Organic Cultivation of Frenchs Beans and Production Guide
French Beans, also known as green beans or string beans, is one of the most popular leguminous vegetables as a dietary food. It is a green vegetable which belongs to the family of Fabaceae and genus of Phaseolus. Because of its short duration and nutritive values it is grown widely.
It is usually grown for tender vegetables, shelled dry beans and green beans and has a very good source of Calcium, Protein, Iron, Phosphorus, Carotene thymine, Riboflavin and Vitamin C. Being leguminous they are very tasty and nutritious too.
The mature seeds and tender beans of French Beans both are used as a vegetable.lt is a short duration crop so mostly grown as kharif crop (summer crop) but if irrigation facilities are properly available it can be grown as a Rabi crop (winter crop).
Varieties of French Beans
The French Bean varieties are classified into two groups which are:
- Bush or dwarf types
- Pole or climbing types
The below varieties which are found are suitable for the northern region.
- Dwarf types – Pant Anupama, Contender, Pusa Parwati, and Arka Komal.
- Climbing types– RCMFB-1 Kentucky Wonder.
Selection of Seeds in Organic farming of French Beans
In organic French Beans production, seed selection is a very important step. The seeds of French Beans should be carefully selected from farmer’s fields which are raised organically or from certified organic farms. In the absence of organically produced seeds, we can use the seeds (those are not treated with chemicals) from local high yielding varieties. The choice is locally demanding and disease resistant varieties which are available as both long and short duration varieties.
The common varieties which are grown are: Arka Komal,YCD 1, Ooty 1, Indam 2, Premier Arka Anoop and Arka Subidha, etc.
Soil and Climate Requirement for Organic French Beans farming
Before starting with Organic French Beans farming, understand the following points in regard to its Soil and Climate Requirement:
- The soil used for french organic beans farming ranges from light sand to heavy clay but thrives well on well drained loam soil. It requires 250 to 450 mm of soil moisture. The moisture stress affects the fibre content, pod colour and firmness of pods.
- It is sensitive to salinity which impose its seed germination, decreases nodule formation and retard plants development. Soil salinity less than 2dSm-1 reduces the yield of the crop. The pH value of the for organic French Beans is about 5.2 to 5.8 which is optimum.
- The organic French Beans require fine seedbed and adequate soil moisture for good germination. To obtain required tilth, deep plugging followed by 2 to 3 harrowing and planking is adequate. To obtain a better yield, the land is enhanced with around 40 cartloads of manure per hectare.
- The organic French Beans are grown through the winters in plains, while it can be grown around the year except for winters in hilly regions. The organic French Beans can be grown on all types of soils but the best suitable for gaining high yield of organic French Beans are mostly clay and loam soil.
- The crop mostly chooses the light soil but it can also be grown in heavy clay soil if sufficient fine organic matter is forked in.
- For greater yield, in winter or autumn, we have to dig in old compost or well rotted manure at one bucketful to the square metre. Then we will leave the ground rough in the winter to let the cold winds and frosts get to it. In the spring season, we will give the soil a light forking and add some organic fertiliser.
- French Beans are usually warm season vegetables which cannot tolerate frost.
- It cannot tolerate heavy rain and stagnation.
- The seeds of French Beans don’t germinate below 15 °Celsius.
- The plant drops blossoms in rainy or hot weather.
- For the growth of organic French Beans and for the high pod yielding, mean air temperature of 20° Celsius to 25° Celsius is optimum.
- The high temperature which is more than 35° Celsius and severe cold can interfere with pod filling.
- For the vegetative growth of these organic beans, low temperatures are unfavourable.
Land Preparation in Organic French Beans farming
The best suiting soil for the organic French Beans is sandy to heavy clay soils with the pH value range from 5.5 to 6 with more than 1% of organic carbon. It is very much important to conduct a soil test once a year to check the levels of pH, organic carbon macronutrients (NPK), micronutrients and microbial load in the field.
But if the organic carbon content is less than 1%, we have to apply 25 to 30 tons per hectare of FYM (farmyard manure) to the main field and plough the field 2 to 3 times to mix the manure thoroughly. At a distance of around 7 metres from non organic fields, a suitable buffer zone must be provided between non organic fields and certified organic fields to prevent drift of prohibited materials onto certified organic fields.
Seed Rate and Seed Spacing in Organic French Beans farming
For dwarf beans, nearly 50 to 75 kg per hectare of seed is required. And for pole type beans, the seed rate is around 25 kg per hectare. The seed rate changes with the seed size. A seed rate of bold seed will change accordingly with the test weight of 350 to 450 grams, needed 120 to 140 kg seeds per hectare whereas in small seeded varieties, it varies from 80 to 100 kg per hectare. With row properties, the seed rate differs in intercropping.
The seeds are usually sown in rows which are 30 cm apart. The choicest depth of sowing is 8 to 10 cm and the plant to plant spacing is 12 to 15 cm. The increase in plant density increases the pod yield. To get a good yield of these organic beans, the plant population should be 2.5 to 3.0 lakh plants per hectare. For better ventilation and to minimise the rapid spread of foliar diseases, a wider spacing of 45 cm x 15 cm is suggested for Organic cultivation of these French Beans.
Sowing Time and Process in Organic French Beans Farming
The Organic French Beans can be sown twice in a period of 1 year, firstly in January-February and secondly in July -September in the plains and March to June in the hills. The French Beans are grown throughout the year in three seasons namely: Summer – February to March, Kharif – June to July and Rabi – October to November. The sowing of the unirrigated crop is done by drilling around 45 cm distance.
Whereas the irrigated crop is taken on ridges and furrows at a distance of 60 cm and then the seeds are dubbed on both sides of ridges at 20 to 30 cm spacing. The seed rate for drilling is 80 to 90 kg per hectare whereas for dibbling it is 40 to 50 kg.
Irrigation Requirement in Organic French Beans Farming
- The French Beans are shallow rooted and are sensitive to both water stress and water excess condition.
- For achieving a good crop, a little moisture should remain even in the rainy seasons.
- At a critical period of growth, the plants susceptible to water stress are flowering, pre-blooming and pod filling.
- Due to excessive evaporation loss or low moisture, the deform pods can result from water stress.
Organic Nutrient Requirements for French Beans farming
Although the French Bean is a leguminous crop, it is poor in its capability of atmospheric nitrogen fixation, so it needs more nutrients in comparison to other leguminous vegetables.
A well developed French Bean crop can remove 40 kg P, 130 kg N, and 160 kg K per hectare from the soil. Nitrogen is mainly required for the cultivation because it imparts energetic vegetative growth and dark green colour to plants and produces early growth. But excess nitrogen can harm nodulation and nitrogen fixation.
The plant gives the best response to Phosphorus application as it stimulates early root development and growth, boosts fruiting and seed production, and hastens maturity. Likewise, potassic fertiliser being a catalyst for various reactions improves the water holding capacity of plant tissue which stimulates enzyme activity, quality of the product, and increases the nitrogen fixing ability of the plants.
For an average fertile soil, at the time of preparation of land, 25 to 30 tons of farmyard manure (FYM) per hectare must be applied. For a good yield of these organic beans, 80 to 60 kg P2O5, 120 kg N, and 50 kg K2O per hectare are suggested. Full doses of P and K and half of the
Nitrogen must be placed in bands of 7 to 8 cm away from the seed, at the time of planting and the remaining Nitrogen is used as a top dressing during the flowering time. Fertiliser placement studies using radioactive 32 P labelled fertiliser in French Beans have shown that deeper placement at around 5 cm depths result in the maximum utilisation of Phosphorus. The French Bean gives the best response to foliar application of micronutrients, mainly Mo, Mn, B, Cu, Zn and Mg when each applied at the rate of 0.1% which has been found to promote quality and yield of pods.
Pests and Disease Control in Organic French Beans farming
We have to maintain the area around the seedlings weed free and aerated with regular hoeing. The simplest and most satisfying tool for hand weeding is an oscillating hoe.
The plant is attacked by a wide range of insect pests including Aphids, Coleoptera, and Hemiptera. There are more than 150 species known of insects and other invertebrates which have been listed as pests of French Bean but only a few are recognised as being economically important. The most important insect pests of this crop are blister beetles, hairy caterpillars, bean bugs, and aphids. Mainly the insects damage the crop by the direct feeding on leaves, damaging to developing pods, stem, and through the transmission of virus like bean dwarf mosaic virus.
These insect pests can be controlled by several methods namely pesticide application, (mainly rotenone, malathion, parathion and cryolite) biological control and cultural practices.
Pesticides can only poorly control aphids, white flies and thrips because of the rapid development of insecticide resistance. So it is important to use the insect-resistant varieties to decrease losses caused by insect feeding.
The organic French Bean mainly suffers from several diseases which mostly include fungal, bacterial and viral diseases. The bacterial diseases like brown spots, common blight, wilts and halo affect production severely.
The fungal diseases includes angular leaf spot, Alternaria leaf spot, anthracnose, ascochyta leaf, pod spot, rust (Uromyces phaseoli), white mould(Sclerotinia sclerotiorum), root rot and damping- off(Pythium spp.). The root diseases become more dangerous when bean roots are unable to escape the pathogen due to edaphic factors.
The conditions which can hamper root growth and predispose bean plants to severe Fusarium root rot infection are namely drought, low temperatures, water-logged or flooded conditions and soil compaction. The seed loss is particularly severe when the disease occurs in the pod filling and the flowering plants periods.
Beet curly top virus (BCTV), bean common mosaic virus(BCMV), sometimes called as Ruga verrucous are the most common viral diseases which can result in a considerable loss in many bean growing areas. To decrease the severity of these diseases one can use fungicides, pesticides and bactericides.
Though, the pathogens which cause most of the above diseases are seed transmitted or live for long periods on plant residues, in soil or alternate hosts. Therefore, for the management of bean diseases and pests, one can make use of disease -resistant varieties and healthy seeds in combination with appropriate cultural practices.
The slugs can run all our bean plants in no time. We can use a beer trap or organic slug bait. The black bean aphid can be a problem in August and July. We can also spray with the natural insecticide ‘Pyrethrum’ or can wash off with a strong jet of water. Growing marigolds nearby organic French Beans can benefit as they attract many beneficial insects like ladybirds who love to eat blackflies.
The footrot and downy Mildew can be a problem but with the good crop rotation, this can simply be controlled.
The common diseases are:
- leaf spot
- common mosaic
- collar and
- stem rot
Common organic control measures are:
- chose disease-free seeds
- remove and destroy affected plants
- control the vectors to control diseases
The use of appropriate time of harvesting and sowing must be practised. One can make use of foliar spray of around 3% Panchagavya at the interval of 10 days from first month after planting will help to decrease these diseases. Or one can also use the spraying of Pseudomonas fluorescens and Trichoderma viride by 10 gram per litre of water to control these diseases.
The common insects are:
- Bihar hairy
- Blister beetle
- Bean bug
Common control measures are:
- One can spray 4% Neem seed powder solution (you can take 4 kg neem seed powder and mix it well with 10 litres of water and keep it overnight.
- Next morning, filter it and mix with 100 litres of water and spray). Or you can spray neem oil 3%. (neem oil from expellers).
- Then you can spray 10% of ginger, garlic, chilli extract on 45th, 60th and 75th day after planting is also suggested as an alternative.
Harvesting of French Beans
Frequent picking of these beans will encourage extra pod formation and will produce a bigger crop. One should take care that we must pick young and tender pods always. If you let them grow more than 10 cm they become tough. You should hold the stem and pull the pod in a downward direction to avoid damage when picking French Beans.
The crop of these beans will be generally ready for picking by 40 to 50 days after sowing based on the season of cultivation and variety.
One should harvest in cool periods, such as early morning or late afternoon. You can harvest your organic French Beans from July till the first frost. It is more important to pick your pods frequently at least once or twice a week to get more beans. After harvesting, shift the harvested produce to shade without delay. Further, there will be two to three pickings to be done at 4 to 5 days of interval.
Yielding in Organic French Beans farming
Throughout there are 12 to 15 tonnes/hectare of marketable Organic French Beans yields can be achieved by adopting good organic production technology.