How can humans achieve "banana freedom"? First, cure the "cancer" of bananas!

1. Overview

1.1 Banana’s function and value

Banana (Musa nana Lour.), a perennial herbaceous plant of the genus Musa in the family Musaceae, has been recorded in Chinese herbal books of all dynasties. For example, the "Daily Materia Medica" records that bananas have medicinal value in treating fever, thirst, dry cough, constipation, and hemorrhoids. Bananas are one of the four major fruits in the world, with high yield and wide distribution, nutritious flesh, sweet and soft, and high economic value. They occupy an important position in the international fruit import and export trade. Legend has it that the ancestor of Buddhism, Sakyamuni, gained wisdom after eating bananas, so bananas are also called "fruits of wisdom" and "sources of wisdom". Bananas produced in Guinea are large, each weighing more than 1 kilogram. They are eaten after being steamed and taste like pork, so they are called "pork bananas".

In my country, bananas are an important multi-purpose crop. In addition to being eaten fresh, they can also be processed into juice, jam and other products. They also have the function of inhibiting fungi and bacteria, effectively improving people's stomach, intestinal and digestive functions, and preventing constipation, anemia and stroke. With the attention paid to fruit production in various places, my country's banana industry chain has been continuously expanded. Driven by the adjustment of agricultural industrial structure and market demand, the banana industry has become a pillar industry for fruit farmers in tropical regions of my country to increase their income and become rich, and has played an important role in increasing agricultural efficiency and farmers' income.

1.2 Current situation at home and abroad

1.2.1 Current World Situation

Bananas, native to southeast Asia, are important economic and food crops in tropical and subtropical regions. They are widely distributed in tropical and subtropical regions around the world and are listed as one of the world's four major fruits along with apples, grapes and citrus fruits. Bananas are grown in more than 130 countries/regions around the world. Currently, the world's main banana producing countries/regions are India, China, Indonesia, Brazil, Ecuador and the Philippines.

Bananas have a short growth cycle and high yield, second only to wheat, corn and soybeans in global agricultural product trade. According to FAO data, from 2011 to 2021, the global banana harvest area has basically stabilized at around 80 million mu, with the minimum value being 75.3961 million mu in 2018. In 2021, the global banana planting area was 80.0529 million mu, an increase of 1.2657 million mu compared with 2020 (78.7872 million mu), an increase of about 1.6%; thanks to the continuous improvement in yield levels, banana production is showing an overall positive growth trend. In 2021, the global output was 124.9786 million tons, an increase of 3.5808 million tons compared with 2020 (121.3978 million tons), an increase of about 2.95%.

1.2.2 Current situation in China

China is one of the origins of bananas, with a cultivation history of more than 2,000 years. Bananas are a dominant fruit that ranks among the top in production and sales in southern and southwestern provinces of my country, and play an important role in the regional economy. At present, my country's total banana consumption ranks second in the world, second only to India, with an annual banana consumption of about 13 to 14 million tons, and per capita consumption of 9.69 kilograms, lower than the global per capita consumption of 15.4 kilograms. With the continuous advancement of domestic logistics and preservation technology, the scope of consumer groups has been greatly expanded, and consumption will continue to grow in the future.

China's banana production areas are distributed between 18 and 30 degrees north latitude, with tropical and subtropical areas between 22 and 23 degrees north latitude as the main economic cultivation areas, mainly distributed in Guangdong, Guangxi, Fujian, and Yunnan. In recent years, Guizhou, Sichuan, and Chongqing have also cultivated a small amount. According to data from the National Bureau of Statistics, in 2022, my country's banana planting area reached 5.05 million mu, the harvested area was 4.67 million mu, and the output reached 11.7768 million tons. Among them, Guangdong's output ranked first in the country, reaching more than 4.8 million tons. The annual banana output in Guangxi Zhuang Autonomous Region is about 3 million tons, Yunnan is about 2 million tons, Hainan is about 1.15 million tons, and Fujian is about 460,000 tons.

2. Banana Cancer

2.1 Banana wilt disease damage

Banana wilt is the most deadly disease in the banana planting and production process. The external symptoms of susceptible varieties (such as CrosMichel) are as follows: In the mature stage, the lower leaves and the outer leaf sheaths of the diseased plants first show a specific yellow color. This yellow lesion first appears on the edge of the leaf and then gradually expands to the midrib. The leaves after the disease quickly wilt, and the petiole bends down near the outside of the leaf sheath. Within a few days, other leaves droop one after another, turning from yellow to brown and drying up. Some leaves hang down without turning yellow, hanging upside down around the pseudostem. Generally, the last top leaf in the center of the pseudostem often extends very late or cannot be pulled out. After a period of time, the whole plant dies, forming a dry stem with dry leaves hanging upside down. Some diseased plants often show a long or short longitudinal crack on the outside of the pseudostem near the ground.

Bananas can be infected at all stages of their growth, from young buds to mature plants. Due to differences in soil types and other conditions at different growth stages, external symptoms vary; different species of pathogens can also cause different symptoms. Banana wilt is highly contagious, destructive, and difficult to effectively control, and has been vividly likened to "banana cancer" or "banana AIDS."

2.2 Overcoming banana wilt

The Institute of Tropical Crops Variety Resources of the Chinese Academy of Tropical Agricultural Sciences (hereinafter referred to as the Institute of Tropical Crops Variety Resources) is one of the national scientific research units in my country engaged in the research of key supporting technologies for the industrialization of tropical fruit trees such as bananas. Aiming at banana wilt, a key problem restricting the development of the banana industry, the Institute's Fruit Tree Research Center has carried out a series of research on the selection and breeding of new disease-resistant varieties and the comprehensive prevention and control technology of banana wilt, and has achieved important results. On April 28, 2024, the wilt-resistant variety "Baodao Banana" cultivated and developed by the Institute of Tropical Crops Variety Resources of the Chinese Academy of Tropical Agricultural Sciences and the "Key Cultivation Technology of Banana Wilt-resistant Varieties" were selected as the leading variety and the main technology respectively.

2.2.1 Baodao Banana

This variety is resistant to banana wilt disease and was selected from the tissue culture variant offspring of Taiwan's "New Taipei Banana". The fruits of this variety are neatly combed, the fruit bunches are even at the beginning and end, the fruit peel is green, golden yellow after ripening, the flesh is light yellow, the edible rate is above 65%, the taste is delicate, the sweetness and fragrance are moderate, the flavor is good, the shelf life is long, and the storage resistance is good. The growth cycle in Hainan is generally 330~360 days, and the yield of a single plant in a high-yield banana garden is 30.0~35.0 kg, which can reach about 72000.0 kg per hectare. It is moderately resistant to banana wilt disease, the incidence of wilt disease in the field is <5%, and the overall quality is excellent. It is suitable for planting in Hainan, Yunnan, Guangdong, Guangxi, Fujian, Taiwan and Southeast Asian countries. This variety has been selected as the leading variety of the Ministry of Agriculture and Rural Affairs for two consecutive years (2023, 2024). At present, the domestic planting area is more than 500,000 mu, and the cumulative promotion area is more than 1.3 million mu.

New banana variety - Baodao banana

2.2.2 Key cultivation techniques for banana varieties resistant to Fusarium wilt

This technology takes the main banana wilt resistant varieties in my country as the core, and aims at the problems of long growth period, unclear nutrition rules and easy exposure of banana wilt resistant varieties. Based on the comprehensive wilt prevention and control technology of "soil improvement + nematode elimination + less soil disturbance + balanced fertilization", it has developed and established a nutrient synchronization supply plan that synchronizes fertilizer supply with crop nutrient demand, and invented a "directional low-position secondary bud retention method" that can overcome the problem of easy exposure and uneven position of bananas when they are planted for a long time. This technology realizes the coordinated development of good varieties and good methods and production ecology in banana production. It effectively solves the problems of the continuous spread of wilt in my country's banana planting areas, the continuous decline of soil organic matter content and pH in banana gardens, the decline of fruit quality, and low production efficiency, and promotes the increase of production and income of growers, providing strong technical support for the sustainable development of the banana industry.

Comprehensive prevention and control technology of Fusarium wilt

Synchronous nutrient fertilization technology

Note: The red buds are the primary buds retained during the first bud retention, and the green buds are the secondary buds retained from around the primary buds during the second bud retention. They will eventually serve as the mother plants for the next fruiting period. The buds retained should be kept in the same straight line as much as possible.

Schematic diagram of directional low-position secondary bud retention technology