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Rural Industries Research & Development Corporation
Summary of full report
by NSW Agriculture, Horticultural Research & Advisory Station, Gosford, NSW Principal Investigator: Dr.Q.V.Nguyen
April 2001
RIRDC Publication No 01/32
RIRDC Project No DAN 125A
Executive Summary
1. Lotus (Nelumbo nucifera GAERTN.) is one of the oldest plants on earth. Archaeologists have found seeds of Lotus in China and Japan that have an estimated age of more than a thousand years and some of these seeds still carry the ability to germinate. These are one of the oldest, demonstrably viable seeds that have ever been reported upon.
2. Lotus is a perennial, aquatic crop grown and consumed throughout Asia. The leaves, flowers, seeds and rhizomes are all utilised but rhizomes hold the largest market share. Flowers could also become a potential new product for the Australian ornamental market as well.
3. It is interesting to note that all parts of Lotus are used in oriental medicine. The leaves are used for diarrhoea, high fever, haemorrhoids, strangury and leprosy whilst the seeds would stop vomiting or soothe irritation of the digestive tract. The lotus embryo is primarily used for nervous disorders, insomnia, high fevers with restlessness and hypertension and the flower pod is used to stop bleeding and eliminate stagnated blood. Stamens are useful in the treatment of male sexual disorders and female leucorrhea. Lotus also contains a large number of aroma substances in the leaves and flowers whilst Lotus rhizomes and seeds are high in calcium and kalium.
Crop Management
4. Variety: The several hundred known varieties of Lotus have been classified into three categories according to their use, eg. rhizomes, flowers and seeds. Some varieties may exhibit one or more of the three characteristics but generally each is classified by its strongest feature. The variety currently grown in Australia for the fresh rhizome market is Quangdong. Growers who would wish to solely target flower and pod markets should use Green Jade and Vietnam-Red. Although seed production at this stage may not be advantageous economically, Green Jade and Vietnam-Red are, however, recommended for seed varieties.
5. Propagation: Propagation by seed can be carried out by scarifying the seed coat and then incubating at 25o-30oC. Seeds should be submerged in a water saturated media. However, propagation by seed will not be true-to-type as Lotus has a high degree of genetic variability.
Vegetative (rhizome) is the most easily employed and most efficient method of propagation. It will also produce true-to-type plants. Seed (certified) rhizomes with at least two segments, which are sealed at either end by an intact node, is submerged in water saturated media at an angle of 15o with the shoot meristem approximately 5 cm below media surface. Tissue culture methods hold promise for the future to produce high volumes of uniform, true-to-type, disease free materials.
6. Pond management: The pond design is critical to Lotus production operations because, once constructed, it is difficult to change. Consideration must be given to water management in terms of acquisition, movement, storage and crop pond management. Traditionally, farm dams which are sealed by compacting, impermeable clays, are not suitable for growing Lotus as rhizomes can grow into them. Hard, compacted clay also causes difficulties with harvesting. A soft top layer of soil is necessary to a depth of approximately 1 m and must contain correct organic matter including manures and other well-rotted, high nitrogen to carbon ratio mulches, which are recommended for Lotus growing.
7. Water Quality: Water quality and availability will play an important role in the success of Lotus cultivation. Growth was not seen to be affected by variation in water pH from 5.5 to 8.0. The correct EC level for a plant in the vegetative stage of growth is between 2.8-3.1 mS cm-1. The ideal depth of water is approximately 10-20 cm. Lotus can tolerate a degree of salt in the soil water solution. This holds promise for growing Lotus in situations where saline conditions and/or high water tables occur.
8. Growing climate: Lotus requires a warm to tropical environment with an average daytime temperature of 25oC, intense sunlight and long day hours for successful growth. Protection of the crop from wind and hail damage is essential.
9. Planting: Transplanting of seed rhizomes ideally should take place before the break of dormancy and after any danger of frost. Plants transplanted after rhizomes have germinated are less likely to establish successfully.
10. Fertiliser: Applications can be split into 4-5 applications as young plants are easily burnt with high rates of fertilising. Correct balance of nutrient is also recommended, and is dictated by maturity stage of the crop, eg. a crop approaching maturity and rhizome formation stage would not be fed with high concentrations of Nitrogen but more Potassium.
11. Insects: The most prevalent pest of Lotus in Australia appears to be Heliothis sp. Caterpillars. Green peach aphid and twospotted mite are also considered to be particularly troublesome.
12. Diseases: Lotus is subject to few diseases such as Powdery mildew (Erysiphe polygoni); waterlily crown rot (Phytophthora sp.) and Fusarium wilt (Fusarium oxysporum) although not exempt.
13. Weeds: Lotus ponds always have potential for invasion by aquatic weed species. These weeds not only compete for space, but also nutrients and, in some cases, oxygen as well. It is recommended that weeds are removed from the pond either by physical removal or use of a herbicide during non-crop period before they can establish.
14. Harvesting: Rhizomes can be harvested when shoots die off and plants go into dormancy, which occurs in autumn. Rhizomes can be picked by hand, backhoe and/or water canon, but, due to lack of suitable mechanical harvesters, rhizomes are presently picked by hand in Australia. Fresh yield of rhizome is in the range of 10-40 t/ha.
15. Postharvest, Packaging & Storage: Lotus rhizomes are very easily bruised and physical damage results in an immediate purple discolouration. To avoid bruising and to maintain high humidity for the rhizomes, styrofoam boxes with sealable lids the size of a standard broccoli box, offer the best possible solution. Use of modified atmospheric packaging is promising for providing longer periods in storage. Lotus keeps best at temperatures between 3oC and 7oC and can potentially last in storage for up to 5-6 weeks.
16. Transportation: Ideally, Lotus should be transported domestically by refrigerated truck. Export freight would be via sea. Airfreight is the alternative, but utilisation could be a factor in prevailing markets with regard to cost.
Markets
17. Domestic market: Demand for Lotus rhizomes for Australian domestic markets is estimated at approximately 1,080 t annually. Australian producers have so far supplied only approximately 100 t of fresh product, the rest being imported in frozen and dried forms from overseas, but mainly from China.
18. Of the several countries in North-East and South-East Asia where Lotus are cultivated and consumed, Japanese markets offer the best opportunities for the Australian Lotus industry. Because of the large A$400 million wholesale market that exists for Lotus, securing even a small part of that market would be a commendable feat for Australian exporters.
19. China, where approximately three million tonnes of Lotus rhizomes were produced on 133,400 ha in 1994, is the major world producer of Lotus rhizomes. China dominates the Japanese import markets with both fresh and salted Lotus.
Australian lotus industry
20. Australian Lotus, which is currently an infant industry in this country, needs to put more effort into research on variety, growing techniques, postharvest storage and handling and market development.
21. The gross margin of Lotus grown on the Central Coast of NSW is estimated at A$2.76/kg.
22. The Australian Lotus industry can
penetrate into overseas, particularly Japanese, markets if we can open
up a trading system directly with supermarket chains. For export to Japan,
quality of locallyproduced Lotus should be based on Japanese standards
and classification.
 
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