Sanitation in Grain Storage and in Mills

Sanitation in grain storage and in mills Bhadriraju Subramanyam, PhD Professor Department of Grain Science and Industry Kansas State University Manhattan, Kansas 66506, USA Tel: 785-532-4092 Fax: 785-532-7010 E-mail: [email protected] Website: http://www.ksre.ksu.edu/grsc_subi

IAOM 4th Annual SE Asia District Conference October 8-10, 2013 Ho Chi Minh, Vietnam Pests associated with feed facilities

Invertebrate pests: Filth flies Cockroaches Mites

Stored-product insects

Vertebrate pests: Birds Rats and mice (rodents) Unsanitary conditions in mills

Birds Product damage and loss

Contamination of food or damage to food

• Cleaning costs • Food destruction • Risk of prosecution • Loss of sales Safety hazard

Slippery when wet… Sanitation

• Grain stored in bins/silos (whole grains) –Removal of dockage/spillage • Processed material in the feed mill/warehouse –GMPs Sanitation of grain • In grain sanitation refers to removal of broken kernel, grain dust, weed seeds, etc • Sources – Grain damage due to harvesting machinery – Manual vs hand threshing – Multiple handling (corn more susceptible to breakage) • Grain handling produces 0.11-0.55% dust by wt • Corn lot subjected to 2.5, 5, and 15 transfers had 0.9, 4, and 9% breakage, respectively – Corn breakage susceptibility inversely related to moisture – Penalties at time of sale – Internal insects produce broken kernels and/or grain dust Dockage in grain

• Corn with 2-3% dockage had 50% of it accumulated in the spout line area • Some accumulate below false floors of steel bins • High moisture area • Insects and molds proliferate in this area Insects in grain residues at elevators (Arthur et al. 2006)

Data from 9 elevators and 1,575 samples. Total number of pest insects found = 46,725. Load-Out Boot Pit 2009 2010 Temperature 40 Feed mill 1 Feed mill 1 30 1200 850

1000 800 10 750 450 0 500 300

250 150 -10

0 0 -20

40 Feed mill 2 Feed mill 2 90 80 30

85 60 20

80 10 40 40

30 0 20 20

Temperature (°C) Temperature 10 -10

Mean no. (insects/kg) no. Mean 0 0 -20

375 40 200 Feed mill 3 Feed mill 3 30 150 20

350 100 10 200

0 50 100 -10 0 0 -20 Jan Mar May Jul Sep Nov Jan Mar May Jul Sep Nov Empty bin cleaning (Purdue Univ. Survey; Martin et al. 1977)

 95% sweep bins  15% vacuum in crevices  9% blow down walls  6% hose down walls

 60% clean augers  45% clean elevator legs  64% re-seal leaky bins  83% clean up outside spills Impact of sanitation of bins (Reed et al. 2003)

Data from 11 elevators, samples from 25 – 138 bins at each elevator. Impacts of dockage • Impedes grain drying, and proper aeration and fumigant movement through the grain mass • Dockage increase moisture content – High moisture content degrades insecticide on grains • Fine particles absorb protectant applied to grain

Wheat condition % retain of 10 ppm malathion applied to wheat Clean wheat 88.2 Wheat with 2.5% dockage 73.0 Wheat with 5% dockage 67.0 Wheat with 10% dockage 53.0 12.5% wheat at 26oC and 60% RH Insecticides recommended

Product Active ingredient Rate Site treated Grain (mg[AI]/kg) Storcide II Chlorpyrifos-methyl + 3.0 + 0.5 Empty bins, Wheat, barley, rice, deltamethrin warehouses, stored oats, sorghum grain Tempo SC β-cyfluthrin 0.01 or 0.02 Empty bins 2 Ultra g/m Actellic 5E Pirimiphos-methyl 6 - 8 Stored grain Corn, sorghum K-Othrine Deltamethrin 0.5 Empty bins, Wheat, barley, rice, SC, warehouses, stored oats, sorghum, corn, Centynal grain rye Evercide Esfenvalerate Surfaces Diasource, Diatomaceous earth 500 - 1000 Empty bins, Wheat, barley, rice, Dryacide, (silicon dioxide) stored grain oats, sorghum, corn, Protect-It peas Diacon-IGR S-methoprene 1, 2.5 or 5 Empty bins, All stored grains, stored grain spices, seeds Spinosad Spinosyns A + D 1 Stored grain All stored grains, including wheat Impacts of dockage

• Effects of dockage on insects varies with the species Species Grain condition No. insects (adult progeny) Maize weevil Whole kernels 1342 90% whole, 10% cracked 1149 100% cracked 75 Flour 50 Red flour beetle Whole kernels 269 90% whole, 10% cracked 245 100% cracked 652 Flour 1417

Pearl millet examined after 76-78 d after infestation at 26.7oC and 65-70% RH Human health issues

• OSHA standards – 15 g/m3 total dust; 5 g/m3 respirable • Explosive concentration, 50-100 g/m3 – Influenced by other factors such as particle size distribution and particle dryness Removal of dockage

• Grain cleaning – No economic incentive – Unless you handle more than 2 million b ushels annually – Cleaning occurs downstream (at mills) • Use of grain spreaders – 17% producers use it; 5% concrete elevators use it; and 11% commercial facilities use it • Coring Leveling and coring

 Leveling • 44.8% of commercial operators leveled the peak  Coring • 28% of farmers • 51% of elevator operators Application of oils • USFDA (1982) approved use of oil to suppress dust • Canola oil, mineral oil, soybean oil – Grain for human food-0.02 by wt – Grain for animal feed-0.60% by wt – 0.03 to 1.0% suppressed dust by 90% • Helps improve insecticide coverage • Has adverse effects on grain physical properties Benefits of grain cleaning

• Increased storage capacity • Reduced incidence and growth of insects/molds • Improved aeration and fumigant distribution • Improved coverage of protectants on grain • Reduced explosion hazards • Improved air quality • Load uniformity when unloading • Decreased occupation exposure of workers to dust • Economic benefits for marketing clean grain Sanitation alone will NOT control insects • Sanitation remove food for insects • Beetles live for several months to a year, without food • Always apply an insecticide to empty bins floors, warehouses, or feed mills after sanitation Why are pests present?

Food

Shelter Moisture Prevent access to food/facility

• Sanitation (cleaning practices) • Create pest barriers • Prevent pest entry points into the mill • Store grains or finished feed properly on pallets • Sanitary design of equipment to eliminate food within equipment • Pest (insect) resistant packaging material for finished feed Remove spillage

Avoid clutter: Potential harborage sites for rodents/insects Eliminate unsanitary conditions outdoors Building exterior

Have an 18 ft vegetation-free barrier zone

Shrubs should not be too close to building Rate mill infestation by location for sanitation

Probability of infestation or product loss

High Moderate Low Zero

Daily Production Floors Areas; receiving Weekly

Monthly Spouts; Bathrooms conditioner Yearly Building

Cleaning Cleaning frequency exterior Eliminate flat surfaces and remove unused equipment Flat surfaces Storage of unused equipment Sanitary design aspects Sanitary design aspects Deny pest entry into your mill Rodent entry point Poor door seal

Improper stocking or storage practices

Give 12 inches of space between the wall and pallets Pallets, 6 inches off the floor

Pest management tactics Grain chilling

Heat treatment: Raising the ambient air temperature to 122-140oF (50-60oC), and maintaining these temperatures for 24-36 hours-MILLS, EQUIPMENT, ONE ROOM, BINS

Electric heater Gas heaters

Steam heater

Fan Duct carrying heat Once a Year from gas heaters Silo heat treatment

54 Heat treatment of silos

Kills insects in 6-8 h Mills need 24 h Controlled atmospheres for mite and insect control

• Controlled or modified atmospheres

– Use of the inert gases, N2 and CO2 – Reduce atmospheric O2 from 20.9 to ≤1% http://sgrl.csiro.au/storage/insects/Psocids_ – Increase CO2 from 0.03 to mites/mites.html >40% • Advantages – Increases shelf life of perishables/dry durables – Pesticide-residue free – Kills insects and mites and suppresses progeny – Replacing traditional IPM approaches Modified atmospheres

• Replace oxygen by purging storages with carbon dioxide or nitrogen • To kill insects oxygen level should be <2% • Exposure times are usually longer (14-21 days) • Effective at warmer temperatures >30oC • Bin sealing important Mortality of red flour beetle life stages at 32.2oC

Compressed air 12% CO2 + 0.5% O2 + 87.5% N2

100 100 Eggs 80 Larvae 80 Pupae Adults 60 60

40 40

Mortality (%) Mortality 20 20

0 0 0 20 40 60 80 100 120 140 160 180 0 20 40 60 80 100 120 140 160 180

Time (hours) Confused flour beetle adult mortality at three temperatures

Compressed air 12% CO2 + 0.5% O2 + 87.5% N2

100 120 10oC 80 100 21.1oC o 80 60 32.2 C 60 40 40 20 20

Mortality (%) Mortality

0 0

0 20 40 60 80 100 120 140 160 180 0 20 40 60 80 100 120 140 160 180

Time (hours) Modified atmosphere for products

EcO2 terminal in Thessaloniki Modified atmosphere for silos EcO2 terminal in Thessaloniki EcO2 terminal in Thessaloniki

EcO2 terminal in Thessaloniki EcO2 terminal in Thessaloniki Exclusion tactic for rodents/insects/birds

Photo 6

Remove this structure or modify as suggested in Photo 1

Smooth and paint Do not have a light below this structure

Smooth and paint See Photo 1 comments regarding strips

Need a rodent Need a rodent trap trap

Gap below floor and shutter; should avoid such gaps as they are large enough for rodents and insects to enter Exclusion tactics

• Use of screens at eaves • Sealing of pest entry points into the silos • Screens on windows • Closing doors • Pest-proofing buildings Slip-concrete structures

• Help exclude pests Hermetic structures for raw grain and finished products Cocoons™

Having the shape of a cube, impermeable to gases (hermetic), manufactured of white PVC, flexible, UV resistant. Designed for in or outdoor storage, for agricultural and non-agricultural commodities, dry and in bags. Can be installed at any location in minutes. Annual post harvest loss less than 0.25%. Effective life span 10-15 years.

150MT Cocoons Cargill, Philippines

150 MT Cocoons Rwanda Cocoons Bayer Philippines. Hybrid Rice.

Cocoon in Laos. Grainbank.

Cocoons in Rwanda. Food Security

Cocoons in Miramar, Costa Rica. Organic Coffee. G-HF and V-HF Cocoons™

G-HF CocoonsTM V-HF CocoonsTM Hermetic Fumigation with CO2 Vacuum-Hermetic Fumigation Available in 5MT till 50MT, with For rapid fumigation of identical configuration as standard commodities of high value or for Cocoons. In addition there is a gas storage of commodities at low O2 inlet near the bottom and a gas levels. outlet of 6” Ǿ at the top. Provided This technology eliminates all with all additional equipment for stages of insect development in

CO2 injection. This method is three days at room temperature. El being used for “fumigation” of a Cocoon The V-HF Cocoon is commodity and rapid elimination of connected to a vacuum pump to all stages of insect development reduce the O2 in the Cocoon to a level lethal to the insects.

Cocoa in USA Tobacco in Israel February 4, 2009 February 4, 2009 Sanitation also means wearing proper apparel in mills

Apply pesticides inside mills after sanitation • Crack/crevice application • Cyfluthrin, fenvalerate, hydroprene • General surface application • Diatomaceous earth • Fogging • Resmethrin, Dichlorvos Aerosols (fogging)-packaged finished products

Kill exposed insects Lighting

• White lights away from buildings • High pressure sodium lights near buildings • No lights near doors and windows Rodenticides and baits

• Anticoagulants – Multiple-dose: Diphacinone, Chlorophacinone, Warfarin – Kill rodents in 3 – 18 days – Single-dose: Brodifacoum, Bromadiolone, Difethialone – 1-2 grams will kill rodents after a single feeding • Non-anticoagulants – Bromethalin – 2.5 – 8 grams to kill rodents – Death in 12 h – 4 days – Zinc Phosphide: succumb in 17 minutes, death in 12 - 24 hours

– Cholecalciferol (Vitamin D3) 3 Rings of defense Baits Tamper-proof bait boxes Baits-pellets

Liquid baits Prune trees to reduce birds from roosting Netting to exclude birds Tactile deterrents for birds

Coils

Spikes

Ledge wires

Ledge wires Bird spikes Sloped ledges exclude birds First inspect, monitor, assess, and evaluate

• Inspection – Visual (part of GMPs) – Inbound and outbound material, mill interior and exterior – Identifies source of pests, sanitation issues • Monitoring – Traps and mechanical devices • Assessing – Pest density and distribution • Evaluation – Implement tactics, evaluate impacts/benefits Traps and mechanical devices Sampling insects • Insects can be detected in grain by sampling grain with several devices or by probe traps • Determining number of insects in a grain sample is useful for making pest management decisions • As you take more samples you will be able to accurately estimate insect density • The FGIS standards of grain sampling may not always be able to accurately determine insect density Sources of Uncertainty Affecting IPM Decisions

Sampling Initial insect Management population methods

Environment Knowledge of Insect population dynamics Final insect population Discounts received Sampling

Modified from Kenkel et al. (1994) Grain bulk

• Probe sampler • Spear or trier Vacuum probe for bulk-stored grain Recommended Sampling Intensity for Seed in Bagsa. 1 to 6...... * 95 to 104.....15 195 to 204...... 25 7 to 14...... 6 105 to 114.....16 205 to 214...... 26 15 to 24...... 7 115 to 124.....17 215 to 224...... 27 25 to 34...... 8 125 to 134.....18 225 to 234...... 28 35 to 44...... 9 135 to 144.....19 235 to 244...... 29 45 to 54.....10 145 to 154.....20 245 to 254...... 30 55 to 64.....11 155 to 164.....21 255 or more.....30 65 to 74.....12 165 to 174.....22 75 to 84.....13 175 to 184.....23 85 to 94.....14 185 to 194.....24 •For lots of 1 to 6 bags, sample each bag and take a total of at least 5 cores or handfuls. aSource: Knapp, A. D., T. J. Gutormson, and M. K. Misra. 1991. Seed Lot Sampling. North Central Regional Extension Publication 403, July 1991. •North Dakota State University, Fargo, North Dakota. http://www.ag.ndsu.edu/pubs/plantsci/smgrains/ncr403w.htm. Probability of detection

P (x > 0) = 1 – (1 – f)n P = 1- (1 – 0.05)30 P = 0.785 or 78.5%

n = ln[1 - P]/ln[1 - f] n = ln[1-0.95]/ln[1-0.05] = 58.4 or 58 samples/bags f = 1 - [1 – P]1/n f = 1 – [1 – 0.95]1/30 = 0.095 or 0.095 x 100 = 9.5% or approximately 10%.

This value is the maximum infestation frequency (fmax) I should have in order to be 95% sure that if I take 30 bags I will find an infestation. The true frequency may lie anywhere between >0 to 9.5%! Probability of detection versus no. samples

1.0

0.8

0.6

0.4

0.2

Probability of detection Probability

0.0 0 10 20 30 40 50 Number of samples taken Probability of Detection for Insects in Stored Wheat

No. 1-kg Mean no. insects per kg of grain samples per 1000 bushels 0.02 0.06 0.20 0.60 2.0 6.0 1 0.02 0.06 0.19 0.43 0.76 0.95 2 0.04 0.12 0.34 0.67 0.94 1.00 5 0.10 0.28 0.64 0.94 0.99 1.00 10 0.19 1.48 0.87 1.00 1.00 1.00 25 0.42 0.80 0.99 1.00 1.00 1.00 100 0.89 1.00 1.00 1.00 1.00 1.00 Probability of 0.02 is same as 2% (0.02 x 100)

Source: Hagstrum et al. (1991) Pitfall cone trap

• 95 mm x 125 mm cone- shaped with holes • Very sensitive • For surface area of the grain bulk Probe traps

370 mm x 27 mm Funnel and collecting tube Can be inserted into the grain bulk

Trece.com Trap retrieval is critical! Automated counts of insects in grain (OPIsystems.com)

Stormax Insector 150

(a) Flat grain beetle (n=2105)

Rusty grain beetle (n=1284)

Sawtoothed grain beetle (n=1620)

Lesser grain beetle (n=1387) 100 Red flour beetle (n=2432) (b) Rice weevil (n=1834)

Numbers of Insects

50 51.3 cm 51.3

(c)

0 (d) 0 10 20 30 40 50 60 70 80 90 100 110 120 Composite Adjusted Target Peak Amplitude

OPI Systems, Calgary, Canada Beetles PSA1 Indianmeal moths

35 Back room 35 Back room 1 2

30 30

60 24

) 25 25

( 55

t n 50 20

f e 20 20 l 40 16 C m C 35

f 30 12

e c 15 n 15 25

t s 8 i 20

D 15 10 10 10 4

5 A A B B 0 0 D 5 D 5

A A 5 10 15 20 25 5 10 15 20 25 Distance from left front (m) Distance from left front (m)

A=Wild bird food B=Small animal food C=Cat and dog food D=Food bar table Indianmeal moths in a retail store

A May 11 - 18 May 18 - 25 May 25 - June 1 June 1 - 8 June 8 - 15 June 15 - 22 40 40 Before sanitation 30 30

20 20

) 10 10

(

t n 5 15 25 35 5 15 25 35 5 15 25 35 5 15 25 35 5 15 25 35 5 15 25 35

f e June 22 - 29 June 29 - July 6 July 6 - 13 July 13 - 20 July 20 - 27 July 27 - Aug 3 l B

40 After sanitation

m 40

r 30

30 before Tempo

c 20 n 20

t s 10 i 10

5 15 25 35 5 15 25 35 5 15 25 35 5 15 25 35 5 15 25 35 5 15 25 35

60 C Aug 3 - 10 Aug 10 - 20 Aug 20 - 27 Aug 27 - Sept 1 54 40 48 30 42 After Tempo 36 20 30

10 24

18 5 15 25 35 5 15 25 35 5 15 25 35 5 15 25 35 12 6 Distance from left front (m) 0

Sequential contour maps Captures of red flour beetles (Tribolium castaneum) in a facility subjected to July 4, 2006 heat treatment

Mean number of adults/trap/week

Date Press room (n=35) Flour room (n=10) Outside (n=5)

5/30/2006 0.46 0.40 0.50

6/14/2006 0.20 0.42 0.65

6/28/2006 0.32 0.65 0

7/11/2006 0 (100%) 0.09 (86%) 0

7/25/2006 0.03 0.10 0.38

8/8/2006 0 0.05 0.50

8/23/2006 0.01 0.05 0.20 Summary • Sanitation is 90% of pest management • Sampling and segregating infested and uninfested may be important • Choose a pest management method that fits your needs/costs • More research is needed on non-chemical methods • Phosphine is still a valuable product to use – Use should be based on insect sampling data • Understand pest dynamics and intervene at the right time to avoid losses • Treatments of bulk grain is better/cheaper than that of bagged grain • Protect finished products from infestation • Use exclusion and sanitation tactics to complement other management strategies Thank you