Heat Treatment Delays, Doesn't Reduce Germination?

[carolyn137]

Originally Posted by Douglas_OW

Carolyn,

Perhaps this page is what you are looking for:

http://www.kdcomm.net/~tomato/Tomato.../fusarium.html

It includes a brief mention of wind borne soil diseases.

Jim

Thank,thank you Jim, how did I miss that, and I always wear my reading glasses when at the computer, or actually reading anything.

See Worth,I'm the gender opposite of George Washington;I can not tell a lie.

Carolyn

[Nan_PA_6b]

Thanks to Douglas_OW for suggesting this experiment.

Identical to Experiment #1 except this time both heat-treated and not-heat-treated batches of seeds were completely dry.
The same lot of seeds was used here as was used in Experiment #1. 17 seeds of each were sown in identical medium. Germination results were as follows:

Day__Heat treated___not Heat Treated
6_____12_______________5
7_____14______________14
8_____16______________16
9_____17______________16

Note: the days listed were the only days on which changes were noticed.

Conclusions:
1. There was no real difference in germination percentage between heat treated and non heat treated seed when both batches were completely dry. This agrees with Experiment #1.

2. The heat treated seeds were a little quicker to germinate, which agrees with the results of the first experiment. In the first experiment, I assumed I had mislabeled the two batches. Now the same result has shown up twice. An internet search turned up this: "Hot water seed treatment also has the beneficial effect of priming seeds resulting in faster germination than untreated seed...Primed seed has absorbed just enough water to dissolve germination inhibitors and activate the early stages of germination. Primed seed is therefore in a suspended state of growth, so it germinates faster and more uniformly over a broader temperature range..."
http://articles.extension.org/pages/...s-and-coatings
Therefore, I did not mis-label the seeds in Experiment #1; heat treatment does not delay germination, rather it hastens germination.

3. The germination times are much quicker than in the first experiment. Both experiments were done in the same room, on the same table, planted in the same medium. I don't know what could have been different. The room houses the heater and air conditioner. It is possible temperature fluctuations in that room affected germination times, but the actual cause remains unknown.

Nan

[Nan_PA_6b]

Thanks to Worth1 for suggesting this experiment.

Conditions are identical to Experiment #1 except the seeds used are Post Office Spoonful currant tomato seeds, and have been fermented rather than Oxi-cleaned. The seeds were dried for four days, then half were given a hot water treatment. Several hours later, 17 seeds of each were sown in identical medium. Germination results were as follows:

Day___Heat treat___No heat treat
5_______9____________6
6______17___________13
7______17___________16

Note: the days listed were the only days on which changes were noticed.

Conclusions:

1. There was no real difference in germination percentage between heat treated and non heat treated seed when both batches were fermented rather than Oxi-cleaned.
2. The heat treated seeds were a little quicker to germinate, see discussion in Experiment #2.
3. The germination times are much quicker than in the first experiment, see discussion in Experiment #2.
4. Between Experiments #2 & #3, essential aspects of Experiment #1 have been replicated (with the exception of the long germinaton times in Experiment #1). Thanks to JRinPA for suggesting this.

Nan