Pollinations in the Age of Covid-19

​While we wait for Covid-19 travel restrictions to be lifted, I thought you might like to know about how the hazelnut breeding team has been warding off cabin fever:  we’ve been conducting controlled pollinations between several of our top hazelnut selections—while social distancing, of course!  
In my presentation in Brainerd on Feb. 25, I explained our process for screening the new clonal selections that we are preparing to release to the public pretty soon.  But I did not tell you about the work we are doing to develop even better selections—at least we hope they will be!  We are crossing or best selections with each other, with the hope that some of their progeny will be even better than their parents.  Not all will be, but some might.  The theory is that by adding the good genes from one selection to the good genes from another we will get something even better. 
Conducting controlled pollinations is a multi-step process.  First, we had to put on pollination bags to protect the female flowers from being pollinated by their neighbors. This has to be done before the flowers emerge, and before you even know where they will be. Because hazelnuts bloom very early in the spring, we sometimes do this before the snow has completely melted.  Thankfully, this year the snow was all gone when we put on the bags on March 11 and 12. We were especially grateful that the snow was gone because this year we did the pollinations in Lamberton, a three hour drive away in Southwest MN, because that’s where we had the best collection of mother plants this year.  We first tied the branches into bundles using soft clothesline, then slipped long narrow bags (about 3 ½ feet long by 12 inches wide) made of Tyvek housewrap over them, then tied the bags on with more clothesline. We installed144 of these bags this year. The field looked like it had sprouted some kind of weird fungus.
The next step was to collect catkins just as they were starting to release pollen.  That was a little nerve-wracking, because if you collect the catkins too soon they won’t release pollen, and if you collect it too late all the pollen might be gone, and being off by a day or two can make a huge difference.  This year we needed to travel to out-state research sites to collect it (and get permission from the University to travel in the middle of the pandemic), which made it even more stressful.  Once the catkins at the right stage are collected, extracting the pollen from then is a fun kitchen project.  I would have made yellow finger paint with the pollen if it hadn’t been so precious!
Finally, in early April we returned to Lamberton to apply the pollen.  We whipped off the pollination bags and dabbed the pollen on the female flowers with our fingers, working quickly to avoid letting pollen blowing on the wind get to them, then put the pollination bags back on.  Although 

female hazelnut flowers are so small that they are barely noticeable in nature, when they are protected inside pollination bags their dark pink stigmas grow several millimeters long and are beautiful to look at.  The moment when we take off a pollination bag and reveal a bundle of stems with a flower at each node can be quite thrilling.
The final step was to return a couple of weeks later to remove the bags—and to be sure that all the stems were properly marked as to what kind of pollen was used for each so that when we return to harvest the seed in August we’ll know who is daddy for each one.  I like to color code things, so this made for a very colorful field.  (We can’t afford to lose these precious seeds to hungry mice, hence the mousetrap.)
This is a long-term project.  We will not know whether or not these crosses were successful until late June, and we won’t harvest them until late August. Then we’ll stratify (cold treat) them until March, plant them in the greenhouse, up-pot them in May, keep them an outdoor nursery through the summer, and finally plant them to the field in September 2021.  We might harvest a few nuts in August 2025, but won’t know for sure whether they are any good until about 2028. Most won’t be, but those that are might be much better than what we already have.  We will propagate those for replicated trials in 2029 and, depending on how they do in those trials, release them to you in… maybe 2037?  So don’t hold your breath waiting for them.  I expect to be retired by then, but I hope to still be around to enjoy eating them!  In spite of the wait, the idea is exciting to me.
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Best and be safe, Lois