Everything you need to know about French bean cultivation, production and growth. Learn about:- 1. Introduction to French Bean 2. Origin and Distribution of French Bean 3. Composition and Uses 4. Climate Required for Cultivation 5. Soil Required for Cultivation 6. Sowing Time 7. Planting System and Plant Population Density 8. Manurial Requirement Cultivation and Few Others.
Contents:
- Introduction to French Bean
- Origin and Distribution of French Bean
- Composition and Uses of French Bean
- Climate Required for Cultivating French Bean
- Soil Required for Cultivating French Bean
- Sowing Time of French Bean Seeds
- Planting System and Plant Population Density of French Bean
- Manurial Requirement for French Bean Cultivation
- Irrigation Requirement for French Bean Cultivation
- Intercultural Operations of French Bean
- Harvesting and Yielding of French Bean
- Cultivated Varieties of French Bean
1. Introduction
to French Bean:
French bean also known as common bean, kidney bean, dwarf bean, string bean, garden bean, or Haricot bean is best-known vegetable member of genus Phaseolus. French bean is locally named as French bean and Rajmah in Hindi, Shravangheveda in Telgu, and Tinglawari in Kannada. Most of the beans grown for processing (canned, frozen, and freeze-dried) are round podded, while cultivars grown for fresh market are usually flat-podded type. The wax-podded varieties of French bean are generally rendered unfit for human consumption, and their cultivation is restricted only in kitchen/home gardens.
French bean is largely grown in hilly tracks of Himachal Pradesh, Jammu & Kashmir and northeastern states during summer for off-season production and during autumn-winter in parts of Maharashtra, Uttar Pradesh, Karnataka, and Andhra Pradesh.
In northern plains, it is cultivated on a limited scale as autumn or spring crop because of susceptibility to low as well as high temperature. In India, French bean is grown on an area of 150,000 ha with a green pods production of 420,000 MT, whereas, beans for dry seeds are grown on an area of 9,000,000 ha with a production of 3,000,000 MT.
2. Origin and Distribution of French Bean:
South Mexico and Central America are considered the primary Centre of origin of French bean, while secondary Centre of origin lies in Peru-Bolivia-Ecuador region. Yarnell (1965) reported Phaseolus aborigineus as the probable progenitor of cultivated Phaseolus vulgaris. Remarkable variability with respect to seed colour (white, red, ochre-brown, and yellow) is found in French bean cultivars.
It is now generally agreed that Phaseolus originated in the New World. With the help of biochemical markers, Pereira (1990) also reported that the domestication of Phaseolus vulgaris occurred in two independent gene pools, Mesoamerican and the Andes.
3. Composition and Uses of French Bean:
Composition:
Like other legume vegetables, French bean is also a nutritious vegetable. Its green pods are good source of protein, mineral, and vitamins. French bean contains higher amount of protein, vitamin A and C,’ potassium, magnesium, calcium, and phosphorus, however, it is very low in fat content. Many legume seeds are known to contain undesirable factors such as protease inhibitors, lectins, phytates, polyphenols, and oligosaccharides of raffinose family. The nutritive value of its tender pods for 100 g of the edible portion is given in Table 5.1.
Uses:
In addition to the consumption of green pods as cooked vegetable, the newly emerged tender shoots and leaves are commonly used as potherb in many parts of the World. Large and firm immature seeds as well as the dried seeds of some specific French bean cultivars are also eaten as cooked curry. The delicate and tender pods are generally consumed at immature stage before the development of string or parchment layer and when the seeds are partially/underdeveloped.
In case of Haricot bean, fresh or green-shelled seeds are eaten, whereas, in case of pods having string and strong parchment layer only the dried seeds are eaten as pulse. In America, French bean is also processed for the use in off-season when green pods are not available.
French bean is said to be anti-diabetic and kidney resolvent and good for bladder burns and rheumatism.
4. Climate Required for Cultivating French Bean
:
French bean is a warm requiring tender vegetable crop that cannot tolerate frost, high temperature, and high rainfall. Its seeds do not germinate below 15°C, and a most favourable soil temperature for its seed germination is ranged from 18° to 24°C. The crop thrives best at a temperature range of 15° to 25°C, thus in plains of India, it is grown in cool season. Extreme high temperature conditions are unfavourable for its vegetative growth and under a condition of hot or rainy weather, dropping of blossoms becomes a major problem.
Most of the French bean varieties are day neutral except some semi-pole varieties that are short day types in flowering response. Waters et al. (1983) found that nitrogen fixation rate and nodule fresh weight in Phaseolus vulgaris were higher in temperate regions than the regions with hot and medium rainfall conditions.
5. Soil Required for Cultivating French Bean
:
French bean may be grown over a wide variety of soils ranging from light sandy loam to clay soils that are good in water retention capacity, however, well-drained friable alluvial soils are considered best for its cultivation. Heavy clay soils are also considered unfit for its economical production since the crop cannot withstand water logging conditions.
Heavy clay soils also impede the emergence of seedlings, resulting in poor and scattered/inconsistent plant stand, and poor aeration in heavy clay soils adversely affects the nodulation as well as the nitrogen fixation efficiency of Rhizobium bacteria since proper moisture and good soil aeration are essential for the survival of Rhizobium bacteria and fixation of nitrogen symbiotically.
Extreme acidic or alkaline soils are not considered good for attaining proper vegetative growth and for the normal activities of Rhizobium bacteria too. The optimum soil pH is 6.8-5.5 but the highest yield is obtained at a pH ranging from 6.0 to 5.3. If the soil pH is less than 5.0, liming is considered essential.
6. Sowing Time
of French Bean Seeds:
In northern Indian plains, French bean is sown twice once in the month of January-February and second in August-September, however, in southern parts of the country the sowing is done from September to November, while October end is considered optimum in both northeast and central India. In hills, the seed sowing for bush types is done in March and for pole types in June to fetch off-season price.
Corokalo et al. (1992) from their studies concluded that for higher yield, sowing in spring is better over sowing in summer season, but the quality of pods was better with crop sown in summer season. Growing of beans in February in protected structures (plastic tunnels) produced more vigorous plants and yield of superior quality pods.
The seed rate of French bean considerably varies, depending upon variety to be grown, soil type, and the climatic conditions under which the crop is to be raised. For bush type varieties, generally, the seed rate is 60-75 kg/ha, whereas, for pole types 30 kg seed is considered optimum for the sowing of one hectare land area.
Seed quality is a major factor for proper germination and for further vigorous growth of the seedlings. Seed treatment with carboxin has been reported to increase the plant percent stand significantly. Thakur et al. (1991) stated that seed treatment with benomyl, benalaxyl + copper oxychloride, or thiobendazple was found useful in controlling pre-emergence damping off disease, whereas, seed treatment with bitertanol and carbendazim was equally good for the control of post emergence damping-off disease.
7. Planting System and Plant Population Density
of French Bean:
Increased plant population density has been found to increase yield, which can be obtained by resorting proper planting system and season of planting. Generally, bush type beans and beans for summer planting are spaced at narrower spacing, while pole beans are spaced more between rows. In southern parts, ridges and furrows are formed 60 cm apart, and seeds are dibbled 10 cm apart on ridges at a depth of 2-3 cm. At each hill, three to four seeds are sown, and then, thinned to two seedlings as and when they become large enough to handle.
Higher plant population increases yield but narrow spacing reduces colour intensity and uniformity of French bean pods. In hills, the optimum spacing for pole types is 90 cm between rows and 15 cm between plants. Snap beans also show sensitivity to single and twin-drill configurations in yield response. Twin drill plots of snap bean yielded over twice as much as single-drilled bean.
Being a leguminous crop, French bean fits well in many crop situations as a restorer crop (bush type) and grown as an inter-crop with maize (pole type), especially in hills and high rainfall areas. It can be grown as an intercrop in widely spaced cucurbits as well. The seeds are inoculated with strains of Rhizobium culture for enhancing quick nodulation in the areas where it is grown for the first time.
8. Manurial Requirement
for French Bean Cultivation:
French bean responds well to initial application of well rotten farmyard manure/compost and NPK fertilizers. A quantity of about 25-50 tonnes of farmyard manure per hectare should be incorporated into the soil at the time of land preparation since application of manure keeps the soil physical properties favourable for the growth and development of plant and also improves the moisture retention capacity.
In general, a dose of 40 kg N, 60 kg P2O5, and 40-50 kg K2O per hectare is considered optimum in hills. Half the dose of nitrogen and full of phosphorus and potash are applied as basal dose at the time of sowing, and remaining half of nitrogen is top dressed at the time of flowering. In very acidic soils, a basal application of lime is recommended for obtaining increased yield of French bean.
Though French bean is a legume crop, it responds well to starter application of nitrogen, however, increase in nitrogen supply to plants increases the lodging of plants and decaying of pods and decreases nodulation capacity, contrary to this, phosphorus application increases nodulation. High organic matter and phosphorus in soil increases the fresh green pod yield of French bean, however, did not affect relative and total N and K content in soil.
Roy and Parthasarthy (1990) reported that P2O5 in the form of single super phosphate at 120 kg/ha improved snap bean yield. Instead of phosphorus application alone, its application with farmyard manure resulted in more marked effect on green pod yield and quality of French bean. Correa et al. (1990) reported that Mo application and soil inoculation with Rhizobium phaseoli resulted in higher seed yield.
The treatment combination of farmyard manure and dense organic manure gave higher yield of French bean pods, which had high protein and vitamin C content and prolonged shelf life. Choudhary et al. (2001) reported that a fertilizer dose of nitrogen 90 kg and phosphorus 60 kg/ha was the best giving 14.23 pods and 13.75 g grain yield per plant.
Jana and Kabir (1987) reported that a basal dose of farmyard manure 20 t/ha and N, P, K 50 : 80 : 50 kg/ha applied at 6 leaf stage alone or in combination increased the plant height, and pods’ number, length and yield of French bean grown in polyhouse.
French bean also responds to micronutrients. The foliar application of boron, copper, molybdenum, zinc, and manganese each at 0.1% is effective in enhancing yield and quality of pods, however, the crop showed boron toxicity symptoms in plots receiving boron more than 1 kg/ha.
9.
Irrigation Requirement for French Bean Cultivation:
French bean is known to be slightly tolerant to low moisture stress, however, uniform and proper supply of moisture at all critical stages of plant growth, especially at flowering and pod setting stages, results in better growth and improved productivity and yield of good quality pods since a constant supply of moisture is one of the critical factors affecting yield, uniformity, and quality of beans. Irrigation at early phases of plant growth has been found to be incredibly useful.
Lack of adequate soil moisture may result in poor pod setting, reduced pod size and lower number of seeds per pod, and may increase fibre content of pods, hence, moisture stress just before and during blooming can cause serious losses, even in the regions of relatively high average rainfall, irrigation is a necessity for beans on light sandy soils and even on heavy soils. Light and frequent irrigation is more functional than heavy irrigation at long intervals.
Irrigation at 45 kpa resulted in high dry matter production, green pod yield, nutrient uptake and water use efficiency (WUE) compared with irrigation scheduled at 65 or 85 kpa. Borosic et al. (2000) reported that irrigated crop flowered earlier and set nine pods per plant, while the non-irrigated crop set only two pods per plant. They further reported that the yield of processable pods per unit area of irrigated crop was 4.5, 2.4, and 1.6 times higher in three different seasons as compared to corresponding yield of non-irrigated crops.
In an experiment, it was found that grain and straw yield of cultivars PDR-14, HUR-137, and Contender decreased significantly with increasing levels of sodicity of irrigation water, and among varieties, the cv. HUR-137 contained significantly higher sodium content and uptake in grain and straw as compared to PDR-14 and Contender.
10. Intercultural Operations of French Bean:
i. Hoeing and Weeding:
Inadequate control of weeds in early stage of crop growth reduces the yield due to competition with crop plants for nutrients, light, space, and moisture, however, in later stages weed control is not needed since the fully expended canopy of crop smoothers the weeds. Tisdale and Frank (1980) observed that narrow spacing reduced weed competition and hoeing increased the French bean yield on an average by about 11%.
In an experiment, Mishra et al. (1999) noticed that uncontrolled weeds caused 55% reduction in seed yield of French bean. Hoeing during early stages helps keeping the weeds down, improves aeration by making the soil loose around root system and provides favourable atmosphere to the roots for their growth, hence, two to three very shallow cultivation should be done at early stages of crop growth. Deep inter-cultivation will disturb the plant growth due to pruning of roots, as the feeding roots of French bean grow shallow near the soil surface.
Pre-emergence application of bentazone @ 2.0 kg/ha along with Thiobencarb @ 0.5 kg/ha helps in getting better weed control and yield. Cox (1979) recommended the application of Alachlore on soil surface after sowing seeds without incorporating the herbicide into the soil. Bentazone has been found selective in controlling weeds, like Portulaca oleracea, Ambrosia artemisiifolia, Cyperus esculentus, while surflan or Phenoxylene controls Echinocloa colonum.
Both Pendimethalin 1.0 kg/ha and hand weeding were quite effective in controlling weeds and increased the seed yield of French bean. Issac et al. (2000) reported that in absence of a natural infestation of weeds, the crops with a spreading habit expressed similar yield at sowing density of 0, 0.5, 1.0, 2.0, and 4.0 times higher than their recommended population density, and the weed biomass was found lowest in turnips and maximum in dwarf French bean. They further reported that the ability to suppress weeds was independent of crop growth habit but was related to leaf size and plant growth rate.
Mulching is effective in spring/winter planting of French bean, particularly under a condition of low moisture stress. In winters, the use of transparent and black polythene film as mulch increases the soil temperature, promotes earliness, and increases fresh green pods yield, while in hot summer months to conserve soil moisture, mulching with straw is recommended for good plant growth under low moisture stress.
Han et al. (1989) observed that polyethylene film mulch increased the soil temperature and decreased the number of days to emergence and flowering, and increased stem height, number of pods per plant and 100 seed weight for both green and dry yield.
In an experiment on growth and yield of French bean, Mudlagiriyappa et al. (2001) found that application of crop residues and soil solarisation with TP resulted in maximum weed reduction until harvest. The nitrogen fixation under Rhizobium culture and mulching with rice husk is almost three times higher than unmulched plants of French bean.
In French bean to provide support and to accommodate more number of plants per unit area, staking is essentially required for climbing/pole type varieties. The wooden sticks or twigs of forest trees that are locally available can be used for staking purpose. Mounting up of soil around plant base up to first set of leaves gives additional support to the stem and encourages root growth.
In hills, French bean, particularly the vine type, is grown as an intercrop with maize, grain amaranths, finger millet, and foxtail millet. In mid hills, maize + French bean-wheat cropping sequence has high potential. In plains, French bean is quite compatible for intercropping with early potato. French bean is sown with young coffee plantations, cassava, or sugarcane in Brazil. It can be sown between single row of cassava or with three lines of beans between double rows of cassava.
11. Harvesting
and Yielding of French Bean:
Harvesting of French bean depends on its usage. The pods usually become ready for harvesting 2-3 weeks after first blooming. For culinary purpose, the pods are picked at immature stage when they are sufficiently tender, non-fibrous, and before they become tough and stingy or the seeds are adequately large to cause the pods bulged around the seeds.
Yield of French bean is increased as the harvesting is delayed, and maximum yield of most of the varieties can be obtained when harvesting is done 30 days after flowering, however, quality (uniformity of green colour), good texture (tender, firm, and non-fibrous pods) and natural bean flavour are reduced when harvesting is delayed.
Number of maturity indices has been proposed by various researchers to determine the optimum harvest date of beans. Seed length, pod size, pod diameter, seed weight as a percentage of pod weight, and alcoholic insoluble solids are some of the important indices.
Neuvl and Dekker (1989) proposed that seed- pod weight ratio of 12% is an indicator of crop maturity. Using minimum and maximum temperature, sunshine hours, pod yield, and pod quality characters Ferreira et al. (2000) proposed a simple weather driven model to determine the harvest date of green beans.
In India, picking of pods, especially of pole type beans where several harvestings are made, is usually done manually. In large-scale commercial plantings of bush types, one or two pickings are done so harvesting may possibly be done by machines, however, the pole type beans have large duration of bearing as compared to bush types, and hence, several harvestings are made at 3-5 days interval, depending upon the quality desired, and weather conditions.
The best time for the harvesting of dry beans is when larger part of the pods is mature and fully ripe and most of the pods have turned yellow. Harvesting at pre-dry stage did not significantly affect seed yield but reduced the quality of seeds.
Mechanical harvesting reduces the external and internal quality characters of pods as compared with hand picking, and the main problem is damage to the pods, which depends on variety, type of machine used, speed of machine and agronomical practices adopted for raising crop.
Losses in plant height, height of first pod and length of pod have also been reported. Some varieties showed lower losses in mechanical harvesting compared to other varieties. Impact speed of the machine also highly affected the quality of pods. Jech et al. (1998) showed that impact speed above 2.8 m/s damaged the bean pods of five varieties.
i. Storage:
Green beans are highly perishable since they contain more than 90% water, therefore, can be stored only for a very short period under ambient temperature conditions. For longer storage, beans should be cooled rapidly after harvest, preferably to 4-5°C. Vacuum cooling or forced air- cooling method can be used for the purpose, but hydro cooling is more preferable since cold- water cools the beans rapidly and freeze moisture helps to prevent wilting or shrivelling.
Post-harvest browning is one of the reasons for reduced shelf life of fresh beans. It is found that susceptibility to browning is different in different varieties, and washing of pods increased the incidence of browning unless they were dried immediately afterwards. Discoloration of broken ends after 24 hours at room temperature was high in two yellow varieties compared to green varieties. It is also reported that initial level of phenol is high in yellow varieties.
Green beans are generally canned or frozen. The desirable characters for processing are resistance to mosaic disease, long and straight tender pods of medium size with thick walls and small seeds, lack of fibre and strings, bright green colour after blanching and firm skins that do not split or slough off during cooking.
The leucoanthocyanins of beans are converted to anthocyanins during processing, resulting in an undesirable greyish brown discoloration. The cultivar and the preparation methods as well significantly affect the sensory quality and acceptance of processed green beans.
Green beans are harvested, and then, cleaning is done using shaker and blower. The beans are then subjected to size grading, and after that, removing of stems and blossom ends of pods. After this cleaning process, the beans are put into the mechanical cutters, where they are cross cut into small shreds of 1.0-1.5 cm length.
Then these are blanched in steam or in water at 99°C for 2- 3 minutes. Freezing suitability of different varieties of beans are different and varieties such as Lit551, Rofin, Rubicon, Silver and Ulysses performed better after quick freezing and six months storage at -2°C in polyethylene bags.
The harvested beans are subjected to size grading, cutting, and blanching for canning. Stanley et al. (1995) reported that blanching of fresh green beans in acid or CaCl2 resulted in a firm canned product compared with the corresponding control. The cut beans are filled by volume mechanically. The cans are filled with 2% brine, then cans are heated in a steam exhaust box for 5 minutes and sealed hot or steam flow sealed. AU-Van Buren et al. (1990) found that softening of beans texture occurred when the pH was raised from 5.2 to 6.2.
The green pod and seed yield vary considerably with locality, soil type, cultivars and practices adopted during crop cultivation. On an average, green pod yield of bush varieties is 60 q/ha and for pole varieties, it is 120 q/ha. The yield of dry bean or bean seeds varies from 12 to 18 q/ha.
12. Cultivated Varieties
of French Bean:
Based on growth habit, the French bean varieties are grouped as bush type with short internodes, semi-pole type with longer internodes, and the pole type having internodes longer than that of semi-pole type, but in regions of very high rainfall, especially during rainy season, generally, the pole type varieties are preferred for cultivation. The French bean varieties are further classified into string and stringless. Depending on its usage, it can also be divided into four classes viz., vegetable bean, processed bean, dry shelled bean, and seed bean.
The major objective in French bean has been the development of high yielding cultivars having resistance against insect-pests and diseases, but unfortunately, most of the varieties grown in different parts of the country are simple introductions from different countries.
Some of the important varieties developed by the various State Agricultural Universities or ICAR Institutes and popularly being grown on commercial scale in various parts of the country are given as under:
A most popular bush/dwarf type early maturing variety introduced from USA is suitable for cultivation twice in a year in hills. The pods of this variety are round, green, slightly curved at the ends, and stringless. The average yield of fresh green pods is 80-95 q/ha, and its dry seeds are light brown.
A black seeded variety is well adapted to late sowings. The pods of this variety are 11-13 cm long, slightly oval shaped, and become ready for first harvest in 50-60 days after sowing. The fresh green pods yield is about 75-90 q/ha.
A pole type variety is resistant to Angular leaf spot. The pods of this variety that become ready for first picking in 65-75 days after sowing are green, round, 13-14 cm long and stringless. The fresh green pod yield is 105-125 q/ha.
A pole type variety slightly earlier to SVM-1 is introduced from USA. The pods that borne in cluster and mature in 65-75 days after sowing are 20 cm long, flat, meaty, and stringless. The fresh green pod yield is 100-125 q/ha.
A variety developed at Indian Institute of Horticultural Research, Bangalore takes about 70 days from sowing to flowering. The pods are straight and flat with very good cooking and transport quality. The yield of fresh green pods is about 100-120 q/ha, and 100 pods weight is 680 g.
A pole/climbing type white seeded variety developed at Dr. Y.S. Parmar University of Horticulture and Forestry, Solan (HP) bears pods in a cluster of three, and gives fist picking of green pods in 65-70 days after sowing. The pods are 13-14 cm long, round, green and stringless. The average yield of fresh green pods is 120-149 q/ha. It is tolerant to angular leaf spot disease, thus, found very suitable for growing in the hilly tracts during rainy season.
An early bearing variety with straight and upright growth habit developed at G.B. Pant University of Agricultural and Technology, Pantnagar becomes ready for first picking in 60 days after sowing. It possesses resistance against angular leaf spot disease and moderate resistance against mosaic virus. It gives a potential yield of 100-120 q fresh green pods per hectare.
An induced mutant developed at Indian Agricultural Research Institute, New Delhi using x-ray irradiations to a wax podded American variety EC 1706. The pods, which become ready for first picking in 50-55 days after sowing, are straight, flat, 12-14 cm long, dark green, tender and meaty. The fresh green pod yield is 80-85 q/ha.
A variety through simple introduction is suitable for an early harvest, and bears medium sized, curved, tender, meaty, and stringless pods. The seeds of this variety are yellowish-brown.
It is a cross between two pole type varieties and developed by Tamil Nadu Agricultural University, Coimbatore through a selection in F4 generation. Being viny growth habit, the plants require supports for their normal growth. The pods are flat and pale-green in colour.
It is a bush type and dual-purpose variety developed at Tamil Nadu Agricultural University, Horticultural Research Station, Yercaud through pure line selection from a local indigenous type, thus, can be grown for harvesting green pods as well as grains. It yields about 97.75 quintals fresh green pod per hectare.
The pods of this variety are fleshy, round, stringless and pale-green. It takes about 45-50 days from sowing to first picking and gives a yield of about 105-110 quintal fresh green pods per hectare.
This variety is resistant to wilt and comparatively well adapted to warmer conditions. The pods are round, smooth, green in colour but become fibrous and mature very soon if not harvested timely.
The pods are round, tender, fleshy, green and stringless, and become ready for picking in 55-60 days after sowing. The yield of fresh green pods is 115 q/ha.
A pole type variety is suitable for cultivation on an elevation of 1800-2400 m above mean sea level. The potential yield of fresh green pods is 70 q/ha.