20 SEED TESTING INTERNATIONAL www.seedtest.org ASSOCIATION NEWS ISTA Statistics Committee Participates in SANSOR Seed Analyst Webinar – October 2025 Jean-Louis Laffont1 and Kirk Remund2 1ISTA Statistics Committee Vice-Chair; jlc.laffont@gmail.com 2ISTA Statistics Committee Chair; Bayer Crop Science, Missouri, USA; kirk.remund@bayer.com THE ISTA STATISTICS COMMITTEE WAS INVITED BY THE SOUTH AFRICAN NATIONAL SEED ORGANIZATION (SANSOR) to participate in its annual Seed Analyst webinar during the 2025 ISTA Annual Meeting in Christchurch, New Zealand. This webinar series is organised by SANSOR to support continuing education for seed analysts across a wide range of seed testing topics. Dr Jean-Louis Laffont and Kirk Remund (Vice- Chair and Chair of the ISTA Statistics Committee, respectively) accepted the invitation and presented at the webinar held on 15 October 2025. The webinar was hosted and moderated by Thabiso Ntsele (SANSOR), with introductory remarks provided by Sarah Schulze (Chair of the Seed Analyst Committee, SANSOR). The event attracted strong participation, with more than 100 attendees, including South African seed analysts and international participants from ISTA and the wider seed testing community. The webinar covered two main topics: an overview of the ISTA Proficiency Test (PT) programme and the statistical principles underpinning its operation, and an overview of the tolerance tables in the International Rules for Seed Testing (ISTA Rules) and their statistical foundations. The presentation on the ISTA PT programme highlighted the requirements for laboratories to participate in PTs, the associated rating system, and the accumulation of points toward overall performance assessment. Examples were provided for germination and purity PTs, along with an introduction to the statistical dispersion tests used to assess seed lot homogeneity for sample preparation. The Tattersfield and Hampel methods for identifying outlying PT results were also discussed. In addition, ISTA PTs, including other seed determination (OSD) and GMO PTs, were briefly introduced. Several questions from participants were addressed with support from Branislava (Branka) Opra of the ISTA Secretariat. The second part of the webinar focused on tolerance tables in the ISTA Rules. The statistical rationale for tolerances were explained, emphasising their role in accounting for uncertainty due to random sampling and laboratory variability. The theoretical basis of tolerances, including the foundational work of S.R. Miles, was briefly outlined. Practical examples from germination and tetrazolium testing were presented, including more complex situations involving series of germination tests and the handling of out-of-tolerance results. Participants were also informed about the tolerance table calculators developed by the ISTA Statistics and Germination Committees and freely available on the ISTA website. The webinar was very well received, and SANSOR expressed its appreciation to ISTA for contributing to the training and professional development of its seed analysts.
View this content as a flipbook by clicking here.