Tutorial on the Latest Banana Cultivation Techniques and Methods

Bananas originated in Southeast Asia, and are cultivated in Taiwan, China, Hainan, Guangdong, Guangxi and other regions of our country. Bananas are fragrant and nutritious, can be harvested year-round, and are also highly valued in temperate regions. After fruiting, the banana plant dies, and suckers growing from the rhizome continue to reproduce; each plant can survive for many years, and offspring are propagated by transplanting the roots.

Growth Habits of Bananas

Bananas prefer a hot and humid climate, and grow vigorously in deep, loose, well-drained soil. Irrigation cultivation has also succeeded in semi-arid areas similar to southern Jamaica. Wild bananas are grown from seed, while cultivated bananas can be propagated by division using suckers and pseudostems; the first harvest takes 10 to 15 months, after which harvesting is almost continuous.

1. Soil and Water

Banana roots are delicate and have strict soil requirements. Heavy clay soil with poor aeration and poor structure, or poor drainage, is extremely unfavorable to root development. Sandy loam with a clay content of <40% and a groundwater table below 1 m is suitable, especially alluvial loam or humus loam. Practice has shown that if the soil's physical properties are poor, even a very adequate supply of fertilizer and water will hardly promote normal banana growth. A soil pH of 4.5 to 7.5 is suitable, with above 6.0 being best, because below 5.5 Fusarium multiplies rapidly in the soil and wilt disease is apt to attack. Although bananas are not very sensitive to saline environments, soil with exchangeable sodium ions exceeding 300 mg/L is also unsuitable. An average monthly rainfall of 100 mm is most suitable; below 50 mm is a dry season, and bananas suffer from water shortage, which prolongs the bud-emergence stage, shortens the fingers and lowers the yield. If the banana plantation becomes waterlogged or flooded, in mild cases the leaves turn yellow, leaf spot disease is easily triggered, and yields drop greatly; in severe cases the root mass suffocates and rots, causing the plants to die.

2. Temperature

In most distribution areas the annual average is above 21°C, with a few around 20°C. Bananas require high temperature and high humidity. The growth temperature is 20-35°C, the optimum is 24-32°C, and the minimum should not be lower than 15.5°C. Bananas are afraid of low temperatures and avoid frost and snow, and their cold tolerance is weaker than that of plantains and Fenjiao (Cavendish subgroup). The critical temperature at which growth is inhibited is 10°C; when it drops to 5°C the leaves suffer cold damage and turn yellow; at 1-2°C the leaves die. The fruit suffers cold damage at 12°C, and after ripening the peel color turns grayish-yellow, affecting its commercial value.

3. Wind

Banana leaves are large, the pseudostem is brittle, and the roots are shallow, making the plant prone to wind damage. At a wind speed of 25-30 km/h the leaves are torn and the petioles are broken; at 65 km/h the pseudostem breaks or the whole plant is blown over; at 100 km/h the entire banana plantation can be destroyed.

Distribution of Bananas

China is one of the ancient countries that cultivate bananas in the world, and most of the banana varieties mainly grown abroad were transmitted from China. Bananas are distributed in the tropical and subtropical regions of the Eastern, Western and Southern Hemispheres within 30° north and south latitude. There are 130 countries cultivating bananas in the world, with Central America producing the most, followed by Asia. Bananas in China are mainly distributed in Guangdong, Guangxi, Fujian, Taiwan, Yunnan and Hainan, with a small amount also cultivated in Guizhou, Sichuan and Chongqing.

In Guangxi, the main production areas are Lingshan, Pubei, Yulin, Nanning and Qinzhou;

In Guangdong, the main production areas are Zhanjiang, Maoming, Zhongshan, Dongguan, Guangzhou and Chaozhou;

In Taiwan, China, the main banana-growing areas are Kaohsiung and Pingtung, followed by Taichung and Taitung;

In Fujian, they are mainly concentrated in Zhangpu, Pinghe, Nanjing, Changtai, Zhao'an, Hua'an, Yunxiao, Longhai, Xiamen, Nan'an, Putian, Zhangzhou (Tianbao) and Xianyou and other counties (cities, districts);

In Hainan, bananas are mainly distributed in Danzhou, Chengmai, Sanya, Dongfang and other places, of which Dongfang has the largest output.

Propagation Methods of Bananas

Bananas are parthenocarpic and usually have no seeds, so cultivation uses vegetative propagation. However, wild bananas do have seeds and are propagated by seed.

1. Sucker Propagation

Sucker propagation is a relatively common traditional seedling-raising method in banana cultivation. It mainly uses sword suckers (red shoots) and ragged-clothing suckers for propagation. The suckers used for division as planting material generally need to be more than 40 cm tall.

① Red shoot: large at the head and small at the tail, shaped like a bamboo shoot or sword, hence also called sword sucker. It generally emerges in November of the previous year, and when the weather turns warm after the Start of Spring that year it emerges above the ground, appearing red, and is usually used for planting in March, April and May of that year. After planting, its characteristic is that it produces leaves first and then roots.

② Ragged-clothing sucker: ragged-clothing suckers generally emerge in August, September and October of the previous year. Because they encounter drought and cold, they do not grow, and when winter comes the leaves wither. Due to low temperature and lack of water, the upper part grows more slowly while the lower part accumulates nutrients, so the nutrients are abundant; the shape is small on top and large at the bottom, with many roots, and it is generally used for planting in February and March. After planting, it first develops roots and then sprouts leaves.

2. Tuber (Corm) Propagation

Tuber propagation is mainly a propagation method used to cultivate a large number of sprouts and seedlings in a short period. Using the underground stem of a plant that has not yet flowered and fruited, or of a large sucker (sprouting in October-November) as material, the best time for cutting into pieces is from November to January of the following year; most can sprout, and when the seedlings are 40-50 cm tall in April, May and June they can be planted. The advantages of this propagation method are that it can reduce pests and diseases, has a high survival rate, and growth and fruiting are uniform; the plants are shorter in the early stage than those from sucker propagation and are relatively wind-resistant, but it has the disadvantage of low yield in the first generation.

In the method of propagating by cutting the underground stem into pieces, first cut off the underground part of the plant, dig up the corm, leave the pseudostem 12-15 cm high, then cut the corm into small pieces, each weighing about 120 g or more, each bearing one stout bud eye; coat the cut surface with plant ash as a preservative, then, at a spacing of 15 cm between plants and rows, place the pieces flat on the bed with the bud eyes facing upward, cover with soil and grass, and carry out fertilizer management. One week before the sprouts and seedlings leave the nursery, Bordeaux mixture of equal amounts should be sprayed twice in succession to prevent leaf spot disease. If bunchy top diseased seedlings are found, they should be pulled out in time, and lime should be spread to disinfect, to prevent infection. In places where nematode damage is severe, beforehand scrape off the blackened, rotted outer skin of the underground stem, soak it in hot water at 54-55°C (or 5% formaldehyde) for 20 minutes to kill the nematodes, and then raise the seedlings.

3. Division Propagation

Conventional banana propagation mainly uses suckers for division propagation. When the sucker has grown to more than 40 cm, it can be divided, to be kept as the mother plant for the next generation or used as planting material. When dividing, first dig open the soil beside the sucker, then use a shovel to cut between the mother plant and the sucker. After the seedling is dug out, trim off the overly long and injured roots, dry the cut in the shade or smear it with plant ash, and it can then be planted.

4. Tissue Culture

For the production of banana planting material used in large-scale planting, tissue culture rapid propagation technology is mostly used. Using it, not only can a large number of test-tube seedlings be obtained in a short period, but also viruses such as mosaic virus can be eliminated, which is conducive to increasing yield.

① Explant disinfection and primary culture: during operation, in a banana-growing area free of traditional diseases, select a mother plant that is vigorous, bears fruit uniformly and has high yield, and dig up a sucker that has just emerged above the ground as the induction material. During disinfection, first peel off the leaf sheaths outside the sucker and rinse it clean with water. Under sterile conditions, disinfect with 75% alcohol solution for 30 seconds, then disinfect with HgCl2 at a concentration of 0.1% for 20 minutes, then rinse with sterile water 7-8 times, cut off its shoot tip, divide the shoot tip into 2 parts, and place them in an induction medium of MS+3-6 mg/L BA+3% sugar+7.0 g/L agar, place in a dark light incubator, maintain the temperature at 28-30°C, and buds can emerge after 40-50 days of culture.

② Subculture multiplication of clustered shoots: the clustered shoots obtained from the primary culture can be subcultured and multiplied in a medium of MS+3-6 mg/L BA+0.2 mg/L NAA+3% sugar+7.0 g/L agar; under a light environment of 28-30°C and 1500 lx, subculture multiplication can be carried out once every 20-25 days, obtaining a multiplication rate of 2.0-2.7 times. During the culture process there should be sufficient light, and the daily 1500 lx light duration should be no less than 8 hours. If there is no light or insufficient light, the color of the pseudostem and petioles fades, turns green, or even becomes white, affecting the multiplication rate. Subculture generally should not exceed 12 generations, otherwise mutation is easily caused.

Banana Cultivation Techniques

The best time for field planting is spring planting. In combination with the soil conditions of the banana base in Gengma County, the planting methods use trench planting and pit-pond planting. Paddy fields use trench planting, requiring deep plowing of the soil followed by making beds, with two rows per bed, a trench between each bed 0.5 m deep and 0.3 m wide, and beds 100 m long, with secondary drainage ditches to facilitate irrigation in the dry season and drainage in the rainy season; the planting spacing is a wide-narrow row arrangement of 1.7×2.2 m, planting 176 plants per mu; dry land uses the pit-pond planting method, with a planting spacing of a wide-narrow row arrangement of 1.7×2.6 m, planting 150 plants per mu.

After planting, fertilization should adhere to “frequent application, light application, and application at key points”. Two to three weeks after planting, use dilute manure water or a small amount of quick-acting chemical fertilizer diluted in 5 kg of water, applying once every 7-10 days (carried out on sunny days, poured 10-15 cm from the banana base), until budding; as the plant grows, gradually expand the fertilization range along the canopy cover. In addition to routine topdressing, it is also necessary to apply heavy fertilizer twice in combination with intertillage and earthing up. The first is the stalk-change fertilizer, applied in late April to early May, applying 0.3 kg each of phosphate fertilizer and potash fertilizer and 3 kg of ash manure per plant; the second is the fruit-change fertilizer, applied at the Start of Autumn or in late June to early July, applying 5 kg of ash manure and 0.5 kg of compound fertilizer per plant.

After planting, as the plant grows, the new shoots at the base should be removed in time. During the bud-emergence and fruiting stage, according to the plant's growth vigor, determine the appropriate number of fruits to retain, and cut off the flower buds, to ensure an adequate supply of nutrients to the plant.