How so? Pre-soaking seeds may be done by some perhaps but it is hardly a "standard procedure". Much less soaking in willow water. Not only would the majority of gardeners not have access to willow water to begin with, its use and effectiveness is at best debatable.

If any seed is coated or treated it has to be labeled as such per law.

So it boils down to your choice.

Dave

I certainly am not suggesting that everyone should soak their seeds in willow water. It was just a question of "if I have it, is it worth using it for this?"

That's a very good point that seeds that are coated would need to be labelled as such.

The effectiveness of willow water is not an old wives tale. It is well understood that willow stems are good sources of auxins, which are natural plant rooting hormones, though there are good synthetic hormones that do the job as well. Their effectiveness is documented in professional journals for at least rooting of cuttings. I think poplar may be similarly useful.

As for "most gardeners" not having access to willow water, ANY willow will do.

Some germinating seeds will benefit for the ethylene inhibiting substances...some won't...some will see negative effect.

The actual rooting benefit from reduced ethylene inhibition varies greatly from good to near-nothing. It's still a good idea to use a rooting hormone rather than an ethylene inhibitor for most cuttings if you genuinely need to speed up rooting.

...or you could just crush up an aspirin in a quart of water for the same effect without cutting up dozens of willow twigs.

...as far as it's effect on beans...dunno.

Now, by the same token, I don't think IBA will relieve a headache

Salicylic acid is an ethylene disruptor...very similar to acetylsalicylic acid (aspirin).

I was just saying that it isn't clear that aspirin dissolved in water serves the same hormonal purpose as willow water.

My main point with the ethylene is that it's a germination inhibitor for some things (melons/lettuce) and actually helps other things (impatiens)...outside of the rooting effects.

Also, I prefer synthetic IBA/IAA/NAA/GA/etc (depending on the cutting) for important cuttings because willow water has an indeterminate amount of IBA (as well as SA) for the home gardener.

Too much IBA in a solution can slow things down or be more detrimental than using nothing at all. 2500-3000ppm IBA in rhododendrons is wonderful for rooting and root ball size...5000+ppm can easily cause rooting problems and failure.

Rooting a bunch of stuff you're not on a timetable for or you have a lot of source material...sure, willow water...rooting those few cuttings of plant material you don't have a lot of source material access or you need to get it rooted with assurance...I'm going for controlled hormones.

...seed germination, though...I'd check to make sure (if you can find out) that ethylene inhibitors don't disrupt it's germination.

Seeds by their very nature sprout roots efficiently enough on their own. It doesn't require extra special chemical help from us to make it happen. Whether it be soaking in "willow water" or store bought rooting chemicals, I just think it's a little over the top. Plants have been making seeds and the seeds have been sprouting roots to grow new plants for over 350 million years. Humans, and their seed sprouting chemical additives (whether it be from an organic source such as willow, or not) have only been around for a minute fraction of that time.

rooting hormones do have their place and it very well may help in overall germination, but I think it would pretty unnecessary to use it on seeds.

I guess the margin of error in the experiment would be that it would be hard to tell if the increase in germination speed was caused by the additive or simply the soaking itself.