Development of Uniform Blowing Procedures for Grass Seeds · Conclusions and Recommendations 1) The...
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Transcript of Development of Uniform Blowing Procedures for Grass Seeds · Conclusions and Recommendations 1) The...
Presentation Goals1. Importance of Uniform Blowing Point
2. Finding the correct blowing point.
3. Making calibration samples••••
4. Using/maintaining calibration samples
5. Remaining questions•
Importance of
Uniform Blowing Procedures
(UBP)
Current methodVisual-manual separation
Physical properties of empty and filled seeds
Blanks (Inert) Pure seed
1/3 rule
Verification of separated portions by 100-seed weight, TF
0.0000
0.0500
0.1000
0.1500
0.2000
0.2500
1 3 5 7 9 11 13 15 17 19 21 23 25
samples
100 s
eed
wt/
g
seeds in blowings seeds in heavy portion
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
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”
General Blower
Separation by
blowingSample 1 Sample 2 Sample 3
Time saved by using the
blowing procedure
0
20
40
60
80
100
120
140
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Number of Referres/Laboratories
Tim
e t
o c
om
ple
te t
he t
est
(min
)
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 = 23.2
Each bar represents the mean of three samples.
1. Finding the
Optimum blowing point (OBP)
Finding the blowing point
Based on visual separation by 1/3 rule
0
10
20
30
40
50
60
2.3 2.6 2.9 3.2 2.3 2.6 2.9 3.2 2.3 2.6 2.9 3.2
Pure Seed
Empty seed
OO
Air velocity (m/s)
Nu
mb
er
of
seed
s
Sample 1 Sample 2
Sample 3
Finding the BP by visual
assessment in•Paspalum
vaginatum seeds
0
10
20
30
40
50
60
70
80
90
100
110
1.1 1.4 1.6 1.7 1.9 2.0 2.2 2.3 2.4 2.6 2.7
Air Velocity (m/s)
Nu
mb
er o
f S
eed
s
Sam ple 4
Sam ple 8
Sam ple 2
Sam ple 3
Sam ple 1
Sam ple 5
Sam ple 6
Sam ple 7
Sam ple 6
Sam ple 8
Sam ple 7
Sam ple 2
Sam ple 1
Sam ple 3
Sam ple 4
Sam ple 5
Finding BP by Germination
11 12 13 14 15 16 17 18 19 20 21 22
0
10
20
30
40
50
60
70
80
90
100
Germination %
Germination %
Air opening
Finding the BP by
germination
Percentage of germination of TF blowings at different air velocity values of
General blower 4
0
20
40
60
80
100
2.3 2.6 2.9 3.2 3.5 3.8 4.1 4.3 control
Air Velocity (m/s)
Germ
inati
on
%
Low inert matter
Med inert matter
High inert matter
Finding the BP by germination in
Paspalum vaginatum
Percentage of paspalum germination at different air velocities
0
20
40
60
80
100
1.1 1.4 1.6 1.7 1.9 2 2.2 2.3 2.4 2.6 2.7 4 HF
Air Velocity m /s
Ge
rmin
ati
on %
Sample 1 Sample 2 Sample 3 Sample 4
Sample 5 Sample 6 Sample 7 Sample 8
Germination examples of blowings & heavy portion
Germination exampless of blowings & heavy portion
3. Preparation of Master
Calibration samples (MCS)
0.0 2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0 4.2
Air velocity m/s
Relativ
e N
o. o
f seed
s
Heavy fraction
(Red se eds)
(fully mature seeds)
Light fraction
(Gre en see ds)
(empty and under-developed seeds
( less than 1/3 endosperm development)
Optimum blowing point for TF at a certain blower
mix
red & green
Finding the blowing point for tall fescue
using a master calibration sample
Red structures represent pure seeds
Green structures represent inert
Verifying Uniformity of
Master Calibration Samples
1 . 0
1 . 5
2 . 0
2 . 5
3 . 0
3 . 5
1 2 3 4 5 6 7 8 9
S a m p le s
Air
velo
cit
y m
/s
B l o w e r 2
B l o w e r 4
B l o w e r 6
Master calibration samples
4. Use and maintenance of
master calibration samples
Finding the blowing point for tall fescue
using a master calibration sample
Air gate
opening
Equivalent
Air velocity
(EAV)
Heavy florets
in
Light fraction
Light florets in
Heavy fraction
13.5 2.8 m/s 13 31
11 32
16 35
------------- ------------ ------------ -----------
13.9 2.9 m/s 19 16
20 16
23 18
Average 20.7 16.7
------------ ------------
-
------------ -----------
14.1 3.0 m/s 35 8
37 10
36 9
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
Amount of light-weight inert blown out from three blind samples
In-house verification across 7 General Blowers
0.0
0.5
1.0
1.5
2.0
2.5
1 2 3 4 5 6 7
General Blowers
% L
igh
t in
ert
blo
wn
Low inert content Med inert content High inert content
0.0
1.0
2.0
3.0
4.0
5.0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Number of Referees/Laboratories
% lig
ht
inert
ma
tter
Sample 1 - Low inert Sample 2 - Med inert Sample 3 - High inert
Mean = 0.97; Sd = 0.06
Mean = 2.02; Sd = 0.14
Mean = 3.85; Sd = 0.25
Separation of lightweight inert
First year referee
Comparison of Total Inert by
UBP and ISTA
0.0
2.0
4.0
6.0
8.0
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
No. sample
% I
nert
ma
tter
Proposed blowing procedure ISTA method
Results of all samples are within tolerance using the proposed blowing procedure or ISTA method
Conclusions and
Recommendations1) 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. ••
Advantages and
OpportunitiesSimplicity
Repeatability
Efficiency/Cost control
UBP can be developed for other
grasses
Challenges1. Training and Education Needed
3. Researchers/Developers Needed
4. How are we going to deal with so
many species?????
One Final Idea!!!!
Air velocity profile of a general blower
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
10.0 10.5 11.0 11.5 12.0 12.5 13.0 13.5 14.0 14.5 15.0 15.5 16.0
Air-gate opening of the blower
Eq
uiv
ale
nt
air
ve
loc
ity
(m
/s)
1.5
3.5
2.5
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.
