Search found 414 matches

by Larry Davis
Sat Mar 14, 2020 11:39 am
Forum: Rose Hybridizers Association Forum
Topic: Strat Question
Replies: 6
Views: 144

Re: Strat Question

Again, I don't think there is any clear answer. If I had a hundred seeds, I'd plant half after cleaning them out of the hips, and put the other half into vermiculite moistened with calcium nitrate and keep in the fridge until they sprout. Of course that will/might cost you a couple months of potenti...
by Larry Davis
Fri Mar 13, 2020 10:35 pm
Forum: Rose Hybridizers Association Forum
Topic: Strat Question
Replies: 6
Views: 144

Re: Strat Question

Not a silly question, just hard to answer. Generally it seems that simply storing fresh hips in a refrigerator is not enough to make them think they have been stratified. But outdoors they are not at a constant 4 C. Depending where you live, they may have gone through multiple cycles of freeze and t...
by Larry Davis
Fri Mar 13, 2020 7:32 pm
Forum: Rose Hybridizers Association Forum
Topic: Unique black spot resistance gene from 'George Vancouver' is better characterized
Replies: 12
Views: 383

Re: Unique black spot resistance gene from 'George Vancouver' is better characterized

Really good news. I wonder where RKO got the resistance. Not apparent from its short-range family tree I suppose? The notes I have on that say RKO is the same parentage as (Radsweet) Alaska. and a half-sib to Brite Eyes. Namely Radtee x Radral. But Radral (Carefree Celebration) is Radorg x Rader whi...
by Larry Davis
Mon Mar 09, 2020 9:25 pm
Forum: Rose Hybridizers Association Forum
Topic: Germination of crosses I'm excited about
Replies: 13
Views: 610

Re: Germination of crosses I'm excited about

Finally have flowers from some crosses with Above and Beyond, and my #1100 (similar growth habit but descended from R foetida bicolor). This at least shows that the recessive reblooming trait will pop up at a decent frequency. No count yet to get a % but it is several % at least. Best news is that I...
by Larry Davis
Mon Mar 09, 2020 9:09 pm
Forum: Rose Hybridizers Association Forum
Topic: maximum germination temperature
Replies: 6
Views: 196

Re: maximum germination temperature

What you did is exactly how HSP are induced in crop plants and model plants like arabidopsis. Generally, if the stress is removed soon the plant recovers. In fact it become resistant to an even higher temp, up to some limit. The upper limit even after preparation by inducing HSP is quite species dep...
by Larry Davis
Sun Mar 08, 2020 7:14 pm
Forum: Rose Hybridizers Association Forum
Topic: maximum germination temperature
Replies: 6
Views: 196

Re: maximum germination temperature

Do I actually "know" the magic temp? No, but Semeniuk and Stewart discussed optima for stratification and germination, and the tendency for seeds to go back into dormancy above certain temps, if not fully after-ripened. I just looked back at my review (on this website) and find that they used 29.3 C...
by Larry Davis
Sun Feb 23, 2020 2:56 pm
Forum: Rose Hybridizers Association Forum
Topic: Coutts #4
Replies: 11
Views: 608

Re: Coutts #4

Carefree Sunshine (probably climbing sport) is a far better bush than SKO in my experience. And I have yet to keep anything from SKO selfs, despite planting a couple hundred. Paler than pale flowers and single only. CS on Silver Moon has produced a couple really nice flowering bushes but again extre...
by Larry Davis
Sat Feb 22, 2020 10:02 pm
Forum: Rose Hybridizers Association Forum
Topic: RHA Newsletter coming your way!
Replies: 4
Views: 334

Re: RHA Newsletter coming your way!

Are batches of newsletters still on their way? Or am I non-renewed? @ weeks and counting.
by Larry Davis
Mon Feb 17, 2020 10:15 pm
Forum: Rose Hybridizers Association Forum
Topic: Coutts #4
Replies: 11
Views: 608

Re: Coutts #4

Plazbo says "I still think sifting through the tiny % of rebloomers in the f2 of (modern x species) x self/sib is more interesting and to turn up useful breeders than jumping straight to another garden rose and further diluting the species compliment before having a useful breeder. I mean whats the ...
by Larry Davis
Sun Feb 16, 2020 9:58 pm
Forum: Rose Hybridizers Association Forum
Topic: Coutts #4
Replies: 11
Views: 608

Re: Coutts #4

Thank you Don for quoting that article. I probably read it decades ago when looking up all the articles I could find on hardy rose breeding, in all the rose annuals back to 1918, but had forgotten entirely some parts (90% or so) of it. But it raises a serious question for me now. By what criteria wi...
by Larry Davis
Mon Feb 10, 2020 10:39 pm
Forum: Rose Hybridizers Association Forum
Topic: Homemade rooting hormones
Replies: 6
Views: 259

Re: Homemade rooting hormones

Thank you. I was thinking the opposite because traditional outdoor winter planting of hardwood cuttings occurs in something like a coldframe. I've tried the burrito method in my basement which is rather cool in winter, and in a cold greenhouse. Neither worked. Next time I'll go for a warm lab. BTW, ...
by Larry Davis
Mon Feb 10, 2020 7:15 pm
Forum: Rose Hybridizers Association Forum
Topic: Homemade rooting hormones
Replies: 6
Views: 259

Re: Homemade rooting hormones

Apple, or banana peel. Back around 1980 I deliberately added low level ethylene to cuttings and got callousing at both ends. But for some CV the leaves dropped off and roots refused to form. I get callous in the burrito method but have really bad luck making the transition to rooting. Maybe I need t...
by Larry Davis
Sat Feb 08, 2020 10:17 pm
Forum: Rose Hybridizers Association Forum
Topic: Germination of crosses I'm excited about
Replies: 13
Views: 610

Re: Germination of crosses I'm excited about

So, there is hope. I do have a couple flowers opening but I worry they are selfs of the female in the cross. Most of the A & B so far have red young foliage and no sign of a flower bud. I thought that A & B seeds sprouted fairly quickly. But some Lynnie seeds from Kim R. which I stratified Nov 2 jus...
by Larry Davis
Fri Feb 07, 2020 10:31 pm
Forum: Rose Hybridizers Association Forum
Topic: Germination of crosses I'm excited about
Replies: 13
Views: 610

Re: Germination of crosses I'm excited about

I generally don't talk about germinations, waiting to see flowers. I had germination about a month ago and the first flowers are popping up. These were seeds put into cold stratification back in August. Most interesting will be the considerable number with Above and Beyond as the pollen donor and on...
by Larry Davis
Tue Feb 04, 2020 11:37 pm
Forum: Rose Hybridizers Association Forum
Topic: Homemade rooting hormones
Replies: 6
Views: 259

Re: Homemade rooting hormones

Personally I am very skeptical. Willow water might have benefit and salicylic acid in that, and aspirin (as an acetyl ester) definitely are plant hormones but not usually associated with rooting. Salicylate is a mobile signal for resistance to many plant pathogens. If honey has any hormonal ingredie...
by Larry Davis
Wed Jan 29, 2020 11:13 pm
Forum: Rose Hybridizers Association Forum
Topic: Petite Knock Out Rose - AVOID
Replies: 31
Views: 1564

Re: Petite Knock Out Rose - AVOID

An important point that Don mentioned is "practitioner of the art". He also noted that such a person might not be able to reproduce the work based no the process patent. But my take on patents is that if it is obvious to practitioners of the art, it is not patentable under a regular patent. A patent...
by Larry Davis
Tue Jan 28, 2020 11:44 pm
Forum: Rose Hybridizers Association Forum
Topic: Petite Knock Out Rose - AVOID
Replies: 31
Views: 1564

Re: Petite Knock Out Rose - AVOID

These days, DNA techniques are so cheap that you don't really need a specific single gene to tag. Just compare a bunch of markers on several chromosomes that represent the haplotype (particular arrangement of different alleles in this cultivar). Works exactly like the DNA database that the govt uses...
by Larry Davis
Mon Jan 27, 2020 10:31 am
Forum: Rose Hybridizers Association Forum
Topic: Worms eating seeds
Replies: 15
Views: 394

Re: Worms eating seeds

I just looked up the enchytraiedae and find that they are called potworms. They are like miniature earthworms. They eat decomposing plant material in pots in greenhouses among other places. Maybe also California pot too.
by Larry Davis
Mon Jan 27, 2020 10:27 am
Forum: Rose Hybridizers Association Forum
Topic: Worms eating seeds
Replies: 15
Views: 394

Re: Worms eating seeds

I forwarded Joe's photo to our nematode specialist in Plant Pathology. He says they are too large to be plant/soil nematodes. Gnat larvae is the most likely guess though he mentions a family I never heard of or even now how to say ( enchytraeidae) as a possibility. There are larger nematodes but the...
by Larry Davis
Sun Jan 19, 2020 10:33 pm
Forum: Rose Hybridizers Association Forum
Topic: Germinating seeds
Replies: 5
Views: 177

Re: Germinating seeds

I tried a post earlier but it disappeared. Look on the home page for RHA, under publications. You will find a review that I wrote in 2010. It cites Tincker, at Wisley in the 1930s burying seeds in pots of damp stuff for the winter to vernalize and getting good germination when he took them out and p...