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Roses in the Garden: Rosette Virus, Mosaic Virus, and Recommendations

Rose Rosette Virus…What does it look like?

By: Judy O’Mara

We’ve had several reports of rose rosette virus in the K-State Plant Disease Diagnostic Lab this spring. It is not hard to identify based on symptoms. Basically, the growth on the plant becomes increasingly deformed. It starts with an individual rose cane that either elongates, or gets bunchy with lots of shoots (witches broom). The foliage can be reddish-purple or green and strappy (see below). Very characteristic for rose rosette virus is the production of excessive thorns along the canes of the deformed shoots. Symptoms on the plant get worse over a few weeks. In an odd way, it can sometimes look like a bridal bouquet.

Left unchecked rose rosette virus will kill the infected plant and continue to spread to nearby roses via its insect vector (Phyllocoptes fructiphilus), an eriophyid mite. This tiny mite is not visible to the eye, resides in new growth and crevices, and is spread by the wind.

Pruning out deformed portions of the plant is not an effective control strategy as the disease can overwinter in the roots. Upon seeing symptoms, infected plants should be dug up (including the root ball) bagged, and removed from the site.

For more information on this disease see the K-State fact sheet on rose rosette virus.

Rose Mosaic Virus…How do you spot it?

By: Chandler Day

Have you seen yellow oak leaf or netted patterns on your rose bush leaves? If so, you most likely have a disease called Rose Mosaic Virus. This rose disease is relatively common in Kansas landscapes and symptoms can vary from wavy yellow lines or ring spots to mottled oak leaf and mosaic patterns. Rose Mosaic Virus spreads through vegetative propagation and does NOT move around via insects or mites. Another rose disease, rose rosette virus, will kill the infected rose plants, while rose mosaic virus disease will not. Plants infected with rose mosaic virus will produce symptoms on the rose plant every year for the remainder of its life.

The best ways to prevent viral diseases on your rose bushes are to start by buying non-symptomatic plants that have leafed out, or certified disease-free roses. Symptomatic plants in the landscape should be dug up (with the root ball), bagged and discarded.

Photos by Megan Kennelly/KSU

Rose Garden Observations and Recommendations (Coming Soon)

By: Brooke Garcia

Following an extremely wet spring, I’ve noticed several roses to be impacted by Black Leaf Spot. With continuous rainfall and high humidity, this fungal disease thrives. As this fungal disease develops, you can begin to notice black spots on the leaves. The leaves often times will turn yellow, eventually dropping from the plant. An easy way to spot this on plants (despite seeing the dark black spots and yellowing leaves) is to look at the bottom of the plant. The bottom portion of the rose shrub will most likely look bare, without leaves.

Despite having all of our recent rains, I’ve noticed some roses appear to be performing well given the circumstances. My recommendations are purely coming from an observational standpoint. On the other hand, many of these roses in particular were surrounded by other rose plantings that were impacted by both Black Leaf Spot and Rose Rosette Virus.

Here are the following rose recommendations:

  • ‘Honey Perfume’
  • ‘Princess Charlene De Monaco’ Hybrid Tea Rose
  • ‘Coral Drift’
  • ‘Lemon Drift’
  • ‘Top Gun’

 

 

Extreme Heat Precautions and Safety Tips

By: Michael Bear

Heat is one the leading causes of weather-related deaths and injuries in the United States. Excessive heat causes hundreds of deaths every year. Heat can affect people in a variety of settings and while dangerous heat is associated with the summer season, it can occur in the spring and fall as well.

The risk

When exposed to high temperatures your body sweats, which evaporates to cool your body. Hot and humid weather challenges your body’s ability to cool itself because your body sweats a great deal to try to maintain your body temperature. Over time this increased sweating leads to dehydration and your body temperature becomes elevated. Increased levels of humidity make this worse as the high water content of the air hampers the evaporation of sweat on your skin. This can result in heat exhaustion or heat stroke. Those most at risk for heat illness include infants, children, the elderly, overweight people and those who are ill or have certain medical conditions such as high blood pressure.

Heat exhaustion

Heat exhaustion is a mild form of heat illness that may develop after days of exposure to high temperatures and inadequate fluid intake. If not treated, heat exhaustion may become heat stroke. A person suffering from heat exhaustion may have cool moist skin. Their pulse rate will be fast and weak and their breathing will be fast and shallow. Additional warning signs of heat exhaustion include:

  • Heavy sweating
  • Paleness
  • Muscle cramps
  • Tiredness
  • Weakness
  • Dizziness
  • Headache
  • Nausea or vomiting
  • Fainting

Heat exhaustion first aid

  • Drink cool beverages without alcohol or caffeine.
  • Move to an air-conditioned environment.
  • Take a cool shower, bath or apply cold compresses.
  • Rest

Heat stroke

Heat stroke is the most serious of heat-related illnesses. It occurs when the body is unable to cool itself because the ability to sweat fails. A victim’s body temperature will rapidly rise within a few minutes. Heat stroke can cause death or permanent injury if it is not treated quickly. Warning signs of heat stroke vary but can include:

  • An extremely high body temperature — above 103 degrees Fahrenheit.
  • Red, hot and dry skin without sweating.
  • Rapid, strong pulse.
  • Throbbing headache.
  • Dizziness.
  • Nausea.
  • Confusion.
  • Unconsciousness

Heat stroke first aid

  • Call 911 immediately. Untreated heat stroke may result in death or disability.
  • Move the victim to a shady and/or air-conditioned area.
  • Cool the victim rapidly using whatever means available such as a cool shower or bath, garden hose, or sponging with cool water.

Prevention

Like many hazards, there are steps you can take to avoid becoming a victim of heat illnesses:

  • Drink lots of water and avoid alcohol and caffeine.
  • Limit strenuous outdoor activities.
  • Wear light colored, light weight clothing.
  • Use sunscreen.
  • Take breaks in the shade as often as possible.
  • If working in the heat, increase workloads gradually. Allow new employees and workers who have been off for more than a week more frequent breaks.
  • Change your schedule so outdoor work is performed early or very late in the day.
  • NEVER leave kids or pets in vehicles.
  • Check on the elderly, sick and those without air conditioning.
  • Be aware of the symptoms of heat illness and take action if you see someone at risk.

Sources

Rethinking Zoysiagrass for Home Lawns

Kansas State University teamed with Texas A&M to develop a new cultivar of zoysiagrass called Innovation, that’s suitable for lawns and golf courses. Pictured is Ted Wilbur (left), owner of Sod Shop in Wichita, Kansas and Jack Fry, horticulture professor at Kansas State University. Wilbur was the first to grow Innovation commercially in Kansas.

K-State, Texas A&M develop new cold-hardy variety for home landscapes and golf courses

OLATHE, Kan. – Who doesn’t love the look and feel of a soft, green carpet of grass underfoot? Even better if it’s resistant to pests and requires less fertilizer than other grasses. A Kansas State University professor believes that zoysiagrass can fit the bill for home landscapes – even in Kansas and surrounding states.

Zoysiagrass is well known as a warm-season grass commonly grown across southern tier states for its dense, weed-resistant and slow-growing nature (think less mowing), plus it requires about half the water needed for cool-season grasses typically grown in the nation’s midsection.

Those who choose to grow zoysia should be aware, however, that as a warm-season grass, it goes dormant and turns brown in mid-October and may not green up again until late April.

“The determining factor for whether any warm-season grass that can be used here is winter survival,” said Kansas State University horticulture professor Jack Fry.

Kansas and other states across the middle of the country are in what’s called a transition zone, where both warm- and cool-season grasses can grow but weather extremes can prove challenging and sometimes injure or kill the grass. In order to improve on a longtime favorite zoysia called Meyer, Fry and his K-State colleagues teamed with Texas A&M Agrilife researchers to develop a new zoysia cultivar.

Their aim was to develop a cultivar that is as cold-tolerant as Meyer for areas in the transition zone, but also to offer improved characteristics, such as finer leaf blades and even better density which blocks out weeds.

The K-State team worked with Ambika Chandra, associate professor at Texas A&M, to develop a new hybrid that was ultimately named Innovation. The new hybrid can withstand the cold that can sometimes blanket the central U.S. as well as Meyer does, but also exhibits better quality, meaning it has a darker green color, finer leaf blades, better density and good uniformity.

Zoysiagrass is already widely used on golf course tees and fairways in Kansas and across the transition zone, but less so on home lawns, Fry said. When drought water restrictions come about, however, it’s a good choice for home lawns.

Zoysia, and especially newer cultivars like Innovation, also require less fertilizer or pest treatments to stay healthy than typical cool-season grasses such as tall fescue or Kentucky bluegrass.

To develop the new cultivar, the researchers used traditional plant breeding, crossing cold-hardy types with other southern-adapted types that offered high density and finer-textured leaf blades.

That density results in almost no herbicides being needed during the growing season, Fry said.

To get from initial crosses – about 1,500 in all – to the final product took about 13 years, Fry said. Along the way from those initial crosses, 35 looked promising, so were planted in 5-foot by 5-foot plots in Kansas and Texas and evaluated by the researchers, who then narrowed the list to seven.

Those top seven hybrids were tested at additional sites across the transition zone in Missouri, Oklahoma, North Carolina, Tennessee and Virginia. The result is Innovation, which was released for commercial growth and sales in 2015. It is currently available via licensed distributors through a company called Sod Solutions, which has sub-licensed production to 15 sod producers in eight states.

What’s next? A new phase of the K-State-Texas A&M research is under way which aims to identify grasses that have superior resistance to a disease called Large Patch, and there may even be types that are promising for use on golf greens, too, Fry said.

Post featured by: https://www.ksre.k-state.edu/news/stories/2019/05/zoysia-for-home-lawns.html

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More information about zoysiagrass is available at

https://www.bookstore.ksre.ksu.edu/pubs/mf683.pdf

or in a Clemson University fact sheet, https://hgic.clemson.edu/factsheet/zoysiagrass/

A Day for Daylilies

Dividing Daylilies

By: Brooke Garcia

My backyard is currently a construction zone, and I have spent the last month dividing iris and daylily plants in efforts to save them from being ran over by the Bobcat (and no I’m not talking about the animal). With our future garage being built, we have had to move hundreds of iris and daylily plants into a new garden bed. Being a horticulturist by trade, I couldn’t see these plants go to waste.

I know it isn’t the ideal time to be moving these plants around, as several of them have recently bloomed. Generally, I’d suggest to wait to divide these plants until they have completed their bloom cycle (late summer/early fall). You can also divide them in the early spring prior to blooming, but this could impact their blooms later in the season. The steps to this process are relatively simple, but you should expect your hands to get a little dirty. It can also be a little time-consuming.

Step 1: Dig up a clump of daylilies with a shovel or hand trowel. I have found the process moves more quickly when you grab a shovel and do larger sections. In our case, we had hundreds to move…. so the bigger the clumps, the better!

 

Step 2: Trim the daylily leaves and flowers to a height of 8-12 inches. Pictured above on the right, you will notice the final clump cut back to approximately 12 inches.

Step 3: Separate the clump of daylilies into smaller clumps. My preference is to keep the clumps in groups of 2-3 plantings to keep the transplant looking full. Looking at the pictures below, the bottom left shows a single plant divided from the clump of daylilies. Pictured on the bottom right, I kept two plants clumped together for one single planting.

 

Step 4: Loosen the soil away from the roots of the recently divided plants. Next, trim the roots of your plants to stimulate new root growth. Only trim a small amount of the roots, as this will be enough to stimulate new healthy growth. (See pictures below)

Step 5: You’re ready to plant your newly divided daylilies! Be sure that you choose a sunny location in your garden with well-drained soil. Generally, I dig a hole 2-3x the size of the root ball of my plant. Once you place your newly divided plant into its newly dug home, add additional compost or garden soil into the hole. Gently pack the soil around the new planting. Be mindful to keep the crown of the plant above the soil line.

Step 6: Don’t forget to water your freshly divided daylily plants. If you plan to transplant more, space the plantings 12-18 inches apart to give them room to grow. Daylilies can begin to get crowded after 4-5 years.

Daylily Leaf Streak

By: Judy O’Mara

Daylilies are a great fit for Kansas. There are many varieties that grow well here. I particularly like browsing the photo gallery at the Flint Hills Daylily Society chapter (https://www.flinthillsdaylily.org/gallery) for my favorite ones. They are mostly problem free but I did recently see some daylily streak (Aureobasidium microstictum) on a recent walk. It isn’t that common in Kansas, but wet conditions this spring likely the triggered the disease.

Daylily leaf streak starts as long yellow streaks that turn a reddish brown. Heavily infected leaves scorch back and die early.

The disease is favored by moderate temperatures and wet conditions. Daylily streak can spread by splashing water droplets. Although you can’t manage the rain, you can time irrigation so that your plants are watered in the morning. This allows leaves to dry out quickly and reduce conditions that favor disease development. A mature daylily planting can be crowded leading to poor air circulation and prolonged periods of leaf wetness. Good plant spacing will improve air flow and help to dry out plants quickly. The disease can also be moved on tools, so avoid working around wet plants

Inspect plants when purchasing them and always start with healthy, disease-free plants (ie no spots on the leaves). If just one plant in the landscape is showing symptoms, you might be able to stay ahead of the disease by picking off and dispose infected leaves. Daylily leaf streak will overwinter in the leaf litter, so cleaning up the flower bed will help to reduce the amount of disease that is carried over to the next growing season. If daylily leaf streak shows up annually, it might be worth isolating the problem daylily from the rest of the planting.

The best strategy for managing day lily leaf streak…is through the use of resistant cultivars. Disease susceptibility varies and lists of resistant varieties are not easily available. A few varieties reported by Clemson University are: Betty Bennet, Edna Spalding, Ella Pettigrew, Globe Trotter, Nancy Hicks, Pink Superior, Ron Rousseau, Sudie, Tropical Tones, Upper Room, and Winsome Lady. (https://hgic.clemson.edu/factsheet/daylily-diseases-insect-pests/)

Turf disease update

Megan Kennelly, KSU Plant Pathology

Moisture and humidity are causing continued disease activity in both ornamentals and turf.

Below is some dollar spot activity in untreated controls in a fungicide study. As you can sort of tell from the photo, the disease has gotten to the point where the infection centers are not just off color but are also sunken/pitted.

If you are struggling with dollar spot control, consider your fertility regime. Low N can make the turf more susceptible, but high N comes with its own issues. Check your nozzles and spray equipment to ensure good coverage. Be sure to rotate among different modes of action. For more details check the dollar spot section starting on page 14 of THIS DOCUMENT.

 

We are getting some heat and humidity, and brown patch is becoming more active. Typically we think about brown patch as affecting tall fescue, perennial ryegrass, and our putting greens. However, this disease can affect bluegrass, too. This photo shows a sample from a Kentucky bluegrass fairway. You can see the fungal mycelium. With all the moisture, foliar Pythium also came to mind as a possibility, but in the microscope it was clearly the brown patch pathogen.

In the photo below, you can also discern that this is a heavy clay soil – see how shiny and glossy it looks. And, there is a thatch layer starting to build up, which can lead to its own set of problems. This site already has an aerification plan in place for fall.

 

The final disease I want to mention is Pythium root rot in putting greens.

Saturated soils alone can cause major decline in root systems. Unfortunately those same conditions can trigger Pythium root rot. The photos below illustrate typical symptoms I’ve seen recently, including several already this week:

When you pull up a turf core, the root system does not cling together well, and the whole core kind of lacks structure. If you wash them off, they are brown and mushy.

Canopy is thinned out and yellowing:

In the microscope the roots are dark, sloughing outer tissues, lacking root hairs, and have Pythium oospores present. (The physiological decline from wet soils alone can also cause browning, lack of root hairs, etc)

Here are a couple of resources about this disease:

https://turfpath.missouri.edu/profile/pythium_root_rot/index.cfm

and:

https://www.turffiles.ncsu.edu/diseases-in-turf/pythium-root-rot-in-turf/

National Pollinator Week!

Did you know it was National Pollinator Week?

In honor of National Pollinator Week, I wanted to share a video of bees pollinating on a Southern Magnolia tree that was located at the John C. Pair Horticultural Center in Haysville, KS. They caught my eye, as they were very “busy bees.”

Click on the link below to watch the video:

Video of Pollinating Bees

In addition to my short video, there is a wonderful video called “The Beauty of Pollination – Moving Art”. It is worthwhile to watch. Truly incredible!

For more information about National Pollinator Week, you can visit the official website. It’s not too late to celebrate. You can always plant a pollinator plant or take time for a garden walk to appreciate the pollinators in your garden.

Publication: Annual White Grubs in Turf

Dead spots in an otherwise healthy lawn may be a sign of white grubs. Grub damage varies from year to year and may be severe. The annual white grub is the most common grub pest of turf- grass in Kansas. It is the larval stage of the masked chafer beetle, Cyclocephala spp., which completes its life cycle in a single year. Six masked chafer species have been recorded in Kansas, all with similar developmental cycles: Cyclocephala lurida (southern masked chafer), C. borealis (northern masked chafer), C. pasadenae(southwestern masked chafer), C. hirta (western masked chafer), and Cyclocephala longula and C. melanocephala, which do not have common names.

To read this publication, visit this link to read it through the K-State Research and Extension bookstore.

Time to ‘Get Ready’ for Bagworms

By: Dr. Raymond Cloyd

For those of you that have been waiting patiently or for some… impatiently; it is time to ‘get ready’ to spray for bagworms. In due time, bagworms will be present throughout Kansas feeding on broadleaf and evergreen trees and shrubs. Therefore, now is the time to initiate action against bagworms once they are observed on plants. Bagworms are primarily a pest of conifers; however, they have expanded their host range to include a number of broadleaf plants, such as; rose, honeylocust, and flowering plum. It is important to apply insecticides when bagworms are small to maximize effectiveness and subsequently reduce plant damage.

To read additional information about this topic, continue reading this post that was featured in the KSU Extension Entomology Newsletter.

 

Removing Mosquito Habitats: Tips and Tricks

By: Brooke Garcia

You know it is spring or summer when the mosquitos are out for blood. However, they seem especially terrible this season, following a tremendous amount of rainfall in the NE Kansas area. It is difficult to enjoy our favorite activities outdoors when we are constantly being bitten. As an avid gardener, I have found it hard to withstand being outdoors for long periods of time. I’ve recognized the importance of implementing methods to suppress and eliminate mosquito habitats after a series of bites leaves me itching for revenge.

To overcome this 2019 mosquito battle, I wanted to provide you with some tips and tricks to reduce the mosquito populations surrounding your favorite places and spaces. For starters, eliminate pools of water in your garden. These can be found in planters, saucers, gutters, tires, tree holes, plastic covers, low spots, and/or any additional areas where water can be contained. As much as we enjoy our bird baths and water features, it is important to provide weekly maintenance to them. This includes emptying and changing out the water to remove potential mosquito habitats. If you happen to have a swimming pool, circulation of water and appropriate treatments are needed to eliminate mosquito habitats. In addition, avoid over-watering. As I was driving in Manhattan today, following a night of rain showers, I noticed someones sprinklers going off. The runoff and wet ground is only adding to this mosquito problem.

As far as chemical and/or organic methods of removal go, using appropriate barriers of protection against bites is highly advised. If you prefer not to use DEET, this is my go-to Insect Repellent recipe:

  • 1/2 cup water
  • 1/4 cup witch hazel
  • 45 drops of eucalyptus oil
  • 30 drops of lemon oil
  • 10 drops of peppermint oil
  • 6 ounce spray bottle

Be sure to shake well before applying often. Store this out of direct sunlight, and it should keep for 6-9 months.

Adding lemongrass and/or citronella into your planters or landscape are also advised as ways to reduce the mosquito population around your home.

Remember the structural barriers in which mosquitos can enter a building, home, or screened-in area. It is important to cover any holes or crack that may be found around windows and doors. If your screen door has a small hole in it, covering it with a piece of tape is a temporary fix until the screen can be replaced.

The overall goal is to avoid being bitten. It is our hope that these methods can easily be implemented into your life, or those surrounding you.

USGA: Improving The Cold Tolerance, Pest Resistance And Overall Quality Of Zoysiagrass

Post provided by USGA By Cole Thompson, assistant director, Green Section Research

Genetics ultimately determine how well grasses tolerate the stresses of golf as well as the most suitable playing surfaces and geographic regions for use. At times, management strategies may compensate for genetic shortcomings. For example, many cool-season grasses have excellent quality at very low cutting heights but require frequent irrigation and pesticide applications to mitigate damage from heat, drought or pests. Alternatively, some warm-season grasses tolerate drought and potential pests better than cool-season grasses, but may not provide the desired aesthetics or have the cold tolerance necessary to excel in colder regions. These compromises can make turfgrass selection challenging, especially in regions with diverse environmental conditions.

Because reliable turfgrass performance and resource efficiency are becoming more important to golf facilities, many are opting to use warm-season grasses and risking potential injury during harsh winters. In the case of ultradwarf bermudagrass putting greens, covering during low temperatures accounts for insufficient cold tolerance in the transition-zone region of the U.S.A. This is effective, but another strategy is to improve the genetics of warm-season grasses to diminish tradeoffs and reduce the resources required to deliver high-quality turf in a challenging environment.

Zoysiagrass is a warm-season grass that has already helped golf courses in the transition zone to use resources more efficiently. There are several species of zoysiagrass with different morphologies and cold tolerances. In general, zoysiagrass cultivars provide a high-quality playing surface with lower water, fertilizer and pesticide requirements than cool-season – and even some warm-season – grasses. The cold tolerance of Zoysia japonica cultivars – e.g., ‘Meyer’ – has made them ideal for fairways in the transition zone. To improve quality and further improve cold, shade and pest tolerances, the USGA has supported zoysiagrass development at Texas A&M University since 1983. The cultivars ‘Diamond’, ‘Cavalier’, ‘Crowne’ and ‘Palisades’ were developed and released from this support.

Since 2004, scientists at Texas A&M have partnered with colleagues at Kansas State University and Purdue University (since 2012). Initial success has come from crossing Zoysia japonica types with Zoysia matrella types, which have finer and denser leaves but less cold tolerance. ‘Innovation’ is a new cultivar released from these efforts, which has better quality and similar cold tolerance than ‘Meyer’ – the current standard-bearer for zoysiagrass in the transition zone. Since 2012, this group of scientists has worked to incorporate large patch disease resistance into their higher-quality, cold-tolerant zoysiagrass hybrids. They developed more than 2,800 new zoysiagrass hybrids and evaluated them in Dallas, Texas; Manhattan, Kansas; and West Lafayette, Indiana, from 2012 through 2014. The hunting billbug emerged as a problematic pest during this cycle of evaluation and hunting billbug resistance has since been a trait of interest. Researchers then selected the best 60 hybrid lines and evaluated them in 10 transition-zone locations from 2015 to 2018.

The 10 best hybrid lines have been advanced from the most recent evaluations for further testing. Large patch and hunting billbug resistance are improved in these lines when compared to ‘Meyer’, and some have better cold tolerance than ‘Meyer’. In 2018, the researchers began crossing these hybrid lines with lesser used zoysiagrass species such as Zoysia pacifica, Zoysia minima and Zoysia pauciflora, which have an even finer texture than Zoysia matrella types. Their ultimate goal is to produce zoysiagrass cultivars with all the aforementioned traits for fairways, tees and even putting greens.