1- grain storage - reed

8/3/2019 1- Grain Storage - Reed

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Receiving and Storing

U. S. Grain at Destination

Carl Reed

International Grains Program


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Grain Export from the U. S.

Trigo

Maz

Soya

Sorgo

Inland Export

Route New


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Exported U. S. CornAverage m.c. 14.3 %

Average TW 72.8 kg/hl

Average BCFM 2.7 %

Average Damage 2.7 %

M.C. other grains

Wheat 11.5 13.0%

Sorghum 13.5%

Soybeans 12.2%


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Receiving and Storing U. S. Corn

Contract specifications are critically

important.

If the grain is to be stored in a warmclimate, special precautions must be taken

Dealing with moisture variations

Dealing with variations in broken kernels and

fine material

Quality maintenance in storage (>6 weeks)


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Dealing with Moisture Variation

If grain must be stored.

Segregate by moisture at reception Use wetter grain first


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Example of Moisture Variation


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Ship Date Truck Temp m.c.Pacific Bulker 5/25/00 1 26 14.0

Pacific Bulker 5/25/00 2 25 15.1Pacific Bulker 5/25/00 3 24 15.0

Pacific Bulker 5/25/00 4 25 14.9







Pacific Bulker 5/25/00 12 25 13.9

Pacific Bulker 5/25/00 13 24 13.7

Pacific Bulker 5/25/00 14 22 14.7

Pacific Bulker 5/25/00 15 23 15.1

Pacific Bulker 5/25/00 16 23 14.7

Pacific Bulker 5/25/00 17 22 14.5


Med Faith 6/21/00 1 22 13.9

Med Faith 6/21/00 2 23 14.7

Med Faith 6/21/00 3 21 13.8

Med Faith 6/21/00 4 22 14.3

Med Faith 6/21/00 5 22 14.1

Med Faith 6/21/00 6 21 14.4

Med Faith 6/21/00 7 22 14.7Med Faith 6/21/00 8 22 14.9

Example of Moisture Variation

*

*

*Compaia

CentroAmericana


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Dealing with Fine Material in Corn

Sample and analyze to know FM level

Clean before storage, or Core bins before storage


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Dealing with Insects in Any Grain

Recognize that commercially-handled grain is

infested Insect density has to be high before the infestation

can be detected

More insects are tolerated in feed grains than in

wheat May fumigate en-route, or

Fumigate at destination


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Life Cycle of Stored Product Beetles

Eggs

Larva

Pupa

Adult


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Life Cycle of Stored Product Beetles

Eggs

Larva

Pupa

Adult

These forms are invisible ingrain samples


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Laboratory Study on

Probability of Detection

010

20

30

4050

60

70

80

0 1 2 3 4 5 6

Insect Density (#/kg)

Proba

bilityofDetection(%)

Hagstrum et al. 1985. Environ.

Entomol 14:655-661

The USDA study showed that

when 1 insect/kg was present,

a single, 1-Kg sample had a 1-

in-3 chance of containing an

insect.

The study showed that the

probability of detecting insects

is about 3 times smaller than

what probability alone would

predict.

Si ifi f S li


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Significance of Sampling

Probability Numbers There are 1,000 one-kg samples in a MT of corn

If the insect density is 1/kg, then there are 1,000insects per MT

If the lot subsample represents 120 MT, and thegrain contains 1 insect/kg, there are 120,000insects in the grain represented

The probability of detecting insects if a one-kgsample is taken is one in three

If the true insect density is only one in 10 kg,thenthe probability of detection is one in 30.

If only one of every 10 insects in an adult, the

probability of detection is one in 300


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Dealing with Mold-Produced

Deterioration

Segregation by moisture at reception

Control of fine material Use of mold inhibitors

Maintain cool temperatures

If grain arrives cool, maintain cool temperature Use aeration if needed


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Common field fungi including species ofthe generaFusarium, Cephalosporium,

Cladosporium, etc. are common in the

soil and inside plants of growing corn.


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The field molds require a high moisturecontent in their environment. By the time

corn has dried enough to harvest, the field

molds have become dormant.


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Grain arrives at storage infected with dormant field

molds. In handling equipment and bins it is inoculated

with a new group of molds, those that can survive in

dry grain in storage.


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Molds and Mycotoxins

Myco = mold Aflatoxin produced

byAspergillus flavusand others.

Zearalenone produced by Fusariumroseum and others

DON (vomitoxin) one of several tricho-thecenes produced byFusarium tricinctumand others.

Almost always produced

on the plant*, though the

fungus can grow in storage.

Field fungus toxin

produced in the field.*

Field fungus toxin

produced in the field.*

*Or field-type situation


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Molds and Mycotoxins - 2

T-2 another tricho-thecene produced byFusarium molds

Fumonisin produced byFusarium moniliforme andothers

Ochratoxin produced byand Penicillium species,

Aspergillus ochraceus, andothers

Field fungus toxinproduced in the field.*

Field fungus toxinproduced in the field.*

Both field and storagefungi, toxin productionappears associated withstorage of cool, dampgrain

*Or field-type situation


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Field-Type Situation?


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Field-Type Damages


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What does grain-mold biology mean

for importers of US grain? At harvest, the US domestic market quickly

identifies the origin of any grain containingmycotoxin

Exporters attempt to avoid grain from thatproduction area

Exported corn is assayed for aflatoxin, and anygrain can be tested for toxins at the purchasersrequest

Exported grain is dry, so toxin can not beproduced in the grain unless it gets wet


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Root of Infected Embryo

Mold Spores and Hyphae

Eff t f G i M i t


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Effect of Grain Moisture on

Growth of Storage Molds

0

20

40

60

80

100

120

0 2 4 6 8 10 12 14

Weeks at 25 C

A.glaucusInfect

ion(%)

18 % m.c.16.5 % m.c.14.6 % m.c.Linear (14.6 % m.c.)Linear (16.5 % m.c.)Linear (18 % m.c.)

Effect of Temperature on


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0

5

10

15

20

25

15 16 17 18 19 20 21 22 23 24 25

Temperature ( C)

Monthsto0.5

DML

14 % m.c.

15 % m.c.

16 % m.c.

Effect of Temperature on

Growth of Storage Molds

59 F 77 F


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y = 1.4x + 3.3

R2 = 0.95

0

10

20

30

40

0 4 8 12 16 20

Weeks of Storage

Dam

agedKernels(%)

Bin Avg

Linear (Bin Avg)

Increase in damaged kernels in corn at

14.6 % m.c. and 24 28 C75-82 F


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0

20

40

60

80

0 2 4 6 8 10 12

Weeks at 25 C

Inte

rnalInfection(%)

A. glaucus

Fusarium

Increase in Infections byA. glaucus and

Decrease inFusarium spp. at 14.6 % m.c.

D i T l M ld C f 18 0 %


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Decrease in Total Mold Counts of 18.0 %-m.c.

Corn on General-Purpose Agar over Time

0

20

40

60

80

100

0 2 4 6 8 10 12

Weeks at 25 C

InternalInfection(%)

025

50

75

100125

150

175

200

cfu/g(00

0)

All Aspergillus spp.

Rose Agar


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Oxygen Consumption Over Time (averages by mold inhibitor and dose)

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

0 5 10 15 20 25 30 35 40 45 50

Days of Incubation

mgO2/hr/kgDM

Untreated

Prod B 0.1 kg/tProd A 0.1 kg/t

Respiration of Pellets


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Corn at 15.0 % m.c. Treated with

Product A

0.0

1.0

2.0

3.0

4.0

5.0

1 11 21 32 42 54

Days of Incubation

mgO2/h/kgDry

Untreated

0.5 kg/t

1.0 kg/t

2.0 kg/t

3.0 kg/t


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Aeration


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Effect of Grain Temperature

on Rate of Deterioration

60

80

100

120

140

160

180

0 2 4 6 8 10Weeks of Storage

Perc

entKernelsInfecte

dbyMolds*

* Percent Infection

as % of Original 14.3 % m. c. and 86 F

14.3 % m. c. and 77 F

R d ti f A ti f


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Recommendations for Aeration of

Imported Corn* in Warm Climates

Do not aerate

If the grain is cooler than 20 C and the graintemperature is stable

When the air is as warm or warmer than the grain

Aerate only when air is at least 3 C cooler thanthe grain

Monitor aeration with grain temperature

monitoring system, stop as soon as cooling iscomplete

Only if the grain is heating should aeration beused regardless of the air temperature and RH

*stored less than 3 months


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Receiving and Storing

U. S. Grain at Destination

Carl Reed

International Grains Program

1- grain storage - reed

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