Ready for Hop Harvest?

It’s almost harvest time, folks! With such a hot, dry year, be prepared for some varieties to be ready earlier than usual. Remember to check the labels on any pesticides you are using to allow the appropriate window between the last pesticide application and harvest.

Have you seen our fact sheet on determining when hops are ready for harvest? Check it out here:

Also, we have a handy calculator for dry matter/moisture content math:

Hop harvest timing from 2012 to 2015 at Borderview Farm, Alburgh, Vermont.
Hop harvest timing from 2012 to 2015 at Borderview Farm, Alburgh, Vermont. Click on image to enlarge.

In addition, we put together a chart of harvest dates in our hopyard over the past four years. If you’re located in the Northeast, this might help you ballpark your harvest window.

Note that we use two opposite terms at hop harvest time–dry matter and moisture content. We harvest at a dry matter of 22 to 27% (that’s 73 to 78% moisture). Then, when we dry hops after harvest, we dry them to a moisture content of 8 to 10% (that’s 90 to 92% dry matter). This interchange of terms might seem confusing but that’s just what is used throughout the industry. One more note on dry matter: Since dry matter is the opposite of moisture content, dry matter will increase as hops mature in the field. So if you measure your hops at 18% dry matter, they’re not ready yet!

Good luck with harvest and remember to keep calm and hop on!

See Hops at Upcoming Annual Field Day, July 28

Bird's eye view of our hopyard.
Bird’s eye view of our hopyard.

WHAT:  UVM Extension Northwest Crops and Soils Field Day

WHEN:  Thursday, July 28, 2016

TIME: 10 am to 3:30 pm

WHERE: Borderview Farm, 146 Line Road, Alburgh, VT

If you haven’t had a chance to sign up for our Annual Crops & Soils Field Day, register today, as it is just around the corner.  Our theme this year is “Eat It, Drink It, Feed It, Fuel It – Conducting Food System Research Crop by Crop” and we will be featuring the end-products made from the crops we’ve been researching at a ‘Tasting Tent.’

We will be touring the hopyard along with other research trials we are conducting. Hops specific presentations will include:

  • Small-scale harvesters by
  • Fertility in our hopyard
  • Pest scouting and identification
  • On-going research trials on Biofungicides and crowning
  • Q and A with the team
Folks tour the hopyard at past annual field day.
Folks tour the hopyard at past annual field day.

Highlights of the day will also include:

  • Tour of research trials
  • New research crops including industrial hemp and milkweed
  • Tasting Tent – several Vermont businesses with locally grown products
  • Innovative equipment
  • Organic weed control strategies
  • BBQ chicken lunch
  • And much, much more!

Register today!! Cost is $25 per person (non-farmer) and $10 per farmer.  Includes lunch and CCA credits.

See you at the Field Day! And until then, keep calm and hop on…

Summertime and the Living is Easy…Especially if You’re a Two Spotted Spider Mite

Adult female two spotted spider mite with prominent black spots on each side (photo courtesy of D.G. James).
Adult female two spotted spider mite with prominent black spots on each side (photo courtesy of D.G. James).

As we are approaching the hottest time of year, with temperatures projected for the 90’s midweek, it is a great time to remind you to be on the lookout for two spotted spider mites. These tiny cousins of spiders also produce webbing, though spider mites use it to protect themselves (from the elements, natural enemies or pesticides), not to catch prey. Spider mite damage occurs when they jam their mouthparts into, and then sucking the life out of, your hops.

Stippling caused by  two spotted spider mite damage.
Stippling caused by two spotted spider mite damage.

At this point of the season, spider mite feeding causes a characteristic stippling of leaves which, at low to moderate levels, doesn’t cause economic injury since there is no apparent effect on yield or quality later in the season. Heavy infestation of two spotted spider mites can lead to reduced photosynthesis or even defoliation. This has led to the economic thresholds in the Pacific Northwest ranging from an average of 5-10 mites per leaf in mid to late July. In other parts of the world, thresholds of up to 60 mites per leaf are used.

Two spotted spider mites on the underside of a hop leaf.
Two spotted spider mites on the underside of a hop leaf.

Hot, dry, dusty conditions, those typical of August, tend to favor rapid two spotted spider mite population growth. Unfortunately, August is also when hop cones are maturing. If spider mites make their way into cones there can be a decrease in quality, and severe spider mite infestations can cause hop cones to become brittle and shatter. So monitoring two spotted spider mites from now until harvest is crucial to ensure mite infestations don’t get out of control.

It is important to recognize that pesticide applications, particularly broad-spectrum insecticides and repeated application of sulfur, can actually exacerbate the problem. Following an insecticide application, spider mite populations are generally quick to rebound, much quicker than natural enemies like spider mite destroyers. This allows spider mites to reinfest your yard without any natural control. Whereas using selective miticides can enhance biological control.

For additional information on two spotted spider mites and much, much more, check out the newly updated Field Guide for Integrated Pest Management in Hops. And of course, keep calm and hop on…

Hop Plant Growth Phases from Spring to Summer

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!

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!

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

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

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

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

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:

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

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