A few of my green hips have seeds across the top that are currently red in color.
Are these definitely already dead?
I have been spraying my plants and their hips with fungicide.
If not yet dead, is it possible to harvest these few top seeds without damaging the rest of the hip that needs to ripen further? Has anyone ever tried this?
If I harvest these exposed seeds at the regular harvest date (early-mid October) and scarify to expose the inner seed core, is there any chance of germination?
This is my first year back into rose breeding, and because my plant numbers are low and I will have few hips to harvest, I am looking to save as many seeds as possible.
Cathy
Central New Jersey, still 1.5 to 2.0 months to go before hip harvest time
Cathy, I experienced the same thing last year—red exposed seeds. The forum was so helpful in explaining to me that those are exogenous seeds (outside of the hip). In my case, the hips that have them, are generally also “bursting at the seams” with other seeds. The redness may be from the sun scalding those exposed seeds. I received so much good information from people ont his forum regarding this phenomenon. You can probably find the thread by going to advanced search in the upper right hand corner and typing in the word exogenous. This is such a wonderful educational tool.
Also, in my case, it was mainly the open pollinated hips that did this. I sowed the exogenous seeds with the other open pollinated seed, realizing I had nothing to lose. Looking back, I wish I’d sown them separately just to see how the results compared.
Cathy, Tom is right on-there are several great threads regarding this issue. But if you are short on hips and seeds why not take advantage of some of the offers of excess seed that should appear soon? (As soon as everybody gets heavily into the seed/hip harvest and realize that 15000 seeds of one variety is a bit much). You can reap the rewards (sounding all preachy now) of what others have done and leap frog a few yrs ahead in your efforts to improve whatever quality you are seeking to improve upon. Because we are all making attempts to get better resistance, etc., most of us have found a few key varieties to use with whatever else strikes our collective and individual fancies, along with taking advantage of great specie crosses from Basye, Buck, Kordes, Moore among quite a few others. When I started to use some of these seeds I was extremely pleased with the sudden improvements on so many planes. And it would have taken me forever to have come even close to “reinventing” the crosses that are already done and waiting for us to take further steps in improving aspects of health, etc. I do not have the room to be indiscriminate, but I have been very pleased with how these are integrating into my efforts for a new, better class of healthy rose.
I remove most of the open pollinated hips and only allow my crosses to mature. I am only keeping a few OP hips to practice scarification for improved seed germination.
The exogenous seeds are on my precious crosses. I will plant them separately to see what happens.
I will search on exogenous to see what others have learned.
I will also look for the free seed posts later this fall.
However, I also breed daylilies and Asiatic lilies, so I will have plenty of seeds to deal with in addition to the roses.
Has anyone done a controlled comparison of a nitrate treatment and an enzyme treatment?
""Title: Microbial enhancement of seed germination in Rosa corymbifera ‘Laxa’
Authors: Morpeth D.R.(1); Hall A.M.(2)
Authors affiliations: (1): Writtle College, Writtle, Chelmsford, CM1 3RR, UK (2): Environmental Sciences, University of Hertfordshire, College Lane, Hatfield, AL10 9AB, UK
Published in: Seed Science Research, volumn 10, pages 489-494, (2000).
Abstract: “Germination of native tree and shrub species from seed can be unpredictable. Germination of Rosa corymbifera ‘Laxa’ was 2% under normal commercial conditions. This was obtained in the presence of the natural microflora found on the seeds. The microflora originated on the hips and the seeds become inoculated during extraction. Exclusion of microbes from such pretreatments resulted in no germination. Inoculation of surface sterilized seeds with members of the natural microflora resulted in 3% germination. The addition of GarottaTM, a commercial compost activator, to the commercial pretreatment increased germination to 95%. This high germination percentage was sustained over a 5 year period using seeds from the same stock bushes. Addition of the compost activator resulted in a 20-fold increase of microbial activity in the pretreatment mixture, indicating that enhanced microbial growth resulted in higher and more predictable germination percentages.”
This paper has been cited by 29 more recent scientific papers.
I don’t know if you recall it–but back in late 2002 or early 2003 I sent a copy of my grad school Plan B research project to you regarding rose seed germination. The research project you just cited (above) regarding the use of compost activator was reprinted in an old RHA Newsletter–sometime around 1996. It served as the basis for one of the treatments in my project (and it was also the first time I set eyes on a RHA Newsletter and that newsletter inspired me to join the RHA—but I digress). I also did the Driselase treatment in several different strengths and for varied periods of time–which were then combined with varied periods of both warm and cold stratification. In the end, no treatment proved significantly better than 12 weeks of cold stratification followed by germination at 60F evaluated for a period of 6 weeks. I do not think the compost activator was harmful to the seeds, but it did pose problems if you are doing your germination in baggies or petri dishes. The article on the use of compost activator talked about seed beds for germination and that seed planting had to be carried out before temperatures in the seed beds got too high–this should have been a big clue to a potential problem I didn’t pick up on when I applied their protocol to my experiment carried out under lab conditions. So, if you are attempting to germinate your seeds in actual seed beds, the addition of activator may be useful–but it is detrimental under lab conditions or for those of us who carry out germination in baggies. The activator must be essentially used up/depleted during a period of warm stratification prior to cold. Otherwise, any remaining unused activator will begin working again when seeds are brought to warmer conditions for germination. The remaining activator can generate temperatures in the seed high enough to put the seeds into a second dormancy and no germination will occur. The end result of the experiment showed that occasionally, a period of warm stratification prior to cold can be beneficial but in most cases, it is not necessary, especially with modern cultivars. No treatment (compost activator or Driselase) was significantly better than 12 weeks in the cold prior to germination.
Julie, I remember you sending me something about your germination experiments, but not the details of my reply. I searched my old e-mails and cannot find any from you on this subject (not surprising due to the number of disk crashes over the years). Do you have any correspondence from me on the subject? I remember there was someone who tried the enzymes without sucess but used tap water. I think that person was on the West Coast.
This earlier thread explains why Julie Overom got different results than the British got. The main problem with her experiment appears to be that she used an organic media, peat, instead of an inert one, vermiculite. The compost activator attacked the peat and heated up the mixture.
However, she did not discuss her Driselase experimental set up.
Thanks, Larry. I just found a 2011 RHA thread on calcium nitrate and will study it today. Sounds like the chemical is available online, or maybe through my Farmtek or A.M. Leonard catalogs. I will check.
I was also struck by one mention of a 60 degree F germination temperature. Back in the early 90’s I thought 40-50 degrees was the optimum temp for germinating rose seeds. I’ll do some further research on that too.
While the compost activator I used in my experiment did heat up both the peat-based germination mix (Promix) and the seeds, it was not actually harmful to the seeds. By the end of (12 weeks of room temperature stratification + compost activator) prior to 12 weeks of cold stratification before germination was carried out a 60F, most of the CA had been used up and there was some improvement in germination, but the increase was not statistically better than the standard control of 12 weeks of cold stratification only–and it took far longer ( 24 weeks compared to the 12 weeks for the control) due to the time required to “compost” the seeds to a point that weakened the seed coats enough for germination to proceed. The decreases in germination found in the experiment occurred with shorter treatment times which did not allow for completion of the composting prior to cold treatment. In those cases, composting resumed with removal of the seeds from the cold for germination and it caused the heat generation that produced a secondary dormancy.
Henry, don’t bother trying to find anything in old emails–a copy of the entire project was sent to you via snail mail, probably in late 2002 or early 2003. You may have kept it somewhere but look for a paper file and it may have been in a hard binder. All the original files are on floppy discs that I can no longer access and the research papers I used as a basis for the experiments have been in storage for years in an off-site garage, so all I have at home is the same copy of the project that I sent to you.
While I don’t have the original research paper here at home that served as the basis for the experiment, the Driselase experiment pretty much followed the published research project protocol. We used 1, 2, and 3% concentrations of Driselase (very expensive at the time) and treated rose seeds (R. nitida, R. glauca, an Ag Canada pool of seeds, and a Buck pool of seeds) in those solutions for a period of 24 or 36 hours and then exposed them to varying periods of cold or warm and then cold stratification. Some of the treatment combinations produced slightly better results than the stratification control of 12 weeks in cold stratification only–but no results were (statistically) significantly better. The standard cold stratification was faster, cheaper, and far less labor intensive. Since we were looking at it from the perspective of the U of Minnesota breeding program in existence at that time, those factors were important. We were also looking for a method that could be applied to the large variety of genotypes produced in a breeding program. The whole experiment was really too large and should have been broken up into several smaller experiments, but we were trying to quickly determine which of several different approaches could be used to improve the germination of a wide variety of seeds.