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Old August 20, 2007   #1
Patrina_Pepperina
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Default How I cross pollinate

This is some info I typed up previously, which may be of interest. Craig and I were asked how we cross pollinate in one of the Dwarf Project threads, but I thought my answer would be better here in Crosstalk. There are probably as many ways of making crosses as there are people who try it, so the following info is just some of the methods I've used so far.

Emasculating the flower:

I tend to choose a flower that is the first of its cluster because I read that it's the best one to pollinate (in general). I have tried removing the petals and anther cone at various stages from before the bud has even started to open to when it is just starting to open its petals, and I think that it's better to wait for it to open slightly. The anther is still quite soft and immature, and looks slightly yellow. It's a good idea to have a sharp thumb nail to pinch off some of the sepals (as a marker), but I always try to leave at least 3 sepals on top of the flower to protect the stigma/stamen from the sun.
  • Lift the potted plant onto a table so you can work at a comfortable height.
  • Open the sepals of the chosen flower (tweezers or fingers). Pinch off the lower sepals to mark the flower.
  • Gently hold the bud and make a tiny slit in the anther cone with the tip of a razor blade or craft blade. Only insert it a tiny amount so you don't damage either the ovary or the top of the stigma, then carefully slide the blade a little towards the tip of the cone to make a tiny slit.
  • With the blade tip in the middle area of your slit, lever some of the anther outwards section by section so that you can remove it with tweezers, or with a scraping motion of the blade itself. OR try to grasp the side of the anther and petals with tweezers (guessing where the stigma and ovaries are lying inside the anther) and pull straight outwards - you might be lucky enough to take off the whole flower section in one hit. I usually find this less successful because it's very easy to damage the stigma or ovary.
  • Mark the flower cluster with a twist tie, or a piece of string, and leave the bud to mature for 2-3 days, depending on how closed/open the flower was in the beginning. (I usually apply pollen on day 3, 4 and 5!)
Have some tags ready to write on it the parents and the date. The ones I use are small white tags with white strings, the ones often used to mark prices on articles at craft stores. If you already know who the parents will be, you could write it on the tag and hang it on the emasculated bud with the date you intend to apply the first pollen.

Collecting pollen:

I usually only choose my male parent on the day of collecting pollen for the first application because I choose a plant with the most flowers that I think are at a good stage. I always use an electric toothbrush for gathering pollen. I try to apply pollen for 3 days in a row, and prefer to do it when there is shade on the flowers, which is either early in the morning or in late afternoon for my garden. Sometimes there is more pollen in mid morning, and sometimes not until later, but I always try the morning first so that I can both pollinate the flowers before any insects come visiting, and also gather the excess pollen before they do.
  • Decide whether you want to gather the pollen in a small shot glass (for applying with a fine brush), or on your finger for dabbing pollen on the stigma, or whether you'll take a whole flower to the female bud (like Carolyn's book shows).
  • Gently buzz the top of the flower on its sepals with an electric brush while you have the flower "in" the glass (as far as it's possible, not easy sometimes), or with your finger underneath (also not easy because the flower moves around while it's getting buzzed - sometimes you can hold the flower with the same hand as the finger getting pollen.
Applying pollen:
  • A brush gathers the pollen off the glass surface quite well, but doesn't apply it to the stigma very easily - pollen seems to stay trapped in the brush fibres. Not as many seeds using this method.
  • Transferring the pollen from a finger works quite well if you are gentle, otherwise sometimes the stigma breaks. Position your fingerprint area under the anther when you buzz the flower - this area is larger than the fingertip .
  • Dismantling a flower and dabbing the anther cone directly to the stigma transfers a lot of pollen if you dab near the tip of the cone! The pollen seems to gather in the curves of the cone tip quite well, especially after you have buzzed the top of flowers (on their sepals) with an electric toothbrush, so when using this method I sometimes take off anthers from previously buzzed flowers without damaging their ovaries or stigmas. This way you still get a fruit from the donor flower
  • My preferred way is to take a whole anther cone plus petals with tweezers from the donor, carefully place it over the stigma of the emasculated flower, holding it in position by the petals, then buzz the tip of the donor flower for half a second. This works well for me and gives the most seeds and sometimes I use this method for all three applications. Often I put the donor flower backwards over the emasculated stigma as well, kinda trying every way possible to transfer pollen. The trick is to only apply VERY gentle pressure with the electric toothbrush and to be very careful placing the anther over the stigma. Too much pressure will shake the flower too violently and probably break or damage the stigma!!!
Another danger with the last method is not holding the flower in position carefully enough, and so sometimes it breaks the stigma. I prefer to use this method on day one, because It doesn't clog the tip of the stigma before the second and third days' applications. Sometimes the finger method really thickly coats the stigma, and if the days are windy or hot, the pollen dries out. Maybe in humid weather this won't be so much of a problem.

Mark the new Hybrid:
  • Write the donor parent's name on the tag in large letters so that you can see it quite easily, and so you don't accidently put the wrong pollen on that flower for the second and third applications! I really pay attention just before applying the pollen that I have the right flower!!!
  • Maybe name the new hybrid on the tag as well - helps when you have more than one so that you get used to which ones you're dealing with and checking up on etc.
GOOD LUCK and have lots of FUN!
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Old August 21, 2007   #2
johno
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Thank you Patrina. This old boy needs all the advice he can get!
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Old August 22, 2007   #3
vegomatic
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My first attempt was a total washout. If tomatoes depended on me to pollinate them, they'd be extinct! Thanks for the tips!

-Ed
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