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What's Hoppening: Musings from the Hopyard!

Hop Plant Growth Phases from Spring to Summer

Posted: June 30th, 2016 by hoppenin

As we’ve transitioned from spring to the official start of summer on June 21, our hops have been going through all sorts of physiological changes. Technically speaking, hop plants go through a number of growth phases throughout the year, called “phenophases.” Back in 1995, German researcher Rossbauer and colleagues published an article, outlining specific phenological growth stages of hops, as follows:
HPA - Hop Growth Stages Cover Photo with rossbauer cropped

  • Stage 0: Sprouting
  • Stage 1: Leaf development
  • Stage 2: Formation of side shoots
  • Stage 3: Elongation of bines
  • [They did not include a stage 4]
  • Stage 5: Inflorescence emergence
  • Stage 6: Flowering
  • Stage 7: Development of cones
  • Stage 8: Maturity of cones
  • Stage 9: Senescence, entry into dormancy
Main hop bines reach the top wire (6/29/16)!

Main hop bines reach the top wire (6/29/16). Now we’re ready for the reproductive phase!

While knowing when these individual phenophases occur may help us better fine tune the timing of our management practices, we generally lump hop growth into two phases–vegetative and reproductive. And, because hops are photoperiod sensitive (meaning that day length drives their production), the summer solstice generally marks the transition from their vegetative growth to reproductive growth.

During the spring months, hops focus their growth in the main bines, which climb upright, as well as the leaves growing on these bines. While the day length continues to get longer, the plant is pushing to get the main bines as tall as possible. The amount of vegetative growth ultimately determines how much the plant will yield, so it is important to manage plant health aggressively during this time.

Lateral bine development.

Lateral bine development.

By June 21, hopefully the main bine has reached the top wire of the trellising system (16 feet) since after that point, the length of day gets shorter, and the plants will transition to the reproductive growth phase. The plants may grow a bit taller but vertical growth generally slows. Instead, the plants focus on growing lateral shoots extending from the main bines where the hop cones form. From this point, we’ll see the production of burrs which develop into flowers and then cones.

And in a couple months, before we know it,  we’ll be harvesting our hops! Until then, keep calm and hop on…

Minor Pests = Minor Problems!

Posted: June 22nd, 2016 by hoppenin

The three major pests of Northeastern hopyards—potato leafhoppers, two-spotted spider mites and hop aphids—can cause significant economic losses. For that reason, we keep a close eye on their populations in our research yard by scouting weekly.

Hop looper.

Hop looper.

From time to time, other pests pop up in our hopyard, but because they don’t seem to affect yields, we consider them to be minor pests. We have been seeing greater-than-normal numbers of hop loopers chewing their way through hopyards in Vermont this season. These lime green caterpillars with characteristic “racing stripes” appear to only inch along, but they can defoliate bines at pretty good clip. However, because they don’t cause economic injury, nobody should be losing any sleep.

Another minor pest that we usually find in Northeastern hopyards is, fellow defoliator, the eastern comma caterpillar. Covered with ominous looking spikes, these caterpillars are harmless to the touch and are seemingly harmless to hop grower’s bottom line. In some years, they can easily be found chewing up our bines, but this year it seems they have taken a back seat to the loopers.

Eastern comma caterpillar.

Eastern comma caterpillar.

An additional minor pest poking tiny holes in our hop leaves is the hop flea beetle. The characteristic shot-hole damage of these jumpy little fellas is never found above knee height, and doesn’t seem to affect mature plants.

We have also spotted a variety of other pests that are present at very low numbers in our yards—other caterpillars, thrips, froghoppers, etc.—but like all minor pests, they are of relatively minor concern.

In case you were wondering, there is one pest commonly found in Northeastern hopyards that is conspicuously absent from this blog post–the Japanese beetle! Depending on where you are located and who you talk to, these little ninjas may strike fear into the hearts of growers of many crops (including hops) or merely evoke a passing thought. Regardless, expect to see the skeletonized leaves in the wake of their feeding in your hopyard over the course of the next few weeks.

And of course always remember, keep calm and hop on…

Potato Leafhoppers Have Arrived!

Posted: June 7th, 2016 by hoppenin

First, second, and third instar potato leafhopper nymphs.

First, second, and third instar potato leafhopper nymphs.

It is leafhopper season again and those pesky insects have been spotted at our research hopyard at Borderview Research Farm, in Alburgh, Vermont.  This is a great time to start scouting for insects as well as for disease to ensure proper management of all hop pests. So far, this season has not been conducive for the hop pests that thrive in wet conditions, such as downy mildew and aphids, but the potato leafhoppers have arrived right on schedule.  Potato leafhoppers are migratory insects transported via wind currents from the southern United States, generally appearing in the Northeast between late-May and mid-June.  Our first sighting was on June 2, 2016.

To scout for potato leafhoppers, examine the back of a hop leaf for little torpedo shaped insects with distinctive green coloration.  Young potato leaphoppers, or nymphs, are flightless insects and can be seen scuttling around the leaves in a side-to-side fashion. Adults can also be scouted by checking the backs of the leaves, or for a easier approach, you can just give your plants a little shake and watched the adult potato leafhoppers fly off the plant or jump from leaf to leaf.  At our hopyard, we have only observed adults so far, but that means the nymphs aren’t far behind. Within one season, there are usually two or three generations of leaphoppers present in northern hop yards.

Hopperburn: visual V-shaped chlorosis injury caused by potato leafhopper.

Hopperburn: visual V-shaped chlorosis injury caused by potato leafhopper.

Potato leafhoppers are an economically damaging pest that can cause hopper burn, which is a distinctive yellowing of the leaves in a V-shaped pattern, eventually leading to leaf tip necrosis.  Hopper burn decreases leaf photosynthetic activity and can cause plant production to suffer.

One of the best ways to combat potato leafhopper damage is by planting an alfalfa or red clover trap crop. Potato leafhoppers prefer to feed on these legumes and can be redirected from your hop yard with strategic plantings on the outskirts of the yard or in the drive row.

Stay vigilant and keep scouting!

Important Hop BULL-etin

Posted: May 18th, 2016 by hoppenin

Stringing our hop yard.

Stringing our hop yard.

Things are now in full swing at our hop yard at the Borderview Research Farm!

Last week, we sprayed Avenger, an organic herbicide (OMRI listed), to set back the weeds in preparation for mulch application. We will go back through and hand weed up close to the plants before applying the mulch near the end of the month.

This week, our big project is stringing the hopyard! Our planting density is between 622 and 872 plants per acre, and we tie 2 strings per plant. Our density is on the lower side because of the experimental layout for our hop research. Commercial yards are often closer to 1,000 plants per acre.

Bull shoots growing above the rest; don't train the bulls shoots, remove them.

Bull shoots growing above the rest; don’t train the bulls shoots, remove them.

In preparation for training, we have an important BULL-etin for you: have you ever noticed that the first, most aggressive shoots that come up from your plants are different from the rest? These are called “bull shoots,” and are generally the first shoots to emerge. They tend to be stiffer, more brittle and more hollow than the bendy, softer regular shoots, and can sometimes be more purple in color. Bull shoots produce fewer sidearms than regular shoots and, therefore, yield fewer cones! Therefore, we recommend that you remove them by cutting them or yanking them out – they should yank out pretty easily. Removing the bull shoots will allow your hop plants to focus their energy on the secondary shoots, which have more frequent (close together) leaf nodes and therefore will produce more sidearms and more cones.

We’ll keep you posted on our progress. Until the next post, keep calm and hop on!

Gearing Up for Training

Posted: May 3rd, 2016 by hoppenin


Hops making their spring debut at Borderview Research Farm in Alburgh, VT on April 29, 2016.

Our hop bines have finally made an appearance and we are now gearing up for training.

Hops in the Northeast should be trained as early as possible. Keep in mind that it takes about 30 days after crowning for plants to be ready to train, so if you haven’t crowned by now, skip it! In time, our team hopes to identify more precise times to crown and train that are applicable to our region.

Crowning and training dates vary substantially by variety. Aroma hop varieties tend to grow slower than alpha varieties. Therefore, aroma varieties should be trained first and early. Hop farmers in the Pacific Northwest have farm- and variety-specific training dates. Unfortunately, the dates used by farmers out west are way too early for our short growing season (we’d train then if we could!), but they might give use some insight into the relationships between varieties.

Below are typical training dates for Washington:

  •     Cascade, Centennial: May 1-5
  •     Nugget, Chinook: May 8-12
  •     Galena: May 17-21

Last year at Borderview Farm in Alburgh, Vermont, we trained our hops (3 to 4 bines per string) during the week of May 20.

With hop production, we pay attention to the summer solstice. In general, the vegetative part of the season occurs before June 21 — this is the period where hop plants will grow quickly, putting on a large amount of biomass in a short period of time. The reproductive growth phase occurs from June 21 until harvest — this is when we’ll see the production of burrs which develop into flowers and then cones. Hop plants are triggered to produce burrs based on a combination of day length, the number of nodes present, temperature, and the environment. Each variety has different sensitivity to day length (photoperiod).

Our training dates last year gave plants 33 days of vegetative growth to reach the top of the trellis and have enough vegetation and developed side arms for cone development. That means plants needed to grow 6” per day, to reach the top of the 192” trellis by June 21. Many did make it by then, but we wish we had been able to train earlier so that all could have made it.

Farms in the Northeast can find the best dates to crown and train hop varieties by documenting when you crowned and trained each variety. Carefully note the day that each variety flowered, and the harvest date. Train Cascade first and as early as possible. Fit in other varieties based on the date they produce burrs on your farm in relation to each other. And, when in doubt, train as early as possible!

Until next time, keep calm and hop on.

Hop Equipment Info Gets New Home

Posted: April 18th, 2016 by hoppenin

hopequipsiteWorking closely with farmers, UVM Extension agricultural engineer Chris Callahan, UVM engineering students, and Heather Darby and the staff at the NWCS program have developed prototypes for small-scale hop-related equipment. The info for this equipment had been posted on a wiki site which was giving us (and many of you) some trouble.

So, we’ve created a new webpage page to view information on the Hop Oast, Hop Harvester, and small-scale hop balers. Working with Chris, we’ve moved the plans for the oast and harvester over to FarmHack, a website maintained by a community of farmers that share information in an open-source format embracing inventing, fabricating, tweaking, and improving equipment and things that break.

We think farmer-to-farmer collaboration is key to improving these and other equipment innovations, and feel that FarmHack is a good fit. Anyone can join FarmHack for free and, in addition to hop equipment, there are hundreds of other equipment innovations posted on the site used by farmers worldwide.

Missed the 2016 VT Hop Conference? Proceedings are Now Available

Posted: April 11th, 2016 by hoppenin

IMG_0522If you missed the 2016 Vermont Hop Conference or would like to review some of the presentations, the online proceedings are now available.

The 7th Annual Vermont Hop Conference was held on February 19, 2016 in Colchester, Vermont, and was organized by the University of Vermont (UVM) Extension Northwest Crops and Soils Program. It included presentations from experts and farmers from around the country who addressed agronomic and soil fertility considerations, spring training, scaling up production, recent UVM hop research findings, and more.

Video recordings of all presentations have been compiled into an online proceedings, available at: https://catalog.extension.org/product?catalog=VT-2016Hops.

There is a one-time fee of $35 to access the proceedings. Please let us know if you have any questions.

Hopping into Spring with Crowning

Posted: April 4th, 2016 by hoppenin

Welcome to another hop season! We are gearing up for the growing season and first on the to-do list is spring crowning.

As you know, Downy Mildew (DM) is a major concern for us in the Northeast and we must use every tool we have to manage it. DM can overwinter in the plant crown and will emerge with the first shoots–if left unchecked, it can spread and try to increase its foothold in your yard.

“Crowning” is the practice of removing new growth as well as the very top of the hop crown early in the season. Removing new growth without going as deep as the crown is often referred to as “scratching” or “pruning.” Crowning is typically accomplished through mechanical means, but removing shoots by other means such as chemical burndown or flaming is also known to be effective, but does not affect inoculum living in the crown.

Crowning reduces the amount of plant material that is above ground and available for DM spores to land on during wet spring conditions that are ideal for infection. Cutting the plant back is an advantage for managing disease; however, it also reduces the time the plant has to grow to the top of the trellis, which may likely reduce yield. This is why the timing of crowning is so critical – we want to crown early enough that the plant has ample time to grow back.

Our team has been conducting trials on timing at our hopyard at Borderview Research Farm in Alburgh, Vermont. So far, our trial results suggest that  crowning in mid to late April has yielded the best results. For example, in 2015, our early crowning date (23-April) yielded better than the late crowning date (13-May) AND performed better than control plots that were not crowned at all. The later date in May had a larger reduction in disease, but suffered in yield. So, it seems like early crowning is the sweet spot between good yield and disease management. See the full results of our crowning trial here: 2015 Hop Crowning Trial.

We think that crowning early may have the added benefit of allowing the soil to warm quicker by removing excess material covering the soil and generally turning/aerating the soil a bit. We mulch our hop yard, and the mulch can act as an insulating layer, keeping the hops cooler than the air temperature in spring. The high yields from our early-crowned hops may be partly due to warmer soil temperatures.

Walk-behind trimmer outfitted with crowning blade.

Walk-behind trimmer outfitted with crowning blade. Photo credit: UVM Extension Northwest Crops & Soils Program.

Crowning Equipment Options

Want to know what equipment to use? There are several options!

For small acreages, if you are on a budget and/or would like to test crowning in a small section of your yard this year, it might make sense to use something similar to a walk-behind trimmer. We currently use this unit for crowning. It has been modified with a metal blade with teeth to better cut plant growth. One challenge to using this piece of equipment, other than time, is consistency. Where other implements cover the whole bed at a constant height, this trimmer is used to target the specific plants as their shoots appear from the ground, and relies on the operator to maintain consistent depth.

Our team is currently shopping for a tractor-mounted crowner. The unit has sharp discs that prune back growth while the rotation of the discs spreads soil and mulch above the blades. This tool may be a good fit for those who hill their hops and need to cut the bed height down at the beginning of the season.

Crowner by John I Haas. Photo credit: UVM Extension Northwest Crops & Soils Program.

Crowner by John I Haas. Photo credit: UVM Extension Northwest Crops & Soils Program.

Other implements have tines that cultivate the soil surface and remove growth (like the John I. Haas crowner pictured on right). What ever equipment and technique you choose to use, crowning is an important practice for disease management, and also has a large effect on the growth timing of your plants. Remember that you want those plants at the top of your trellis by the beginning of July, so your crowning and training should be built around achieving that.

Stay tuned for future posts on training. Until then, keep calm and hop on!

Don’t miss out on attending our Vermont Annual Hop Conference!

Posted: February 12th, 2016 by hoppenin

IMG_0979WHEN:  Friday, February 19, 2016

TIME:  9:00 a.m. to 4:00 p.m.  Registration starting at 8:15 a.m.

PLACE:  The Hampton Inn Vermont Event Center at 42 Lower Mountain View Drive, Colchester, VT 05446

Join us to hear information about hop agronomy and fertility management, hop growing challenges in England (including diseases), scaling-up production, updated hop research, efficient management and trellis construction, training of your hop yard, and maintaining hop quality during and post-harvest.  View our detailed agenda.

Register today for the 2016 Annual Hop Conference!  And if you are unable to join us in person, choose to watch it via a live broadcast.

NOTE:  When arriving at The Hampton Inn, do not use the Front Entrance.  Follow the signs to the Conference Entrance (2nd driveway on right).  Then as you go around the building, you will see Entrance C to the Conference Center.  Please use this entrance.

Mark Your Calendars: NeHA Annual Meeting at Cornell Hops Conference, 12/5/15

Posted: November 5th, 2015 by hoppenin

The annual conference of the Northeast Hops Alliance will be held in conjunction with Cornell University’s Annual Hops Conference, scheduled for December 5, 2015 from 8 a.m. to 5 p.m. at Morrisville State College in Morrisville, New York.

This is a great opportunity to network with brewers, educators, and hop growers, as well as to learn the latest research on hop production. This year, speaker’s will include: Tim Weigle, Dave Combs, Dr. Rob Sirrine, Jessica Lyga, Rich Michaels, Dr. Paul Matthews, Kevin Riel, Dr. Chris Nyberg, Dr. Jason Townsend, Steve Miller, Dr. David Gadoury, as well as UVM’s own Dr. Lily Calderwood and Chris Callahan.

Registration is $75 for NeHA members and $85 for non-members–please plan to register by November 23. More information can be found in the October 2015 edition of the NeHA newsletter at: http://www.northeasthopalliance.org/ and/or at: https://events.cornell.edu/event/cornell_hops_conference.
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