Interesting story. Question: are there any known conifer antifreeze proteins that help some species survive cold winters better than others ? ....for example Z3 species vs. tropical ones ? ....does grafting on to hardy rootstock make a difference because of it ? http://www.physorg.com/news92411624.html March 06, 2007 Fluorescence microscopy reveals why some antifreeze proteins inhibit ice growth better than others Antifreeze or ice structuring proteins found in some fish, insects, plants, fungi and bacteria attach to the surface of ice crystals to inhibit their growth and keep the host organism from freezing to death. Scientists have been puzzled, however, about why some ice structuring proteins, such as those found in the spruce budworm, are more active than others. <SNIP>
Hi Jaro, Grafting onto a host understock doesn't exchange the flow of "juices" from hardier to non-hardier. If a zone 3 rootstock is used and the top-growing portion (scion) dies, lets say it's a zone 5, it's a complete death for both host and scion. That's how I remember this question having or not having merit in the past. The best example of some such increase, is that grafting to Thuja allows another scion to 'increase hardiness' only in that it can now be grown in clay soils (Chamaecyparis obtusa) whereas on it's own roots, it would die. Another which takes the spectrum another entire direction is the current use of Abies firma as a rootstock and now other fir scion/grafts are able to grow in heated southern climates and elsewhere (the East Coast) where firs used to bite the dust. A lot of scientific fact has been generated in this area lately. Could Spruce Budworm antifreeze genetics be applied/injected into the embryo of any living thing... absolutely. They do it all the time. That's as far as I'm willing to comment however. The article already answers that question. Dax
I was under the impression that the majority of a plant's 'anitfreeze' capability is due to high sugar concentration in the cells. The same sugar anitfreeze solution also reduces the desiccation over the winter months. Simon
OK, so what supplies/controls the sugar concentration in a grafted plant -- the rootstock or the graft ? ....or is it just a matter of proportions, rootstock mass vs. graft mass ? Do the cells in (sub-)tropical conifers have low tolerance for sugar concentration ? (are they diabetic ? :O) Are you sure there are no antifreeze proteins in conifers ? ....the article says that "some plants" have them -- what plants are those ? ....surely they must be boreal evergreens of some sort ?
All I know is this Jaro - Bob Fincham lightly says in his grafting video that a grafted form of Chamaecyparis obtusa onto Thuja occ. 'could' provide a little juice. He abruptly then goes right into conversation regarding how the thuja roots 'increase' hardiness by means of soil adaptation. So he does make reference that the rootstock may have impact on the amount of anti-freeze agent it shares with the scion or even visca versa because there's always two ways of looking at an issue such as this. It's definitely the rootstock that is pumping what it receives in terms of energy through photosynthesis as well as what it pulls from the earth. I can't really think of it any other way. His video I should have made mention is during the times of not so great quality VHS recordings (1980's???) so maybe that's why he was reluctant to comment more about this. And all I know is this: Many things are factored in for grafts for both scion and rootstocks such as vigor or root system formation; soil types, water, you name it they all contribute but in the end I think not a lot of this matters anyway. What "is" known is that the rootstock must be hardy and the scion must be hardy. If they ever start producing Abies firma with anti-freeze agents in it, no one will need it! A whole new market. The beginnings to a new modern area of being able to stay warm no matter who you are, what you are, or where you are! lol Surely there is some humor here! Dax
I also seem to remember reading somewhere that lightly fertilizing a plant late in the season will increase the salts in the plant and "improve" the plant's hardiness a bit. Not sure if this is true or not? Has anyone else heard this? Thanks, Mike
Hi Mike, Only one guy I've worked with ever recommended fertilizing in the fall. He'd recommend it mainly for deciduous trees as I do recall quite vividly. This was in zone 5in Illinois)),, no correlation however. Off subject, I was told to fertilze my Japanese Maple heavily with nigrogen in spring for seed production and last year I got my first crop ever from a tree I bought in a 35 gallon container and planted in 2001. Acer palmatum 'Seiryu' was the tree. It was huge when I planted it)) That's all I ever heard. That nurseryguy was one sharp critter though so who knows. Not me. Dax
