Development of Uniform Blowing Procedures for Grass Seeds

Transcription

1 Seed Laboratory Development of Uniform Blowing Procedures for Grass Seeds Example

2 Presentation Goals 1. Importance of Uniform Blowing Point 2. Finding the correct blowing point. 3. Making calibration samples 4. Using/maintaining calibration samples 5. Remaining questions

3 Importance of Uniform Blowing Procedures (UBP)

4 Current method Visual-manual separation

5 Physical properties of empty and filled seeds Blanks (Inert) Pure seed 1/3 rule

6 100 seed wt/g Verification of separated portions by 100-seed weight, TF samples seeds in blowings seeds in heavy portion

7 Recent Advances in AOSA Using uniform set of Master calibration Samples (MCS) to find the correct point Using the Equivalent Air Velocity (EAV) to reproduce the point indefinitely

8 UBP is needed for: Tall fescue, Ryegrasses; Fine fescues; Poa secunda; Koeleria macrantha; Bromus spp; Urochloa ramosa; Panicum spp; Echinochloa frumentosa; California oatgrass; Poa numeralis; Paspalum vaginatum; Deschammpsia cespitosa; Wheatgrass; and other grasses. Some people simply suggested UBP for All grasses

9 General Blower

10 Separation by blowing Sample 1 Sample 2 Sample 3

11 Time to complete the test (min) Time saved by using the blowing procedure Blowing method AOSA method Mean of all labs using the blowing method = 10 min; Sd = 3.6 Mean of all labs using the AOSA method = 43 min; Sd = Number of Referres/Laboratories Each bar represents the mean of three samples.

12 1. Finding the Optimum blowing point (OBP)

13 Number of seeds Finding the blowing point Based on visual separation by 1/3 rule O O Pure Seed Empty seed Sample 1 Sample 2 Sample Air velocity (m/s)

14 Finding the BP by visual assessment in Paspalum vaginatum seeds Sample 3 Sample 6 80 Sample 4 70 Sample Sample Sample 8 20Sample 2 Sample 8 Sample 7 Sample 3 Sample 5 Sample 4 Sample 1 Sample 2 10 Sam ple 7 0 Sam ple Air Velocity (m/s)

15 Finding BP by Germination Germination % Germination % Air opening

16 Finding the BP by germination Lowinert matter Medinert matter High inert matter

17 Finding the BP by germination in Paspalum vaginatum Percentage of paspalum germination at different air velocitie HF Air Velocity m / Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Sample 6 Sample 7 Sample 8

18 Germination examples of blowings & heavy portion

19 Germination exampless of blowings & heavy portion

20 3. Preparation of Master Calibration samples (MCS)

21 Optimum blowing point for TF at a certain blower Light fraction (Green seeds) (empty and under-developed seeds ( less than 1/3 endosperm development) mix red & green Heavy fraction (Red seeds) (fully mature seeds) Air velocity m/s

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23 Finding the blowing point for tall fescue using a master calibration sample

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25 Red structures represent pure seeds Green structures represent inert

26 Verifying Uniformity of Master Calibration Samples B l o w e r 2 B l o w e r 4 B l o w e r 6

27 Master calibration samples

28 4. Use and maintenance of master calibration samples

29 Finding the blowing point for tall fescue using a master calibration sample

30 Air gate opening Equivalent Air velocity Heavy florets in Light fraction Light florets in Heavy fraction (EAV) m/s m/s Average m/s

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32 Blower Calibration Measure the Equivalent Air Velocity When the UBP is used on the purity working sample the gate opening is adjusted to match the equivalent air velocity value established during the calibration for the kind of seed being tested. This setting will be blower specific! D. Meyer CDFA/PPDC 2006

33 Amount of light-weight inert blown out from three blind samples In-house verification across 7 General Blower % Light inert blown General Blowers Low inert content Med inert content High inert content

34 % light inert matter Separation of lightweight inert First year referee Mean = 3.85; Sd = Mean = 2.02; Sd = 0.14 Mean = 0.97; Sd = Number of Referees/Laboratories Sample 1 - Low inert Sample 2 - Med inert Sample 3 - High inert

35 Comparison of Total Inert by UBP and ISTA 8.0 Results of all samples are within tolerance using the proposed blowing procedure or ISTA method No. sample Proposed blowing procedure ISTA method

36 Conclusions and Recommendations 1) The development of calibration samples should start in correct identification of the optimum blowing point. 2) It is important to use a uniform set of Master Calibration Samples. This is a condition for assuring uniformity across labs. 3) Care should be taken when using master calibration samples. Uniformity of MCS should be monitored. MCS can/should be reconstituted when necessary. 4) The use of EAV is critical in the system. It eliminates repeated use and variation of MCS and it reproduces the OBP indefinitely.

37 Advantages and Opportunities Simplicity Repeatability Efficiency/Cost control UBP can be developed for other grasses

38 Challenges 1. Training and Education Needed 3. Researchers/Developers Needed 4. How are we going to deal with so many species?????

39 One Final Idea!!!! Air velocity profile of a general blower Air-gate opening of the blower

40 Acknowledgements The Oregon Seed Council and the Oregon Department of Agriculture. AOSA-SCST laboratories for their questions, ideas, guidance and participation in referees. Grass seed cleaners for feedback on usefulness of calibration samples. OSU seed laboratory staff for their tireless research and development effort.