AU Lotus Project - book excerpts

The following information on lotus (from Historical Description by Xuemin Ni [1987]) was translated by and provided to us by Dr. Hongwen Huang, Director of the Wuhan Botanical Institute, as another resource from the people who have been growing lotus for 1000s of years.

Lotus of China

Table of Contents
Chapter One: Origin and History of Lotus
Chapter Two: Geographic Distribution of Lotus and Its Position in Botanical Classification
Chapter Three: Morphology and Chromosome Structure of Lotus
Chapter Four: The Biological Characteristics and Growth Habit of Lotus
Chapter Five: Chemical Composition and Utilization of Lotus
Chapter Six: Cultural Practices of Lotus

1. Origin of Lotus
Lotus is an ancient plant and is one of the earliest plants in the Gymnosperm. Lotus was growing in the northern Hemisphere in many low and watery areas about 135 million years ago. It was found in the extreme north of North America, the extreme northeast of Asia near the Shahalin Islands. Petrified lotus seeds have been found in various areas of China during recent oil exploration.

There are only two kinds of surviving lotus varieties today. One has pink or white flower (Chinese lotus), Nelumbo nuceifera, Gaertn. Its distribution is in Asia and northern Australia. Another kind has yellow flowers (American lotus), N. pentapatala (Walter) Fernald (= N. lutea Pers.), and its distribution is in the Americas.

In China lotus has a history of at least 7,000 years according to recent archeological studies and C14 analysis. It is evident that lotus had grown along the Yantze River and Yellow River area before that time. About 70 years ago, many lotus seeds were found buried for nearly 1,000 years. Recorded history of lotus dates back to about 3,000 years. It is widely distributed in China now with over 100 different cultivars.

There have been suggestions that lotus may have originated in India. However, detailed study of Professor Hsu Jin, a noted paleontologist, failed to find any petrified lotus seeds in India in his forty years of research. Japanese scientists also consider the origin of lotus to be China. These facts clearly indicate that the origin of lotus is China rather than India.

2. Lotus in Chinese History and Literature
In China lotus is a very used and economically important aquatic plant; its flowers have been appreciated by poets and scholars as well as ordinary citizens alike for thousands of years. The Chinese have developed a romance to lotus flowers. The use of lotus root, (botanically stem) as food has a history of three to five thousand years. The seeds are also used as food and are known to be healthful. Immature seed pods and leaves are used in culinary preparation. All parts of the lotus plant, in one form or another, are used in Chinese medicine.

Artists painted lotus. Poets and scholars wrote poems and essays about lotus. Lotus also has religious significance in Buddhism. Chinese peoples have close feelings about lotus. Because of its long history in China many people throughout the history have made special studies about the lotus.

1. Position of Lotus in Systematic Development of Gymnosperm
In the development of plants, lotus is considered as one of the earliest among the dicotyledons, but it has certain monocotyledon characteristics. From the structure of the seeds, the cotyledons are covered by a shell-like structure with characteristics similar to a monocolyledon plant. Its nodes, between the section of stem and the hairy-like roots, are also characteristics of monocots. According to current studies, it is suggested that the ancient lotus plant is a dicot but has a close relationship to the monocots. It can be said that lotus occupies a unique position in the systematic development of the gymnosperms.

2. The History of Lotus in the Study of Botanical Classification
The genus Nelumbo generally has two species, namely H. nucifera, Gaertn (China lotus with pink or white flowers) and the other is American lotus with yellow flower (N. pentapetala (Walter) Fernald). Both are in the order of Nymphaeaceae. In 1888, Caspary Nymphaeaceas should be divided into 3 suborders, that is, Nelumboideae, Cambomboidead, and Nymphaecideae. Later some systematic botanist considered these three sub-orders to be individual orders in the family Ranale. Because of its unique characteristics some even suggest that lotus should be in a separate family.

3. Mutual Relationship in the Lotus Genus
Although the two varieties (Chinese and American) of lotus distribute separately in two hemispheres separated by large bodies of water and geographically wide apart, there is a very close resemblance between the two. They are quite similar in botanical forms with only differences in plant size, flower color and leaf appearance. The American lotus is still growing in a natural environment, but the Chinese lotus has gone through many changes with many new cultivars. However, from the genetic basis such as the number of chromosomes, appearances and size, they are comparatively similar. It was speculated that lotus was separated when the continents drifted apart. There are no variations in reproduction. The rate of fertilization of these two species and fruit setting are both above 80%. Germination and seedling formation rates are also quite high in both. These conditions are rare in plants belonging to same group.

Because of continuous cultivation, many different cultivars and kinds appeared. Since lotus is generally propagated asexually from the underground stem, it can maintain its genetic characteristics. Lotus can also be propagated sexually. Under natural conditions, cross-pollination takes place. This is also the basis for the change of characteristics.

4. Geographic Distribution
Lotus is widely distributed in the world. It grows in Asia, Oceania, North and South America and Australia. The Chinese lotus (N. nucifera) is grown in Asia and Oceania from the Caspian Sea in the west to Japan in the east and from the Soviet Union in the north to the northern part of Australia. However, most of the lotus in the world is grown in China, Japan, India, the Philippines, and Indonesia. The center of cultivation of this species is in China. The N. pentapatala or the American yellow lotus is found in North and South America. The center of this species is in the United States.

In China the main distribution of lotus is along the Yantze River, the Yellow River and the Pearl River in the south. Lotus for seed production is grown mainly in Jiangxi, Fujien, Eunan and Hubei provinces. Lotus edible underground stem (lotus "root") production centers are at Hubei, Jiangsu, Jiejiang, Shangdong, and Guangdong provinces. Lotus flowers are mainly cultivated in Wuhan, Hangzhou, Shanghai, Beijing, and Soozhou metropolitan areas.

Lotus is an old dicotyledon plant with many monocotyledon plant characteristics. For instance, the leaf vein system and the two cotyledon leaves are some of the dicotyledon characteristics. On the other hand, the hairy root and the conductive cell structure in the stem all reflect those of a monocot.

Lotus root system is hairy and indefinite. The taproot does not develop. The root grows underground at the internode of the stem. There may be 5 to 8 bunches around each internode, and each bunch may have 7 to as many as 21 strings. The average length of these root strings is about 10.0-12.5 cm. The young seedling plants have few roots which become more abundant while growing. During the growing season, the root may be white or light purplish in color. When the underground stems become mature, the roots turn dark brown. The main function of the roots is for the absorption of water and nutrients and for anchoring of the plant.

The stem of the lotus is the underground type (Root-like stem). It branches out in the soil. In the early stages of development it resembles a whip or a stolon. In the later stage, the first few sections of the stolon grow and become obviously enlarged and swollen to form the "ou" or the so called lotus "root" which is botanically a stem. More stolon can originate from each internode. Small hairy-like roots also originate there and grow downward. Leaf and flower stalks also start from these internodes. The stolon is thin and long, white in color. The cross section of the underground stem can be round or oblong. The lotus "root" has dorsal and ventral distinction. In the ventral side there is a shallow but distinct trough or depression. In some varieties this feature is not too obvious. The cross section of the lotus "root" is round with a hexagonal feature. There are many air ducts of various sizes. These ducts are also found in the stolons and stalks of the leaves and flowers. When the lotus "root" is snapped and pulled apart a viscous liquid resembling silk may extend to more than 10 cm. This is a thick, sticky polysaccharide along the duct wall. There are primary, secondary, and tertiary "ou" or the lotus "root". The primary "ou" generally has 3 to 6 sections, and each section may vary from 10-20 cm in length. The second and tertiary "ou" may have only one or two sections.

Lotus has three kinds of leaves. When the leaf is in its first stage floating on the water surface and small, it is called a coin leaf. When fully grown it is called a floating leaf. When it extends on its stalk above the water it is called a standing leaf.

The flowers are bisexual, having both the filament and the ovary. The color and shape of the flowers vary with the different cultivars.

Fruit generally includes both the seeds and the hull. It is the developed ovary and the ovules. The seeds are hard and eliptical. Generally the seeds are 1.6-1.8 cm in length and 1.1-1.2 cm wide weighing between 1.1-1.4 grams. The shell around the seed is very hard. After the shell is removed, that becomes the seed inside the seed coat which can be brownish red or tan color. Commercially it is the red or white lotus seed. The seed also has the cotyledons and the germ which is in an air space.

1. Special Properties of Lotus Seed
There is an old saying in China that "the lotus seeds will never decay in a thousand years". Recently viable seeds have been dug up from various parts of China which may be 1,000 to 2,000 years old. That the lotus seeds may survive so long could be attributed to their hard shells around the seeds and the nearly impermeable seed coats. Studies have shown that the inner gas composition of the lotus changed little during storage, and the seeds may contain as much as 200 mg/100 g of dehydroascorbic acid (vitamin C). The ascorbic acid content of most seeds decrease with storage, but it changed little in lotus seeds during long terms of storage. These conditions may be the cause of longevity of the lotus seeds.

2. Growth and Development
Lotus is a perennial. Each year it has a complete cycle from budding, leafing, flowering, fruiting and the formation and maturing of the underground stem (the lotus "root"), and finally the rest period. It differs from those plants that form leaves first followed by flowers or those that form flowers first and then the leaves. In lotus, during its early growing period, the leaves are formed first and then the flowers, but later both leaves and flowers come out simultaneously. Fruit formation of the lotus also differ from other plants. Lotus will continuously flower and set fruit throughout its growing period.

There are five distinct stages of growth for lotus, namely, young seedling, mature seedling, flowering and fruiting, maturing of the underground stem (the edible lotus "root"), and resting or over-winter. The young seedling stage occurs from seed germination or from planting of the underground stem to the appearance of the first standing leaf. The seed has a very hard shell. Under its natural state it is very difficult for it to germinate. Commercially the seeds go through a machine to break the shell, and the seeds are soaked to hasten germination. After absorbing sufficient water and oxygen, the rest period is broken and the germination process begins. At 20 - 25C the first cotyledon leaves appear in 5-7 days. Coin sized leaves can form in another week. Short underground stem sections start to grow upward in an -"S" shape. At the section node, light purplish red indefinite roots begin to form. The stem continues to grow and finally falls down in the mud. The underground stem continues to extend and floating leaves gradually appear above the nodes. After 4-6 days floating leaves have formed and standing leaves appear, thus ending the young seedling stage.

In asexual propagation, the underground stem section is placed in the mud, and generally buds start to grow around the first part of April with leaf buds first. The first few leaves are coin leaves. Then the apical bud starts to grow into stolons followed by floating leaves. After 6-7 floating leaves are formed, standing leaves appear thus ending the young seedling stage of the asexually propagated lotus plant.

The time from the appearance of the standing leaves to the time of flower bud formation is considered as the mature seedling stage. Due to the season of the year when the temperature is optimal, growth during this stage is very rapid both upward and downward for the branching of the underground stem as well as the extension of the stem. On average, one section and one leaf bud are formed every 5-6 days. Usually after the leaf petioles comes above the water surface, the leaves spread out in about 3 days. The size of the leaves and the heights of the petioles vary. Generally after 5-7 leaves have appeared, flower buds begin. The plant then enters the flowering and fruiting stage.

The flowering process is continuous in the growth of lotus, lasting about 2 months. The times of flowering differ with different varieties and probably with the temperature. Lotus grown mainly for flowers may bloom for 3 months. In some varieties grown mainly for the underground stem for food (lotus "root"), such as the 'June Early,' the flowering sometimes is not very distinct. Generally speaking, when the plant growth reaches 7 sections of the underground stem, flower buds form axillarialy from the leaf bud. Sometimes they form side by side. After a few days both the leaf and the flower rise above the water. Finally, the flower stalk rises above the leaves. Under normal conditions there are two stages in the flowering, the budding and the blooming. The budding period may be about two weeks and flowering may last 3 or 4 days. These also vary with different varieties. During the bud growing stage, the stalk would grow rapidly especially during the night. After the flowers open, the elongation of the stalks would cease.

The flowers exhibit a light sensitive rhythm. They open in the morning and close at night. For a single flower the cutside petals begin to loosen after midnight of the first day, and the center begins to open. The second day is the full bloom. The petals begin to unfold from outside toward the center after midnight. By 5 or 6 A.M. the flower is completely opened. Each variety may exhibit its special shape or form in its flowers. After noontime, the petals begin to close. Sometimes they re-unfold somewhat at 4-5 P.M. and close again after dark. But the petals do not close as tightly as before. Sometimes and in some varieties they cannot close completely. On the third day the petals will open again, but the flower petals are not as tightly arranged. The color also begins to fade. By evening the petals will close again. By the fourth day the flower is fading. Both the outside petals and the filaments begin to shed, and the flower will fail to close in the evening. By the fifth day all flower parts would have dropped. Some varieties may last 6 days. For the compound petals variety, as the older petals fall new ones continue to form and enlarge. Such flowers may last almost two weeks. Ovules remain in flowers that have been pollinated and fertilized.

Fertilization to seed maturation may last about 30 days. There are also two separate periods in this process. The first is the maturing of the seed pods and the second the maturing of the seeds. After pollination, fertilization may occur in 6-8 hours. The seeds mature in about 30 days. Each ovary becomes a seed. The pods shrivel and turn dark or brown.

Lotus is pollinated mainly by insects. Generally its flowers are cross pollinated, but self-pollination does occur. Both the color of the flower and its scent may attract the insects. The important pollinating insects are from the following families: Hymenoptera, andrenidae, apidae (bees), and Halictidae although insects from many other families have also been noticed.

Flowering and fruiting may last about 3 months. Light is important to lotus flowering which is photoperiodic. Flowering can be induced by prolonging the daylight by artificial means or delayed by shortening the daylight. Flowering and fruiting are also affected by temperature which also influence the insect activity during pollination.

From the appearance of the final leaves to the drying of the top is the maturation of the lotus underground stem stage. In autumn, the growth of the above water plant parts gradually slow down and the nutrients begin to flow downward. The underground stolons begin to enlarge and thicken with the accumulation of carbohydrates to form the edible lotus "root". Maturation of this underground stem requires a certain temperature range. During cultivation shallow water is required to produce higher temperatures thus hastening the formation and maturation of this edible part of lotus "root".

The over-winter stage is from the time the plant top becomes yellow and wilted to the beginning of the appearance of leaf buds the following spring. The fleshy stem or the lotus "root" can be harvested for food. It can also be left in the ground to over-winter. This period can be from 5-8 months. In cold regions as long as the lake bottoms do not freeze solid, these "roots" can be safely left there over the winter in the mud.

3. Relation of Lotus Growth to Different Environmental Factors
Lotus is an aquatic plant with a morphological structure suitable to store and conduct a large amount of air. It has a definite capability to adapt to water but has definite requirements for water depth and flow rate of the current. These requirements, however, vary with different varieties. The requirement for water quality is not too strict; however, the discharge of phytotoxic chemicals from certain chemical industries is detrimental. Regions that once had an abundance of lotus plantings have been found to have no lotus due to discharges of toxic waste.

Lotus can adapt to most soil as long as there is no hardpan. It can grow at pH 5.6 to 7.5 but the optimum is at pH 6.5.

Lotus is a light loving plant and grows best when it is not shaded. In Wuhan, during the lotus growing period (April-August), average sunlight is between 4.6-9.0 hours per day. When the sunlight is abundant it also increases the temperature which favors the lotus growth.

Optimal temperature of lotus growth is between 20 and 30 degrees C. with water temperature at 21-25C. During the early planting time the temperature should be at least above 15 C. otherwise both the seed germination and seedling growth are hindered, resulting in some decaying. The growth of the seedling then increases with the temperature. By June, when the temperature during the day reaches 30C, the growth is the fastest. Growth is slowed when the temperature of the air is near 40C. During the seed maturing and the maturing of the lotus "root", high day temperature and lower night temperatures are optimal.

A strong wind can break leaf and flower stalks. Broken leaf stems may allow water to enter the underground stem and cause decay. Water in the flowers spoils the flower appearance and hinders pollination.

Young seedling may be affected by blue mold. Buds or small leaves with mold on them may influence growth and photosynthesis. Certain underwater plant feeders may devour some buds. When the plants mature the flower and leaf stalks have some protective sharp protrusions to discourage them.

Lotus may have some resistance to sulfur dioxide. The lotus "root" production near Wuhan city which has high S02 in the air seems to be not affected.

Lotus is an important economic aquatic crop. Every part of the plant has economical values. Lotus is used in many ways in our daily life. The underground stem, the lotus "root" is a staple food item in China, and immature lotus "root" and lotus seeds are crispy and sweet and are favored as summer delicacies. The lotus "root" can be processed into flour and used in cooking. Together with mature lotus seeds, the edible "root" contains an abundant amount of starch, sugars, proteins, lipids, vitamins and minerals. They are easily digested and are a good and nutritious food for all ages. They are also made into candies. Other parts of the plant are used in medicine. The fruit pods and leaves are sometimes used as wrappers. The flowers, used in landscaping and gardens, are beautiful and fragrant during the summer months.

Our laboratory analyses showed that underground stems, lotus "roots", of 33 varieties contain 8.4-22.7% starch, 1.4-4.8 total sugars, 0.2-2.4% reducing sugars, c.9L-2.44% protein; .07-1.02 free amino acid, 25.9-35.0 mg vitamin C, 0.13-0.19 mg vitamin B6 per 100 g. There are other minor constituents such as lipids and phospholipids, flavonoids, caroteens and, xanthophylls, and many minerals. The seed composition of 33 varieties is 38.3-57.8% starch, 8.5-19.1% total sugars, 0.8-6.3% 'reducing sugars, 1.5-2.4% lipids and 17.1-25.4% protein.

The main use of lotus "roots" (the underground stem) is for food. Many parts of the plants, such as the dried seed pods, seeds, leaves roots and flowers, are used in Chinese traditional medicine.

Many parks and gardens in China have lotus ponds in the landscape. Small scale plants, suitable for patios or indoors, have been developed. Plants can be planted in tubs or even in bowls of different sizes.

1. Methods of Propagation
Lotus can be propagated by seeds or by underground stem division. In this manner, the original characteristics of the mother plant are preserved; flowers can be enjoyed; and the lotus "root" harvested in the same season. This is the propagation method of choice by the farmers. The method of propagation by seeds is mainly used in breeding new cultivars.

Sexual propagation: Time of planting. Average temperature of seed planting should be between 15 and 25 C. In most parts of China seeds can be planted from March through June but mostly in March or April, and both seeds and the edible lotus "root" can be obtained in the same season.

The seeds selected should be fully-grown. The best seeds are from those just ripened. To hasten germination, the seed coat is manually clipped at the tip. Care is taken not to injure the cotyledons. The seeds are then soaked in water at a temperature of 15-25C for 3-5 days, the water being changed each day. Greenish cotyledon leaves would appear.

A good seed bed is essential. The soil is first turned and raked level to make a 1.0-1.2 meter seed bed. The length can vary. The soaked seed is placed in a row; the distance between the seed may be 1.0-1.5 cm. Bamboo frames are constructed above the seed bed and the entire planting is covered with plastic. Water is added to cover the seed bed to a depth of 3-5 cm. If the seed is to be planted in a tub or in a bowl, fertile mud is placed in the container to a depth equal to 1/2 - 2/3 of the container. One seed is planted in each tub of 1-1.5 meter diameter. Water is added to cover the mud to a depth of 3-5 cm. If the temperature is not sufficiently high, the tub can be covered with plastic.

When the seedlings in the seed bed have 4 floating leaves they can be transplanted to the field. During transplanting an amount of mud should be carried around the roots, and care should be taken to avoid the breaking of the fragile leaf stalk. The water is maintained at 3-5 cm above the soil surface. About 600-700 plants cover 1 mou (1/6 acre). Only one plant is transplanted into each bowl or tub.

Vegetative propagation: In most of central China along the Yantze River, the lotus grown for seeds, flower or the edible lotus "root" is planted in the first part of April with pieces of underground stem. By that time the apical buds on the stem section have already begun to grow. If planted too early, the temperature may be to low and the seed stem section may suffer cold injury. If planted too late the apical bud may already have sprouted and have small coin leaves which may be injured during the planting. In South China lotus may be planted in late March around the Spring equinox. In north China, because the season is late, it may be planted in May or June depending on the temperature. Because of transplanting, or replanting and the need of flower forcing, lotus for seed production and for flowers only must be planted separately to facilitate necessary management. During planting care must be taken to prevent the breaking of the leaf petioles, which have already started to grow. Lotus planted before June can be expect flowering in the same year. In several regions of South China there may be two crops in the same year. The fleshy stem from the first crop can be planted in June for a second crop of the edible lotus "root".

Selection of seed stems: The seed stem should be taken from plants of the desired characteristics. The apical bud and the side buds, if present, should be sound. For planting in the field, either the main stem or the branch stems may be used. For planting in tubs, only the main or the secondary stems are used. In the latter case, they must have two or three sections and the last section should be intact. For small tubs and bowls, small tertiary stems can be used as well as those nodes that have side buds. At each end of the node, about 1/2 inch of the stem is preserved. Whole stem pieces can also be used in these small planters. Under certain circumstances the stolons can be used. Similarly, both ends of the node on the stolon should be preserved and they should be planted without delay. If not planted on the same day they are dug up they should be covered with straw and sprayed with water to prevent the wilting of the leaf buds. If they are to be transported to another location care should be taken to prevent mechanical injury as well as from wilting.

Method of planting: Planting density and amount of seed pieces used vary with varieties and the purpose of the crop. Early maturing varieties are planted closer than the late ones. Field plantings are closer than lake or pond plantings. More stem nodes and stem tips are used than the whole stems. The smaller the size of the seed pieces the closer the planting distance. For each mou (1/6 acre) 80-100 pieces are used or approximately 300 kg of the whole stem. If stem tips are used as many 450-500 pieces may be used per mou (1/6 acre) weighing about 100 kg. About 100 - 250 seeds are planted in one mou (1/6 acre). To plant in a container, only one plant to each.

Planting arrangement: For deep water 2-4 stem pieces are tied together with straw. Make a hole with your foot and use a planting fork to push the bundles into the mud. After the insertion of the bundle, more mud is piled on it to cover the seed pieces. Another method is to place 2-3 seed pieces in a straw bag. Rocks may be placed in the bag and the entire bag sunk into the lake.

2. Cultivation and Management
Lotus can be planted wherever there is water and mud. It can be a lake, pond, rice paddy, tub, or even a large shallow jar or bowl. There should be sufficient light and the water depth should not be more than 1.5 meters. The bottom mud should be about l0-20 cm. These requirements are necessary for artificial ponds or lakes in gardens. It is best if each pond only contains one single variety. If more than one variety is desired they should be separated into small ponds. If lotus is planted in the paddy, irrigation should be available. Soil should be fertile and about 20-30 cm deep in mud.

For variety collections or exhibitions or for breeding work, tubs or bowls should be used. Growing in containers is also good for indoors or on patios for private enjoyment. For variety selection it is essential to know the purpose of the planting. Lotus for flowers can be planted in lakes, ponds, or in tubs. In large parks or gardens, flowering varieties with long blooming periods are best. Flowers should have intense color and an abundance of flowers. Small plant varieties are more suitable for tub or bowl plantings. For seed production only, a lake or paddy is generally used. The paddy is more suitable to production of edible lotus "root" as it is more convenient to harvest. They can also be planted in lakes. For planting in the paddy, use the best local variety. For lake plantings use varieties that can tolerate a deeper water level and mature later.

Soil used for container culture can be taken from a lake or pond bottom or other fertile soil and blended into mud. Place it in the container to a depth of 20-30 cm and about 10-15 cm from the rim.

Basic fertilizers: Lotus prefer rich and fertile soil. Lake or pond bottoms contain large amounts of organic matter. Lotus field, lake, pond, or paddy that are not fertile should be supplemented with various organic matter such as an oil press cake, manure and green manure. If the soil is too acid, wood ash or lime can be added. The organic matter in the containers should be well mixed.

Management: Regardless of where the lotus is planted, the removal of weeds is necessary. During the period between planting and harvesting 2 or 3 weeding practices may be needed. The first time at the appearance of sprouting, the second time after the floating leaves, and the third time after the standing leaves.

Side application of fertilizer: Lotus (for flowers) does not usually require side dressing unless the leaves are turning yellow during the growing period and the size of the leaves are smaller than normal. Some side dressing of fertilizer may be necessary. Lotus grown for seeds may require the addition of fertilizers: once at the time when one or two standing leaves have appeared, and a second time when the standing leaves have ended. One of the ways to add fertilizer consists of pouring liquid fertilizer through a large pipe containing a mixture of 1% urea, .0l% dipotassium hydrogen phosphate, and .05% boric acid.

Water level: The water requirements for lotus vary at different stages of growth. Lotus for root production has more critical water requirements than lotus for flower production or for seeds. Generally, at the time of planting, water level should be about 5-10 cm. As the standing leaves grow, it can be raised to 30-60 cm. The water should be lowered to about 5 cm at the time of maturing of the lotus "root". Shallow water raises the temperatures and is beneficial to young plants. As the leaves grow the summer temperature and the evaporation rate increase and higher water levels are needed. At the time of stem maturing, higher soil temperature encourages this process.

Changing the direction of growing stem: During growing season, the submerged stem may grow toward the edge of the pond; they should be carefully turned toward the center.

Low temperature and strong wind: The plants should be protected from the elements (prevailing winds) by planting wind breakers on the side of the lake or the pond. In large lakes, the farmers would plant other aquatic plants several meters from the lotus planting as a buffer from the waves created by strong winds. Container planting should be placed so that the plants are protected from strong winds. Stakes near the flowers, which are tied to them, can prevent their breaking.

In most areas of lotus production in China, the plants can safely pass the winter without damage. Where the temperature is extremely cold, containers can be buried in the soil or mounded with soil and covered with straw. Small containers should be moved indoors during severe cold.

Crop rotation: The commercial production of lotus can be rotated with other economic aquatic crops such as water chestnut and wild rice stem. Lotus can also rotate with rice. In other cases fish can be raised together with lotus.

Principle insects and diseases of lotus:
Rhopolosiphum nymphaeae L.
Prodenia iitura Fabricius
Donacia provosti Fairmaire
Cnidocampa flavescens Walker
Parasa consocia Walker
Cryptothelea variegata Snellen
Cryptothelea minuscula Butley
Lymantria dispera L.
Anomala corpulenta Motschulsky
Tendipes nelumbus Tokunaga et Kuroda
Control measures suggested for these insect pests are spraying, baits and trapping.

Other aquatic pests:
Snails, Radix swinhoei (H. Adams) Helix gramium H.
Worms, Branchiura sowerbyi Bedd.
Control measures for the above is by soil treatments.

Water rodents: Hydromy sp. The major damage by this pest is the loss of seeds. Control is by baits.

Alternaria melumbii (Ell et Ev) Enlows et Rand
Fusarium bulbigenum C. et M.F. ne
Alternaria can be controlled by spraying with fungicide and fusarium by crop rotation.

Other diseases are:
Cercospora nymphaeacea Cke. et Ell
Gleosporium nelumbii Tassi
Phoma nelumbii Cooke et Massee
Gandelospora nelumbii Sakaguchi
Ascohyta sp. And Phyllosticta sp.

3. Harvesting and Storage
Harvest of lotus "root": Depending on the location and variety, lotus "root" harvest can vary from July to October. The "root" is carefully dug from the soil. Some are left in the soil for the growing of the following year.

Harvesting of the seeds: Seeds are harvested manually as soon as the seed pods are gathered. They are removed and sun-dried. After the culls and extraneous materials are removed they are packaged.

4. Storage and Transportation.
The fleshy "root" cannot be stored too long after removal from the soil at room temperatures. In winter months it may be stored for about one month. During early summer or spring it may last 10-15 days. Refrigerated storage could prolong the shelf life. For storage the "root" should be well matured. The presence of mud on the "root" is not harmful. Broken pieces can be sealed with mud. When transporting, the "root" should not be piled too deeply. They should be covered with leaves or straw and frequently sprayed with water.

Lotus seeds should be stored in cool and dry storage areas with good ventilation. The floor of the storage area should have a layer of rice hulls about 20 cm deep. On top of that place a layer of straw mat and oil cloth. The seeds are piled on that about 5 or 6 seeds thick. They should be turned frequently. Rodent damage should be prevented as well as insect loss. During transportation protect them from rain and high humidity.

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