Historical Paper - Volume 2 2008 - International Seed Testing ...

HISTORICAL REPORT FROM THE PURITY COMMITTEE
Development of ISTA Purity Analysis and Determination of Other Seeds by Number
from 1924 to 2006
HANS ARNE JENSEN
Valmuevej 3, Slagslunde, DK-3660 Stenløse
Denmark
Content
1. Summary ................................................................................................................... 2
2. Introduction............................................................................................................... 3
3. The Purity Committee .............................................................................................. 3
3.1 Committees prior to the Purity Committee ................................................. 3
3.2 Members and chairpersons of the Purity Committee from 1956-2006 ..... 3
4. Function of the Purity Committee ............................................................................ 6
4.1 Planning of the working programme .......................................................... 6
4.2 Terms of reference....................................................................................... 7
4.3 Working groups ........................................................................................... 8
4.4 Contacts with the ISTA Secretariat ........................................................... 10
4.5 Correspondence ......................................................................................... 10
4.6 Meetings .................................................................................................... 11
5. Development of the ISTA Rules ............................................................................ 11
5.1 The first ISTA Rules ................................................................................. 11
5.2 Size of working samples ........................................................................... 11
5.3 Tolerances .................................................................................................. 14
5.4 From stronger method to quicker method ................................................. 15
5.5 Evaluation of weed seeds .......................................................................... 16
5.6 The three component rule .......................................................................... 17
5.7 Pure seed definitions (PSD) ...................................................................... 18
5.8 Multiple seed units (MSU) and seeds with appendages ........................... 18
5.9 Blowing of grasses .................................................................................... 20
5.10 Testing chemically treated seeds ............................................................... 22
6. Workshops and other training activities................................................................. 22
6.1 Workshops ................................................................................................. 22
6.2. Other training activities ............................................................................. 23
7. Equipment ............................................................................................................... 24
7.1 Development of facilities for purity analysis ............................................ 24
7.2 Size grading ............................................................................................... 26
7.3 Image analyses (seed scanner) .................................................................. 26
7.4 Cleaning equipment ................................................................................... 27
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