practical considerations of commercial seed storage · practical considerations for commercial seed...

Practical Considerations of Commercial Seed Storage

Tim Loeffler

Monsanto Company

St. Louis, Missouri, USA

June 11, 2018

Practical Considerations for Commercial Seed Storage

Business considerations for commercial seed storage.

Seed storage starts early and is critical for customer satisfaction

Key criteria for seed storage and using vigour data

Seed packaging materials and practical considerations

Goal: Maintain commercial quality from harvest to the customer

Business Considerations

3

“Setting Expectations”

Seed Storage – Business Considerations“Setting the expectations”

Business • Working capital & cost of goods

• Additional investment & maintenance of facilities

• Can impact lab capacities

• Obsolescence impacts profitability

Field seeds• Large volumes

o Soybeans / grains – produce & sell

o Hybrid corn – must manage returns

• Product line refresh is frequent

• Competitive market - New varieties are often introduced at high volumes

Vegetable seeds• Small seeded species, higher value

• Larger seeded species, lower margins

• Product line refresh is less frequent

o Trend is decreasing

The business risk to carry inventory can be high

Intended Storage Periods & Market Quality

Soybean

6 Months 1 year 2 years 3 Years 4 years 5 years 6 years 7 years

Corn - Hybrid

Vegetables - commercial

Vegetables – parent seed

Rice – Varietal

Ambient

Ambient

Controlled storage: 10C / RH control varies

5 to 15C / 30 – 50% RH

~5C / 30% or less RH

Rice – Hybrid / High value Controlled storage: 10C / RH 50%

• Seed storage criteria is connected to:o Seed valueo Intended inventory shelf life o Market quality

• Considerations vary for field and vegetables seeds

Species Germ Vigour Usable Transplant

Corn 95%+ High N/A

Soybean 90%+ High N/A

Melon 90%+ High 90%+

Pea 85%+ High N/A

Pepper, Tomato 92% High 85%+

Market Quality Requirements - Examples

What about cost to carry inventory?

Year 1: Produce 1000 kgCarryover inventory 0 kgTotal Liability 1000 kg

Year 2: Produce 1000 kg Carryover inventory 1000 kg Total Liability: 2000 kg

Year 3: Produce 1000 kgCarryover inventory 1000 kgObsolescence 1000 kgTotal Liability: 3000 kg

Inventory costs continue to accumulate over shelf life the seed

Production, Processing, QA, Costs

Inventory Carrying Cost

COGM

$20 / Kg$20,000 +

$0 / Kg$0

$20 / Kg$20,000

$20 / Kg$20,000 +

$2 / Kg$2,000 + $20,000 (Value of inventory)

$21 / Kg$42,000 100% saleable)

$20 / Kg$20,000 +

$2 / Kg$4,000 + $42,000 (Value of inventory)

$34 / Kg$68,000 (67% saleable)

Some reasons for Obsolescence:

• Drop in Germ, Vigour or UT

• Lack of market acceptance (disease resistance, etc.)

• Over-production

• New variety introductions

Seed Storage Starts Early

7

“Focus on the Customer”

Securing Quality – Harvest to Customer Delivery

• Seed storage begins at or near physiological maturity.

1. Miles, D.F., D.M. TeKrony and Egli, D.B. (1988). Crop Science 28,700-704. 2. D.M. TeKrony and D.B. Egli,. (1997). Accumulation of Seed Vigour During Development and Maturation in Basic and

Applied Aspects of Seed Biology, pp. 369-384.

Late development

Brown layer (PM)(Maximum Quality)

Black layer (HM)(Seed storage)

• Seed vigour accumulates during development and maturation.

Key factors contributing to seed storage potential

Many operational decisions are made based seed moisture content

Genetic background

Harvest timing & handling

Seed drying

Seed conditioning & technology

Seed storage conditions

(Temp & RH)

SpeciesCategory

SpeciesTarget

Moisture

Field Seeds

Rice 11-12.5%

Corn 12%

Soybeans 8.0-14.5%

Vegetables

Cabbage 5.5-6.0%

Carrot 7.0-8.0%

Cucumber 6.0-7.0%

Lettuce 6.0-6.5%

Onion 6.5-7.5%

Peas 10.0-11.0%

Spinach 8.0-9.0%

Tomato 6.0-7.0%

Process for Field Seeds - Corn

Harvest Drying Bulk Storage Seed Processing Treat & DryingPackaged Storage

Customer

Shipment

Returns

Critical Step #1:Harvest moisture ~30-35%

Critical Step # 2: Drying to ~12% Seed moisture

Distribution Center

Wet Seed Transport Precision DryingTarget 6.0-7.0%

Conditioned Storage #1Target Temp: 8-15C

Conditioned Storage #3Target temp: 8-15C

Shipping Container

PRODUCTION OPERATIONS

Conditioned Storage #2

Target temp: 8-15C

Receiving

Sanitation

Seed Processing

Seed Technology

Process for Vegetables

Multiple drying processes may

occurTarget 6.0-7.0%

HarvestDrying &

Bulk StorageSeed Processing

Seed Treatment (On Demand)

Distribution

Harvest moisture: 18-21%

Process for Grains (Rice)

Drying moisture: 11-12.5%

US / Brazil / Europe Production System

• Market: High value / Varietal ratio is 50-50% (US)

• Planting: Direct seeded

• Mechanical harvest / bulk bin drying

• Delivery: Bulk or mini-bulk packaging (US)

Asia Production ProductionSystem

• Market: Hybrid / Varietal ratio is 50-50% China, increasing rapidly in India

• Planting: Transplanted

• Hand harvest or small equipment / Open air drying

• Delivery: Small packaging

Key Criteria for Seed Storage

13

“Using Vigour Data”

Seed Vigour Tests used to predict Seed Storage

SpeciesCategory

Species Vigor Tests

Field SeedsCorn Cold Test

Soybeans Cold Test, AA, EC

Vegetables

Broccoli, Cabbage, Cauliflower, Chinese Cabbage, Spinach, Carrot, Onion, Eggplant, Pepper, Tomato, Cucumber, Melon, Squash, Watermelon

SSAA

Peas EC

Sweet corn Cold Test, SSAA

1. Collect germ and vigor data – by variety2. Rank seed lots from high to low vigor3. Consider inventory usage

Decide risk assessment Hold higher vigor batches

4. Focus on the customer to avoid complaints High vigour seed lots for stressful

planting conditions Work with customers with good

practices on lower vigor batches

Using Vigor Data

Using Seed Vigour to Manage Seed Storage

Batch Rank Germ EC Field Stress Storage Potential

2 1 95 15 Wide range Long



6 4 88 23 Moderate Moderate




1 8 98 47 Low (Ideal) Short

Germ and Vigour (EC) Example - Peas

High Vigour

Low Vigour

Seed Storage Practices

SpeciesCategory

SpeciesRH

30%RH

60%

Field Seeds

Rice 9.0 12.6

Corn 8.4 12.9

Soybeans 6.5 9.3

Vegetables

Cabbage 5.4 7.6

Carrot 6.8 9.2

Cucumber 5.6 8.4

Lettuce 5.1 7.1

Onion 8.0 11.2

Spinach 7.8 11.1

Tomato 6.3 9.2

Peas 8.6 11.9

EMC

1. Harrington, J.F. (1960). Drying storing, and packaging seed to maintain germination and vigor. Seedsmen’s Digest. 11 (1): 16.

Most vegetables

require continuous conditioned

storage

Target Moisture

Storage Practices Temp RH

11-12.5% Ambient Ambient Variable

12% Conditioned 10C 50%

8.0-14.5% Ambient Ambient Variable

5.5-6.0%

Conditioned,Plastic lined

8 – 15C 30%

7.0-8.0%

6.0-7.0%

6.0-6.5%

6.5-7.5%

8.0-9.0%

6.0-7.0%

10.0-11.0% Ambient Ambient Variable

Practical Storage Conditions

Seed Packaging

17

“Considerations are shorter term”

Packaging Strategies and Considerations

Compliance(Non-negotiable)

• Seed lot integrity

• Labeling – meets all Country & Local requirements

• Regulations may drive material usage (i.e. biodegradable)

Business

• Treat / pack for next growing cycle

o Once packaged, seed usage should be within 1 to 2 years

o May require re-packaging

o Seed treatment can impact shelf life

• Materials must be cost effective

• Brand image

Technical

• Low moisture vapor transmission rates

• Volume to head space

• More sustainable materials

• Packaging automation

Best materials maybe comprised by cost & operational efficiencies

Thank You

Contributors

Jim Thompson – Rice Tec

Testo RH Probes

Packaging: Bulk Containers

Card Board Containers

• Packaging Materials:

oTriple wall

oKR = Kraft paper

oMDH = Med High Perf Kraft Paper

• Products

oVegetables

oUsed in storage and shipping between plant sites; Not to customers

Flexible Intermediate Bulk Container (FBIC)


• Reinforced woven Polypropylene

• Internal baffles to maintain shape when stacking and shipping.

• Products:

oCorn

oSoybeans

oRice

Bulk Boxes/Hard Sided Containers


• 60# Specialty Kraft (brown)

• 50# or 55# Polar White

• Products:

oCorn

oSoybeans

Packaging: Bags

Multi Wall Bags – with HDPE Liner

• Packaging Materials

o60# Specialty Kraft (brown)

o50# or 55# Polar White

o0.5 mil HDPE liner

• Products:

oCorn

oSorghum

oAlfalfa

oWheat

Multi Wall Bags – Without Liner


o60# Specialty Kraft (brown)

o50# or 55# Polar White

• Products:

oSoybeans

oCotton

oVegetables

Packaging: Small Packaging

Cans

• Packaging Materials

oRolled steel w/ tin plate

oLid / bottom = steel

• Products:

oVegetables – raw seed, pelleted seed

oBeen in used since 50 – 60’s

Pouches

• Packaging Materials/Film Specifications:

oStructure: 12 microns PET / 9 microns ALU Foil / 12 microns PET / 75 microns PE

PET = Polyethylene Terephthalate

ALU = Aluminum

PE = Polyethylene

• Products:

oVegetables – re-sealable

Foils

• Packaging Materials/Film Specifications:

oFilm Specifications: 12 mic PET / 12 mic Met PET / 90 mic Natural PE

PET = Polyester

Met PET = Metalized Polyester

PE = Polyethylene

• Products:

oVegetables – small volumes

1. Harrington, J.F., (1963). The Value of Moisture-Resistant Containers in Vegetable Seed Packaging. California Agricultural Experiment Station. Bulletin 792.

Seed Storage Practices

SpeciesCategory

SpeciesRH

30%RH

60%Target

MoistureStorage Practices Temp RH

Expected Shelf Life

Field Seeds

Rice 9.0 12.6 11-12.5% Ambient Ambient Variable <1 year

Corn 8.4 12.9 12% Conditioned 10C 50% 2-3 years

Soybeans 6.5 9.3 8.0-14.5% Ambient Ambient Variable <1 year

Vegetables

Cabbage 5.4 7.6 5.5-6.0% Cond, Plastic lined 8 – 15C 30% 3-4 years

Carrot 6.8 9.2 7.0-8.0% Cond, Plastic lined 8 – 15C 30% 2-3 years

Cucumber 4.3 8.4 6.0-7.0% Cond, Plastic lined 8 – 15C 30% 3-4 years

Lettuce 5.1 7.1 6.0-6.5% Cond, Plastic lined 8 – 15C 30% 2-3 years

Onion 8.0 11.2 6.5-7.5% Cond, Plastic lined 8 – 15C 30% 2-3 years

Peas 8.6 11.9 10.0-11.0% Ambient Ambient Variable 1-2 years

Spinach 7.8 11.1 8.0-9.0% Cond, Plastic lined 8 – 15C 30% 2-3 years

Tomato 6.3 9.2 6.0-7.0% Cond, Plastic lined 8 – 15C 30% 3-4 years

EMC Practical Storage Conditions

1. Harrington, J.F. (1960). Drying storing, and packaging seed to maintain germination and vigor. Seedsmen’s Digest. 11 (1): 16.

What measurement systems are used for Seed Moisture Content?

Type MethodTime per

testGrams /

testDestructive

?Usage Decisions

Hot air oven Oven 1-17 hrs 5 gms Yes All crops Calibration

Memmert UFE 500 Oven 60 min 10 gms Yes Small seeds Process, Storage, Treat & Pack

Computrac Max 400

Oven 9 min 5 gms Yes Small seeds Process, Storage, Treat & Pack

LCGC Oven 4-11 min 2.5 gms Yes Small seeds Process, Storage, Treat & Pack

Steinlite SL95 Capacitance 12 sec 500 gms No Beans, peas, corn, soy Harvest, Receive, Drying

GAC 2100 Capacitance 16 sec 300-500 gms No Beans, peas, corn, soy Harvest, Receive, Drying

EE-KU (TH) Capacitance 90 sec 50-100 gms No Small seeds, corn Process, Storage, Bulk ship

Aquamatic 5100 Capacitance 10 sec 200 gms No Small seeds Process, Storage, Bulk ship

Aqualab Water activity 3 min 10 gms No Small seeds Seed priming

Testo RH Probes RH 10 sec Probe No Small seeds Process, Storage

How long can seeds survive?

• Seed can have a longevity of many years

• Key factors contributing to seed longevity

o Seed chemistry – influences Equilibrium Moisture Content

o Seed moisture content

o Storage temperature and Relative Humidity

o Insect management

• Modifying seed moisture, temperature or storage atmosphere can increase seed survival (2,3)

o Ultra-dry seeds

o Hermetic conditions

• Many models have been developed to predict seed survival (4,5)

Species CultivarAge

(years)Germ %

Sweet corn Earligold 46 84%

Eggplant Minnoval 48 80%

Pea Alaska 51 94%

Melon New Ideal 53 76%

Tomato Marmon 60 82%

1. Roos, E.E. and D.A. Davidson, (1992). Record longevities of vegetable seeds in storage. HortScience, 27:,393-396. 2. Hong, T.D, Eillis, R.H., Astley, D., Pinnegar, A.E., Groot, S.P.C. Kraak, H.L., (2005). Survival and vigour of ultra-dry seeds after ten years of hermetic storage. Seed Sci & Technol., 33, 449-460.3. Demir, I. and Ozcoban, M. (2007), Dry and ultra-dry storage of pepper, aubergine, winter squash, summer squash, bean, cowpea, okra, onion, leek, cabbage, radish, lettuce and melon seeds at -

20°C and 20°C over five years. Seed Sci. & Technol., 35, 165-175 4. Eliis, R.H., and E.H. Roberts.(1981). Improved equations for prediction of seed longevity. Ann. Bot. 45, 13-30.5. Shande, T., D.M. TeKrony, D.E. Egli, and P.L. Cornelius. (2000). An alternative model to predict corn seed deterioration during storage. Crop Sci. 40,463-470.

Longevity of select vegetable seeds (1)

Business strategy is to produce, sell to reduce inventory risk

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