July Nebraska Hop Update

Hops are in full reproduction growth mode, sending side arms out full of burrs that will soon be lupulin-filled cones. Early harvested varieties in Nebraska, such as Centennial and Willamette, have already developed cones, though their readiness for harvest is still a few weeks away. We are at a critical point in the season to take the necessary precautions to prevent advances of insect pests and diseases as cone development continues full force.

What should I be doing at this time in my hop yard?

You should be scouting at a minimum 1-2 times per week, walking your yard in different routes each visit, and if manageable, walking your entire yard each time. Identify pests and their economic thresholds, and treat accordingly.

You should be implementing cultural practices to encourage air movement and reduce disease and competition.

  1. Remove weeds in the hop rows to reduce competition for water and nutrients, and to help reduce disease pressure and increase air movement.
  2. Defoliation of lower leaves by mechanical hand stripping or application of AIM EC + crop oil should be done to remove the bottom 2-3 feet of leaves and excess shoots. Be sure stems are woody before chemical defoliation. Apply at a rate of 2-3.2 fluid oz/A to basal 18 inches of plants. When making additional applications, allow 14 days between applications. With harvest approaching, be aware of any chemical’s pre-harvest interval (PHI). AIM has a 7 day PHI.

Recently defoliated hop row in Michigan, July 2018.

What is happening in hop yards across Nebraska?


Downy mildew: Recent rain events, cooler temperatures, overcast days, and sitting water has been the perfect recipe for increased downy mildew presence. You should be making regular applications of fungicides, rotating modes of action to decrease chances of resistance development. With burr and cone development, it is especially critical to prevent downy mildew infections.

foliar DM 2018

Foliar downy mildew present on a cascade hop plant, July 2018.

Fusarium canker: Storms and wind events coupled with loose coir on trellises have and continue to cause breakage of bines around the base of the hop crown. Fusarium is a fungus that thrives in wet soils and has been known to cause minor issues in hop yards in Eastern Nebraska. Ensuring your trellis and coir is tight will help reduce instances of fusarium damage in your hop yard.


Question mark caterpillars: A new potentially problematic pest to hops in Nebraska (but has been recorded elsewhere) is the question mark caterpillar, Polygonia interrogationis. The damage is similar to that of Japanese beetles, with the potential of completely defoliating plants in a matter of days.

Japanese beetles: Japanese beetles continue to wage war against hops in the Eastern part of the state. Applications of bifenthrin appear to keep them at bay for 5 or so days. We are continuing to monitor changes in populations as the season progresses.

Minimal presence of twospotted spider mites (TSSM), potato leaf hoppers, grasshoppers and hop aphids are being reported at this time. It is important to scout regularly for these pests and treat when economic thresholds are reached. TSSM (threshold for treatment = 6-10/leaf) and hop aphids can potentially be quite detrimental and cause total yield loss in worse case scenarios.



Leaf mottling and other leaf discolorations are being reported by growers, indicating hop mosaic virus and potentially other viruses. Confirmed infections appeared in hop yards across the state are likely caused by infected plants at establishment. Be aware as you seek to expand your current hop yard or establish a new hop yard that the industry is unregulated in most states including Nebraska, and sources stating “propagation from virus-free mother stock,” “guaranteed virus free stock,” etc. does not guarantee anything. Be aware of spreading the virus among plants in known infected hop yards as well. If you have questions about reliable sources for hop plants, please contact me directly. You may find my contact information here. For testing, submit samples to the Plant and Pest Diagnostic Clinic at UNL. For directions on submitting samples, please visit: https://cropwatch.unl.edu/plantdisease/pest-samples.

Upcoming Events

To learn more about managing pests at this time of the season and what you should be doing to prepare for harvest, join UNL Extension & the Nebraska Hop Growers Association for a field day on July 21st at Oak Creek Hops in Kearney, NE, 10 am – noon, followed by a tour and discussion with the brewer at Thunderhead Brewing Co. (201 F Ave, Axtell, NE 68924). RSVP by emailing katie.kreuser@unl.edu or by selecting “going” on the facebook event here so that we have enough food and materials. 


Chinook hops happily climbing in late June, 2018.




Seasonal Hop Update

The summer solstice is behind us, and growers are watching as bines stretch to reach the top wire, and beyond in some instances. By this time during the season, growers are able to see which varieties are vigorous compared to others, and can makes notes for future determinations of spring pruning and training. Here in Nebraska, we experienced some above average temperatures leading up to Memorial Day weekend, and more recently in parts of the state, we watched a significant amount of rain fall and temperatures fell in to the 60’s. In looking at the forecast this morning, more high heat is anticipated in the coming days. Here’s what to keep an eye out for in your hop yards in the coming weeks.

  1. Heat/water stress: Symptoms such as leaf tip wilting or necrosis, or wilting bines could be a sign that your hops are not receiving adequate water. Plants have a significant more amount of biomass as compared to before Memorial Day, and should thus be given more water.
  2. Downy mildew: With recent rain and cooler temperatures, be on the lookout for foliar symptoms of downy mildew, as well as infected side shoots (pictured below.) For more on hop downy mildew management, read here:  https://nebraskabinetimes.files.wordpress.com/2018/04/hop-downy-mildew-nebguide.pdf

    downy lateral shoot

    A hop downy mildew infected side arm.

  3. Potato Leaf Hoppers: Numbers have been present and populations are increasing as reproduction occurs. Damage has been reported throughout the state. Their pierce-sucking mouth parts and saliva damage the leaves, causing severely damaged leaves to curl, and within days, a yellow halo and necrotic leaf margins become visible. While not economic threshold has been established, severe cases should treat with insecticides such as bifenthrin. Scouting of previously affected hop varieties should be spot checked multiple times per week, especially following storm events.
  4. Twospotted spider mites: While weather conditions are necessarily conducive for spider mite infestations, applications of insecticides for other insect pests, along with drying air and warming temperatures encourage building mite populations. Be aware, especially as flowers and cones begin to develop, as TSSM can cause complete economic loss. They are best managed while populations are low. Often times, TSSM will infest on the edge of a hop yard and move along the row and move inwards. Following spray applications or during ideal weather conditions, edges of hop yards should be scouted carefully.
  5. Japanese Beetles: Japanese beetles showed up in the past couple of weeks. Due to cool temperatures, their activity has been fairly minimal, however, some isolated populations have been severely skelotonizing plants. Generally, the majority of concern for damage by Japanese beetles is in regards to the leaves, however, in a few rare cases, they have nibbled on the cones.
  6.  Weeds: I cannot say enough regarding weed control as the season continues to progress. The competition for water, nutrients, and light are detrimental to your yields. It is important to control weeds – using hand weeding and careful applications of herbicides. Your soils should be nice and soft from recent rains – now is a great time to take advantage and do some hand pulling 🙂
  7. Nutrient management: Growers are beginning to see burring if they haven’t already. Now is the time to begin scaling back nitrogen applications, however, as a grower in the height of the season, you should continue to make small (2-5 lbs/A) weekly applications of nitrogen to help the plant maintain its large biomass as it prepares to set cones. Now is also an excellent time to take samples for petiole testing to analyze a variety of nutrient levels in your hops.
  8. Viruses: Recent high temperatures may be the cause of foliar symptoms of viruses such as apple mosaic virus appearing in hop yards. Be on the look out for these symptoms. If you think you have symptoms present, please contact me at katie.kreuser@unl.edu with a photo of the infected plant/leaf.
  9. Scout: Scout regularly! It’s far easier to treat problems as they arise than when they’re much larger.


RSVP for our upcoming field day!

July Field Day –  Oak Creek Hops & Thunderhead Brewing Co.

Kearney, NE

Saturday, July 21, 10 am – 12 pm

Join us for a light breakfast, a tour of Oak Creek Hops, and a seasonal pest management update. Attendees are welcome to convene for lunch following at Thunderhead Brewing Company. Lunch and beverages will be available for purchase. RSVP to katie.kreuser@unl.edu.


Nebraska Hop Seasonal Update

Hops are well on their way up the coir across the state. Here’s what you should be aware of in your hop yards currently.

  • Agronomic practices.
    • Training should be completed at this time. Bines should be wound clockwise around coir or twine.
    • Extra bine removal. This improves airflow reducing downy mildew risk. This can be completed manually, or chemically once bines are 6-10’ tall and woody towards the base. Chemicals, such as carfentrazone (Aim) can be used. The bottoms 3’ should be removed.
    • Weeding. Along with extra bine removal, this also improves airflow and reduces disease risk in hop yards. At this time of the season, Clethodim (Select Max) may be applied to annual and perennial grass weeds; glyphosate, pelargonic acid (Organic), and 2,4 D may be applied to broad leaf weeds. ***Read the chemical’s label and follow directions carefully. Be aware of wind speed and temperatures when applying as drift may occur. Most herbicides will damage hop plants when in direct contact. Photo below of glyphosate damage.glyphosate damage 3
    • Irrigation. Regions of the state vary dramatically in rain. Ensure that your plants are receiving adequate water to continue rapid growth. Hops need 10-14” of water per day. Watch for heat and water stress during periods of high heat and lack of rainfall.
  • Scouting. 
    • It is important to pay close attention to your hop plants during the growing season to prevent major infestations.
    • Walk diagonally across your yard in order to cover both edges and inner portions of your plants; revisit hot spots for disease or insect pressure in the past. Scouting should be done once per week during the growing season at a minimum.
    • Proper diagnosis ensures that the correct treatment can be pursued.
    • Be aware of nutritional deficiency symptoms.
  • Fertility. 
    • Late May to late June is a critical time frame for hop production & fertility applications.  
    • Hops need adequate Nitrogen (N) and other nutrients to reach the top wire prior to beginning reproductive growth in late June/early July.
    • Liquid applications of N through drip are best, however, granular may be your best option. When applying granular, work N into the soil and add water.
    • To determine where your hop plants N needs are in the middle of the growing season, measure the internode length at the end of June. If the internodes are longer than 8”, then too much N has been applied. If internodes are shorter than 8”, more N is needed next season.
    • Remember that some N is still needed when hops are in the reproductive phase. They are adding a lot of biomass, and need small amounts of N periodically.
    • In addition to soil tests each year, it is recommended to conduct tissue tests/petiole tests to provide a detailed nutrient analysis. If deficiencies are found, foliar or granular treatments may be applied.
  • Pests
    • Downy Mildew. Disease pressure has been significant despite recent high temperatures. If symptoms are present in your hop yard, treat accordingly.
    • Potato Leaf Hoppers (PLH). Adults arrived in recent weeks in storm currents.
      • What to look for: tiny, bright green, wedge shaped insects; leaf curling; yellowing halo and/or burned leaf margins (“hopper burn”).
      • While there is no economic threshold known for PLH, it is recommended that treatment begins when ~6 PLH are present per leaf. There are beneficial insects and sprays to control PLH. Be aware insecticides will wipe out beneficial insect populations too. If opting to treat, scout regularly following applications for secondary infestations of spider mites.
      • PLH are cultivar specific (Mt. Hood, Tettnanger, Newport, Chinook, and Triple Pearl).IMG_4483
        • Twospotted spider mite. If you grow in dry areas, be aware of mites. Infestations often begin in one corner and spread.
          • What to look for: bronze or white appearance on leaves from feeding of mites reducing photosynthesis (heavy infestations).
          • If more than 4 spider mites are detected per leaf, a pesticide application may be necessary. Mites can cause total crop loss if left untreated.
        • Hop aphids. These may begin to appear later in the season, but growers should be aware of aphids when they are scouting.
          • What to look for: pear-shaped, 1/10”, some have wings.
          • They remove nutrients and moisture from plants with sucking mouth parts, and secrete honey dew which encourages secondary organisms to grow such as sooty mold. Both damage the quality of hop cones.



***Treated Acres versus Sprayed Acres: When planning applications of any herbicide, one should refer to the label before taking any action. Generally, application rates are listed on labels as pounds, pints, or quarts per acre. Most herbicides are applied over the hop rows, otherwise known as banded applications. Calculating the correct amount for a banded applications is important for your hops. There are 43,560 square feet in one acre. In a 1 acre hop yard with 14 feet between rows, there are 3,111 feet of row (43,560/14). Bands are approximately 4 feet wide, resulting in 12,444 square feet or 0.28 acre of area to treat (3,111 x 4). Following the label without calculating banded applications could result in much higher concentrations of herbicide being applied, and therefore causing severe damage to your hop plants.
Steps to Calculate Banded Rates1
A. Divide total square feet of one acre by row spacing in feet to determine feet of row per acre. (43,560/14 = 3,111 ft)
B. Multiply the feet of row per acre by the band width in your hop yard to determine the square footage to be treated. (3,111 ft x 4 ft = 12,444 sq ft
C. Divide treated area by area of one acre to calculate the percentage of one acre to treat. (12,444/43,560 = 0.28 = 28%
D. Multiply the percentage of acre to be treated by the label broadcast rate (in this example, 1 pound). 0.28 x 1 pound = 0.28 pounds
E. Multiply the percentage of acre to be treated by the recommended volume of water for an acre to determine the amount of water to use per acre. 0.28 x 30 gallons = 8.4 gallons
1. ID-462-W – Hops Production in Indiana, Integrated Pest Management Guide for Hops in Indiana 2015


Upcoming Events – Save the dates!

July Field Day –  Oak Creek Hops & Thunderhead Brewing Co.

Kearney, NE

Saturday, July 21, 10 am – 12 pm

Join us for a light breakfast, a tour of Oak Creek Hops, and a seasonal pest management update. Attendees are welcome to convene for lunch following at Thunderhead Brewing Company. Lunch and beverages will be available for purchase. RSVP to katie.kreuser@unl.edu.

August Field Day – 6th Meridian Hops

Yankton, SD

Saturday, August 4

UNL Hops is teaming up with the South Dakota Specialty Producers Association & 6th Meridian Hops to present a Growing Hops Tour. The event will include a tour of 6th Meridian Hops, oasting, baling, and pelleting demonstrations, a presentation on “Late Season Downy Mildew Management,” and opportunities for networking. Hop producers, interested growers, brewers, and the general public are welcome. RSVP at Growing Nuts & Hops SDSPA ToursAugust 4th Agenda. 


Harvest Demonstrations

So your hop cones are ready for harvest. Now what? Join Nebraska Extension for demonstrations of the Hopster 5P hops harvester in action.

Friday, August 17

Panhandle Research & Extension Center, Scottsbluff, NE lead by Stacy Adams and Gary Stone.

Friday, August 24

UNL East Campus, Lincoln, NE lead by Stacy Adams and Katie Kreuser.

Hop Training

Hops across Nebraska are vigorously regrowing from chemical and mechanical pruning events in recent weeks, and the time to train is here.

Pruning and Training Record 5 11 2018  c.xlsx.jpg

“Training time is one of the most critical factors in determining yield, due to the relationship between plant height and day length, which affects flowering.” 

-Spring Activities, USA Hop Growers of America

Training you hops involves the selection of 2-3 bines of about 2 feet in height per string per plant, and guiding them clockwise around the string. The plant’s trichomes and response to touch and light will continue to guide the bines up the string. The remaining bines may be chemically burned down later in the season. You may find that some varieties, like Chinook, have already begun training themselves up the bines (and often more undesirable bull shoots). You should remove those bines from the string and re-select bines to train in this case.

For those with baby hops, you should not prune until the following season.


Research has shown that when determining when to train your hops, it is better to train too early rather than too late. In one such study in the Czech Republic, studying some of the less vigorous hop varieties, they found that yields were reduced by about 10% when trained to early, however, when trained too late, yield loss averaged 40%. In general, varieties harvested early should be trained early, and those harvested later should be trained later. Each variety is case by case though, so going by seasonal notes is in a grower’s best interest. No matter your location, all hops should be trained by June 1. (If you are growing on a trellis other than a commercial 18′, recommendations for training date will vary.)

With a few years of hop agronomic data now collected in Nebraska, we’re able to make better predictions about optimal training dates. In your own hop yards, records of spring weather, plant vigor, fertility applications, and other data is critical to select optimum pruning and training dates in future seasons.

For controlling weeds during this time of the season, growers should focus on grassy weeds and wait until bines are around 8-10 feet tall to control broad leaf weeds.

Scouting is important throughout the season. Keep an eye out for downy and powdery mildew, two spotted spider mites, hop aphids, and potato leaf hoppers that will blow in with storms. Walk different routes through your hop yard at least once each week, and keep detailed notes.


*2018 Nebraska Hop Acreage Survey*

Nebraska Hop Growers: In the coming weeks, we will be contacting you through the Nebraska Hop Growers Association or through the Nebraska Hop Extension Listserv to collect information for the USDA NASS. We will be asking for your name or name of your hop farm, the county where you’re growing, and your acreage or number of hop plants strung for 2018 harvest. Please plan to be a part of this survey as it helps us in future funding opportunities including supporting Nebraska Extension agent support.

Thank you in advance!




  1. Introduction to Hop Production
    • Friday, June 8, 4-6:30 pm
    • Plant Science Hall, Room 199; Hop yard tour weather permitting
    • Cost: $10
    • Email Katie at katie.kreuser@unl.edu to register.

Field Days

  1. Saturday, June 2: Homestead Hops, York, NE
    • 8:30 am – light breakfast & socializing
    • 9:00 am – hop yard tour and pest management update
  2. Saturday, July 21: Oak Creek Hops, Kearney, NE
    • 10:00 am – light breakfast & socializing
    • 10:30 am – hop yard tour and pest management update


**3rd Annual Nebraska Grower & Brewer Conference**

January 13-14, 2019 (Sunday-Monday), Embassy Suites, Lincoln, NE

Hops & Nitrogen Use

Hops need both macro and micronutrients to carry out the necessary plant functions to produce their cones each season. Nitrogen is one of the most, if not the most, important nutrient in order for it to reach the top wire and support the biomass the plants build as it matures each growing season. Hop variety, application timing, the type of nitrogen applied and the soil type in which your hops are grown are factors to consider when developing a fertilization plan for optimized growth.

From the moment hops break dormancy, nitrogen is required. This is because at that time, they are using carbohydrate reserves from the previous season until photosynthesis resumes in the new season1. The total nitrogen applied each season is “the amount needed to replace what has been taken up by the plant biomass for fully-grown bines, is approximately 110 lbs/ac/year (cones-45 lbs/ac, crop residue-65 lbs/ac)2.” Depending on soil and varying management practices, hops have a nitrogen use efficiency of about 65%, suggesting that 35% of nitrogen applied is lost to the environment through leaching, etc. If hops need 110 lbs N/ac/yr, but are only taking up 35% of that applied, then about 170 lbs N/ac/yr should actually be applied. (Nitrogen fixing, compost and other additions should be subtracted from that amount.) When comparing one spring banded application to many fertigation applications through May and June, a greater loss is anticipated from the former scenario. Similarly, when growing hops in regions of sandy soils, higher rates of nitrogen are recommended to be applied. Upon reaching the end of June, when hop plants transition from vegetative growth to reproductive growth, a grower should have added about 150 lbs N/ac cumulatively. Growers with varieties that perform less vigorously may benefit from addition nitrogen, whereas more vigorous varieties may need less nitrogen. Baby hops, or first year plants, require about 80 lbs N/ac in total.

To gain a better understanding of overall season nitrogen applications, view a graph “weekly and cumulative nitrogen application for hops in Michigan” on page 15 in the 2018 Michigan Hop Management Guide. While the onset of the spring hop season is delayed in Michigan compared to Nebraska, the bulk of nitrogen should be applied in the 1st-3rd weeks in June. Due to the amount of biomass that hop plants continue to put on as they flower and develop cones, nitrogen applications should continue, but taper significantly in amounts applied.

One way to gauge your plants’ response to nitrogen applications is to measure internode length near the end of June. If internode lengths are greater than 8 inches, nitrogen applications should be reduced. Similarly, if the internode length is less than 8 inches, then a grower should increase their nitrogen applications. Signs of nitrogen deficiency include stunting, yellowing leaves, reduced growth, and poor cone development.

Growers who notice small leaves emerging from their cones close to or during harvest are seeing a symptom called “angels wings,” which occurs when too much nitrogen is added too late in the season. Keep in mind too that excessive applications of nitrogen can lead to disease and insect issues.

angel wings

A hop cone with “angel wings.”

  1. Gingrich, G., J. Hart, and N. Christensen. 2000. Fertilizer Guide: Hops. FG 79. Oregon State University, Corvallis, OR.
  2. Lizotte, E. and R. Sirrine. 2018. Michigan Hop Management Guide. Michigan State University, East Lansing, MI.

To prune or not to prune.

Spring in Nebraska went from zero to sixty quickly. Weather patterns shifted, and hop plants emerged and took off in the warming sun and soil. For hop growers looking back at last year’s field notes, this is not a time to panic. I repeat. This is not a time to panic. This spring is rather normal for Nebraska, just not the norm of the past few years. So let’s talk about preparing for training — pruning.

A general rule of thumb for crowning, the practice of removing the top part of the hop crown prior to or just following hop emergence, requires a hop plant ~3 weeks for recovery and new shoot growth. This is a recommended practice for those growing in clay soils or on hills. Pruning is the practice of removing hop shoots at the soil surface, and is used to time shoots for the ideal training date. For some growing regions, late spring arrivals may mean that there is no time for a single pruning, whereas other regions may prune multiple times with early spring vigor to properly time training. Generally, hops take ~2 weeks to fully recover from a pruning.

Now with this in mind, we’re at April 30th and some of you have shoots 8-10″ tall and haven’t pruned yet. Training is recommended to occur around May 21-25th in Nebraska, however, we have begun a study to fine tune this recommendation. If you time pruning with those training dates, you have ample time to prune. Keep in mind too, the studies of pruning and training that have been conducted elsewhere have shown that yields are far more negatively affected by early training than late training (by 10-30% in yield reductions).

Questions? Contact Katie Kreuser at katie.kreuser@unl.edu.

hops pre pruning

A Chinook hop plant on UNL’s East Campus awaiting spring pruning. (April 24, 2018)


  1. Introduction to Hop Production
    • Friday, June 8, 4-6:30 pm
    • Plant Science Hall, Room 199; Hop yard tour weather permitting
    • Cost: $10
    • Stay tuned for registration information.
  2. Hop Scouting Workshop – Midwest Hop Producers
    • Saturday, July 14, 8:30 am-4:30 pm
    • Cost: $150
    • Stay tuned for registration information.
  3. Hopster Harvest Demonstrations
    • Friday, August 17, Panhandle Research and Extension Center, Scottsbluff, NE
    • Friday, August 24, UNL East Campus hop yard, Lincoln, NE

Field Days

  1. Saturday, June 2: Homestead Hops, York, NE
    • 8:30 am – light breakfast & socializing
    • 9:00 am – hop yard tour and pest management update
  2. Saturday, July 21: Oak Creek Hops, Kearney, NE
    • 10:00 am – light breakfast & socializing
    • 10:30 am – hop yard tour and pest management update
  3. Saturday, August 4: 6th Meridian Hops, Yankton, SD
    • Full day field day including a hop yard tour; harvest, drying and baling demonstrations; late season downy mildew management and more.
    • Social to follow; food and beverages will be available to purchase through Counterfeit Curbside.
    • Stay tuned for registration information.


**3rd Annual Nebraska Grower & Brewer Conference**

January 13-14, 2019 (Sunday-Monday), Embassy Suites, Lincoln, NE

Hop Yard Updates

It looks like spring might finally make an appearance in the next week or so. Hopefully that is the case because the hops have some growing to do! Despite some cold temperature and snow recently, hops are beginning to emerge, thanks to some sunshine, warmer temperatures and plenty of spring time moisture. Soil temperatures, emergence and growth may be behind in comparison to last year, but last year, everything was ahead. (What does your field notebook say around this time last year?) For preparation and tips on crowning and pruning, you can refer to an earlier post on Spring Pruning Practices. Below are hops emerging on UNL’s East Campus plots on April 16, 2018 prior to any pruning.


While pruning, keep an eye out on your plants for weeds and signs of downy and powdery mildew. This is exceptionally important if you had either  disease presence in your hop yard last year. In preparation for management, I have a few resources linked below to help with herbicide use and weed management; downy mildew management, fungicide use and resistance management. Print and share these resources as needed.

Nebraska Herbicides for Hops

Nebraska Fungicides for Hops

Hop Downy Mildew NebGuide

To check for registered fungicides, herbicides and insecticides in Nebraska, you can visit the Nebraska Department of Agriculture’s Pesticide Registration website.

For upcoming UNL Hop Workshops & Events, visit our website. You can follow along on Twitter and Facebook.