Inoculating Captan treated seed?

[Stvrob]

I Just noticed the cream pea seed I was fixing to plant is treated with Captan. I was going to inoculate the seed. Do you think the Captan will kill the rhizobia in the inoculant?

[RayR]

The bad news is... yes CAPTAN will inhibit the nitrogen fixing bacteria in your inoculant.
The good news is...the CAPTAN is only on the seed coat. Would you believe they use this stuff as a soil drench and foliar sprays too? Now that would be real bad because it can kill all kinds of organisms.

I would soak the seed in water overnight to dissolve as much CAPTAN off the seed as possible and then rinse the seed good in a stainer. It might even be better to take another step and pre-sprout the seeds on a coffee filter or paper towel first before you inoculate and plant.
You can also put some additional inoculant deeper down in the planting hole where the roots and the bacteria can meet up.

Thiram is another toxic fungicide used for seed treatment, I've done the same procedure for that too.
Any traces of CAPTAN or Thiram will be broken down by resistant bacteria, so they are not persistent in the soil.

Oh! Wear waterproof gloves when handling CAPTAN or Thiram, they ain't good for people either.

[Stvrob]

Thanks Ray. I read one article that suggested that the innoculant would be fine with Captan, but then many other articles said it would either severely inhibit, or kill all the bacteria. I was thinking too of a soil treatment an inch or two below the seedbed, but I don't have enough innoculant to do that, unless I could figure out a way to propagate more. I wonder if I mixed a yeast extract (fermented, then killed yeast) with molasses , and then added a tablespoon of peat based innoculant and bubbled it with an aquarium bubbler for a day, if that would work? Then used the solution to dampen say 1/2 gallon of peat moss ? and used this peatmoss to make a thin layer just below the seedbed? Seems like a lot of work, and no way to know if I've actually propagated the rhyzobia.

[RayR]

I think it's a very complicated process even with the right equipment. First you need a live culture which means you'd have to extract it from live root nodules. I don't believe you can do it with a dry inoculant as a source since the spores are inactive.
If you are planting where you have previously grew peas that were inoculated, the bacteria are still in the soil. I verified that when I grew peas with inoculant in containers one year and the next year I grew peas again without inoculant and I got good root nodulation that year too. I always leave the roots in the soil at the end of the season so I know the Rhizobia will still be there.

[Stvrob]

Ray,
I was expanding part of my garden onto a dry lakebed. Its pretty much dry fine sand with a little bit of sparse vegetation. The lake has been way down for the past several years and I don't think its coming back any time soon, so I wanted to grow a few some peas and beans and other plants that wouldnt require a lot of fertilizer to maybe build up the soil a bit. Don't want to invest too much effort, because the lake could fill up afterall, at which time I would be bass fishing thru my cowpea beds.