Questions on bench grafting

I may have made a mistake, hard for me to believe but…:slight_smile:
I brought my rootstock in early to cleft graft and to allow it to callus for a few weeks before setting it in the nursery row.
Should I leave the rootstock in the fridge till my usual grafting time or can I bench graft and store them in the fridge?
I will wrap both scions and rootstocks in large plastic bags to keep the hydrated.

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You can graft now and store them in the fridge; they can callus even in the fridge, and you can also plant before they callus.

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Thanks!

Do they callus regardless of temperature? I have seen people suggest using 65 degrees to callus. I am sort of confused about this, wlll bench graft in about ten days. Thanks for any info.

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From a few years ago, I vaguely recall storing my grafted rootstocks in a small cooler, to keep the temp on the roots low and the tops at room temp. I don’t think I did it for that long- maybe a week, but I think they did better than my previous attempts at bench grafting.

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I thought I saw 50ºF for apple bench grafts. It is warm enough to callus, but cold enough to keep them dormant.

I also saw a study somewhere that compared calluses formed at cold and warm temperatures. One was stronger than the other. I think it was slow growth that produced a stronger graft union.

Of course, stone fruits are different story.

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This paper is pretty detailed (Page 435):

  • Apples: Slow callusing at 45-50F (very slow in the 32-45F range), retarded above 90F and killed at 104F. Too high uses up stored carbs too quickly and affects survival.

  • Grapes: optimal at 75-80, 85F+ forms soft, fragile callus. Slow below 68 and stops below 60F

  • Mango: like grapes or hotter

http://lists.ibiblio.org/pipermail/nafex/2007-March/025421.html
Ed Fackler:

  • Peaches: 70F
  • Plums: similar to apple

I’m planning to do some peaches onto plum stock, so I may try this again…

http://horticulture.oregonstate.edu/system/files/onn050615.pdf
Interesting article about a “hot callousing” device. It seems to mostly help with grafting nut trees. (I almost said “grafting nuts”, but that could have covered most of us…).

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Many years ago I worked at a nursery that did bench grafting in March of apples and pears. After grafting, the grafts were brushed with wax and then allowed to
callus for about two weeks at about 50 degrees. Then they were boxed up and stored in the cooler until they could be planted in the fields mid-April to mid-May as time permitted.

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We put all of our apple and pear bench grafts in an unheated room that typically is in the 50-60 degree range for 2 weeks and then either plant them out or put into cold storage depending on weather conditions at the time

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