As you might have read on my previous post about the science of seed storage, one of the most important ways to increase the longevity of stored seeds is to limit the moisture level. Seeds can be dried down to an acceptable level with warm air, whether outside on a screen or in a forced-air dryer. But over time, the seeds will tend to come to an equilibrium with the air around them, so the seed moisture will typically rise in storage. Unless you put something else in the package to absorb the moisture from the air.
That something else is a desiccant. The packet of silica that says “do not eat” in bags of chips is one kind of desiccant. But silica gel is likely not cheap or available enough for a small scale farmer to use. So at ECHO Asia we’ve been looking at other options.
The one described in this video (starring yours truly and posted on the ECHO Asia youtube channel), is parched rice. All you have to do is put rice in a hot wok and cook it until it pops. The resultant puffed rice stuff is more absorptive than regular non-treated rice. In my experiments I found it can absorb up to 10% of its own weight in moisture.
So, next time you’re putting your seeds in storage (whether you’re in Southeast Asia or elsewhere), consider packaging them with a handful of parched rice. Even better, store some with a desiccant and some without and see if it makes a difference.
It’s all about experimentation.