2023 APSA Seed Technology Webinar - Session 2 25 July 2023 / 12:00 pm - 2:00 pm (GMT+7)

Hosted by APSA Standing Committee on Seed Technology, the webinar series on Seed Technology is organized exclusively for APSA members only. This year is the third year APSA will be holding this webinar series, and will focus on such topics as Seed Priming, Seed Drying, Seed Disinfection, Seed Quality & Seed Vigor.

2023 APSA Seed Technology Webinar - Session 2
25 July 2023 2023 / 12:00 pm - 2:00 pm (GMT+7)

Seed Drying

12.00 - 12.10

Opening Remarks
Mr Farhan Tahir, Co-Chair, APSA Standing Committee on Seed Technology  

Moderator: Dr Woosik Kang, Member, APSA Standing Committee on Seed Technology

12.10 - 12.40 

Basic principle of seed drying
Prof. Kent Bradford, Distinguished Professor Emeritus in the Department of Plant Sciences at the University of California, Davis

12.40 - 12.55

Q&A Session

12.55 - 13.15

Seed drying models: vertical drying and horizontal drying 
Mr Johan van Asbrouck, Executive President, Rung Rueng Consulting Co., Ltd. (Rhino Research) 

13.15 - 13.25

Q&A Session

13.25 - 13.45

Seed drying models: box dryer and smaller batch dryers 
Ms Zahra Abdolmaleki, Process Engineer, Seed Processing Holland 

13.45 - 13.55

Q&A Session

13.55 - 14.00

Wrap up and closing remarks
Mr Kun Hao, Member, APSA Standing Committee on Seed Technology

Speaker Bio & Abstract

Kent J. Bradford
Distinguished Professor Emeritus, Seed Biotechnology Center
Department of Plant Sciences, University of California, Davis, CA USA

Kent J. Bradford is a Distinguished Professor Emeritus in the Department of Plant Sciences at the University of California, Davis. Originally from Texas, he earned his B.S. in Biochemistry and M.S. in Horticulture from Michigan State University and his Ph.D. in Plant Physiology from the University of California, Davis. After a postdoctoral fellowship at the Australian National University, he joined the faculty at UC Davis in 1982 and served as the Chair of the Department of Vegetable Crops from 1993 to 1998 and as Vice Chair for Teaching and Curriculum Development in the Department of Plant Sciences from 2006 to 2010. He founded the UC Davis Seed Biotechnology Center in 1999 and served as its director until 2019. He received a Fulbright Scholar award in 1999 to teach in Argentina, the Career Seed Science Award from the Crop Science Society of America in 2002 and the Lifetime Membership Award from the International Society for Seed Science in 2021. He was elected a Fellow of the American Association for the Advancement of Science in 2003, and received the faculty Award of Distinction from the College of Agricultural and Environmental Sciences at UC Davis in 2007. He served as Interim Director of the UC Davis World Food Center in 2017-2018 and Associate Director in 2019-2020. He was advanced to Distinguished Professor at UC Davis in 2013 and retired as Emeritus in 2019.

Dr. Bradford’s research interests span diverse areas of seed science from seed germination and conservation to mathematical modeling and molecular biology. He has published 200 peer-reviewed research and extension articles and book chapters, co-edited three books and co-authored a textbook on seed development, germination, dormancy and storage. His current interests are in the genetic and molecular mechanisms regulating seed dormancy and germination, in mathematical models to describe seed germination and dormancy behavior, and in seed and food drying and preservation methods, particularly for humid climates. As director of the Seed Biotechnology Center, he supported the creation and commercialization of new technologies to improve crop performance, quality and sustainability and the continuing education of plant breeders and seed industry professionals. He taught University and Extension courses on plant physiology, seed biology, biotechnology, ethics and philosophy of science.

Basic Principles of Seed Drying and the Dry Chain Concept
Kent J. Bradford, Distinguished Professor Emeritus, Seed Biotechnology Center, Department of Plant Sciences, University of California, Davis, CA USA

Seed longevity during storage is strongly affected by seed moisture content (MC). In general, each 1% increase in seed MC decreases seed lifetime by half. Thus, it is critical to dry seeds to a safe moisture content after harvesting. In addition, seeds also will absorb or lose water to the atmosphere depending upon its relative humidity (RH). Thus, if seeds that are initially dried are stored in porous containers, their MC may increase if the external RH is high, reducing their storage life. This presentation will discuss the basic principles of seed drying and the advantages or disadvantages of different drying methods. In addition, it will discuss the importance of maintaining seeds at low MC after drying by storing in containers that are impermeable to water. This is particularly critical in tropical climates where ambient RH is often high. We have termed the combination of adequate drying along with hermetic storage the “Dry Chain”, in analogy to the “Cold Chain” in which refrigeration is used to store fresh products at low temperatures from harvest to the consumer. In the case of the Dry Chain, sufficient drying and proper packaging can adequately store seeds for agricultural purposes without requiring refrigeration. 

Mr Johan van Asbrouck
Chair, APSA Standing Committee for Seed Technology
Executive President, Rung Rueng Consulting Co., Ltd. (Rhino Research)

As the Executive President of Rhino Research, Johan Van Asbrouck has also worked as a collaborator and as a principal investigator on Horticulture Innovation Lab projects related to seed drying. Van Asbrouck is a technology provider for the seed, grain, food and postharvest industry, with a focus on drying and storage of seeds and commodities, seed development, germination and stress physiology. His role focuses on adaptation of new technologies towards customers needs, adaptation of existing technologies towards new user groups, and re-engineering existing technologies for new areas and uses. He is fluent in Dutch, French and English. Van Asbrouck has previous professional experience as a safety engineer, industrial engineer in biochemistry, and horticultural engineer. He holds a master's of business administration.

Ms Zahra Abdolmaleki
Process Engineer
Seed Processing Holland 

Zahra is a Process engineer at Seed Processing Holland (SPH). She is a member of both Process Engineering and R&D department. She has a master's degree in engineering (Energy and Environment). Specialised in thermo-fluid dynamics. At SPH she is focussed on different drying technologies and optimum process design to develop innovative and sustainable seed drying machines and installations. 

To make seed drying technology more sustainable and efficient, it is important to adopt optimal process control with closed-loop systems and individual drying per batch. Reducing ventilation and drying energy through efficient airflow management and high-efficiency heat pump dryers is crucial. Utilizing state-of-the-art control techniques ensures precise conditioning of dried seeds with minimal energy consumption. Implementing individual drying sections or cabinets connected to a central heat pump further enhances flexibility and reliability. These sustainable innovations contribute to optimal seed quality while minimizing energy usage and environmental impact in seed drying processes.

These techniques are all delivered by SPH in both large capacity Conditioned Seed Box Dryers, Cabinet Dryers and Small batch drying system solutions.

Small batch seed drying needs to be very sensitive. Considering different seed varieties like cucurbits or solanaceae family, which need a very close look to the drying conditions, SPH is providing good solutions to have a very precise control over different drying terms like temperature, relative humidity, seed moisture content, drying time and ensuring even air flow through the seeds by use of fluid bed or drum drying to get a uniform final result.

The box drying concept incorporates individual fan control and RH control per box, with a central heat pump that operates with a sustainable low GWP refrigerant. These systems allow for drying different seed species simultaneously without interference, with fan speed and ventilation controlled according to specific drying curves. The heat pump is designed for closed loop drying but also has an integrated ventilation function for favourable ambient conditions. Another variation of the concept includes individual process control per section, suitable for different types of seed drying boxes. These arrangements offer flexibility and independent operation, with the Dry Air Generator making the drying process efficient and energy-saving. The use of a central heat pump with secondary energy distribution further optimizes energy usage.

Overall, these sustainable drying systems ensure optimal product quality, minimal energy consumption, and reduced environmental impact.

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