. Can fixes nitrogen in the soil, which increases the green color of the leaves, responsible to make food for the plant. Other nitrogenous fertilizers like urea can also be used.

Spray the crop with gatit super growth® 50g/20l or lavender super growth & vegetative® 20ml/20l which provide essential nitrogen among other nutrient elements.

When the crop begins flowering and setting pods, spray it with gatit super flowers & fruits® 50g/20l or dimiphite® 20ml/20l or goldchance multisuper k® 50g/20l or lavender super flowers & fruits® 20ml/20l. These are rich in nutrient elements, which promote production of quality pods. Application of vitabor gold® 30ml/20l also prevents flower abortion. Gukoresha vitabor gold® ml30/l20 nabyo birinda ukugwa kw’ indabo.super flowers & fruits® ml20/l20.

2.Weeding and mulching

Weeds infestation significantly lowers the production potential of the crop as they compete with crop for growth factors and harbor diseases and pests, and therefore, proper weed management is very crucial. Apply HOTLINE® 450SC at a rate of 50ml/20L, which is a pre-emergent selective herbicide controlling both broadleaf and grass weeds. At flowering, weeding should not be done in order to prevent disturbances to the crop, which would cause shedding off flowers.

3. Irrigation

Moisture availability affects uniformity, yield and quality of the produce and therefore watering is essential in cases where rainfall is inadequate. It is also advisable to grow the crop on ridges and use furrow irrigation in heavy clays because French beans are very sensitive to water logging. . Lack of water during flowering and pod formation causes flower abortion and curved pods leading to reduced yields.

9. Pest and diseases control

a) Pests in french beans

Pest

Damage

Management

Bean seed fly

Source

https://www.infonet-biovision.org/PlantHealth/Crops/Beans

The bean seed fly, also known as seed corn maggot, resembles small houseflies. It is about 1cm long. This causes patchy emergence of seedlings. If damaged plants emerge, they are stunted, weak and fail to develop into productive plants.

Treat the seed with insecticide before sowing

Limit the amount of organic matter before planting in areas with a known history of bean seed flies.

Avoid sowing into recently ploughed land in areas where this fly is a problem.

Respect crop rotation

Aphids

Source https://plantvillage.psu.edu/topics/bean/infos

Small soft bodied insects on underside of leaves and/or stems of plant; usually green or yellow in color, but may be pink, brown, red or black depending on species and host plant

Aphid infestation is heavy it may cause leaves to yellow and/or distorted, necrotic spots on leaves.

stunted shoots

Aphids secrete a sticky, sugary substance called honeydew, which encourages the growth of sooty mold on the plants.

If aphid population is limited to just a few leaves or shoots then the infestation can be pruned out to provide control

use tolerant varieties if available;

reflective mulches such as silver colored plastic can deter aphids from feeding on plants;

use of insecticides in large infestations

Armyworms (Beet armyworm)

Source https://plantvillage.psu.edu/topics/bean/infos

-Singular, or closely grouped circular to irregularly shaped holes in foliage

-Skeletonized leaves

-shallow, dry wounds on fruit

egg clusters of 50-150 eggs may be present on the leaves

-young larvae are pale green to yellow in color.

Biological control by natural enemies which parasitize the larvae

there are chemicals available for commercial control

Corn earworm Helicoverpa zea

Source :https://plantvillage.psu.edu/topics/bean/infos

Larvae damage leaves, buds, flowers, pods and beans
Young caterpillars are cream-white in color with a black head and black hairs. Eggs are laid singly on both upper and lower leaf surfaces and are initially creamy white but develop a brown-red ring after 24 hours and darken prior to hatching.

Monitor plants for eggs and young larvae and also natural enemies that could be damaged by chemicals;
Bacillus thuringiensis or Entrust SC may be applied to control insects on organically grown plants
Appropriate chemical treatment may be required for control in commercial plantations.

Cut worm

Source https://plantvillage.psu.edu/topics/bean/infos

-Stems of young transplants or seedlings may be severed at soil line
Irregular holes are eaten into the surface of fruits
Larvae causing the damage are usually active at night and hide during the day in the soil at the base of the plants or in plant debris of toppled plant
Larvae are 2.5–5.0 cm (1–2 in) in length; larvae may exhibit a variety of patterns and coloration but will usually curl up into a C-shape when disturbed.

Remove all plant residue from soil after harvest or at least two weeks before planting, this is especially important if the previous crop was another host such as alfalfa, beans or a leguminous cover crop
Plastic or foil collars fitted around plant stems to cover the bottom 3 inches above the soil line and extending a couple of inches into the soil can prevent larvae severing plants
Hand-pick larvae after dark; Apply appropriate insecticides

Mexican bean beetle (Epilachna varivestis)

Source https://plantvillage.psu.edu/topics/bean/infos

-Damage on leaves
-Lacy appearance on leaves.
-adult insect is an orange-brown beetle with black spotted on the leaves.

Plant varieties may be less attractive hosts for the beetle,
early varieties maturing may escape damage form beetle
beetle populations can be reduced by remove overwintering sites such as brush and leaves on the ground;
Apply insecticidal soap to leaf undersides if infestation is heavy

b) Diseases in French beans


Disease	Symptom	Management
Rust Source isoko https://www.plantwise.org/KnowledgeBank/factsheetforfarmers/20127802224	The disease is caused by the fungus Uromyces appendiculatus. The presence of slightly raised small white spots, on the surface of the lower leaf. The spots turn red to dark brown after a few days.	Crop rotation. Use of tolerant varieties. Chemical sprays such as: Baycor 30% EC, Bitertanol, Anvil, Alto 100SL or Dithane M45 should be applied after every two weeks.
Angular Leaf Spot source https://beanipm.pbgworks.org/angular-leaf-spot	Leaves, stalks, and pods have angular brown or red colored spots. Purple edges and grey to brown centres. The leaves may then fall prematurely.	By use of healthy, certified seeds. Treat Seeds using chemicals such as fernasan-D, at 3gm per kg of seed. Spray with chemicals such as benomyl (or benlate).
Root Rots Source https://www.infonet-biovision.org/PlantHealth/Crops/Beans	Affected plants show yellowing and drying of stem at soil level. Stunting may also occur. The crop may also show poor seedling establishment. Uneven growth. Chlorosis and premature defoliation of severely infected plants.	Seed dressing with a chemical such as: Fernasan-D, at 3gm per kg of seed, or Quitozene. Drenching with chemicals such as: Brassicol (or Quitozene), Benomyl (or Benlate), or Bavistin, during the vegetative stage.
Bacterial Blights Source http://ipm.uconn.edu/documents/raw2/Bacterial%20Bean%20Blights/Bacterial%20Bean%20Blights.php?aid=115	The disease is spread through splashing from exuding lesions and plant debris. Plants show ring-like spots on the leaves, drying of leaf margins, yellowing and water soaked pods.	Use of certified seeds. Rogueing and destruction of affected plants. Crop rotation. Chemical sprays using copper-based fungicide such as kocide 101.
Anthracnose Source https://www.greenlife.co.ke/bean-anthracnose/	The fungus is seed-borne and affects all aerial plant parts. It is spread by rain splash, wind or mechanical contact. The disease is characterized by appearance of sunken, brown spots with black edges on pods; angular brown sports on leaves; and oblong stripes on stems.	Use of certified seeds. Field sanitation. Crop rotation. Use of resistant varieties. Foliar sprays using chemicals such as Benomyl, Mancozeb, and propineb.
Bean common Mosaic Virus (BCMV) Source https://www.growveg.com/plant-diseases/us-and-canada/bean-mosaic-virus/	The disease is seed-borne and aphids transmit it. The symptoms of this disease vary with variety, stage of growth, and environmental factors. They include a mosaic (i.e. mottling, Curling and stunting of leaves) Systemic Necrosis and local malformations. The leaves may roll malform and general stunting of the pant. The plant produces excessive number of Lateral shoots.	Use of certified seeds. Koresha imbuto z’ indobanure. Plant resistant varieties. Rouging of infected plants. Control of aphid vectors using insecticides.
Powderly mildew Source : https://www.growveg.com/plant-diseases/us-and-canada/bean-powdery-mildew/	Attacks stems, leaves, flowers, and pods, which appear covered with white Powderly growth which turn black latter. In severe cases, the leaves turn yellow and drop off.	Field hygiene. Crop rotation. Chemical fungicides eg. Dithane M45, Antracol, Bayleton.
Downy mildew https://www.liberaldictionary.com/downy-mildew/	The underside of leaves exhibit white to greyish growth which later cover whole leaf surface.	Field hygiene. Crop rotation Chemical fungicides eg. Dithane M45, Antracol, Bayleton.

10.Harvesting, post-harvest handling and storage of French beans

Harvesting

It begins 6 to 8 weeks after planting depending on the variety and ecological conditions. Harvesting is best done in the morning but not when the crop is too wet and is achieved through carefully picking the pods off the plant with the stalks, and not pulling. This should be done at regular intervals depending on the market specifications, for instance, twice a week for the fine French beans and three times a week for the extra fine beans, and can continue for around a month. Harvesting the beans while young encourages more production, and the beans are tasty.

Yield

A hectare can produce 4 to 6 tonnes of French beans depending on the management and variety.

Handling

Care should be taken in order to conserve the quality of the produce. For instance, the harvested beans should not be left in direct sun, and the harvest boxes should not be overfilled.

Sorting and Grading

Harvested ponds of French beans. Source Imisogwe y’ imiteja yasaruwe. Isoko https://www.farmers.co.ke/article/2001341581/all-you-need-to-know-about-farming-french-beans

Sorting is done in order to get rid of broken, twisted and perforated pods as well as plant debris while grading should be done according to size of the produce.

Packing

Operations involved in packing result in boxes of produce that must be in conformity with the European Union quality standard for French beans (standard EC 912/2001) and each box packed for the export market must display the product characteristics, i.e., name of producer/exporter, size, category, origin, etc.

French beans harvesting https://www.johnnyseeds.com/growers-library/vegetables/about-snap-beans.html

Storage

Soon after packing, the produce should be kept in a cold room. At 4oC, and a relative humidity of about 80%, French beans can store for a week.

11.Marketing

The major outlet for French beans is the European Union market, and the export market in Rwanda falls into two major seasons, i.e. high demand season ( September to March, where major supply is mainly from irrigation) and low demand season (June to September, during the long rains when supply is too high, thus lower prices.) Information from NAEB shows that the beans are currently exported to France and the UK and that in November 2016 and probable markets opened in UAE in the Middle East.

Sorting and Grading of French beans for markets. https://mambo.hypotheses.org/164

12.References

https://cropnuts.com/french-beans-farming-guide/

https://www.selinawamucii.com/produce/fruits-and-vegetables/rwanda-french-beans/

http://farmbizafrica.com/markets/1952-exporter-looking-for-farmers-to-grow-french-beans-and-passion-fruits

http://www.nafis.go.ke/vegetables/french-beans/disease-control/

https://steemit.com/life/@holisticmom/excited-newbie-grower-sees-first-seeds-pop

https://beanipm.pbgworks.org/angular-leaf-spot

https://www.infonet-biovision.org/PlantHealth/Crops/Beans

https://www.growveg.com/plant-diseases/us-and-canada/bean-mosaic-virus/

https://www.liberaldictionary.com/downy-mildew/

https://www.greenlife.co.ke/french-beans/

https://garden.org/learn/articles/view/448/