TSP and bleach for seeds

[tz]

Is there any reason to do a two part Trisodium phosphate, bleach soak when processing seeds? It looks as if mixing the two is OK, and is recommended for stripping mildew (which I have to do in the garage at some point this summer). Making up a solution of 10% TSP and 10% bleach for a single 15 min soak would be easier than a two step process, if it works as well.

[Tom Wagner]

I know what you mean by combining the two and complete the process more quickly. The problem is with time. The TSP soak can be done fast but it is vastly more effective with a soak upwards of 20 minutes.
The Chlorine rinse is just that .....a rinse that does not have to last long. Two long of of chlorine rinse bleaches the seed too much and can harm the seed.

The operation of TSP is to get rid of all the oils, waxes, organics, dirt, inhibitors, so that the chlorine rinse acts on all surfaces of the, now, clean seed to make sure the pathogens are killed, not just dissolved by the TSP.

If the phone rings during the TSP (Trisodium Phosphate) treatment, I can leave the process without too much damage, however, walking away from a chlorine rinse is bad news.

I like to start or finish the TSP treatment with the abrasive action of the crystals of TSP on the seed in the tea strainer. Rubbing with your finger, preferably with a glove, speeds up the removal of the gel and allows the rest of the TSP to soak away on the seed crevices, groves, hairs, etc.

I almost forgot the hot water treatment of 120 plus degrees F.

Tom Wagner

[tz]

I was going by your recommendation in this thread


tatermater.proboards.com/index.cgi?board=general&action=print&thread=10


"Some seed in solanaceous crops such as potatoes, tomatoes and pepper, traded from folks not treating their seed may be soaked for 15 minutes in a 10% solution of trisodium phosphate followed by a 30 minutes soak in a 10% solution of household bleach as a disinfectant. I prefer to do this at seed extraction time, however."

I did the quoted proceedure above last year and it did bleach the heck out of the seeds and scared me so I did my second batch with a shorter bleach soak. The germination was faster with the long bleach, but they were two different varieties (Katahdin vs All Blue)

A couple of places recommending long soaks

tgrc.ucdavis.edu/seed_germ.aspx

Which is using half strength (50%) for 30 minutes for old tomato seeds.

and this
ipm.illinois.edu/diseases/rpds/915.pdf
using 10% for 40 minutes for various seeds

Neither of those were dealing with potato seeds, which are much smaller so your comment on the danger is much appreciated.


Diluting the bleach down to maybe 5% and being vigilant about the soak time would possibly be safe.

This can all be tested pretty easily except for the long term effects. What is your experience with storage longevity of bleached vs over bleached seeds? Is it a damage done thing or gets worse as time goes on?

[Tom Wagner]

TZ

So few places even go into the Hot Water treatment 122 F., TSP treatment, and chlorine bleaching, that I was pleased that you were able to link my statements with the 18 year old article for Illinois and the 14 year of the TGRC report.

There are variations to the method I noticed. I won't go into them here, but I rarely treat old seed that has been around for years, and I don't dry the seed after the TSP treatment before the chlorine rinse.

I suppose I should not be surprised of the germination of the Katahdin/All Blue did better with the long soak of chlorine vs. short soaks. As you asked, would the long term effects of storability be affected?....perhaps, because the seed coat is, and can be damaged by the longer chlorine soak, which gets rid of the inhibitors and physically scarifies the seed a bit more than I would like. The know when you have used too much chlorine or too long of soak if the seed is paper white.

A virus like TMV has a fairly short shelf life on the seed. If you plant newly harvested tomato seed or potato seed, the chances that the infection present earlier is still there. That is why the three way treatment is so important. If you save the tomato seed/potato seed for two years or more, most of the virus expired.

I have tried to incorporate the TMV res. into my heirloom type tomatoes, so that I have one more control over the disease. Virus res. in potatoes is obviously selected for, albeit I achieve it by multiple generations of breeding the generations of seedlings that tolerate the presence. I take the serendipity as it comes.

The Illinois report is valuable in the fact that they talk about Tobacco Mosaic Virus, and other pathogens. I want clean seed, and even if my actual practices are not totally measured or exacting, I think I make a better effort towards the packing away clean seed than by fermentation alone.

Tom Wagner

[guest1]

ppppppppppppppppppppppppppppppppppppppppppppppppppppppppppp

Note....I edited this post after I saw the thousands of the letter p....

I left just a smattering to let the spammer know I can delete or edit the spam.

Tom Wagner

[matthew]

Wow, that is a lot of P's! I have never seen spam like that before.

May I ask why you have strategically inserted a couple of g's and n's? They seem to be located rather far from the "P" key for it to be a simple typo?

I appreciate originality in all things, and I can honestly say that this is both the most original and also the most pointless spam I have ever seen. Bravo!

[JANIE HANSEN]

WHAT IS THE RATIO FOR TREATING TOMATO SEEDS WITH TSP?

[Tom Wagner]

I use it straight onto the tea strainer and rub the TSP and seed together until the gel dissolves but in water I go about 10% TSP in hot 121 F water