Can anyone recommend a fungicide for treating to-be stratified seeds? Is using a fungicide even a good idea?
-Jwindham
Jonathan, this advice from Jim Sproul regarding stratification should serve you well:
“…seeds can be placed directly into ziplock bags bare, with a spritz of a very small amount of water. No more paper towel, and I gave up Captan years ago”
http://www.rosebreeders.org/forum/viewtopic.php?f=2&t=45366&start=10#p45514
I take a more bare bones approach to Jim’s method and don’t include the squirt of water. It doesn’t seem to make a difference with germinations. The parents which germinate well, still germinate well and the “miffy ones” remain “miffy”.
Kim, are you starting with dried seeds? Don’t they at least need to be hydrated (ie if previously dried, then soaked) before stratification?
I sometimes use diluted hydrogen peroxide, but don’t know that it makes much of a diff. I do use a little peat too, which probably isn’t really necessary any more given the quality seal on ziplock baggies.
I think some fungi help break down the seed coat, but of course, others attack the sprout immediately.
No Don, I shell all the seeds from the particular cross, rinse the fibers off it needed with plain water, then pat them dry to remove the excess and put them in the baggie with a label and into the refrigerator. If they come out clean, they often are a bit damp and won’t need rinsing. Those just get put in the baggies and refrigerated. When I plant, I prepare the table and start placing the seeds in rows. Once they are filled, the entire table is covered with soil and watered in well. I don’t let them dry out much before they are watered again. There is little fear of rotting as the tables are four feet in the air with nylon window screen supported by hardware cloth, with wooden slats spaced about a foot apart to hold the screening in place. If they are soaked, it all drains out well. It’s moisture control potting soil so it retains moisture and drains efficiently. The only issue I have is fungus gnats and those are due to the dampness of the climate. They are EVERYWHERE just like the Crane Flies, but they don’t seem to be adversely affecting the seedlings. Things are growing and already flowering. Not bad for only having been under soil about eight weeks.
So Kim, you don’t scrape off the bits of pulp when you put them in the baggies?
I rub them between my fingers or in a wire strainer, even scraping it off with a small, sharp pair of scissors if pulp adheres to the seeds, but I’m not obsessive about removing it. Too much left on them will result in mold and it seems to inhibit germination when it does. But, I’ve tried streamlining the process so it isn’t as “obsessive”, expensive, toxic and time consuming as possible. I do it for FUN, not to add to my “work load”.
That’s why I’m asking. I’m facing a huge amount of seeds to process soon and I’ve always tried to remove the pulp with a knife after rubbing around in a strainer, as I am under the impression that it inhibits germination. If I didn’t have to do that, it would save me a huge amount of time and sore fingers.
What I have also done was to take large quantities of the same seed and placed them in a heavy wire kitchen strainer. Use an old pie plate or other shallow dish and make a paste of your favorite kitchen cleanser then nestle the bottom of the strainer down into the thick paste and work them around with a pestle or anything useful as one to rub off the pulp and grind up the fibers. Do it as long as you feel necessary then rinse well to remove all of the ground up material and cleanser. I usually then spread the seed across paper toweling on a bath towel until they are as dry as desired then bag them. Not all are going to have fiber and pulp adhering to them. Some will and some just won’t rub off easily, but many have. The cleanser, if it contains bleach, will also help to sterilize the seeds against fungi and bacteria which might damage newly emerging seedlings. It’s the rinsing well with the drought that’s the issue with that method here, now. If nights remain as cool as they appear to here during summer, I will probably just plant the seeds as they ripen and not worry about any pulp and fibers, letting them break down as part of the soil. Isn’t that what they do in “Nature”?
This might be slightly off topic from the subject at hand,
Does anyone have a preference of when they take hips, at present I have some in varying stages of color/ripeness. They vary from green to yellow to orange to red and even black(dead I guess), is there a better germination from which stage of ripeness.
David, I was thinking of posting the same off-topic question, lol. Some have said, less ripe seeds germinate better. I’ve been reluctant to take them earlier than when they start to turn color.
I have been attempting to time them from the date of pollination so I take them between three and a half to four months. Any later and the vermin got them before I did. Hopefully, I won’t have THAT problem here in town. It was always a terrible problem on the edge of the “wilderness”.
Kidd & West (1920) The Role of the Seed-coat in Relation to the Germination of Immature Seed.
“In this connexion it is interesting to note that Demoussy (5) found that hydrogen peroxide increased the percentage of germination of old Cress seeds. Hydrogen peroxide has a lethal action upon the saprophytic flora of the dead seed-coats. He suggested that non-germination in these old seeds was to some extent due to the respiratory action of moulds or bacteria present in the seed-coat, attributing to them a role in causing dormancy similar to that which we are here attributing to the respiratory activity of the living testa.”
http://bulbnrose.x10.mx/Heredity/KiddWest/KiddWestSeeds1920/KiddWestSeeds1920.html
Babcock (1912) reported that hydrogen peroxide allowed unripe seeds of corn (maize) to germinate. He also wrote, “Unbroken seeds never germinate in the digestive tract of an animal, because free oxygen to support direct respiration is not available. In this case, temperature and moisture conditions are ideal for growth and when voided, in the excrement, and exposed to air, such seeds in general germinate quickly.”
http://bulbnrose.x10.mx/Heredity/BabcockImmature1912.html
Wild roses manage to reproduce themselves without having their seeds scraped and sterilized, unless we allow that passage through the digestive tracts of animals accomplishes these treatments.
John Cook, who gave us ‘Radiance’, among other varieties, wrote in 1915, “Growing rose seedlings is a very slow business. It takes five months to ripen the seed pod, a month to rot the hip and from five to twelve months for the seed to come up. These seedlings are very much subject to mildew, and some die in their infancy. Fifty per cent. of the seeds will not germinate, twenty-five per cent. will come single, and out of the remaining you might obtain two or three varieties worth growing.”
Thank you all for your input.