Copyright ISU, duplication or distribution without written permission is prohibited Seed Conditioning Technology (Part 1 of 2) Agronomy / Horticulture 338 Seed Science and Technology Fall 2017 Alan Gaul Seed Conditioning Specialist 515-294-4011 agaul@iastate.edu Review Topics Conditioning Applications Harvest & Storage Issues Material Handling Basics Separation Methods Pre-cleaning / Preparation Cleaning & Sizing Upgrading Equipment* Treating & Packaging* Definitions & Quality Tests Pending Lab Discussions * more detail in 2 nd presentation Seed Corn Why Condition Seed? Soybeans Adzuki Beans Threshing & Moisture Removal Weed Seed & Foreign Material Diseased & Immature Seed Improve Appearance, Uniformity Add Protective Coatings Additional Conditioning Issues Harvest Seed Extraction Threshing Drying Specialized Treatments Images Courtesy of Prairie Habitat and Seed Processing Holland Production Facilities General Conditioning Flow Diagram Harvest Receiving Pre-Cleaning Cleaning Separating & Upgrading Midwestern seed plants are gradually becoming larger, more complex industrial facilities Bulk Storage Objectives: Remove All Contamination Minimize Seed Loss Remove Low Quality Seed Maximize Capacity Minimize Labor Required Treating & Bagging Storage Shipping Grower 1
Basic Soybean Flow Diagram Harvest Pre-Cleaner Bulk Storage Air Screen Cleaner trash Spiral/Belt Separator oblong Gravity Separator light Color Sorter Light Dark Seed Treater Bagging Line Finished Seed Harvest Ear Corn Plant Pre-Cleaner Bulk Storage Air Screen Cleaner Typical Flow for Seed Corn trash Color Sorter Width Sizer Thickness Sizer light/dark broken Thickness Sizer Indent Cylinder Sizers short Sized Corn Bins Gravity Separator(s) light Seed Treater Bagging Line Finished Seed Harvest & Storage Concerns Ear Corn Harvest & Receiving Picking Receiving Limit Mechanical Damage Reduce cylinder or rotor speed Avoid running at partial capacity Avoid Varietal Contamination Extensive cleaning is required Maintain Quality in Storage Limit incoming moisture Pre-clean seed if possible Level bin and aerate properly Careful drying may be needed to reach safe moisture levels Husking Sorting Drying Wet ear corn is harvested & transported to plant Husks are removed and off types sorted manually Husked corn is then dried prior to shelling Shelling Ear Corn Harvest Issues ADVANTAGES Early Harvest of High Moisture Corn Field Loss Reduction (Fungi, Insects, Weather) Potential for Double Crop in Warm Climates Additional Time for Post Season Operations Visual Inspection for Quality Control DISADVANTAGES High Initial Investment for Ear Corn Facilities High Labor Costs for Sorting & Handling High Fuel Cost for Drying Truck Unloading Rerun Distribution Conveyor Feeder Husker Sorting Belt(s) Shelled Corn Husks Rogue Feeder Husker Sorting Belt(s) Husk & Sort Facilities Feeder Husker Sorting Belt(s) Sorted Corn Discard Husk & Discard Ear Corn Dryer 2
Single Pass Ear Corn Dryer Type Diagrams Double Pass Single Pass Ear Corn Dryer Types Double Pass Single Pass Reversing Based on Airflow Pattern Bin Qty for Series Airflow Airflow Direction Changes Key Differences: Management Complexity Airflow Volume Required Energy Efficiency Single Pass Reversing Single Pass Lowest cost per bushel Small lots shallow depth limits Single Pass Reversing Modular independent bins Relatively simple management Double Pass Energy Efficiency More difficult to manage Production Ear Corn Shellers Axial Flow Configurations Round Bar or Perforated Cage Rotor Speed affects Seed Damage MUST maintain Product in Hopper Conical Cage Automated Shelling Lines Typically Found at Larger Seed Research Operations Sorting Sheller Cleaner Color Sorter Round Bar Cage Perforated Cage, Integral Cob Blower Automated batch operation Pneumatic seed transfer Typically 12-20 ears per batch Treater Packeting Material Handling Systems Elevator Legs Belt Conveyors Drag Flight Conveyors Vibratory Conveyors Pneumatic Conveyors Gravity Spouts and Letdowns Mechanical Damage during Conditioning Auger Damage Moisture Effect Germination vs Sequence for 2 Moisture Levels 3
Mobile Conveying Equipment Portable Belt Conveyor Screw Conveyor Pneumatic Conveyor Conventional & Continuous Cup Legs Conventional High Capacity Compact Easily Enclosed Lower Cost Vertical Lift Only Some Damage Boot Cleanout Flexible Layout Multiple Discharge Minimal Damage Self Cleaning Limited Capacity Maintenance Higher Cost Typically for stationary vertical lift applications Trend for continuous cup leg designs for high value or fragile seeds Continuous Cup Vibratory Feeders & Conveyors Variable Feeder Receiving Conveyor Self Cleaning Multiple Outlets Moderate Cost Transfer Conveyor Horizontal Only Limited Distance Vibration Issues Letdown Ladder Letdown Devices Letdown Ladder Commonly Used Easily Fabricated Modular Design Relatively Compact Can be Rubber Lined Multiple Small Impacts Spiral Letdown Less Common Eliminates Impacts More Difficult to Build Harder to Rubber Line Need to Match Spiral Slope to Seed Type Spiral Letdown Mechanical Damage Detection Unloading Receiving Leg Belt Conveyor Air Screen Cleaner Cleaner Leg Inclined Spout Leg 1 Belt 1 Cleaner Leg 2 Spout 1 Screen Shaker Percent Broken Seed Soybean - % Splits (10/64 Slot) Corn - % BCFM (12/64 Round) Seed Coat Damage Soybean Soak Test Corn Fast Green Dye Minimizing Mechanical Seed Damage Reduce seed velocity Minimize drop height in spouts or transfer points Use lowest RPM needed to provide required capacity Use a larger conveyor running at lower speed Use the lowest possible incline angle Reduce impact, abrasion, crushing or shearing actions Eliminate pinch points and sharp edges Run in conveyor to polish rough surfaces prior to use Run most conveyors at (or near) Full Capacity Consider rubber or plastic product contact surfaces Modify conveyors if needed to avoid crushing seed Take extra precautions at cold operating temperatures 4
Dry Granular Separation Principles Separation based on Differences in various Physical Properties Common principles used: Aerodynamics/Terminal Velocity Approximate Seed Size Seed Dimensions (L-W-T) Seed Shape (Rolling Resistance) Product Density Color Differential Most real world applications require multiple techniques Seed Cleaning - Physical Properties Aerodynamic Properties (terminal velocity): Aspirator Seed Size & Shape: Air Screen Cleaner Dimensional Separation: Length, Width, & Thickness Sizers Rolling Resistance: Spiral and Belt Separators Specific Gravity (Density): Gravity Separator & Destoner Color (UV, visible spectrum, NIR): Color Separator Surface Texture: Velvet Roll, Vibratory, Magnetic Separator Affinity for Liquids: Buckhorn Separator Electrical Characteristics: Electrostatic Separator Types of Contamination Foreign Material - Plant parts, stones, dirt, bugs, etc. Other Crop Seed Alternative crops Weed Seed - Other undesirable non-crop seeds Mechanical Damage Chipped or broken seed Varietal - Other varieties of the intended crop Physiological - Physical or biochemical issues Pathological - Seed diseases and/or insect damage Tools of the Trade (1/4) Aspirator Vertical or inclined air column Usage: Pre-cleaning or removal of light contaminants Air-Screen Cleaner One or two aspiration columns Multiple perforated screens Usage: Removal of light contaminants, undersized, and oversized material LMC Corporation and Westrup USA Aspirator Examples Scalping Aspirators Scalperator Inlet Cross Sections Outlets Pneumatic Column Conical (Spout) Multiple Pass Cascade Aspirator Many different aspirator configurations are available Primary difference include number of air passes through seed, length and slope of aspiration column Designs are typically adapted for specific applications Images courtesy of LMC, Forsberg, Kice, and SeedTech Systems Combined Scalping Reel and Aspiration in same machine Simultaneous oversize and light material removal Common for high capacity removal of trash from seed Air Scalping Aspirator Courtesy of Carter-Day Int l & Westrup USA 5
Size, Shape, & Aerodynamics - Air Screen Cleaner Screen Example Example - Air Screen Cleaner Results Upper Air Oversize Undersize Lower Air Clean Seed Soybeans Vaughn & DeLouche, 1968 Air and Sieve Operations Removes FM, Light, Broken, Undersize, & Oversize Seed Air-Screen Cleaner Seed Corn Flax Hole geometry & size determined by application Layout affects capacity and screen efficiency Size specified in English or Metric Multiple screen sizes are typically used for most seed applications Screen Perforations Round Wire Mesh Triangular Parallel Slot Cross Slot Herringbone Slot CIMMYT Slide Archive Screen Selection Achieves maximum removal of foreign material and minimum removal of good product Removal of foreign material by cleaner improves effectiveness of other downstream processes Mechanical screen shaking equipment can be used to provide more consistent results and permit shaking tall screen stacks Screening / Sizing Terminology Screen Input Screen Input Screening / Sizing Efficiency Oversize Material ( overs ) Undersize Material ( thrus ) Screening Terminology: Scalping Removal of Oversize Material from Product Sifting Removal of Undersize Material from Product Sizing Dividing the Product into two Size Ranges Efficiency is based on the desired operation type Oversize Material ( overs ) Undersize Material ( thrus ) Sifting Efficiency (undersize removal) Percent of Total Undersize Material passing thru the screen Screen Capacity is limited by desired sifting efficiency Scalping Efficiency (oversize removal): Percent of Total Oversize Material passing over the screen Scalping Efficiency may be close to 100% for spherical seed 6
Tools of the Trade (2/4) Indent Cylinder or Disc Separator Indented pockets sized for length separation Usage: Separation of long from short material (ex: wheat/oats) Precision Sizer Rotary cylinders with Round or Slotted perforated holes Usage: Sizing or removal of contaminants based on Width or Thickness Carter-Day Int l and Oliver Manufacturing Co. Width Thickness Length Seed Size Definitions Same thickness, different width Same width, different thickness Same width & thickness but different length Length Grading Indent & Disc Separator Laboratory Indent Cylinders Indent Cylinder Disc Separator Removes Short or Long Seed from Primary Fraction Traditionally operated in batch mode Newer machines capable of either batch or continuous flow Used for Cylinder Selection and Cleaning Small Lots Adjustments include Size, Speed, & Trough Position Images Courtesy of Westrup USA, Inc. Disc Separator V Pockets (Spherical) De-Sticking Sunflowers R Pockets (Cylindrical) V ( Vetch ), V +Width (mm), V2.5 thru V6.5 R ( Rice ), R +Width (mm), R 3.5 thru R6 Square (desticking), Letter Designation K, L, M, AC, EE, J, A, MM, B, RR-SS, DD, AE-AD, SS-DD Square Pockets (Desticking) Stems and sticks are hard to remove using conventional perforated screens Lifting sunflowers from sticks can be accomplished using either a disk or indent cylinder separator 7
Width and Thickness Sizer Sizing Flow Diagram (4 Sizes + Discard) Input From Cleaner Over 19R Over 15R Width Round Hole Thickness - Slotted Vaughn & DeLouche, 1968 12S Over 11.5S Over LF LR SF SR Discard Typical sizing stack uses multiple machines to create desired sizes Cylinder quantity is based on flow rate at each machine location Cylinder capacity depends on % thrus and desired efficiency Oliver Manufacturing and Carter-Day International Sizing Cylinder Selection Cylinder Selection Factors: Fractional quality evaluation Percent breakout by fraction Size range limits (plantability) Marketing requirements Oversize Discard Large Medium Small Undersize Discard Round Lab Sizer Slotted Capacity (BPH) 100.0 90.0 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 Sizing Cylinder Capacity Round Hole 0 20 40 60 80 100 Percent s Slotted Hole 1VT-S 1VT-R Capacity is typically rated at 95% efficiency (or higher) Cylinder capacity is higher for round hole configurations Cylinder capacity increases with higher percentage of thrus Adapted from Carter-Day Data (1995) Flat Screen Sizing (modular cleaners) Tools of the Trade (3/4) Spiral Separator Inclined helical flights sloped to match rolling speed Usage: Separation of spherical from non-spherical products Alternate to cylinder sizers on seed corn applications Limited evidence of reduced mechanical damage, possibly greater for round seed (Popp, 2003) Sizing efficiency is typically lower than for cylinders Capacity is less than equivalent air screen cleaner Belt (roll) Separator Inclined moving belts Usage: More precise separation based on differences in rolling speed of various products Image Courtesy of Westrup USA, Inc. Profile Industries, Q-Sage, and Harada Sangyo 8
Shriveled or Oblong Seed Causes Static Spiral Examples Immature Seed Diseased Seed Frost Damage Field Conditions Drought Other Factors Images courtesy of Profile Industries Rotary Spiral Examples Belt Separator Single Core Multiple (4) Cores Core Replacement Images courtesy of Profile Industries Original Draper Belt design single slope Later modified to use dual belt slope Provides multiple fractions, fewer collisions Multiple belts stacked to provide more capacity Flat Shriveled Round Flat Round Single Belt Oblong Belt Separator Samples Tools of the Trade (4/4) Gravity Separator Reciprocating inclined fluidized bed to float light from heavy Usage: Density separation of light weight or heavy product Color Sorter Optical separation based on differences in color or intensity Usage: Removal of dark and/or light discolored material Oliver Manufacturing and Satake USA 9
Fluidized Bed Density Separation Destoner Two Density Fractions Removes Heavy Material Optical Detection & Separation Accepts Destoner Gravity Table Gravity Separator Continuous Density Range Multiple Fractions Possible Removes Low Density Seed Rejects Color Sorting Equipment Provides Two Color Fractions Removes Light or Dark Material Seed Coating Treating & Coating Seed Treating Equipment Continuous Flow Seed Pelleting Provide Pathogen Protection Improve Planter Performance Better Product Appearance Increase Seed Size (Pelleting) Automatic Batch Used to Apply Treatment or Coatings: Correct Proportion of Seed & Chemical Acceptable Appearance & Product Flow Proper Application Rate Uniform Seed Coverage Seed Images Courtesy of Seed Processing Holland Images courtesy of Gustafson Equipment (Bayer) Packaging Storage and Shipment Conventional Bag Filling Bulk Bag Filling Package Type Factors: Market Requirements Volumetric Issues Desired Automation Downstream Handling Equipment Availability Warehouse Considerations: Space Requirements Material Handling Facilities Possible Climate Control Traffic Control and Security 10
Common Quality Control Measurements Moisture Content (%) Test Weight (lb/bu or kg/hectoliter) Broken Seed (BCFM or Split %) Seed Coat Damage (%) Seed Count (seeds/lb, TKW) Visual Defects (%) Packaged Units (weight or count) Flow Rate (lb/hr, bph or tons/hour) Discard or Fraction Percentage (%) Separation Efficiency (%) Good Product Yield (%) Defect Concentration (%, G:B ratio) Measurement variability Divider Screen Shaker Test Weight Moisture Measurement Technology Air Oven Dryer Capacitive Meter Near Infrared (NIR) Air oven dryer is the measurement standard Other meters are calibrated against oven Electrical meters - resistance, capacitance, or near infrared (NIR) Brown-Duvel Brown-Duvel - high MC, frozen seed Single Kernel Density Definitions Bulk Density Typically called Test Weight for most seed applications Weight of a given volume of seed, INCLUDING void spaces Measured by weighing a container filled under controlled conditions Very commonly used for both seed and grain applications Particle Density Sometimes also called Kernel Density or Seed Density Weight of a seed volume EXCLUDING void spaces Seed volume measured by liquid displacement or a gas pycnometer Specific Gravity Ratio of particle density to water (specific gravity of water = 1.0) Test Weight Devices Bulk density measurement Weight per unit volume English lbs per bushel Metric kg per hectoliter Tends to correlate well with seed quality parameters Image provided courtesy of Seedburo Equipment Company Split and BCFM Percentages Splits Based on 10/64 Slotted Screen (%) BCFM (Broken Corn & Foreign Material) Based on 12/64 Round Screen Screen Shaker to Minimize Variability (30 strokes) Typically 500g or larger sample Seed Coat Mechanical Damage Tests Sodium Hypochlorite Soak Minimal Damage Limited Swelling Slight Damage Some Swelling Wrinkled Coats Fast Green Dye Test Minimal Damage Limited Staining Good Quality Slight Damage Minor Staining Storage Concerns Dilute Bleach Solution (5:1) 5 Minute Soaking Interval Severe Damage Rapid Swelling Loose Seed Coats Severe Damage Embryonic Staining Poor Germination Commercial Dye Solution Stains Exposed Starch 11
Visual Defect Percentages Visual Observation (light & dark %) Possible to partially automate using fast green dye, image processing, or other methods Tends to be very subjective operator effects BadGoodRatio DefectQty GoodQty SortEfficiency Reject_Defect_Qty Total_Defect_Qty Typically tracked over time to monitor for possible process changes or optimize adjustments 100 Variation Seed Count / Size Relationships Seed is a biological product with variable size, shape, and density Seed Count provides an approximate way to quantify average seed size Typical Seed Mixture Density Size The result tends to vary based on seed dimensions, shape, and weight Units are typically expressed as either seed count (seeds/lb) or TGW (grams per 1000 seeds) Conversion Equation: Shape Fewer Seeds per Pound Sample size is application dependent Typical Seed Counter Applications Rough estimate of seed size for a given variety or seed lot Quantify differences between seed sizes within the same lot Estimate seed size differences between multiple fractions from gravity tables or other separation processes Calibration of weight-based seed treaters for newer systemic products using per seed application rates Quantify blend proportions for integrated refuge products Calibration of weight-based bagging scales for high volume bagging operations and seed quantity based labeling Packet filling for research or high-value seed applications Newer devices may provide additional sample analysis tools Mechanical Seed Counter Examples Vibratory Bowl Rotary Disc Vibratory Pan Rollers Multiple feeder designs Total vs Batch Operation Images courtesy of the respective manufacturers Counter Calibration Calibration sample - ten sets of 100 seeds each Combine the 10 sets and carefully pour 1,000 seed calibration samples into counter Start the counter and run until all seeds have been counted Final count should be within +/- 2 seeds Adjust counter and repeat test if required Effect of Counting Speed on Seed Count Reduced Accuracy Limit Speed for Accurate Counts Compensate for Seed Size 12
New Optical Imaging Counter Online Unit SSC Lab Unit Loaned by Process Vision (Richmond, VA) Rapid 2D counting and sample analysis Evolving to include additional capabilities Also using to analyze spiral testing results RIB Percent Aspect Ratio Basic Separation Efficiency Concepts Defined by the intended process goals Recovery (removal) of contaminants ( removal efficiency ) Recovery of good product ( good product yield ) Separation efficiency (seed recovery adjusted for discard levels) Feed Product Discard Seed Defects Complete contaminant removal will typically also remove a small amount of good product Sample Flow Calculations (Defect Removal) Given weights of timed samples from each fraction Can estimate flow rate and fraction percentages Grade samples to determine defect concentration Can also estimate defect removal rate Similar calculations possible for most operations Sample Description Sample Weight (lb) Sample Time (sec) Flow Rate (lb/hr) Machine Fraction (%) Defect Conc. (%) Defect Flow Rate (lb/hr) Defect Percent (%) Accepts 40.0 20 7200 98.4 0.1 7.2 16.7 Rejects 2.0 60 120 1.6 30.0 36.0 83.3 Total Result 7320 100.0 43.2 100.0 Note: Calculations shown assume sample time base is not equal Sample Flow Calculations (Yield) Given weights of timed samples from each fraction Can estimate flow rate and fraction percentages Grade samples to determine defect concentration Can also estimate defect removal rate Similar calculations possible for most operations Sample Description Sample Weight (lb) Sample Time (sec) Flow Rate (lb/hr) Machine Fraction (%) Seed Conc. (%) Seed Flow Rate (lb/hr) Seed Percent (%) Accepts 40.0 20 7200 98.4 99.9 7192.8 98.8 Rejects 2.0 60 120 1.6 70.0 84.0 1.2 Total Result 7320 100.0 7276.8 100.0 Note: Calculations shown assume sample time base is not equal 1 Rate / Efficiency Level 0 Hypothetical Separation Graph Operating Range? Adjustment Level Statistical Process Monitoring (SPC/SPM) Process watching for change detection Process Overall variation components: Random, Short Term Baseline Non-random, Long Term Variation (to be eliminated) Measurement System Q Examples: Xbar (average) Range (max-min) Standard Deviation (s) 1 2 3 4 5 6 7 8 9 10 11 Upper Control Limit Time Lower Control Limit Out of Control Point Shewhart Control Chart Dr. Stephen Vardeman (IE 361) 13
Typical seed separation methods are based on physical differences Machine principles may involve size, shape, density, and/or color Multiple machines can improve results and minimize seed loss Process sequence can often be important for good results Understanding characteristics of various contaminants and related equipment capabilities can be useful for difficult separations Review and Discussion Seed Conditioning Lab Location ISU Tower Lab Pending Lab Seed Corn Process Shelling & Aspiration Air-Screen Cleaner Color Sorter Sizing Gravity Table Seed Treater (Packaging) Aspirator Catwalk Seed Receiving Area Station 0A Lab Sheller Station 0B Crippen H-434 Air- Screen Cleaner Oliver Voyager GVX-1020 Gravity Station 0E Stairs Catwalk Crane Bay Westrup Belt Separator Mitchell Leg Forsberg 10M2-S Rotary Spiral Forsberg 40V Gravity Test Weight Measurement Heid Gravity Catwalk and Stairs Station 4 LMC Gravity Leg 4 El-Con Leg Sortex Color Sorter Pilot Plant Lower Level Scale Seed Conditioning Lab (Lower Level) Dust Filter Scale Bagging Scale Electrical Panel Air-Oven Dryer Cabinet Cabinet Cabinet Tool Box Screen Shaker Brushing Machine Westrup Air-Screen Cleaner Equipment Table Carter-Day Batch Sizer Workbench Soybean Samples Forsberg Destoner Station 1 Scale Divider IMD Seed Counter Equipment Table OptiCount Imaging Counter Cabinet Hand Screens for Sizer Efficiency Analysis Station 3 Station 5 Small Equipment Lab Hege Lab Treater Shop Equipment N Harada Belt Separator Ball Counter BMC Batch Treater Dust Filter Forsberg TKV-25 Gravity Seed Conditioning Lab Upper Level Station 0D Stairs Leg 1 Dust Filter Carter-Day 1VT Sizers Carter-Day 1VT Sizers Scale Crane Bay Mitchell Leg Satake DE Color Sorter Cabinet Profile Spiral Leg 4 Satake Color Sorter Station 0C Station 2 Scale Table Pilot Plant Upper Level Carter-Day #3 Uniiflow Gustafson GLCPS Treater Oliver 212 Sizer Stairs Storage Shelving Mezzanine Level Carter-Day Fractionating Aspirator Station Sequence: 0) Cleaner, Batch Sizer, Counter (L) 1) Air-Screen Cleaner (L) 2) Satake color sorter (U) 3) Seed Sizing Stack (U) 4) Oliver gravity (L) 5) BMC Treater (L) N 1 Sample Analysis & Cylinder Verification Air-Screen Cleaner Rotary Batch Sizer Imaging Counter Clean seed prior to sizing Create 4 seed sizes Evaluate size %, seed count 14
Station 2: Satake Color Sorter Outlet Spouts Accept Sampling Valves Input From Cleaner Station 3: Sizing Stack Over 19R Over 15R Satake ScanMaster IE Review Operation at four dark trip levels Each group runs one setting Collect timed sample weights Evaluate sample quality Calculate: % Discard by Fraction and Defect Removal Efficiency 12S Over 11.5S Over LF LR SF SR Discard Timed samples have been collected in advance to save time Evaluate each sample to verify sizing efficiency for each stage Estimate flow rate, sized fraction percentage, and efficiency Sampling Locations Station 4: Oliver Gravity Separator Station 5: BMC Batch Seed Treater X H M L Review concepts and demonstrate operation Collect 3 timed sample weights Light, Medium, and Heavy (1 per group) Record sample weight and related run time Lab sample analysis Model GVX-1020 Voyager Gravity Review basic components, product flow, and operation Verify chemical and seed metering rates using closed circuit calibration tubes and timed sample weights Given: Initial batch weight, pump speed and cycle time Calculate: Estimated seed capacity, chemical application rate, and anticipated hourly chemical usage Gustafson / BCS model BMC laboratory batch treater References & Acknowledgements Seed Conditioning Technology. Volume 2A-B. Gregg, B.R. 2010 Seed Processing and Handling. Vaughn, Gregg & Delouche. 1968 Managing Grain After Harvest, Bern. 2005 (AE 469/569 textbook) Seed Science and Agronomy Department archives ISU Seed Science workshop presentations (2006-2013) Various websites, including www.gipsa.usda.gov (seed images) Various Industry Brochures, Operator s Manuals, and Discussions: Advanced Sort Industries Seymour, IN AEC Enterprises St. Charles, Iowa ArrowCorp, Inc. Winnipeg, Manitoba Ball-Coleman (STS) Chicago, IL Buhler Sortex Stockton, CA Carter-Day Int l Minneapolis, MN Cimbria Bratney Co. Urbandale, IA Crippen Manufacturing St. Louis, MI Forsbergs, Inc. Thief River Falls, MN Harada Sangyo Ageo, Saitama, Japan LMC Manufacturing Donalsonville, GA Kice Manufacturing Wichita, KS Oliver Mfg. Rocky Ford, CO Profile Industries Rogers, MN Westrup USA Dallas, TX Satake USA Stafford, TX Seedburo Chicago, IL Universal Industries Cedar Falls, IA ISU ** Thanks for your continued support for the ISU Seed Conditioning Program** 15