- By Lois Braun
I've been meaning to write to report on hazelnut harvest for over a month, but once harvest began life got really crazy for me. We started harvesting on August 14th this year, starting with our wild American selections, which tend to ripen first. That was earlier than we normally start. I had heard that small grain harvest was 10 days earlier than usual, due to our earlier than usual spring and warmer than usual summer. We don't know how weather patterns affect hazelnut ripening, so we just decided to pay extra attention this year, especially since we had some research trials for which we could not afford to lose nuts to squirrels and other nut thieves. You would think that after working with hazelnuts for 17 years I'd finally have a better sense of when to harvest them, but I haven't.
It turns out that we probably jumped the gun a bit, judging by how difficult it has been to get some of the nuts out of their husks. The way you tell if a nut is ready is by whether or not it "turns" in the husk. That is, can you pry it out of the husk cleanly, which becomes possible when the plant lays down an "abscission layer" between the shell and the husk. The problem is that not all the nuts on a given plant ripen at the same time, and the squirrels and mice (and blue jays and crows and turkeys and raccoons and what not) are in the field all the time whereas we are not. That was especially a concern at those of our research fields that are far away, such as at Lamberton where we did our controlled crosses this year. So we sometimes pick some of the nut clusters early just to avoid losing any of them.
Ultimately, our harvest season went on longer than usual this year--we even picked a few more late selections yesterday, Sept. 22! Come to think of it, in past years I have noticed that an early spring usually correlates with a more drawn-out harvest, whereas a late spring correlates with a more concentrated harvest. It is as if with an early spring the plants know they have more time, and take it.
Our early and drawn-out harvest was in contrast with the commercial growers, who didn’t start until the beginning of September and who were mostly finished by the 16th. Not only can they afford a little loss, but they need to wait until the nut clusters, not just the nuts within the clusters, are starting to abscise from the stems, which makes them a lot easier to pick. They also need to wait until the majority of plants within their rows are ready, whereas we researchers, picking by hand, pick each plant as it is ready. This is one of the big reasons why getting clonal varieties will be a big help: when we can plant entire rows of the same variety we’ll be able to machine harvest them all at the optimal time, which will reduce a lot of the nut loss.
In spite of the amount of work involved, harvest is my favorite part of the whole annual cycle. The work is outdoors at a time of year when the weather is usually beautiful, though sometimes on the hot side (I like hot weather); it is physical but not strenuous; and you can either listen to the birds or chat with fellow pickers while you do it.
I also like harvest because that is when I get to see the results of all our past hard work. This year was especially gratifying for three reasons.
First, some of the selections that we identified as being superior in past years, the ones we are attempting to micropropagate so we can pass on to you, continued to look very good this year. I have been a little more hesitant than other members of our research team to tout their worth, but with each passing year I get a little more confident of their value. We now have a few solid rows of some of our best selections, and nothing affirms their worth as much as seeing an entire row of good-looking hazelnuts!
As an aside, I’ll pass on some good news, though I'm not sure that I should spread this because I don't want to jinx it: one of our top selections has finally made it out of being coddled in the micropropagation lab into a nursery bed outdoors! Assuming all goes well there, these plants should become available to growers by next fall, in large numbers, with other selections possibly to follow. If the micropropagation lab can figure out how to do one selection, they ought to be able to figure out another!
Second, this was the year in which the plants grown from crosses I made in 2014 finally started to bear nuts, and some of those nuts are notably bigger than most other Midwest hybrids. These are what we’ve been calling our “2nd generation”, with the 1st generation being those I mentioned above. I had been despairing about the progeny from my controlled crosses, because none of the crosses I made in 2012 or 2013 look very desirable. However, not only do the 2014 progeny have larger nuts, but some of them are high yielding too. Often there is a trade-off between nut size and yield, so I have been very reassured to see that some of these plants may capture both.
What makes this work especially interesting is that we have started to observe some clear family patterns. It's gratifying to spot a plant in the row and say "I bet I know what the parents of that plant are", look at my record and see that I'm right! Part of what plant breeding takes is simply learning to recognize the faces in the neighborhood.
It's still too early to know if these plants will continue to bear well. Given that we have 10,000 such seedlings in the field, the probability that several of them will combine many of the traits we're looking for and over multiple years, is good. We like to evaluate them for at least three years before selecting them for replicated trials, after which it will take about another seven years to propagate them and grow them out to see which perform well in multiple locations. By about 2030 we should know which ones are worth micropropagating to send out to growers.
Third, this year we harvested a lot of seed from the controlled pollinations that I reported on in my last blog post. I estimate we harvested about 10,000 seeds, so assuming we get 50% germination, a year from now we'll be very busy transplanting. (About half of those will go to the University of Wisconsin, where a post-doctoral student will be studying their genomics in order to develop better breeding strategies.) Then, assuming we chose the right parents to cross, in about 2026 we should be at about the same stage with this 3rd generation of improved Midwestern hazelnuts as we are now with our 2nd generation. That means they ought to be available to growers in about 2036-17 years from when their seed was pollinated! Hazelnut breeding is a slow process, but fortunately, we don’t have to wait until 2036 for the first results to be available. Those might be coming just next year!