On 30 Dec 2013, at 21:30, Nhu Nguyen wrote: > Alberto, I've read about this boiling technique but being trained as a > microbiologist, it doesn't make much sense to me. Boiling the water and the > equipment helps, but doesn't stop the problem. If you want to be perfectly > clean, you'd have to boil the container, the lid, the water. The seed > coating will probably have inoculum on them already so you need to do a > surface sterilization. I suggest a 10% bleach solution + a drop of > detergent for a couple of minutes. Then wash out the bleach solution with > three good washes with sterile water, all the while working in a > containment hood where no microbes can get in. It's a pain. An alternative: hydrogen peroxide from the drugstore. My own training is as a chemist and I have the sense that H2O2 is less likely to harm the embryos. Innoculum on the seed coat is an underappreciated source of pathogens. A friend once lamented his inability to grow Linum flavum compactum from seed: no matter what he did, the seedlings would keel over shortly after germination. I suggested peroxide; he tried it; it worked beautifully Another friend who at one time ran a small but interesting nursery told me that he drenched all his seed pots with captan, and had much better results. Captan is off the market now, but some PBSers may still have some on hand. At the other end of the spectrum is the practice of using living soil with lots of organic matter and microbes in it, which was briefly discussed on this mailing list a while ago. -- Rodger Whitlock Victoria, British Columbia, Canada Z. 7-8, cool Mediterranean climate