Hi Fellow fruitgrowers! Im living 52°north in Netherlands. While all my fruit trees are budding up, my cherrykose ( cherry-apricot, prunus salicina x armeniaca) is already fully flowering, amazing white blossom! I dont see my bumble friend flying around yet so i was wondering:
Can i hand polinate the flowers like i do with my peppers indoors? The tree is supposed to be very self fertile. Thanks in advance!
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Yes. I do the same.
Generally these interspecific hybrids of Prunus require an identified pollenizer.
So you would have to know which cultivars were used to make the cross that you have and which others are compatible with what you have. My guess is it’s most likely going to be a plum interspecific hybrid, an apricot interspecific hybrid as there’s much simpler compatibility grouping in Plum and apricot than in cherry. There is also far less self-incompatibility in apricot and Plum than in cherry. Have you checked the flowers to see if anthers are open and shedding pollen or is a lack of that is the reason why bees are not visiting?
If you are going to hand pollinate then I assume you already know how to harvest Prunus anthers, pollen, from them and how to identify when the pistils are receptive.
Just the name has cherry in it but its an apricot hybrid with red flesh hence the name cherrykose. And no i dont know anything about hand polination of prunus, but good to know it is possible;)
So this is a hybrid only of apricot and Japanese Plum with no cherry as part of the hybridization? If I understand you correctly you mean that “cherry” is just used as a descriptor of fruit color?
In any case the parameters of compatibility and successful pollination are so complex in Prunus species with or without interspecific hybridization it’s not possible in this forum to explain it all and unless you know what is going to be compatible with what you have you could spend years as a scientist trying to figure out what will work for your tree and still may or may not be able to do anything about it to get fruit on your tree. I worked in Prunus reproduction and breeding for many years and this is not just a question of how do I go about collecting pollen and applying it to the flowers on my tree.
I could email you a couple of good scientific articles that demonstrate these problems if you wish to send me your email address. Let me know if you want to do that. Otherwise my best recommendation to you is go back to the source of where you got this tree and ask them what will be compatible with it as a pollenizer.
Amazing that your salicina x armeniaca (plumcot) hybrid is fully flowering at 52 degrees north! It is being grown under glass? Apparently, you were informed that the accession is self-fertile. I would certainly hand-pollinate using a small camel hair brush.
Bumblers are certainly bigger than honeybees. In California, we sometimes had problems with honeybees being ineffective at pollinizing plumcots due to their excessive pistil length. Bees would circle and harvest from the anthers without touching the stigma. Perhaps it is better with larger bumble bees. Anyway, I would touch the anthers of some open flowers and twirl my brush in them, then move to the stigmas of other open flowers. You couldn’t help but to assist fruit set.
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Great im about to do that! I will also start to make an underground hidout for bumbles in next winter with an old planter waterer im burying in the soil with some mice nest straw inside. Then hopefully i have some early working polinators around the tree next spring. Would be really helpfull since all my other prunus species are still month away from flowering, where there seems to be no problem at all with polination. Hopefully those bumbles then can do the job the bees cant! Ps awesome blossoms on that picture. Ill send one of mine soon. Thanks everyone
Wow! Nice bloom there. Looks like you should have the opportunity for fruit with all the bloom present. I will say your bloom looks much more plum-like than the salicina.x armeniaca hybrids I’ve seen. I didn’t see any excessively long pistils in your posted photos,- perhaps that is not a problem with your cultivar. You might get by with manual pollination by a few sharp raps on the branches throughout the day when it is bright and sunny. If you can do it when pollen is shedding, the vibrations are enough to effect pollination. Best of success to you.
Do you have a particular style that you recommend? I’ve been trying to settle on a good brush for hand pollination of avocados for a few years and haven’t found one I like yet. My main problem is I can’t avoid getting nectar on the brush and then the pollen gets all clumpy.
No particular style, but generally the cheaper the better. We have used simple/cheap model paint brushes,- you can usually find them in hobby stores in packs of a dozen or 25. Generally, you will find variation among them and settle on some you like better than others. The nectaries are a problem, and you best avoid them by swirling lightly and trying to avoid the base of the floral column and the stigma. It also helps to put the brush in your mouth and exhale through the brush,- attempting to pass the humidity from your breath to your brush hairs. Working quickly and avoiding nectaries, your brush can collect more dry pollen. Best of success to you.
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I’m sure it’s something that gets easier with practice, but I’ve struggled with that (for avocados at least). The distance between the anthers and the nectaries is so little, and the nectar is often flowing enough that it drips when the flower is tapped. But I’ll work on my fine motor skills!
Perhaps with your avocado case there, you might want to avoid the cheap brushes! Art supply stores give you a very good selection of various styles & stiffnesses of brushes, as well as size. Maybe you need a brush that is small enough for you to get directly at the opening anthers and able to carefully avoid the stigma & nectaries?
How do you harvest pollen and how do you know when the pistils are ready to receive them?
Pluck the anthers as soon as the flowers have opened and before the anthers dehisce. Place them on clean paper at room temperature and once they have dehisce (after about 24 hr) sift the pollen from the anthers so that the pollen remains dry. The pistils are ready when the surface appears wet. This is the time to apply the pollen with a small camel hair brush.
Alternatively you can cut flowering shoots from a compatible tree and hang them in the canopy of the tree that you want to pollinate. If you have pollinators present they will carry the pollen for you.
Prunus pollen is sticky, unlike wind carried pollen such as walnut or grasses, so it requires physical collection and deposit by pollinators or people and will not transfer readily just by tapping or shaking the tree.
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