Myanmar

Postharvest Technologies for Fresh Leafy Vegetables in Myanmar Kyaw Nyein Aye, Ph.D. Associate Professor Yangon Technological University Insein, Yangon, Myanmar Introduction Vegetables play important role in human nutrition. Apart from ascorbic acid (vitamin C) which is principal vitamin supplied by fruits and vegetables, leafy vegetables are rich source of essential nutrients such as vitamin A, folic acid and beta-carotene. A substantial proportion of the carbohydrates found in leafy vegetable represents as dietary fiber. Moreover, many therapeutic drugs in alternative medicine are originated as extract from leaves since they have miracle ingredients. In Myanmar, like other Asian countries, people are fond of having vegetables in their daily diet. Although there are very few export items of leafy vegetable from Myanmar, some organic leafy vegetables has long been entering into the value chain market. And, the application of postharvest technology for the leafy vegetables is also a common practice in the country traditionally and commercially. Postharvest handling like packaging, cooling, preserving for freshness of leafy vegetables are used all over the country in usual ways of farm-to-market. In this report, the status of postharvest technologies for fresh leafy vegetables in the country is presented by introducing the related organizations and their activities. The use of chitosan, a biopolymer derived from chitin, is also reported as a pre and post harvest technique for the prolong shelf-life of crops and vegetables. Leafy Vegetable Production in Myanmar According to the survey, sown areas of vegetable are 405,000 hectares and that of kitchen crops such as chili, onion and potatoes are 263,250 hectares in the country (MOAI, 2007). Many of vegetable crops were grown organically. Generally, the vegetable growers have carrots, spinach, beans, peas, cauliflower, baby corn, chilies, asparagus, lady-fingers, eggplants, celery, rosella, mushrooms, drumstick, squash, green mangos, leeks, cucumbers, potatoes, tomatoes, chayote, various cabbages, kale and more. The Pyin Oo Lwin and Inle Lake areas produce a wide variety of vegetables, while Bago specializes in growing lady-fingers (okra) and rosella leaves. Many kinds of kitchen crops like chilies, onion and garlic Mandalay and Sagaing Divisions. Figure 1 shows the map of vegetable growing areas and Table 1 shows the crop calendar of some leafy vegetables. When the market is very competitive, the growers can enjoy on-farm sales tipped on their sites. Normally they have to bring their produce to a buying depot situated on the main road and sell it for the day-to-day price. There can be, in some areas, a sort of growers' association selling their commodity direct to the wholesalers. Marketing systems are varied from region to region and from crop to crop. The main means of transport is trucks and the major flow of commodities is to large markets and to the border areas. Retailers are also very active in distribution of fresh produce in the local and street markets to the consumers even up to their doorsteps in remote villages and fields. There is no or very few quality

assurance system for the public consumption. The quality management throughout the commodity chain is mainly physical based on local materials and traditional wisdom (Aung et al., 2005). Fresh fruits and vegetables and their processed products are the leading products in market in the tropical region especially in the countries in Southeast Asia. Increasing the shelf-life of these products has been the aim of researchers as it benefits import, export, local sales as well as industrial processing.

Figure 1. The map showing the annual total sown area of vegetables (MOAI et al., 2005)

Table 1. The crop calendar and their average yield in a year in Myanmar Sr. 1

2

Crop Name Mustard

A. Gree n Gra m (Rai n) B. Gree n Gra m (Win ter)

Major Grow Area SGG MDY MGW KCN KYR

Seasons Growing Nov.

Harvesting Feb. to Mar.

MGW SGG MDY YGN PGUe AYW MGW SGG

May. to Jun.

Sep. to Oct.

Nov. to Dec. Feb. to Mar.

3

Cabbage

SHNs PGUe PGUw

May. to Jul. Nov.

Aug. to Oct. Mar.

4

Broccoli

SHNs

May to Jul.

Aug. to Oct. Feb. to Apr.

Unit Basket (equiv. to 25 Kg)

Yield (per acre) Avg. Max. 11 6 11 6 11 6 11 8 11 8

Basket (equiv. to 25 Kg)

10 13 10 10 14 14 10 14

14 15 15 20 20 20 20 20

Viss (equiv. to 1.67 kg) Viss (equiv. to 1.67 kg)

4000 5000

7000 6000

4000

7500

SGG Oct. to Nov. 3500 6000 AYW SGG = Sagaing Division MDY = Mandalay Division MGW = Magway Division PGU = Pegu Division (PGUe = Eastern Pegu Division, PGUw = Western Pegu Division) KCN = Kachin State KYR = Kayar State YGN = Yangon Division AYW = Ayarwaddy Division SHN = Shan State (SHNs = Southern Shan State) (MOAI, 2007)

Postharvest Technologies: Myanmar Experience Myanmar has only one packing house owned by Yangon City Development Committee with the facility of 3 cold storage rooms at 10 tons capacity and some postharvest handling machines for various kinds of fruits and vegetables. An exporting company has contracted to produce the packages of fruits and vegetables to sell to Singapore market. They treat the lettuce and broccoli with 1 degree Celsius chilled water containing disinfectant prior to pack with air-tight plastic bag for cargo flight. For local consumption around Yangon metropolitan area, the big wholesale market is located at the bank of Yangon River. The practice of the handling is not very systematic, almost no postharvest technologies involved, only water washing and bulky packs by bamboo strings. The middlemen, vegetable brokers, collect from the farm places and bring to the wholesale market. The brokers have shops in the market and resell to vegetable dealers for day to day selling to the local dwellers. The bulks of vegetables packed by huge bamboo baskets are transported by pickup or truck cars from the farm after harvesting and arrived overnight at the wholesale market called Thirimingalar Zay. There is a plan to develop a bigger wholesale market at the outskirt of Yangon in near future. Myanmar's first ever horticulture show was inaugurated during early May of 2007 on a grand scale to encourage fruit and vegetable growing. The four-day horticulture show at the Myaypadetha Island near the Kandawgyi Lake displayed a variety of fruits and vegetable produced by different regions in the country. The horticulture show is attached with a seminar on Myanmar fruit, vegetable and flower with resource persons submitting papers on the aspects. The research data and growing techniques including postharvest technologies were presented from related organizations such as Food and Agriculture Organization of the United Nations, Ministry of Agriculture and Irrigation, Ministry of Commerce, Ministry of Education, Ministry of Science and Technology and Myanmar Fruit and Vegetable Producer and Exporter Association which organize and promote the country’s fruits and vegetables. Myanmar Fruit and Vegetable Producer and Exporter Association would aim to utilize the latest technologies in fruit and vegetable cultivation and value-added manufacturing by importing higher quality seeds and modern agricultural machinery. One of the key aims of the association would be to set up a special production zone for agricultural exports that would attract local and foreign investment. The association is targeting regional markets as well as Myanmar consumers. Unlike in the past, when people were limited to buying whatever fruits or vegetables were in season, new advances in growing technologies, postharvest technologies, transportation and trade mean that many varieties of produce are now available year-round. The association would also be involved in research activities and promote the use of vegetables as well as carrying out research and training programs. Moreover, the access to international research and overseas training opportunities would assist the development of the vegetable crop sector. Under the Ministry of Agriculture and Irrigation, two key institutions have been doing the research activities with related to leafy vegetables. They are Yezin Agriculture University which is located near the capital Nay Pyi Taw and the Vegetable and Fruit Research and Development Centre of Myanma Agricultural Services which is located in Hlegu Township, Yangon Division.

The Vegetable and Fruit Research and Development Centre, established in 1986, has research works at vegetable and plant tissue laboratories, tissue culture and reproduction and gives instructions of cultivation methods and postharvest technologies to the vegetable growers and producers. Therefore, plenty of vegetables and fruit can be produced and available in the market with application of the findings of the research works by the center. The centre has been conducting on vegetables and fruit grown in the region and imported species. The centre produces new seeds of vegetables and production of hybrid vegetables is under experiment. The researchers are making efforts to become the centre on which vegetable growers and consumers can rely so that the kind of vegetable and fruit of high quality will be produced based on their expertise and experience. Similarly as Yezin Agricultural University, the universities under the Ministry of Science and Technology and the Ministry of Education have also been doing their researches to contribute the agriculture and food science including those related to the leafy vegetables as well. Especially, department of biotechnology from Yangon Technological University has done doctoral researches such as analysis pesticide residues in leafy vegetables and application of chitosan in agricultural sector. Under the Ministry of Commerce, an organization called Myanma Agricultural Produce Trading (MAPT) has laid down several objectives, in line with government’s trade policy, including the assistance for the enhancement of better quality crop production striving for export promotion. MAPT undertakes laboratory analysis and testing of soil and water, quality of food grains and extends technical assistance on postharvest technology. MAPT’s one of the functional centers, Postharvest Technology Application Center which is based in Hlegu is serving the postharvest activities, research, development and extension works especially food grain, fruits and vegetables and issuance of certificate related to quality of crops and analytical results of chemical compositions, pesticides residues, Aflatoxins etc. Myanmar is an agro-based country and postharvest technology is essentially needed for the economy of the whole country. However, the fresh produce supply chain has not yet been systematically growing throughout the country. Post-harvest decay and desiccation are the two major causes of short shelf-life of horticultural crops. Decay of fresh produce can be reduced to a certain extent by minimizing the mechanical damage and enhancing the natural resistance of the produce by storage at low temperature and by optimizing the conditions (controlled atmosphere: modification of oxygen and / or carbon dioxide concentration) that would slow the ripening process. Diseases of postharvest products vary for different kinds of fruits or vegetables and depend on kind of products and causative agents. Fresh fruits and vegetables can be infected before and after harvest by different species. The use of pesticides in the agriculture is threatening the quality health of consumers. The residues after harvesting could be detected in some leafy vegetables. In Myanmar, the organophosphate type of pesticides are being legally imported with several brand names such as Acephate, Dimethoate, Malathion and Chlorpyrifos. Table 2 shows those pesticide residues in various leafy vegetables detected during a week after application of pesticide spraying on the trial cultivation fields.

Table 2. Pesticide Residues in Various Leafy Vegetables Detected During a Week after Application Days after Application of Various Pesticides on Different Leafy Vegetables 1 3 5 7

Pesticide Residue in Green Gram Leaves Acephate pesticide concentrati on (ppm) 2.48 2.40 2.11 0.95

Dimethoate pesticide concentration (ppm) 3.20 3.06 2.76 2.65

Pesticide Residue in Mustard Leaves Malathion pesticide concentration (ppm) 0.34 0.20 0.14 0.08

ND = Not detected

Chlorpyrifos pesticide concentration (ppm) 0.22 0.02 ND ND

Pesticide Residue in Kale Leaves

Malathion pesticide concentration (ppm) 0.33 0.19 0.15 0.13

Chlorpyrifos pesticide concentration (ppm) 0.06 0.04 ND ND

(Theingi Nwe, 2007)

To control the diseases caused by pathogens especially fungi several chemicals have been used. The application of antifungal agent is by far the most effective method to control the diseases. However, chemical control faces problem such as: development of resistance of storage pathogens against fungicides, reluctance of the general public to consume produce treated with fungicides and their threat to the environment. Thus, there is a growing need to develop alternative approaches for efficient control of storage diseases using bioactive substances. Chitosan, a natural polymer of β-glucosamine was found to be fungicidal against fungi. It has been applied by coating on fruits and vegetables such as tomato, pepper, cucumber and strawberry. Chitosan is also known to be a potential elicitor of plant defense system such as chitinase (that can destroy cell walls of pathogens), phytoalexin (antibiotic that is toxic for bacteria and fungi) and synthesis of proteinase inhibitor. Induction of chitinase activity was found also in early stages of germination for several seeds coated with a thin membrane of chitosan and its derivatives. Chitosan appears to play a dual function by interfering directly with fungal growth and also by activating defense processes in host. Application of chitosan in postharvest technology For agriculture, some primary uses of chitin and its derivative chitosan are a seed treatment, growth stimulator and natural preservative. On the other hand, chitin and chitosan also can be used as biofungicides and regulator for seeds and plants (Thazin Han, 2006). Noguchi and Katsumori (1991) reported that treated cabbage seeds by chitosan before germination can make yield higher than control about 47%. Some researchers have seen research effect of chitosan on membrane as it can filter O2 and CO2. Depending upon this property, chitosan is very important role in respiration and photosynthesis of plant. It can also be concluded that chitosan can extend the shelf-life of fresh produce as well. Robert (1989) has used chitosan’s salt as stimulating element. It can be applied following some methods such as dipping seeds and roots in chitosan solution or spraying the solution on leaves, etc. Most of them can increase yield and proteins content in seed and also make plant resistant to diseases. There are many other researches not only apply recommend chitosan as growth stimulating agent but also let the handlers use it as an organic fungicide with high preservative activity. The antifungal effects of chitosan had been demonstrated in several experiments in terms of enhancing chitinase activity. After applying chitosan, plants often contain large amount of chitinase activities that can attack chitin cell wall of pathogen

fungus. Chitosan’s antifungal activity could allow farmers greater flexibility in their postharvesting schedules. Proper handling for organic vegetables The rapid growth of the market for organic crops and advancements in methods to authenticate their origin require a proactive approach to setting acceptable organic farming standards. Systems to detect the presence of agro-chemicals would have to be constantly updated in line with the introduction of new herbicides, pesticides and so on. The present organic farming regime is far from satisfactory. By formulating present methods to produce organic crops, fruits and vegetables, food scientists could come up with recommendations for improved farming procedures and crop handling. Research is an essential component in the further development of organic farming in Myanmar. At the Ministry of Science of Technology and Myanmar Fruit and Vegetable Producer and Exporter Association, researchers and food technologists are currently engaged in a number of organic-farming related researches, including organic fruit and vegetable farming, and utilisation of chitosan as a bio-compatible growth stimulator. To promote organic farming, it is essential that farmers are made aware of optimal procedures to produce safe, high quality crops and alternatives for agro-chemicals. Conclusion To recommend for the postharvest technology development, although the concerned people from the related organizations has gained the knowledge about vegetable handling, they still have lack of adequate facilities so that the certification process for the quality fresh produce, organic vegetables, the supply chain system and modern testing equipments should be improved. The national organizations like Myanmar Fruit and Vegetable Producer and Exporter Association have encouraged the local vegetable growers to produce more quality products and to consult their postharvest development in quality as well as their marketing concepts. Together with developing postharvest technologies for leafy vegetables in Myanmar, the expansion of export market to lead the country’s economy should also be accordingly promoted. Technology transfer and fresh produce supply chain management including exchange of proper handling techniques among the countries in the region are to be strengthened with workshops of this kind. Certifying organic vegetables in Myanmar would require, as a first step, documenting the current status of organic production throughout the country and identifying currently available expertise. The country needs to apply principles of modern agriculture, postharvest and biotechnology in new methods and procedures for organic farming, and training experts and inspectors in the practical aspects of supervising organic vegetable production. Chitosan is bio-compatible and bio-degradable and is used as a fungicide and plant stimulator and shelf-life promoter. Its value as a natural additive in horticulture and postharvest handling procedures would have to be further investigated.

Acknowledgement The author would like to thank AVRDC-ADB RETA 6376 project for organizing the workshop on Best Practices in Postharvest Management of Leafy Vegetable in the Greater Mekong Sub-region Countries. Thanks are also extended to Yangon Technological University and Myanmar Fruit and Vegetable Producer and Exporter Association for the encouragement the research activities in postharvest technologies for fresh leafy vegetables. References Aung H., Htoo S.H.L. and Aung H.P. (2005) Marketing and Distribution Systems of Fresh Produce in Myanmar, ISHS Acta Horticulturae 712: IV International Conference on Managing Quality in Chains - The Integrated View on Fruits and Vegetables Quality. MOAI (2007) Annual Report for 2006-2007 from Myanma Agricultural Services, Ministry Agriculture and Irrigation, Union of Myanmar.

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MOAI, UNDP and FAO (2005) Digital Agricultural Atlas of the Union of Myanmar, issued by Ministry of Agriculture and Irrigation, United Nations Development Programme and Food and Agriculture Organization of the United Nations (CD ROM format) MOC (2007) Annual Reports of the Status of Fruits and Vegetables Export submitted by Myanma Agricultural Produce Trading, Ministry of Commerce, Union of Myanmar. Noguchi and Katsumori (1991) Seed Treatment by Chitin Regulator’s Properties. JapanKokai Tokyo, Koho, Japan. 0308004 Robert L. E. (1989) Salts of Chitin Derivatives, PCT . into Appl.Wo. 8907395 Thazin Han (2006) Production of Chitosan from Various Sources for Use as a Plant Growth Stimulant and Study on the Antifungal Chitinase Activity of Trichoderma harzianum as a Biocontrol Agent, Ph.D. Thesis, Yangon Technological University, Myanmar. Theingi Nwe (2007) Investigation on the Behavior and Fate of Pesticide and Their Effects on the Microbial Environment of the Vigna radiate (Green Gram), Brassica rapa (Mustard Green) and Brassica oleracea (Kale) Cultivation, Ph.D. Thesis, Yangon Technological University, Myanmar.