Proceedinqs of the 7th Internatumal Workzng Conference on Stored-product Protection - Volume 2

Review and prospect of grain storage technology applied inHubei, China

Abstract

Great progress has been made m Chma smce Its foundationThis paper mtroduces 10 applied techmques used m safetygram storage, They are: gram storage with protectants,'double low' storage, ventilation storage, low temperaturestorage, gram storage in open arr , gram drying, quahtymspection and control, gram fumigation, computerapplication and gram storage m countryside The paperprobes mto the trend of gram storage techniques m Chma IIIfuture and puts forward that: cold storage and ventilationWIllbe WIdely developed; there IS a new breakthrough III

nee quality, granary mechanization ISImportant for buildingnational gram reserve depots; apphcation of computer WIllbe rapidly developed

Introduction

Smce the foundation of the People's Repubhc of Chma, greatprogress has been made in gram storage technology.especially in the last 20 years, the level of scientific gramstorage has been raised At present, there are a largenumber of workers who master gram storage technique.scientific and techmcal content of grain preservation IScontmuously mcreasmg 'Four Free' grain depots (pestsfree, deterioration free, birds and rodents free, accidentsfree) have been set up in the whole country, the loss ofstored gram ISobviously decreased. The loss rate of nationalgram reserve depot IS below O.2%, technological level ofgram preservation has been greatly Improved. The paperreviewed the development of gram storage techniques inChma, especially in Huber province, and made prospect forthe development of gram storage techmque m 21 century.

Reviews of Grain StorageTechniques in the Last 50 Years

Through reviewmg developmg history of gram storagetechniques m Hubei province, we can fmd that there is a

1 Gram Bureau of Hubel Provmce, Wuhan 430061, P R Chma

new start every ten years. Expenments on paddy long-termstorage were done, the change of the law of 'threetemperature and three humidity' was mastered in the 50's.Cereal protectants were thoroughly studied, sohd foundationon spreadmg protectants was laid m the 60's 'Double low'(low oxygen. low dosage) gram storage technique wasstudied and spread in the 70's Drying and Ventilationtechmques were developed and machme ventilation waspopulanzed, at same time, stored-pests investigation ofWIdescope was done m Huber provmce m the 80's In the90' s, computers are used in gram depots and microelectromctechmque IS applied m dynamic management of gramreserve. Besides, pest development law of stored-gram mopen air and mtegrated control techmque are studied Allfacts show that scientific techniques have extended thedevelopment of gram storage. The developments of grainstorage techmques durmg the last 50 years are as follows:

The use of grain protectants

Huber provmce IS one of the provmces that firstly useprotectants for grain storage. Lmdane powder was used inthe 50's. Malathion (purity over 95%) was pnmanly usedin the 60's Deltamehtnn and Femtrothion have been usedsmce the 80's Chloorpynfos methyl, Pinnuphos-methyl andValexon are apphed in small expenments MIxed MalathionWith gram in Hubei had gone through three stages:experiments in the 60's, spread in the 70's, development inthe 80's. 50 billion kilograms grain ISdealt by Malathion inthe whole province, many fumigation expenses are savedand stored-gram safety ISassured. Because Malathion ISusedfor a long time and pests develop senous resistance, newprotectants are needed to take place of Malathion MIxtureof malathion and deltamethrin or mixture of deltamethrmand femtrothion are used m BUbel province. There are twokmds of commonmixed drugs: (1) Mixture of malathion anddeltamethnn. Namely, malathion and deltamethnn mixedWIthpottery clay or hull bran powder. The powder contents1% malathion, 0.02% deltamethnn, every kilogrampowder is mixed with 1000kg raw gram, content of vahddrug on gram surface IS lOpp malathion and O.2ppmdeltamethm (2) MIxture of deltamethrm and femtrothIOn.Contents of vahd drug on gram surface are 7ppmfemtrothlon and O.2ppm deltamethnn. These two kmds ofdrugs can mamtam stored-gram free of pests m one year,

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Proceeduiqe of the 7th International Workmg Conference on Stored-product Protectwn - Volume 2

they are specially effective to Rluzopertha dommica

'Double low' grain storage technique

'Double low' (low oxygen, low phosphme dosage) ISdeveloped on the basis of oxygen-free storage Becausethere are some problems of airtight matenals, naturaloxygen- free storage can not kill pests and must apply lowdosage alummum phosphide tablets. The mam pomts of'Double low' are the techmcal Improvement of the depot,the Improvement of the air-tightness of films. timely sealinggram wrth films, rationally applying low dosage Sealmgquahty of the films should meet the standard: gram surfacelooks like glass, no folds, straight lme along the wall andthe film edges should be buned for sealmg. 'Double low'bins, of which doors and wmdows should be double layersand sealed by films, should have workmg chamber andprotective door. A group of personnel needs to be tramed toknow how to seal the film effectively 'Double low' gramstorage techmque has been populanzed in the whole countrydunng the past 20 years There are over 100 billionkilograms gram stored by this method m RUbel Provmce

Ventilation technique of grain storage

Expenments on gram storage by mechamcal draft was atthe Gram Depot No.2 of Wuhan CIty in the 50's, however,this techmque was not apphed until the 80's. On the tnal mPUXIGram Bureau baSIS, mechamcal draft gram storage wasspread m Rubel province in 1984 The tnal results showthat mechamcal draft gram storage has vanous advantagessuch as prolongmg storage period, mamtammg gramquahty, reducmg loss due to msects and molds Mechamcaldraft was populanzed m RUbel provmce from 1984 to 1987,there are about 60% gram stored by mechamcal draft.There are three modes of mechamcal draft: geosyclme type,air-stock box type and pipe layout type The three kmdsventilation bms are efficient to lower temperature of stored-gram, geosyclme ventilation IS more effective m lowenngmoisture, the moisture of short-gram nonglutmous paddystored by this method can be lowered by 2 - 3% RUbelGram Bureau Issued geosyclme drawmg designed byJmgzhou Gram Bureau in 1986 and put forward that newlybUllt gram depot must be laid ventilation geosychne

Low temperature technique

Low temperature by refngera tion has been applied smcethe 80's m RUbel provmce Ronzontal warehouse of SoVIetDmon ongm was remade mto a cold warehouse m GramDepot No.2 of Wuhan CIty m 1980 The warehouse usespearl rock as heat msulation matenal, uses refngerator tolower temperature. Temperature mSlde warehousemamtams at 15°C, the nce (glutmous nce and long-gramnonglutmous nce), whIch IS stored one year m coldwarehouse keeps fresh, the colour, odour and taste of food

made of tlus nee IS normal, however, quality of rice byconventional storage IS aging. Effect of refngerator coldstorage IS good, but power consumption IS too much,therefore, this method IS not spreadTo probe mto economic and effective cold storage

techmque, Storage and Transportation Company of HuangshiCIty did expenments on using wmdow air conditioners tostore nee, peanut, and sesame. The result IS successful. In1986, cooperative group of urban temperature-controlstorage WIth air conditioner of RUbel provmce held adiscussion in Huangshi , It promoted technologicaldevelopment of urban low temperature storage for nee. Thetechmque was spread over Wuhan, Yichang , Shaslu, Shiyanand so onNatural cold storage IS a mam part of low temperature.

Dunng the wmter, open wmdows and doors of warehousescan let cold airs flow through the gram surface and cool gramlayer by layer Turn over gram and dig up gaps can enhanceventilation effect. In RUbel provmce, gram temperature canbe lowered to below 8°C m pIam area or below 5°C mmountam area. RUbel provmce proposed temperature controlstandard of stored-gram m the wmter m 1990, It IS requiredthat gram temperature mside depots should be controlledwithin 20°C. In 1997, they revised the standard, namely,gram temperature inside depot cannot be over 25°C andtemperature of gram in open atr can not be over 28°C insummer and autumn. Gram temperature mside depot can notbe over 18°C and temperature of gram in open air can not beover 15°C m spnng and wmter

Technique of stored-grain in open air

Stonng gram m open air began from the 50's, RUbelGram Bureau drew up 'Operation regulation of fumigation ofgram stored m open air' in July, 1983, which efficientlyprevent fire from happemng RUbel provmce spread mouse-proof goods yard and raised quality of gram stored m openair in 1984 RUbel Gram Bureau drew up 'Managementstandard of grain stored in open air m RUbel provmce' in1990 , gram stored m open air was standardized andsystematized. On- the-spot meetmg of national gram storagewas held m Jmgzhou , RUbel provmce, and experience ofstonng gram m the open air was spread m RUbel province mMay 1991 Charactenstics of stored-gram techmque in openair m Rubel are: (1) CapaCIty of stack is large Generalcapacl ty of stack IS 250 ,000 kilograms gram, and that of thelargest gram bulk IS 1,000,000 kilograms. (2) Mouse-prooffunction IS strong Platform IS 0.7 meters above groundlevel, the surface goes beyond platform 0.15 meters, somouse can not chmb It. (3) There are dIverSIfIed types ofstorage There are fIxed platform goods yard, prefabncatedoverhead goods yard, depot-type goods yard, pool-typegoods yard and bnck overhead goods yard (4) ManagementIS convement. A lot of methods were adopted, such as

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Proceedings of the 7th Internatwnal Worktng Conference on Stored-product Protection - Volume 2

'three proof' (mouse proof, moisture proof, mold proof) atthe foot of a gram bulk, overhead at the top of a grain bulk,the top covered by OIlcloth, mat hung at grain sides, grampiled as ladder, ventilation, protectants mixed with gram,automatic control of the grain temperature. The technique ISquite effective, namely, 'prevent dew, reduce gramscatter, safety through the summer, retard aging' .

Grain drying technique

Experiments on gram drying by dryer were done m Hubeiprovince m the 50's. In 1984, there were two grain machineplants in Xianning and Tianmen, Hubei province thatproduced fluidized-bed dryer. There are 100 fluidized-bed-drying shops and 100 sets small-size mobile fluidized-beddryer built m the whole province withm 5 years. Graindrying by fluidized-bed dryer IS a successful techmque.According to the matenals used, dryer can be divided intosteel dryer and brick dryer. According to Width, dryer canbe divided into small-scale dryer and middle-sized dryer.Middle-sized dryer is 3.8 meters long, 0.42 meters wideand output is 7.5 ton per hour Advantages of fluidized-beddryer are: simple structure, less matenals, easyproduction, convenient repair and suitable for gram depot incountryside The power which can be used is coal and paddyhull, paddy hull can be consumed 50 - 70 kilograms everyhour. However, dryers are not brought into play and mostof dryers are set aside in Huber province.

Technique of quality inspection

Quality inspection of stored-gram IS Important. Therequired reserve period (wheat, 5 years; paddy, 3 yearsand corn, 2 years) is not scientific. If temperature IScontrolled and grains are stored under 15 - 20"( coldgranary, gram preservation time can be prolonged. The keyto the problem IS to find out indexes that can be used toweigh up deterioration degree.Paddy of long-term storage had been studied in Hubei in

the 50's. The results showed fatty acid value can be used asan efficient index for forecasting storage properties,reducing sugar value and salt-soluble protem value canpredict grain detenoration, too. According to 'Controlindexes and determination of grain storage quality' , whichISset by Chengdu Gram Storage Scientific Research Instituteof the Ministry of Internal Trade, experiments on paddystorage quality change were done by Wuhan Gram DepotNo.2 from 1983 to 1985. It proved that germinationpercentage, viscosity and fatty acid value are importantindices for weighing up paddy aging and deterioration.Germination percentage, VISCOSityand fatty acid valueshould be regularly. determined during paddy storage so thatdecision can be made whether the paddy could still be storedsafely.

Technique of fumigation

Technique of grain fumigation develops rapidly m Hubeiprovince. Main fumigant was Chloropicnn, the second wasethylene dichloride and methyl bromide, and hydrocyamcacid was used in grain processing plants in the 50's. Tabletof alummum phosphide has been used since the 70's, it ISmainly used at present Much research work on apphedtechmque of fumigants was done m Hubei province.Researches on control of Bruchues pisonum by chloropicrinwas done m Xiangyang and Luotian early in the 60's. 'Fourrapid' measure (raid harvest, rapid thresh, rapid sunmng,rapid management) was put forward, and Bruchues pisoriumcould be killed before It became the fourth-mstar larvae.Apphed researches on burnmg preparation of calciumphosphide and adding zmc phosphide into acid were carriedout m the 70's It solved the problem of lacking fumigantsIn view of safety, Hubei Gram Bureau set 'Operation rulesof funugatmg stored-insect by zinc phosphide' in Apn11975.Apphcator outside of the warehouse and Circulativefumigation were studied in the 80's Apphcators outside ofthe warehouse are earned batch process m Tianmen GramMachine Plant. Circulative fumigation is studied m Jmgmenand Xiaogan. The technique of aluminum phosphideCirculative fumigation together With ventilation throughgeosycline can reduce dosage, increase effectiveness, so ItISspread and applied.

Applied technique of computer

Programming calculators were tried out to purchase grainsearly in the 80's m Hubei province, the calculator IST1-59type, and is very useful. Computers are used at grain depotm the late 80's. At present, computers at gram depots havethe following applications: (1) Grain condition testing. It ispopularly used to remote temperature testing ( 2 )Equipment control. It IS used for automatic control ofmechanic draft and automatic weighmg. (3) Busmessmanagement. Computers are used to synthesize variousreport forms, It brings into play efficient action in accountmanagement, storage and transport management, gramreserve management, personnel files management andadrmmstration. Besides, computer management systems andcomputer expert systems are studied, but it is not used inpractice yet.

Grain storage technique in countryside

Attention has been paid to the grams stored in the ruralareas m our country. Grain department at all levels preservenational grams, at the same time positively help countrysideto develop gram preservation. Grain stored m countrysidehas gone through three phases, namely, 'Four Free' graindepots were developed in countryside in the 60's. Gramdepartment put forward construction of large depots

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Proceedings of the 7 th Internatwnal Worhng Conference 011 Stored-produc: Protection. - Yolume 2

(countryside gram depots) instead of small ones (nationalgram depots) in the 70' s Experiences of buildingwarehouses, nuxmg drugs WIth gram and feeding cats werepracticed m Hubei province Developing mvisible farmlandwas put forward at the end of the 80's. Attention has beenpaid to grain loss m harvest, thresh, transport, storage andconsumption. Because there are many countryside grambins, WhICh are of Wide distribution and poor conditions,control techmques must be based on 'safety, efficiency,economy' pnnciple , gram developments help farmers tobuild gram bms and promote protectants It took over 20years to help countryside apply protectants for controllmgpests m Huber province Perfect protectant techmque anddeveloping management networks should be further set up toreduce loss m the countryside.

Prospect of Grain Storage Technique

Smce the foundation of the People's Republic of Chma , greatprogress has been made m grain storage technique.However, compared WIth developed countries, greatdifference still exists especially on mechanized equipment.The developing trend of gram storage techmque m ourcountry is that low temperature and ventilation will bewidely used; There Will be a new breakthrough in ricequality; Granary mechanization will be Important m nationalgram reserve depots; Application of computers Will berapidly developed

Low temperature and ventilation

Cold storage means gram temperature controlled below15°C all the year round. Quasi-low temperature storage isgram temperature controlled below 20t:. According tonational condition, we thmk that cold storage shouldaccomplish, (1) Improve techmque of fimshed product ofgram stored m CIties by air condltIoner. ( 2) Applyrefrigeration techmque to get low temperature, remakeheat-msular honzontal warehouses (3) Enhance researcheson mechanical draft, lower gram temperature by

ventilation. Ventilation WIth low temperature Will open anew situation m gram storage.

New breakthrough of rice quality

The main crop m Chma lS nee. With the nsmg Irvingstandard, fme foods are needed, new breakthrough of ricequality IS necessary. In VIew of expenences of Thailand andIndia, the arm of nee quality breakthrough IS (1) Producefine vanety (2) Process good quality. (3) Set up standardof high quality nee

Mechanization of national grain reservation depot

In view of expenences of granary mechanization in thepast, when we build granary m our country, we must payattention to granary mechamzation; moreover, we shouldrationally equip granary machine according to granarycharacteristics. Compared with other countries, we have alarge number of honzontal warehouses. To ensure honzontalwarehouses mechanization, work tower must be built in thecenter of granary, collocates bulks lorries and transportequipment. In the future, our country should build severaldemonstration mechamzed reserve depots, attention must bepard to the mechamzation of bulk transport.

New development of computer application

There are many computers used m national grain reservedepots, but the effect IS not good, and an apphcation ofcomputer m gram depot needs to be further exploited. Weneed to equip gram enterpnses with modern technique,Improve working environment, and raise workingefficiency. We should exploit computer system and trammore personnel. We believe that gram loss can be mmirmzedgreatly If computers can give full play in gram storage

References

Yun Changjie, 1996. Research on the Scientific Storage ofGram. BelJmg, Chma CommerCIal Pubhshing House,411p. (In Chmese)

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