Everything you need to know about banana cultivation and growth! Learn about: 1. Botany of Banana 2. Climate and Soil Required for Growing Banana 3. Orchard Cultural Practices 4. Propagation 5. Planting Operations 6. Flowering and Fruiting 7. Pruning 8. Harvesting and Handling 9. Diseases and Insect Pests 10. Varieties.
Botany of Banana:
Banana is the common name for a fruit and also the herbaceous plants of the genus Musa which produce this commonly eaten fruit. They are native to the tropical region of Southeast Asia. Bananas are likely to have been first domesticated in Papua New Guinea. Today, they are cultivated throughout the tropics.
Banana plants are of the family Musaceae. They are cultivated primarily for their fruit, and to a lesser extent for the production of fibre and as ornamental plants. As the banana plants are normally tall and fairly sturdy they are often mistaken for trees, but their main or upright stem is actually a pseudostem (literally “fake stem”). For some species this pseudostem can reach a height of up to 2-8 m, with leaves of up to 3.5 m in length. Each pseudostem can produce a bunch of yellow, green or even red bananas before dying and being replaced by another pseudostem.
The banana fruit, grow in hanging clusters, with up to 20 fruit to a tier (called a hand), and 3-20 tiers to a bunch. The total of the hanging clusters is known as a bunch, or commercially as a “banana stem”, and can weigh from 30-50 kg. The fruit averages 125 g, of which approximately 75% is water and 25% dry matter content. Each individual fruit (known as a banana or ‘finger’) has a protective outer layer (a peel or skin) with a fleshy edible inner portion.
Both skin and inner part can be eaten raw or cooked. Western cultures generally eat the inside raw and throw away the skin while some Asian cultures generally eat both the skin and inside cooked. Typically, the fruit has numerous strings (called ‘phloem bundles’) which run between the skin and inner part. Bananas are a valuable source of vitamin B6, vitamin C, and potassium.
Bananas are grown in at least 107 countries in popular culture and commerce; “banana” usually refers to soft, sweet “dessert” bananas. The bananas from a group of cultivars with firmer, starchier fruit are called plantains. Bananas may also be cut and dried and eaten as a type of chip. Dried bananas are also ground into banana flour.
Although the wild species have fruits with numerous large, hard seeds, virtually all culinary bananas have seedless fruits. Bananas are classified either as dessert bananas (meaning they are yellow and fully ripe when eaten) or as green cooking bananas. Almost all export bananas are of the dessert types; however, only about 10-15% of all production is for export, with the United States and European Union being the dominant buyers.
The banana plant is a pseudostem that grows to 6 to 7.6 metres (20-25 feet) tall, growing from a corm. Leaves are spirally arranged and may grow 2.7 metres (9 ft) long and 60 cm (2 ft) wide. The banana plant is the largest of all herbaceous flowering plants. The large leaves grow whole, but are easily torn by the wind, resulting in the familiar frond look.
A single, sterile, male banana flower, also known as the banana heart is normally produced by each stem (though on rare occasions more can be produced – a single plant in the Philippines has five. Banana hearts are used as a vegetable in Southeast Asia, steamed, in salads, or eaten raw. The female flowers are produced further up the stem and produce the actual fruit without requiring fertilization.
The fruit has been described as a “leathery berry” In cultivated varieties, the seeds have degenerated nearly to nonexistence; their remnants are tiny black specks in the interior of the fruit. The ovary is inferior to the flower; because of their stiff stems and the positioning of the ovary and flower, bananas grow sticking up, not hanging down.
Some sources assert that the genus of the banana, Musa, is named for Antonio Musa, physician to the Emperor Augustus. Others say that Linnaeus, who gave the genus its name in 1750, simply adapted an Arabic word for banana, mauz. The word banana itself comes from the Arabic word banan, which means “finger”. The genus contains numerous species; several produce edible fruit, while others are cultivated as ornamentals.
Climate and Soil Required for Growing Banana:
Banana is a tropical plant requiring a warm humid climate. It grows well in regions with a temperature range of 10°C to 40°C and an average of 23°C. In warm dry weather, the fruit stops growth and in the cold weather, it is damaged by frost. In cooler climate, the duration is extended, sucker production is affected and bunches are smaller.
Low temperatures i.e. less than 10°C are unsuitable since they lead to a condition called choke or impeded inflorescence and bunch development. Banana comes up well up to an altitude of 1500 M above sea level in the tropics. The hill bananas of Tamil Nadu are raised between elevations of 500-1500 metres mostly under rainfed conditions.
Banana grows well under high rainfall areas. On an average 100 mm rainfall per month appears to be satisfactory for growth of banana. Hot winds blowing in high speed during the summer months shred and desiccate the leaves.
Stagnation of water is injurious and may cause diseases like Panama wilt. Tall varieties are more tolerant to cold temperature above freezing point. The variety ‘Monthan’ or ‘Khasadia’ can tolerate low temperature better than any other variety.
Banana cultivation can be made successful under subtropics if planting is so regulated that bunches emerge before winter so that there is minimum frost damage and choke condition is avoided. This can be made possible by planting tissue culture raised plants at proper time and of specific size. In Punjab, it is suitable for growing in bet area, river banks and central zone comprising Moga, Ludhiana, Fatehgarh Sahib, SAS Nagar, Sangrur and Barnala districts.
Bananas are grown in a variety of soils provided soil moisture is available. Deep, well drained, friable loamy soil with adequate organic matter is ideal for its cultivation. The pH range of the soil should be 6.5 ― 7.5 but can be grown upto pH 8.7. In coastal areas of Maharashtra soils are sandy.
In the plains, banana is grown in well-drained black cotton soils. The medium black and lighter soils of East Khandesh are also suitable. In Tamil Nadu and Andhra Pradesh soils vary from well drained alluvial to the slightly open loamy type of the hill slopes.
Banana is one of the few fruits which has a restricted root zone. Therefore, two soil factors are important for bananas namely depth and drainage. The minimum depth necessary is about a metre.
Saline soils with salinity percentage exceeding 0.05 are unsuitable. Banana can grow well even under slightly alkaline soils. Such soils are found preferable for avoiding the wilt disease which is known to be severe in acid soils. Clones resistant to wilt such as ‘Cavendish’ group and ‘Poovan’ can be grown within a reasonable range of pH.
Orchard Cultural Practices for Growing Banana:
i. Irrigation:
Banana is a moisture loving plant; therefore, its water requirement is very high. It requires adequate soils moisture throughout the year. Irrigation is given just after planting. Banana requires irrigation regularly throughout the year except during heavy rains.
In Western Coast of India, it is normally grown as a rainfed perennial crop. In hilly areas also no irrigation is given. In Bihar, irrigation is given after every 10 days from December to June. Banana growing in most inland areas requires 40-50 irrigation from the time of planting to harvest.
In North Gujarat and East Khandesh, even more irrigation may be required. In banana, trenches are dug between alternate rows which serve to drain off excess water during the rains and later as irrigation channels. In West Bengal, the plants are irrigated at an interval of 10-15 days during dry periods.
Irrigation facility is a must to Cavendish banana, whereas tall cultivars are grown under un-irrigated condition or marginally irrigated condition. In Basrai banana, the plants given 45 kg Nitrogen and irrigated at an interval of 6 days, produced mature fruits 83 days earlier than unfertilized plants irrigated at 14 days interval. In Robusta banana, lateral and vertical spread of root mass increased by decreasing the soil moisture.
Water is crucial for its growth. Little moisture stress can lead to decrease in finger size and colour of leaves. Excess water may lead to breakage of pseudo-stem near root portion, due to rotting.
Drip irrigation can reduce quantity of water and increases yield and decreases number of days to harvest and increases leaf production. In banana cv. Robusta, as the availability of water in the soil increases, the stomatal number per unit area and stomatal size increases, resulting in the improved photosynthetic efficiency and ultimately increase the yield.
Dry soil conditions adversely affect the banana yield, because there is reduction in stomatal size which interferes with carbon dioxide supply and in turn it reduces the photosynthetic efficiency. Water use efficiency is more with drip irrigation as compared to basin system of irrigation. The drip irrigation system saves 50 per cent water and also yields higher.
ii. Intercropping:
Intercrops can easily be grown in banana plantation at the earlier stage of growth. In some parts of India, mixed cropping is also practised. Planting of banana may be followed by planting of intercrops like brinjal, colocasia, turmeric, chilies, bhindi, radish, cauliflower, cabbage, spinach, maize, etc. depending on climatic conditions. Mixed cropping of banana, arecanut, coconut and cassava is a common practice along the coastal belts of Tamil Nadu. Paddy is also grown as mixed crop. Banana is grown as a shade plant for coffee, cocoa, rubber, young mango trees and orange in different parts of India.
iii. Weed Control:
Shallow cultivation at early stage of crop is essential to keep down the weeds and to provide better conditions for plant growth. Weeds can also be checked with the use of herbicides. Diuron @ 4 kg per hectare and Simazine @ 6 kg per hectare control grasses and broad leaved weeds when, applied after planting and repeated 30 days after planting. At Bangalore, application of glyphosate @ 1 kg a.i per hectare at the time of planting followed by 0.5 kg a.i. per hectare at 30 and 60 days after planting of suckers is recommended.
iv. Manuring and Fertilization:
In banana, it is essential to induce quick growth and produce more leaves with longer area. To achieve this, complete dose of manures and fertilizers should be applied by six months after planting. Nitrogen hastens maturity and increases yield. Phosphorus promotes strong root system, healthy rhizome, favours fruit setting and accelerates ripening.
Application of potash increases the number of hands/bunch and finger size, improves fruit quality, develops resistance to diseases and reduces water uptake in banana. The third leaf is taken as standard for analysis for establishing critical values.
In ‘Giant Governer’ cultivar, the nutrient values suggested are- Leaf N around 2.8, P 0.8 and K 3.8 per cent at the vegetative stages (6 months). Banana needs heavy manure near the soil surface because of their shallow rooting. The application of nitrogen should be done at 2, 4 and 6 months after planting. Phosphorus should be applied at planting time. Potash should be given in two split doses-one at planting and another at the time of initiation of flowers.
In Bangalore, the fertilizers recommended for Robusta banana are 200 g N, 100 g P2O5 and 200 g K2O per plant. Nitrogen and potash are to be applied in four equal splits at 30, 75, 120 and 165 days after planting while phosphorus can be applied at the time of planting. For ratoon crop, the requirement of N and P2O5 can be reduced to 100 and 50 g per plant, respectively while K2O is to be applied at 200 g/plant. Complete fertilizers application before flower initiation which normally occurs within 5-6 months after planting.
For Robusta and Basrai, 180 g N, 180 g P and 270 K per plant annually has been recommended. In another field trial 150-200 gN, 40-60 g P and 200-300 g K per plant of banana per year is suggested.
In Punjab, the fertilizers for Grand Naine @ 250g nitrogen and 250 g potash per plant is given in 5 equal doses during April, May, June, July and August. At the time of planting in February – March 280 g NPK (12: 32: 16) per plant is recommended.
Urea is given 60 g per plant in the Month of May. Again, it is applied 60 g in June, and 80 g per plant each in July, August and September along with 40 g MoP in June, 60 g in July and 80 g per plant each in August and September.
Propagation of Banana:
Sword suckers with a well-developed conical shaped rhizome with lanceolate leaves and actively growing central bud, weighing 500-750 g are generally used. While in western and central Maharashtra, well developed rhizomes with dormant lateral buds and “dead” central bud are used. Cut rhizomes called “Bits” are also successfully used for propagation.
Disease free suckers are collected, cleaned and dried in shade for 24 hours. These are dipped in a solution containing 0.5% monocrotophos and 0.2% bavistin and again shade dried for 24 hours are planted in the field.
Micro-Propagation:
Micro-propagation through tissue culture has gained commercial acceptance in banana cultivation. These plants are uniform in age and come to flowering at the same time and the fruits mature uniformly. They are disease free and can be harvested earlier. With proper ratoon technique, it is feasible to have three crops in 28-30 months while the sucker propagated plants yield first crop after 16 to 17 months. The tissue culture plants when planted in the field after necessary hardening yield a crop in 11 months.
The planting is done generally in the beginning of the South-West monsoon. In later planting, the growth of the plants is checked by the onset of the cool weather. In Bengal the yield is poor if planting is delayed till the end of the monsoon. Planting can be done at almost any time in the South, where there is no cold weather.
The planting is done in September-October at the end of the South-West monsoon in Malabar, in December in Travancore, in February-March on the hill-slopes of south India with a high rainfall and in April in the wetlands on the banks of the Kaveri River. In the coastal area of Greater Bombay, planting is done in April, June, August or October.
Planting is done in previously-dug and filled pits about 0.4 x 0.4 x 0.4 metre. The size of the pits is increased to 0.6×0.6×0.6 metre in heavy clay soils. The site for banana-planting should not be windy and wind breaks should be provided. In the interior areas, a temporary wind break of Sesbania grandiflora or jantar or shevri (Sesbania aegyptiaca) is provided on the windy side, five metres away from the banana plants.
The land is cultivated deep several times before planting. In the Bombay area, brushwood is sometimes burnt in the fields in May to heat the soil. The land is manured early before planting, using up to 125 tons of farmyard manure per hectare. Manure (4 to 5 kg per pit) is sometimes added directly to the pits before filling them.
Banana is sometimes planted as an inter-crop between areca-nut and coconut or as a shade plant for coffee and oranges in Malabar and the adjoining areas. In Gujarat, it is also planted between young mango trees to provide shade. Whereas in some other countries a planting distance of seven metres is adopted. In India the plants are generally spaced 2 to 2.5 m. apart in both directions.
The spacing varies greatly according to the variety and climate. The variety Basrai is planted one metre apart in the dry, irrigated areas of East Khandesh, where plant growth is less and yields of up to 100 tons per hectare are obtained.
The Red Banana in the Bassein area, the perennial plantations of Poovan and Monthan in the highlands in the Kaveri delta and the Mala Vazhai planted on the rainy hills in South India are planted 4 metres apart, since the plants grow very large in these places.
After planting, one or two irrigations may be given about four to five days apart. When the suckers sprout, the land is cultivated and in some cases earthing-up of the plants is done. This is especially important in the shallow-planted dormant bulbs of Basrai. In this case, earthing-up is required several times. After the rains, trenches are formed between the rows of banana plants for irrigation.
Banana requires very large amounts of water. After the rainy season from October to February, irrigation is required every week to 10 or even 15 days, and every 5 to 8 days from March to May. The practice of irrigating every alternate day from February to June in Cochin is too excessive. In Bihar, irrigation every 10 days from December to June is sufficient. Trenching requires more water but gives higher yield and larger fruits.
In most inland areas, banana requires 40 to 50 irrigations from the time of planting to harvesting. In North Gujarat and East Khandesh as many as 90 irrigations may be required. In the perennial plantations of Poovan and Monthan in the Tanjore area, 0.6 metre wide and 0.45 metre deep trenches are dug between alternate rows of plants.
During the rains they serve to drain off excessive water and afterwards as irrigation channels. In the hilly areas and coastal areas no irrigation is ever required. During the periods of water scarcity, the soil is covered with mulch of banana leaves. In rare cases, hand-watering has to be done in places like Bassein.
Planting Operations for Banana:
The land should be deeply ploughed, harrowed and levelled properly. Pits of 60 cm x 60 cm x 60 cm are dug sufficiently ahead at points fixed for planting. The pits are filled with a mixture of top soil and farmyard manure or compost (50: 50).
The suckers should be detached from the mother plant along with a piece of underground stem with a few roots. The single sucker is planted in the centre of the pit and pressed well around the base. Immediately after planting, light irrigation should be given.
The time of planting of banana depends on climatic conditions and availability of water. Banana can be planted throughout the year except in severe winter and during heavy rains when the soil is very wet. In the areas of heavy and continuous rains, planting of banana should be done after monsoon i.e. in September-October. In the areas where rains are not so heavy, planting should be done during June-July. In the areas where assured irrigation is available, planting can be successfully done in February-March. The planting in the hill slopes of South India is done during February-March and on the banks of the Cauvery River in April.
Planting Distance:
A spacing 2.7 m x 3.0 m (row x plant) for tall cultivar and 1.8 m x 1.8 m (row x plant) for dwarf cultivars were found most suitable. For dwarf varieties, the distance of 1.2 m x 1.2 x m and 1.8 m x 1.8 m can also be kept profitably. On the other hand, for tall and semi-tall varieties, the distance of 2.4 m x 1.8 m, 2.4 m x 2.4 m and 2.5 m x 2.5 m were also found equally suitable. The plant density of 2500/hectare is recommended for Giant Governor.
Spacing in tissue culture plants of 30 cm size should be planted on 15 February to 7 March in the field at 1.8 x 1.8 m distance. Before planting pit of 0.6 x 0.6 m size should be filled with half farmyard manure and half top soil after mixing with 90 g P2O5 (180g DAP).
Flowering and Fruiting in Banana Trees:
The initiation of the inflorescence primordium of the banana bunch takes place in the heart of the pseudo-stem. It develops to a certain extent before emergence. In cv. Dwarf Cavendish, the emergence of the 11th last leaf indicates approximately the time of transformation of the growing point into inflorescence.
The time from initiation of inflorescence to shooting of bunch varies from 3 months in summer to 6 months in winter in the first planted crop. The initiated inflorescence may ascend rapidly from the base of the pseudo-stem to the top in one month. The flower bud emerges out after all the leaves including the protective leaf has emerged.
Flowers are arranged in two series, numbering about 7-14 pairs. Each of the series is called a hand. The basal nodes of the inflorescence bear female (pistillate) flowers and the upper nodes bear male (staminate) flowers. Sometimes one or two clusters of transitional forms may occur. A bract subtends each cluster.
Bracts are large, spatheceous and of various shades of purple, ovate, closely imbricate, spirally arranged and often deciduous. The bracts rise just before flowers become functional. As the ovaries of the female flower develop into fruit, the growing point continues its growth, bracts rising to expose the male flowers.
Flowers are arranged in nodal clusters, each being borne on the obliquely transverse cushion. Female flowers are large, bearing a well-developed ovary with a long style and reduced staminodes. Female flowers develop into the fruit. In the male flowers, the ovary is abortive, the style and stigma slender and anthers well developed. Edible banana rarely contain pollen.
Male flowers abscise from the base of the ovary and are shed after exposure for a day. In female flowers, the style and staminodes abscise leaving at the top a scar which persists in the mature banana. The ovary of the female flower is trilocular, each loculus containing an axile placenta. Ovules are 2 or 4 rowed in each loculus.
The common type of inflorescence is the one in which the basal portion bears pistillate flowers, which develops into fruits followed by deciduous staminate flowers e.g., ‘Poovan’, ‘Monthan’. The male bud or heart continues to produce staminate flowers till the fruits ripen but in some groups like ‘Nadan’ the heart withers and is dried up long before the maturity of the bunch.
In the second group, the whole inflorescence bears pistillate flowers and hence all the flowers develop into fruits e.g., ‘Ayiranka Rasthali’ and ‘Moongil’. In the third type, the basal flowers develop into fruits followed by persistent male flowers consisting of green rudimentary ovaries with persistent perianth and bracts e.g., ‘Dwarf Cavendish’, ‘Nendran’ etc.
In another type, the basal region bears pistillate flowers which develop into fruits followed by persistent male flowers, which is again followed by deciduous male flowers. The bracts of persistent male flowers are, however, deciduous e.g., ‘Rasthali’ and ‘Chakkarakali’.
Pollination is mainly by bees and birds which visit the flowers for nectar secreted at the tips of the ovary and collected at the base of the perianth. The ovary of the flowers is trilocular with axile placentation.
The fruit of banana is either seeded or vegetatively parthenocarpic i.e., developed without pollination. The vast majority of edible bananas are not pollinated. Some of the cultivated varieties such as ‘Poovan’ and ‘Kaali’ etc. though sterile, set seed when pollinated or when they are grown in the vicinity of a pollen source. Certain cultivars such as ‘Dwarf Cavendish’ are inherently highly sterile and are not known to set seed.
In seeded wild bananas, pollination is essential for fruit development and the mature fruit contains a mass of black seeds. The fruit in the seedless bananas is believed to develop through endogenous auxin stimulation which in seeded bananas is derived from the developing seed. Banana fruit is berry and edible portion is mesocorp and endocarp.
Growth and Development:
The growth pattern of the plant suggested a double sigmoid curve, while the dry matter increase followed a normal sigmoid curve. Throughout the period between the third month after planting and harvest, pseudo-stem contributed maximum to the fresh weight of the whole plant.
Seven months after planting, it accounted for more than half of the total fresh weight of the whole plant (51.3%) and was followed by corm and leaf contributing almost equally to the total fresh weight. After shooting, the contribution of the bunch to the total fresh weight become prominent, contributing about 32.2% of the total fresh weight at harvest and was very close to the fresh weight of the pseudo-stem (36.5%) at the same stage.
Fruit Growth Pattern:
The growth in volume of seeded bananas is sigmoid and that of parthenocarpic fruits is not sigmoid. It was also found that the growth rates are related to certain ovule behaviour and seed content of the fruit and ploidy. In ‘Dwarf Cavendish, a concave growth curve was observed. It took 130 days to reach full maturity after the emergence of inflorescence and fruit weight increase maximum during the final 4 weeks of growth.
The fruit growth in terms of increase in girth, length and volume followed a double sigmoid pattern. Increase in both fresh and dry weight also suggested a double sigmoid curve.
Pruning of Banana:
De-suckering or pruning is the removal of unwanted suckers. These suckers have to be removed periodically as otherwise they compete with the mother plant for nutrients, resulting in lower bunch weight and total yield.
It is done either by cutting off the sucker or the heart may be destroyed without detaching the sucker from the parent plant. Sometimes, kerosene is poured into the cavity left after digging the sucker. In South India, crowbar with a chisel-like end is used for damaging the sucker.
Removal of all suckers upto flowering of mother plant and maintaining only one follower afterwards is the best de-suckering practice. However, under high density planting, it is better to leave the follower after harvesting 75-80% of the plant crop so that uniform cultural practices can be followed.
It has been observed that sucker removal had no effect on yield in the first harvest, but yield in the second harvest was highest in plants left with one sucker (12253 kg/ha), followed by plants left with 2 or 3 suckers (8606 and 8879 kg/ha, respectively) and was lowest in plants without removal of suckers (6721 kg/ha).
Removal of Style, Perianth of Male Bud:
This practice helps in overcoming ‘fingertip’ disease. Remove the perianth and style while the bunch is still young. The male bud or ‘heart’ should be removed immediately after the last hand appears and the fruit starts to curve up.
The perianth and style are easily removed by a light brushing movement of the hand a few days after flowering. If not brushed off, they become brown and shrivelled and it is difficult to remove.
The male bud or heart is used as a vegetable in parts of India and as animal or stock feed in some countries. Removal of male bud is said to favour fruit development. It is a practice recommended for improving the appearance of the bunch as well as to ward off ‘fingertip’ disease.
Harvesting and Handling of Banana Fruits:
Banana is categorized as a climacteric fruit. Fruits do not ripe early and uniformly on the plant. Therefore, they are harvested when they are green and fully mature. The fruits are harvested when top leaves start drying. The colour of the fruit changes from deep green to a lighter green. The ridges on the surface of the skin change from angular to round, i.e. after the attainment of 3/4th full stage.
Banana comes into flowering in 9 months or so after planting. The dwarf bananas are ready for harvest within 11 to 14 months after planting, while tall cultivars take about 14 to 16 months to harvest. The fruits become ready in 3-4 months after flowering. In India, the main banana season is from September to April. The total period required from planting to first harvesting will also depend on type of variety under cultivation, and climatic conditions.
Stage of harvesting of fruits depends on its uses. For vegetable purpose, tender and immature fruits are harvested. For table purpose and for transporting to long distance, the harvesting of mature fruits should be done earlier. The harvesting is performed by cutting the bunch, retaining 15-20 cm stalk, this will help in handling. Tall cultivars usually yield 15-20 tonnes/ha. Average yield of dwarf varieties is 30-40 tonnes/ha. Tissue culture raised plants are known to decrease the time of emergence and maturity of bunches and also improve yield over conventional sucker plants.
Bananas are not usually allowed to ripen on the tree as it takes long time. Moreover, the fruit- peel splits, fruit ripens unevenly and fails to develop good colour and aroma, and hence the marketable quality deteriorates. Therefore, banana needs to be ripened artificially. The bunches of banana are heaped in dry and clean air-tight room and covered with leaves. The fruits are ready within 4 days. Smoke treatment is the common method to induce ripening in Maharashtra and Tamil Nadu.
Smoking is done with straw, leaves and cow-dung in a closed chamber with bunches arranged in a heap for 18-24 hours in summer and 48 hours in winter. After taking the bunches from the chamber, they are placed in a well-ventilated room for development of colour. Besides these methods, chemicals can be used for inducing early ripening. Among them 2, 4-D is the cheapest for inducing artificial ripening. The fruits should be dipped for 10 seconds in 1000 ppm 2, 4-D.
Ethrel @ 5000 ppm with 5 g of NaOH pellet kept in a beaker in the ripening chamber ripened the banana fruits within 48 hours. Mature banana fruits are generally treated with exogenous ethylene gas at 100 ppm for 24 hours at temp 16-18°C and RH 90-95%. The fruits attained uniform colour, excellent quality with shelf life of 4 days at 16 – 18°C and 2 days at 30 – 32°C.
The banana fruits harvested at green mature stage can also be successfully ripened in 4 days by dipping in a solution of ethephon 500 ppm (1.25 ml per litre of water) for 2-3 minutes. The fruits should be air dried and kept at 16 – 18°C and 90 – 95 per cent RH. The fruits attained uniform colour, excellent quality with shelf life of 4 days at 16 – 18°C and 2 days at 30 – 32°C.
After harvesting or ripening, the fruits can be stored for some period. The-fruits can be stored at a temperature of 13°C and a relative humidity of 85-95% for about three weeks. The bananas should not be placed in refrigerator at low temperature as they become black. The shelf life of banana can be enhanced by keeping the fruit in relatively high concentration of carbon dioxide and low concentration of oxygen. Ripening of banana fruits can easily be retarded for 10-12 days at ambient temperature (30°C) held in sealed polythene bags.
Ripening of banana can be retarded significantly with post-harvest dip in 150 ppm GA + 500 ppm benomyl or 150 ppm GA + 6% waxol. Giant Governor cv. of banana treated with a trizole derivative (Bas 111W) resulted delayed ripening. Shelf life of banana fruits and their quality can also be extended 3 days more than the control with the use of ethylene absorbent like vermiculite blocks when they are soaked in potassium permanganate at 100 g per litre and inserted into polythene bags each holding one hand with 12 fruits.
Diseases and Insect Pests of Banana:
The common diseases of banana are:
(i) Shoot rot caused by Ceratosmella paradoxa, for which no control measure is known.
(ii) Panama wilt caused by Fusarium oxysporum var. cubense, which can be controlled by eradicating, affected plants, using disease-free suckers and practising crop rotation.
(iii) Anthracnose caused by Gloeosporium musarum, which can be controlled by spraying with 1%, Bordeaux mixture or any other copper fungicide with a sticker.
(iv) Black finger caused by Macrophomina musae, which can be controlled by removing affected fingers and spraying with 1% Bordeaux mixture.
(v) Bunchy top caused by virus, which can be controlled by using virus-free suckers and roguing out infected plants.
(vi) Main stalk and finger stalk rot caused by Botryodiplodia spp. and Gloeosporum spp., which can be controlled by cutting the main stalk well above the topmost hand and applying some dust fungicide to the cut ends.
The common insect pests are:
(i) Root stock weevil (Cosmopolites sordidus), which can be controlled by selecting insect-free rhizomes for planting and digging and destroying old stumps and by treating pits with 5% Aldrin or Heptachlor dust @ 60-70 kg per pit when new suckers are planted, and by spraying 0.3% Phosphamidon around the base of plant in case of attack.
(ii) Stem borer (Odoiporus longicellis), which can be controlled by uprooting and burning infested plants and by spraying 0.04% Endosulfan or 0.1% Carbaryl (wettable powder).
(iii) Banana beetle (Nodostoma subcostatum), which can be controlled by clean cultivation and spraying as in the case of stem borer.
(iv) Banana aphid (Pentalonia nigronervosa), which can be controlled by spraying 0.03% Dimethoate, Phosphamidon or Monocrotophos.
(v) Cotton aphid (Aphis gossypii), which transmits mosaic disease, is controlled as the Banana aphid (no. iv above).
Varieties of Banana:
Many varieties of banana are grown in India, but the Champa, Poovan or Lal Velchi predominates. It occupies fewer than 50 per cent of the total area. The varieties have a wide climatic adaptability and most of them are grown in several States.
Many synonyms, therefore, exist. In the centres of consumption of North India, there is a demand only for varieties like Basrai with soft, sweet, non-starchy, aromatic, non-acidic pulp, but in the South and in Western India, varieties like Rasthali and Raja Bale with firm, slightly acidic pulp are favourites.
1. Poovan (Champa, Lal Velchi, Karpur Chakrakeli, Chinni Champa):
It is important in all banana-growing areas of India, except the interior areas of Maharashtra. It is a hardy, high-yielding variety with a good keeping quality. The fingers are small, yellow, with firm sourish flesh. The bunch is large, weighs about 25 kg and has 220 fingers.
2. Mortaman (Rasthali, Mutheli, Sonkel):
The fruit is similar to that of Poovan in appearance, but of a much better quality. It is considered to be one of the best table varieties. The bunch is smaller, having about 130 fingers. The fingers on a bunch ripen gradually, but drop off easily.
3. Basrai (Vamankeli, Kabuli, Bhusaval, Mauritius, Jahaji, Pacha Vazhai, or Hirvi):
It is a dwarf variety suited for cultivation in dry interior windy areas under irrigation. It is susceptible to injury from cold and is grown mostly in East Khandesh for export to North India, where it is sold under the name Chittidar. A bunch contains about 130 fingers of large size, sweet acid less taste, no traces of starch in the ripe fruit, and greenish yellow colour.
Fruit ripened at a high temperature often develops black spots on it, hence the name Chittidar. The fingers are slightly curved and the bunch is rather lax. Its yield is high, but the keeping quality is poor. The fingers tend to drop off from the bunch when ripe. It does not bear fertile male flowers, is resistant to Panama wilt, but suffers from the bunchy top disease.
4. Harichhaal (Bombay Green, Malbhog, Sapri, or Pedda Pacha Arati):
It is similar to Basrai, except that the fruit is more green and straight, the bunch more symmetrical and the plant taller. It prefers a moist coastal climate.
5. Nendran (Rajeli):
This is a dual-purpose variety of great importance in Kerala. The fingers are long, angular, prominently tapering and retain some starch even on ripening. It is used as fresh fruit, for cooking, for making banana flour, banana chips and for drying as banana figs.
The keeping quality of the fruit is very good. The bunch is lax and very small. The variety is unstable and produces many variations of the parental form. Among these are included Nana Nendran, Myndoli and Attu Nendran. They thrive in a moist climate.
6. Monthan:
It is a small, stout, straight and angular banana. It is essentially used for cooking, but can also be eaten fresh. The keeping quality is good. It can withstand some cold and is found growing in sheltered places in U.P.
Other important varieties are Chakrakali or Rajabale, with excellent fruit quality, but poor keeping quality and climatically not very adaptable, excellent hill bananas called Mala Vazhai (Sirumalai, Virupakshi, Vannan and Rajapuri, the fruit of which can be dried), Alpan of Bihar, Red Banana (Lalkela or Chen Kadali), Palankodan of Malabar and Safed Velchi of Ney Poovan. The fruits of the Safed Velchi are thin, small, with papery peel, good keeping quality and good fruit quality except that the pulp is dry.
Other cooking plantains are Bontha and Batheesa, which bears only female flowers, resulting in a very long tapering bunch on which the fingers at the base are full grown while those at the apex are just starting growth.