1. AOSA/SCST Region IV - Southwest Referee Phaseolus vulgaris - Organic Media Comparative Germination Testing Presented by David M. Johnston, RST Monsanto Veg. Seed Phys. Lab
Photo Credit: Michigan Dept. of Agriculture 1954

2. Background Information
Prior to 1997, crops designated in the AOSA Rules to be tested using “S” as a substrate could be tested in either sand or soil. These germination test results could be used for the purpose of labeling. In 1997, an AOSA Rules proposal was adopted to remove soil as a “primary testing substrate” for germination testing. The wording for the AOSA Rules change was as follows…………….. “Since it is generally difficult to obtain consistent supplies of soil, it is not to be used as a primary testing substrate. However it may be necessary to use it when seedlings show phototoxic symptoms or if evaluation of seedlings is in doubt.” Soil is still commonly used as a substrate by some labs for comparative testing, investigative purposes and vigor testing with good success.

3. Current Status of “Organic Media”
Federal Seed Act (Sec b) permits germination retesting to be performed with sand or “soil”. The FSA states that “soil” is understood to be “potting soil”…
Canadian M&P (4.5.2c Soil-less mix) states “samples may be retested in a soil-less mix to confirm tests made by other methods, for example testing samples which produced seedlings showing symptoms of phytotoxicity when germinated on paper or in sand. The soil-less mix should be a good quality, organic soil-less potting mix….”
ISTA Rules define “organic growing media” as a mixture of organic fibers (such as peat, coconut, or wood fibers, with size at least 5 mm) and mineral particles (such as sand, perlite, and vermiculite; comprising 20% by volume). Organic growing media can be used for initial germination testing of sunflowers and faba beans. It is also permitted for comparative testing and retesting of other species.
AOSA Rules permit testing pelleted onions that have been treated with a specific seed treatments using organic growing media composed of fine (#3) vermiculite, dry fine peat moss and water at a 1:1:4 ratio by weight. The organic media and seed are placed on an RT and tested. (aka Cornell Test)

4. Referee Purpose and Design
Purpose of this referee was to compare Bean (Phaseolus vulgaris) germination testing using paper (i.e. towel/Kimpac), sand and organic media (composed of approximately 50% mineral and 50% organic media).
There was a bit of variation in the paper media used and the organic media composition (i.e. AOSA 50/50 mix, comm. organic media) used among labs, as well as the testing equipment (i.e. chambers, greenhouses) used to conduct the test.
This referee was not intended to be a formal scientific study but more of a “casual” organic encounter and sort of a “first date” for labs to try using organic media for germination testing.
No. Seeds Tested
Media
Temp.
Light
Test Duration
400 per seed lot
(2 seed lots used)
Paper
Sand
Organic media
25C or
20-30C
8 hr. min.
8 days

5. AOSA/SCST Participants
Calif. Crop Improv. UC Davis Mary Voorhees
Harris Moran Olga Maseda
Incotec Ha Ung
Kent Agri Lab Dianne Gilhuly
Mich. Crop Improv. Randy Judd
New York State Seed Lab Michael Loos and Team
SCST Associate Member Phyllis Dawson
Sorghum Partners Terezo Luera
Eurofins STA Connie Obrien
Syngenta Rebekah Wagner
USDA Seed Lab Pattsy Jackson
Utah State Seed Lab Stan Akagi
Monsanto Veg. Seed Lab Oxnard Seed Phys. Lab Team

6. Paper- Towel/Kimpac Combo

7. Sand & Organic Media - Chamber

8. Sand & Organic Media - Chamber

9. Organic Media – Greenhouse – Sample 1

10. Organic Media – Greenhouse – Sample 2

11. Sample 1 – Statistical SummaryOk
Non-matching letters above graph columns indicate a significant statistical difference.

12. Sample 2 – Statistical SummaryOk
Non-matching letters above graph columns indicate significant statistical difference.

13. Sample 1 & 2 – Normal Seedlings
Sample 1 was a low quality seed lot and sample 2 was an average quality seed lot.

14. Possible Next Steps
This “Proof of Concept” study indicates organic media is a suitable substrate for Phaseoulus vulgaris germination testing.
Conduct a formally designed experiment regarding the use of organic media for germination testing of Phaseoulus vulgaris.
Add the definition of “organic media” to the AOSA Rules.

15. Thank you to…….. AOSA/SCST Participants for all their efforts
Calif. Crop Improv. UC Davis Mary Voorhees
Harris Moran Olga Maseda
Incotec Ha Ung
Kent Agri Lab Dianne Gilhuly
Mich. Crop Improv. Randy Judd
New York State Seed Lab Michael Loos and Team
SCST Associate Member Phyllis Dawson
Sorghum Partners Terezo Luera
Eurofins STA Connie Obrien
Syngenta Rebekah Wagner
USDA Seed Lab Pattsy Jackson
Utah State Seed Lab Stan Akagi
Monsanto Veg. Seed Lab Oxnard Seed Phys. Lab Team
Terry Dunfield for helping to organize the project and
sending the samples to the labs
Riad Baalbaki for statistical analysis and project support

16. Questions & Comments