Pieces of forest tree seed units… …Pieces of unscientific nonsense

Pieces of forest tree seed units…
…Pieces of unscientific nonsense

An illustrated review of
contradictions and inconsistencies
in the ISTA Rules
by a former tree seed scientist

D. George W. Edwards
FTB Forest Tree Beginnings
Victoria, British Columbia, Canada


Using copious line drawings of the 44 tree seed genera included in the ISTA “Rules for testing seeds,” to show their internal structures and how they are affected if the seeds are broken, it is demonstrated incontrovertibly that classifying pieces of tree seeds more than one-half their original size, even if they have the full quota of testa/seed coat (for that size of seed piece) as “pure seeds” is scientific nonsense. Such pieces of seeds have no potential for producing new plants. It is argued that this hiding or burying such broken seeds in the pure seed fraction in the name of speeding up the purity test is not only unethical, but is now completely unnecessary. The practice began in the very first days of seed testing, more than 80 years ago, when laboratory weighing of the purity test fractions was carried out laboriously on old-fashioned beam balances. With the advent of modern seed weighing technology in the form of rapid electronic balances, the rationale for speeding up the completion of the purity test by weighing fewer fractions, as well as including pieces of seeds in with the pure seeds, no longer has any credence, scientifically or otherwise. In fact, electronic balances permit the weighing of broken seeds separately from the other purity components in less time than it took to weigh the mixed “pure seeds” and other components on a beam balance. Proposals are made to radically alter the Rule that classifies pieces of forest tree seeds as pure seeds. Other proposals concern the provision of clear definitions of terminology used, to maintain consistency, and for proper use of italicization.