A hop grower from Yakima gave a talk to some folks in Vermont about growing hops and mentioned that the first shoots that come up are essentially utilizing the sugars/carbs. that were produced and sent back down into the crown during the previous Fall. Apparently, this first flush of growth produces vines that can exhibit very uneven growth which would produce hops that would be in various stages of ripeness come harvest. During the second flush of growth, the plant is utilizing energy which is pulled from the roots which will give more even growth and harvest. I think the whole deal about bigger alpha may be eluding to the fact that certain varieties should be trained early or later to achieve the best crop. That all varies with variety. I’ll try to find the article.
Found the article and here’s a little bit;
After our vegetative stage is over, we’re entering the reproductive stage. By reproductive, I mean it is just
developing its cones. The plant has shifted all of its energy from that vegetative growth. It is shifting now
into the production of cones. The photosynthetic capacity of the plant at this point is maximized so it is
using all that energy basically to produce the cones. At this point, once those cones are mature it can
equal up to fifty percent of the above ground dry matter of that plant. At this point it’s futile to increase
the number of cones. Your yield is pretty much set in terms of cone number. But what you can do is
make sure you are managing the plant properly to get the maximum cone size. That is something you can
change. An unhealthy plant produces a smaller cone versus a healthy plant that produces a bigger cone.
This can be done through water management and nutrient management right at this period, they kind of
overlap. There is a preparation for dormancy. It’s not really a growth stage. I kind of made that up. But
your plant is preparing for dormancy. In August, it starts to push those starches down. It is creating the
starches needed to convert to soluble sugar for energy in the next year. Okay, like I said, that
photosynthetic capacity of the plant is maximized in mid- to late-July. That is what it is really using to
create next year’s energy. This is where Rick had mentioned the hand harvesting and leaving the vines
hanging. This is where that is really important because some varieties, their cones mature early. If you
are out there cutting the whole plant out of the field too early, you are not giving that plant the optimum
chance. Problem we have is that we have to mechanically harvest. We don’t have a choice. We’re not
going to go out and pick eight hundred eighty nine plants per acre by hand. We tend to leave some
material down at the bottom of the plant still green so it is there through the month of September to try to
push as much carb reserves as we can. You will never maximize the yield of a plant on an early harvested
Question: When you say you leave some green material down below, you’re doing your shoot pruning
and stuff, and you have your 4-6 vines that you train and take care of through the summer, in my
experience, I’ll still get a lot of green growth around the base throughout the summer. My tendency is to
leave some of those. Is that the stuff that you are talking about?
Answer: Yeah, I call it “sucker growth.” Leave some of that growth at the bottom. Let it crawl on the
ground. That’s where we tend to get our carb allocation back down to the roots. Some varieties, you
never can get it matched perfectly.
Here’s the whole thing. Very informative.
http://www.uvm.edu/extension/cropsoil/w ... script.pdf