How to Grow Water Bamboo? Understanding Its Biological Characteristics and Cultivation Management Techniques in One Article

Water bamboo, also called water bamboo shoot, was known as wild rice in ancient times. It originated in China and is widely cultivated in areas south of the Yangtze River, especially around the Taihu Lake region of Jiangsu and Zhejiang, where shallow ditches and low-lying fields are often used. The flesh of water bamboo is neat, white and tender, contains large amounts of amino acids, tastes delicious and is rich in nutrients. It can be boiled or stir-fried and is an excellent aquatic vegetable unique to China. Because its harvest period falls in the two vegetable-scarce seasons of May-June and early autumn September-October, it plays an important role in alleviating the off-season supply of vegetables.
I. Biological Characteristics:
1. Morphological characteristics. Water bamboo is a perennial aquatic root-propagation plant of the grass family. The plant height is 1.6-2 m, with 5-8 leaves, and each leaf consists of a leaf blade and a leaf sheath. Where the leaf blade meets the leaf sheath there is a triangular leaf cushion, called the “water bamboo white eye”. The leaf sheaths wrap around each other layer by layer from the ground upward, forming a false stem. The stem can be divided into aboveground stem and underground stem. The aboveground stem is shortened and partly buried in the soil, producing many tillers on it; the underground stem is a stolon that lies horizontally in the soil to overwinter, and several buds at its tip sprout into new plants the following spring, and the new plants can in turn produce new tillers. Because the water bamboo plant is parasitized by the smut fungus, its mycelium grows along with the plant. When the plant bolts and flowers in early summer or autumn, the flower stalk tissue on the shortened stem of the main stem and early tillers is stimulated by the mycelium metabolite indoleacetic acid, and the meristem cells at the base nodes 2-7 proliferate and expand into a fat, tender fleshy stem (fungal gall), which is the edible water bamboo.
Male water bamboo refers to a small number of plants with particularly strong disease resistance, which the mycelium of the smut fungus cannot invade, so no water bamboo can form, and by summer and autumn the flower stalk elongates, bolts and flowers. Gray water bamboo refers to plants that are overmature or whose mycelium grows rapidly, so that the interior of the water bamboo is already filled with dark brown spores, making the quality poor and inedible. The male water bamboo bolts at the center and rises above the female water bamboo, making it relatively easy to identify; it should be pulled out together with the roots in time, and its root stock must not be left in the soil.
2. Growth habits. Water bamboo includes two types: single-season water bamboo harvested in autumn and double-season water bamboo harvested in autumn and summer. Both are propagated by division. In the Yangtze River basin, single-season water bamboo is planted by dividing the clumps from Qingming to Guyu, while double-season water bamboo can be planted in two seasons, spring and autumn, with spring planting around Guyu and autumn planting around Liqiu. Water bamboo can be divided into four stages:
(1) Germination stage. After the beginning of spring, germination begins in March and April. The minimum temperature is above 5°C, and 10-20°C is suitable.
(2) Tillering stage. From late April to the end of August, each plant can produce more than 10-20 tillers, and the suitable temperature is 20-30°C.
(3) Water bamboo formation stage. Double-season water bamboo forms water bamboo once from early to late June and again from late August to late September. Single-season water bamboo forms water bamboo only from late August to early September. The suitable temperature is 15-25°C; below 10°C or above 30°C, no water bamboo will form.
(4) Growth stagnation and dormancy stage. After water bamboo formation, when the temperature falls below 15°C, tillering and aboveground growth stop; below 5°C the aboveground part dies, and the underground part overwinters in the soil.
II. Variety Classification: Water bamboo is divided into single-season water bamboo and double-season water bamboo.
1. Single-season water bamboo is cultivated in spring and can be harvested in the same autumn; thereafter it is harvested once a year from early September to November, called autumn water bamboo or August water bamboo. Once planted, it can be harvested continuously for 2-3 years, then replanted for renewal. The plants grow vigorously, the stolons go deep into the soil, and it is drought-resistant, but the yield is relatively low. Examples include Hangzhou ivory water bamboo, Yidianhong, Qingzhong water bamboo, Zhenwan water bamboo, Meipo water bamboo, Wenzhou late water bamboo, Guangzhou Damiao, and Wuhan Hongmakezi.
(1) Hongmakezi. The water bamboo shell is green, and the lower veins have light red spots, hence the name. The water bamboo flesh is fat and large, 30 cm long and 4.5 cm in transverse diameter, club-shaped, thick in the middle and lower parts, yellow-white outside and white inside, with a single water bamboo weighing 15 g; it is fat and tender with good quality.
(2) Damiao (hard-tail water bamboo). The tender stem is spindle-shaped, 17 cm long and 6 cm in transverse diameter, with 3-4 nodes, and a single water bamboo weighs 15-20 g. It is heat-tolerant and fertilizer-tolerant, with white flesh and a high position of water bamboo formation. The quality is good, with a yield of 1250-1500 kg per mu, harvested in Guangzhou from September to November.
2. Autumn-summer double-season water bamboo is generally planted in spring or summer-autumn. The first harvest is from Qiufen to Shuangjiang in the same year, called autumn water bamboo (rice water bamboo), with a yield of 750-1000 kg per mu. The old plants are left in the field to overwinter, and the water bamboo shoots that regenerate and sprout the next year are harvested a second time from Xiazhi to Xiaoshu, called silkworm water bamboo (wheat water bamboo), with a yield of 1500-1750 kg per mu. After harvest, they can be left again until autumn for a third harvest, with a lower yield, and after harvest they are replanted. Early-maturing varieties include Wuxi early water bamboo, Zhongjie water bamboo, Yan water bamboo, Suzhou Xiaolatai, Zhonglatai, and Hangzhou Mayi silkworm water bamboo, Bandacian silkworm water bamboo, Hezi silkworm water bamboo, etc.
(1) Wuxi Yan water bamboo. It tillers vigorously, is late-maturing, and has fat water bamboo shoots with the best quality and high yield. The surface of the fleshy stem has many wart-like raised wrinkles and is white, with a yield of 750-1000 kg per mu for autumn water bamboo and 1250-1500 kg for summer water bamboo.
(2) Bandacian silkworm water bamboo. The water bamboo shoot is formed from 3-4 nodes, 17.5-24 cm long, 3 cm in transverse diameter, and weighs about 57 g. The surface is light green, the flesh is pure white, and the quality is good. The yield is 350-400 kg per mu for autumn water bamboo and 1250-1500 kg for summer water bamboo.
(3) Suzhou Xiaolatai. The water bamboo shoot flesh is short and round, with prominent nodes forming a plate, shaped like a candle holder, with a pointed tip, thin at both ends and thick and round in the middle, firm in texture, sweet in taste, and low in fiber, with a single water bamboo weighing 30 g. Among mid-maturing varieties, its quality is the best. The yield is 600 kg per mu for autumn water bamboo and 1250-1500 kg for summer water bamboo.
III. Soil Cultivation: Choose a field or low-lying river ditch that is sheltered from wind, faces the sun, has convenient irrigation and drainage, and has loose, fertile soil as the seedling field. In the Yangtze River basin, from mid-to-late December to mid-January (Dongzhi to Xiaohan), dig up the selected water bamboo clumps as whole clumps and temporarily plant them in the seedling field at a row and clump spacing of 50×16 cm, with the planting depth such that the clump mud is exactly level with the soil surface. After temporary planting, apply 1000 kg of human manure per mu as base fertilizer and irrigate a shallow layer of water. During cold waves, the water layer should be deepened; in severe cold, cover the water bamboo clumps with 6-10 cm of rice straw to keep them warm. After the beginning of spring, apply 1000-1500 kg of human manure per mu as a seedling-strengthening fertilizer, and keep the water depth at 3-6 cm at all times. Before transplanting in mid-April, remove the seedlings that grow particularly vigorously, which can reduce the proportion of male water bamboo, and then plant by dividing the clumps.
The water bamboo field should be chosen as clay loam with fertile soil and sufficient water. In winter, plow more than 33 cm deep, and apply 5000-10000 kg of river mud in combination with plowing. When preparing the land the next year, apply 3500-4000 kg of green manure or barnyard manure, or 3000-4000 kg of human manure, as base fertilizer, break it up and rake it level, so that the mud is soft, the fertilizer is sufficient, and the field is level, and compact the field ridges to strictly prevent water and fertilizer leakage. After exposing it to the sun for several days, irrigate about 3 cm of shallow water in preparation for planting.
IV. Sowing: Select clumps 6-7 days before harvesting autumn water bamboo. The seed clumps must conform to the characteristics of the original variety, with relatively short plants and growth vigor that is not excessive, and the heights of the stem-clasping leaves not differing much, but the last 1-2 central leaves markedly shortened, such as when the leaves and the water bamboo white eye are tightly contracted together. When the water bamboo shoot is fat, one side of the false stem shows white, the tillering is vigorous and neat, the node position is low and the clump does not scatter, and the mother plant connected by stolons must form water bamboo early, produce more than 20 water bamboo, and mature uniformly, with mother water bamboo and offspring water bamboo maturing at the same time. At harvest, reselect clumps with plump water bamboo bracts, fat, white and tender water bamboo flesh, and no male water bamboo or gray water bamboo in the whole clump, and mark them well.
V. Cultivation Management: Water bamboo is planted in spring and autumn. Regardless of single-season or late-maturing double-season water bamboo, in the Yangtze River basin, when the mother clump sprouts reach a height of 33-40 cm in April-May, with 3-4 true leaves (in South China, single-season water bamboo is planted in June-July, and double-season water bamboo in July-August). Dig up the water bamboo clumps and split them with a sharp knife along the tillering points into several small clumps, each with stolons and 4-6 strong tillers. Cut off the leaves and retain the leaf sheaths at a length of 16-26 cm to reduce evaporation and help them survive earlier. Dig, divide and plant as you go. The plant and row spacing depends on the planting period, the number of divided seedlings and the number of harvests. Double-season water bamboo uses wide and narrow row planting, with the wide row used as a walkway, a row spacing of 1 m, a narrow row spacing of 80 cm, and a hole spacing of 50-66 cm, with 1200-1500 holes per mu and 7-8 seedlings per hole. For those using small-plant close planting, the plant and row spacing is 73×40 cm, with 2300 clumps per mu. The planting method is preferably diagonal insertion at a 45-degree angle, with the depth such that the rhizome and tiller base enter the soil while the tiller buds are slightly exposed above the water surface. Check once 3-4 days after planting: for seedlings planted too deep, raise them slightly to make them shallower; for seedlings planted too shallow, press them down to make them deeper, and do a good job of replanting to ensure a full stand.
Autumn planting: After the beginning of spring, dig up the old clumps after they sprout, cut each clump into 8-10 pieces, and temporarily plant them in a lotus field or fertile muddy field for seedling raising, always keeping the water depth at 3 cm. By July-August, each hole already has more than 10 tillers, and they are then divided and planted again. Each hole can again be divided into 3 small clumps, which are the small seedlings planted in the production field. Generally, the planting row spacing is 46 cm and the hole spacing is 27-33 cm, with 4000 clumps planted per mu. In this way, one old clump can be divided and planted into dozens of small seedlings for production planting. For those used as the crop after early rice, planting should be completed around Liqiu, and must not be delayed until mid-August, otherwise effective tillers cannot be produced. Because the temperature is high during the planting period, choose cloudy days to dig up the clump seedlings, split the tillers, and peel off the 2-4 old leaf sheaths at the base to expose the tillering nodes and tillering buds so that they can contact the soil and promote rooting, then cut off 1/3 of the upper leaves. Once the seedlings are ready, plant them immediately.
Weeding and cultivating the field can loosen the soil and improve aeration, accelerate fertilizer decomposition, clear weeds, and cut off old roots of the plants to promote the growth of new roots. After the new water bamboo field has been planted and survived, or after the old water bamboo field begins to sprout in spring, until the rows close at Xiaoman, cultivate the field once every about 15 days, for a total of 2-3 times. When cultivating, first drain the water shallow, shallowly turn the soil twice with an iron rake, expose the field until the surface soil cracks, and then irrigate again.
From July to August, the water bamboo formation period begins. Aim to leave one water bamboo per 10 cm square, remove excessive weak and fine tillers, and by early August peel off yellow leaves 2-3 times, stepping them into the soil after peeling to serve as fertilizer, and press a piece of mud in the middle of the water bamboo clump to make the plants spread around the clump, so as to improve ventilation and reduce disease.
VI. Fertilizer and Water Management:
Water bamboo has a long growth period, many tillers and a large fertilizer uptake, and is planted once and harvested many times, so base fertilizer and topdressing must both be emphasized. There are 4-5 topdressings in total, following the principle of “promote-control-promote”. Apply seedling-promoting fertilizer 7-10 days after planting, with 500-1000 kg of human manure water per mu to promote seedling growth. Half a month later, apply 1000-1500 kg of human manure water or 10-15 kg of urea per mu. After that, stop fertilizing to avoid excessive growth. Then the tillering stage begins. From late July to early September (Dashu to Bailu), the tillers of the new water bamboo enter the water bamboo formation stage, that is, when the false stem becomes flat and the water bamboo shoot begins to fatten, apply 3000-4000 kg of concentrated human manure or 5000 kg of pig manure water and 20-25 kg of urea per mu to promote the fattening of the water bamboo shoot and increase the autumn water bamboo yield. The 4th to 6th fertilizations afterward can refer to the management of silkworm water bamboo.
The water level in the water bamboo field should be flexibly controlled according to the growth and development characteristics of water bamboo, following the principle of “shallow-deep-shallow”. Before germination, irrigate 3 cm of shallow water to raise the soil temperature and promote germination. After planting, promote survival and keep the water depth at 5-8 cm. Before tillering, shallow water of 5-8 cm is still suitable to promote tillering and rooting. In the late tillering stage, deepen it to 10-14 cm to control ineffective tillering. During the high-temperature period of July-August, keep the water depth at 13-17 cm, and change the water frequently to lower the temperature, so as to reduce pest and disease damage. From the water bamboo formation stage to 6-7 days before harvest, irrigate water for nurturing the fetus according to the growth of the main stem water bamboo. Initially keep it at about 16.5 cm, then gradually deepen it to 23-27 cm, so that the entire water bamboo is immersed in water, but not exceeding the “water bamboo white eye”. In this way, the water bamboo softens in the water, becoming white, fat and tender, improving quality. In the late water bamboo formation stage, gradually irrigate shallow water to 3-7 cm. After the autumn water bamboo is harvested, keep shallow water of 1.5-3 cm to prevent the root stock from freezing and rotting, so that it can overwinter safely. During the rainy season, attention should be paid to drainage, and the highest water level must not exceed the “water bamboo white eye”, to prevent the bolt stem from elongating. A few days before and after each topdressing, drain the water or keep it shallow, and restore the original water level after the fertilizer is absorbed into the soil.
VII. Pest and Disease Control: During the water bamboo formation stage, there are large borers, striped stem borers and green leafhoppers. In the young larval stage of the pests, apply 100 g of 50% fenitrothion emulsifiable concentrate per mu diluted with 75-100 kg of water and splash it on, or use 90% trichlorfon and 40% dimethoate at 1000 times solution to pour into the heart of each plant after removing old leaves. After Liqiu, aphids, leafhoppers and thrips occur, and 40% dimethoate emulsion at 1000 times, or 200-300 g of 10% leafhopper powder wettable powder diluted with 50-75 kg of water, can be sprayed. For water bamboo rust, spraying 1:800 sodium rust with water gives good results.
VIII. Harvesting: Timely harvesting is the key to ensuring yield and quality, and maturity must be strictly controlled. It is suitable to harvest when the central leaf is shortened, the three outer leaves are fully grown, the water bamboo is markedly fat, the leaf sheath splits, and the water bamboo shows white for 1 cm. If too late, the water bamboo flesh develops, the texture becomes coarse and the quality declines; if too early, the water bamboo is tender but the yield is low. When picking, break it off from the internode below the water bamboo formation, taking care not to damage the adjacent immature useful water bamboo and root stock, so as not to affect the current year's and next year's production. Each mu can yield 1000-1500 kg of shelled water bamboo (the flesh water bamboo is about 70% of the shelled water bamboo). In the early period, harvest once every four days, pulling it up together with the roots when harvesting. Trim the bolt stem and cut the leaves, leaving 33 cm with leaves. Water bamboo is best sold fresh after harvest; if it is to be transported externally, it can be placed with the shell in a cool place and soaked in water, or the water bamboo can be peeled out, tied in bundles of 20-30, and soaked in 1-2% alum water, where it can be stored for about a week.