Tuesday, May 31, 2011

The Bumble Flower Beetle (Euphoria inda) is a good white grub!

Not all white grubs are bad white grubs. The ones we have been seeing at our office lately have been good grubs. Grubs that are doing you a favor by breaking down the cellulose in your gardens and potted plants turning it into the nutrients needed by your plants. These grubs are not the ones that feed on the roots or crowns of your plants and do not need to be nor should they be killed.

These grubs are the larval stage of the Bumble Flower Beetle (Euphoria inda) so called due to the buzzing sound they make when the adults fly. The adults emerge in the fall and feed on overripe fruit as well as nectar and goo that oozes from cuts and abrasions on many plants. The adults overwinter in the soil. You will see them flying again in the spring when they search out decaying wood, piles of manure and other rotten plant debris in which they lay their eggs.

If you conduct a Google or Bing search on white grubs in compost, you most likely won’t find many references to the Bumble Flower Beetle. The gardening forums often refer to the white grubs in compost as Japanese beetle larva and recommend you kill them to prevent them from moving into your lawn or onto your roses.

Why would you want to poison your compost with an insecticide to control white grubs that are not causing any harm and are actually beneficial? Even some of the white grubs found in your gardens are there feeding on the compost and manures you added last fall or this spring and not feeding on your plants. Like the Bumble Flower Beetle most other scarab beetles in Colorado are beneficial and help recycle nutrients in organic matter, such as dung and kitchen waste. Some of the posts on garden forums even recommend the use of Milky Spore Disease to kill these white grubs even though this material is not an effective control option for the scarabs we have in Colorado on this side of the continental divide. Milky spore disease is, however, an effective control option for Japanese beetle, a scarab beetle that is problematic in eastern Colorado. The only population of Japanese beetles that did occur in western Colorado in the town of Palisade was eradicated.

Take the time to look at the last abdominal segment of the white grub so you don’t mistake this beneficial white grub for a damaging one. Ohio State University has an excellent color publication on the various white grubs and their hind ends. To use this publication (http://www.oardc.ohio-state.edu/atru/research/grubs.pdf) you will need a hand lens. Pick up the white grub, flip it over on its back and check its butt. You are looking for the arrangement of spines and hairs on the rastar, the last abdominal segment. These spines and hairs form a distinctive pattern on the rastar of all white grubs other than the Bumble Flower Beetle. If you are squeamish and would like someone else to identify the white grubs you have in your compost or manure pile take them to your local Colorado State University Extension office and have them identified.

This white grub is also common in container grown plants feeding on wood chips, bark mulch, peat moss, and other dead organic matter. They do not feed on the roots of the plants growing in pots but have been shown to move nutrients throughout the container as they feed and move through the planting medium.

Take care when treating so-called insect pests. Some are very beneficial. When you spray for a pest without first getting it identified as a destructive pest you are doing more harm than good. Treat your environment with care! 

Winter mite damage is obvious if you use a hand lens

Last week I visited a lawn that was damaged by what was identified and treated as a fungus problem. While various funguses are common in many lawns this year, especially as a result of the wet cold spring, fungi were not responsible for the dead portion of this lawn. The problem was winter feeding activity of mites.

You could see where the mites had started feeding next to the sidewalk and continued to feed almost in a block-like pattern further into the lawn. The area near the sidewalk was fully exposed to the winter sun and was slightly higher than the sidewalk creating an area that dried out during late fall and winter. This is exactly what these winter-feeding mites like, dry hot turf.

Note the stippling on the leaf blade
caused by the feeding activity of the mites.

Note the purpling due to lack of adequate
nutrient movement to the tip of the blade.

Where dead grass and live grass came together, the tips of some of the grass blades were purple. This coloration is common during cold weather due to the lack of nutrient movement from the roots to the leaf tip. In this instance however, the lack of nutrient movement was due to the cellular damage caused by the mites feeding just below and in the purple region. The area of turf in the first photo is dead and will need to be removed and new sod applied. It will not come back on its own as lawns often do when infected by a disease.

Friday, May 27, 2011

Cytospora Canker of Peach and other Stone Fruit Trees

This past week I visited a peach orchard in Palisade at the request of the owner. His question was how to prevent and manage Cytospora canker (gummosis).

Cytospora enters through wounds such as those caused by
 The majority of the infection in his trees, and it was considerable, had gained entry through damage from sunscald and improper pruning cuts. The sunscald problem (South West Disease) was on the trunks but mostly on the upper side of horizontal branches.

sunscald damage on the trunk is a grat plant for
 Cytosopora to enter

Sunscald is the result of exposure to the winter sun between the months of November and March. Pruning during those months exposes previously shaded branches, especially the upper surface, often resulting in sunscald of that tissue. The bark cracks open due to its alternate freezing and thawing resulting in infection sites. This can be prevented by spraying the newly exposed branches with a mix of one part latex paint and nine parts water. This spray could also be applied prior to pruning. This is the same reflective spray used to protect the trunks of newly planted trees from winter sunscald damage.

This same spray should be applied on the trunk of established trees, especially if pruning or tree removal will expose a previously shaded trunk to the effects of the winter sun. You can learn more about sunscald at my sunscald web page at http://www.coopext.colostate.edu/TRA/PLANTS/sunscald.shtml.

Bad pruning cuts are great spots where Cytospora can
start an infection.

This photo shows sunscald on the upper side of a branch as well as infection of Cytospora through branch stubs. Note the cut made into the bark by a chainsaw. That is another possible infection site.

The infections at pruning cuts were due to leaving long stubs, not leaving enough of a stub, or damaging neighboring branches during the pruning process. Both of these prevent the rapid callusing over of the wound creating a great spot where the Cytospora fungus can invade the tree. Disinfecting the pruning equipment on occasion during the pruning process also would limit the extent of infection. Spraying the cuts with amber (orange) shellac, while time consuming, will help reduce infection at those sites. Pruning during wet weather should be avoided.

Crotch attachmentsa are some of the last areas on the tree
to proper acclimate for winter and thus susceptible to
winter damage and injury if the tree is not properly
prepared for winter.
 This Palisade orchard had a lot of dead wood due to Cytospora infection that needed to be removed making proper cuts in the process. Without clearing out and disposing of the dead wood by burial or fire, the infection potential will increase.

In addition to limiting infection sites for the fungus, keeping the trees healthy is equally important. Cytospora canker is a stress disease. It likes trees that are not in the peak of health. Cultivating the established orchard removes many of the feeder roots of the trees reducing tree health. Applying nitrogen fertilizer after mid-season and not drying the trees out in late summer just before your last irrigation of the year affect winter acclimation and increases the possibility of winter damage. This damage equates to more entry points for fungal attack. You can find more information on winter acclimation at http://www.coopext.colostate.edu/TRA/PLANTS/winteracclimation.shtml.

Proper management of Cytospora canker is critical to the longevity of the orchard. While the steps necessary to avoid infection and clean up diseased trees will take more of your valuable time and resources, you need to decide if these efforts are worth extending the life of the orchard and its fruit-producing years.

If you have a commercial orchard in Mesa, Delta, Montrose or Ouray Counties and would like me to visit your orchard give me a call at 970.244-1840. If you are a backyard orchardist and need a site visit call 970.244.1836.

You can learn more about Cytospora canker in the 2011 Utah-Colorado Commercial Tree Fruit Production Guide available from the Western Colorado Research Orchard Mesa Center (970 434-4364 ext 201) and read more about Cytospora at http://www.coopext.colostate.edu/TRA/PLANTS/gummosis.shtml.

Curtis Swift, Ph.D., Colorado State University Extension, Area Agent - Horticulture

Thursday, May 26, 2011

Evening Primrose Rust

Evening Primrose (Oenothera species) is a common plant in our semiarid area. These plants like to dry out between waterings but have not had an opportunity to dry out this spring due to our rains and are being infected by a rust fungus as a result.

If you have plants that look like this in your gardens, there is little you can do at this stage. Cutting back the plant and hoping it will recover when weather conditions are less conducive to this fungus problem might help. Controlling this disease with a fungicide in native areas is impractical. In home gardens treating with a topical fungicide can help reduce the spread and severity of this disease.

This rust is most likely Puccinia dioicae. Dendy, et al. (http://www.k-state.edu/pdecology/Solidago2001.pdf) reported a much higher incidence of this disease on goldenrod (Solidago), another host of this fungus, during years of higher levels of precipitation than during normal years.

This heteroecious parasite requires two hosts to complete its life cycle. (An autoecious parasite is one that completes its life cycle on the same host. ) Puccinia dioicae produces aecial spores on members of the following families: Asteraceae, Onagraceae (evening primrose), Phrymaceae, and Valerianceae. It produces teliospores on members of the family Cyperaceae, sedges. To effectively control heteroecious rusts, one could destroy the hosts of one of the stages of rust. In this case removing the sedges in the vicinity of evening primrose would help prevent Puccinia dioicae rust pustules developing on primrose and its other broadleaf flower hosts. How far away the sedges would need to be removed is a good question as these spores spread by wind, rain and by other means.

Tuesday, May 24, 2011

Tomato Seedlings Damaged by Herbicide Vapors

Where you decide to start and raise your vegetable transplants sometimes determines whether those transplants live or die. By now your transplants are already at the stage to be planted in the garden or have already been planted. Whether these transplants have the vigor needed for continued growth can be directly affected by where they were started.

Take for example transplants that were started in the same area where herbicides were being stored. In the early stages of development the tomato seedlings grew perfectly. It was not until the temperatures got hotter that these seedlings started to develop strange looking and twisted leaves. Some of the leaves grew much longer and thinner than normal.

The leaves had the characteristic ruffled edges as seen in the photo on the left.
The cause of this distortion was due to vaporization of herbicide located somewhere in the same building, in this case in the garage. Perhaps herbicide was spilled sometime in the last several years and the residue wasn’t adequately cleaned up. As the temperature increased vapors were produced that drifted onto the young seedlings. The herbicide damage might have been due to vaporization of chemical residue around the neck of a bottle of herbicide. The damage may have been due to vapors from a nearby application of herbicide that drifted into the garage when the door was open.

While herbicide-damaged tomatoes may out grow this problem the tolerance for 2,4-D residue and other herbicides on or inside tomatoes is very low. The U.S. Environmental Protection Agencies tolerance of 2,4-D contaminated tomatoes is 0.05 ppm. This is six times lower than what is permitted in horse meat (0.3 ppm). Are you sure you want to eat herbicide contaminated tomatoes or other vegetables? I don’t!

Tuesday, May 17, 2011

Dog Spots and Urine

If you see a lush spot of grass where one our four-legged friends has made a deposit of liquid nitrogen, you will know the lawn needs an application of nitrogen fertilizer.

 The best remedy for this problem is to fertilize with a nitrogen source. This will stimulate the grass into vigorous growth. The resulting green grass will help hide (i.e. mask) the dog spot. The amount of nitrogen to apply will vary depending on how deficient the lawn is of this essential nutrient but it is best to start with a small dose of nitrogen to correct such a deficiency. A half pound of nitrogen per one thousand square foot area of lawn is a good amount to apply if you have a cool-season grass lawn such as tall fescue, perennial ryegrass or bluegrass. Applying more than one-half pound of nitrogen per thousand square feet can result in excessive growth and the need to mow more frequently. Applying more than one-half pound per thousand can also lead to increased lawn disease problems. That is one-half pound of nitrogen not one-half pound of fertilizer.

To figure out the amount of fertilizer to apply for the one-half pound of nitrogen you need to know the percentage of nitrogen in the product. Nitrogen is the first number of three on the label. This number indicates the percentage of nitrogen by weight. Thus if the label says 20-0-0 that means this product contains 20% nitrogen by weight. Convert the percentage to a decimal – i.e. 20% = 0.20, then divide the number of pounds of nitrogen required by this decimal. For example if you want to apply one-half (0.5) pound of nitrogen, divide 0.5 by 0.20. The answer, 2.5, is the pounds of this product you need per 1000 square foot area of lawn to apply one-half pound of nitrogen.


The myth about female dog urine being more acidic and therefore more damaging than male urine, and the myth about reducing the damage caused by urine by adding tomato juice to the animal’s diet or baking soda to its water are just that, myths. The cause of urine burns on lawns (or bushes by male dogs marking their territory) is the amount of nitrogen in the urine and the amount of urine deposited. Before you try one of the numerous treatments said to be effective in reducing dog spots talk with your veterinarian. Treatments not approved by your vet can lead to bladder and other problems.

Another myth that doesn’t work is the use of gypsum to deactivate urine. Amending the soil prior to planting the lawn and aerating to improve the movement of water into and through the soil, however, does help reduce dog spot problems as they increase water movement into and through the soil and helps move the nitrogen below the point of deposition. This helps dilute the nitrogen concentration.

Grass can handle small deposits of urine, but when numerous deposits are made in the same spot, a dead spot surrounded by deep green lush grass will result. The nitrogen overload causes the center dead spot.

Tall fescue and perennial ryegrass are more resistant to the effects of large doses of liquid nitrogen with Kentucky bluegrass being quite sensitive. While Kentucky or Texas-hybrid bluegrasses are more susceptible to urine burns, they also recover faster than tall fescue or perennial ryegrass due to their sod-forming growth pattern.

These spots are not only caused by female dogs. Young dogs of both sexes as well as older male dogs squat when they urinate. Male dogs typically learn to lift their leg by the time they are a year old. If you have every watched a dog, he/she will make numerous small deposits of urine. While our four-legged friends can cause spots in our lawns they are still worth having around. Forget about the small things, or should I say spots, and enjoy spending time with your canine friends.

Nitrogen waste products are created during the breakdown of proteins by the kidneys and expelled in the urine. While about 95% of urine is water, about 2.26% are the nitrogenous waste products creatine, uric acid, ammonia, and urea [(NH2)2CO] with the latter being the highest percentage of the four. The content of the nitrogenous waste products in the urine depends on the amount of protein in the diet. The use of meat or other high protein treats increases the amount of urea that ends up in the animal’s urine. While some of the nitrogenous materials end up in the feces, these more solid deposits release nitrogen much slower than urine and thus seldom burn the grass.
Urea fertilizer common in agriculture is produced from synthetic ammonia [NH3] and carbon dioxide. You may have even purchased a bag or two of urea from a garden center or farm supply store for your own garden or lawn. Other than one being dry and other liquid, the urea is the same whether you buy from the store or collect it every time your pets (or you) urinate.

I read Captain Corelli's Mandolin a number of years ago and a paragraph on urinating in the herb garden struck me as a simple solution to correcting a nitrogen deficiency. This novel tells about the Italian and Germany occupation of the island of Cephallonia during World War II when nitrogen fertilizers were in short supply. Somehow the impression urinating on the herbs was common even when other forms of nitrogen were available.

As with any fertilizer application the rate is critical. Smaller applications spread out over the season would be more beneficial than larger doses which could burn roots and reduce production. The same guidance should be followed as to when to apply urine as if you were using any other nitrogen product.

If you figure the average person produces one-third gallon of urine a day, and it takes about 10 gallons of this liquid for each pound of nitrogen, it will take a month for one person to create one pound of nitrogen. If your friends and neighbors joined the club, you could accumulate a great deal more. You could even store what was produced during the winter for use during the summer. If more meat and high protein products were consumed the concentration of nitrogen would be even higher.
Urine has been used for many years to fertilize vegetables, herbs and other crops so it should be no surprise to read about its used in years past or even today. Don’t however look for me to follow through on this idea. I find using ammonium sulfate and blood meal to be just as easy to apply without the possibility of ending up in jail for indecent exposure. If this liquid form of nitrogen was collected in the privacy of your home and then applied through a hose-end sprayer as one does Miracle Grow and other liquid fertilizers jail time would be avoided.

Monday, May 16, 2011

Equine Herpesvirus EHV-1 Found in Colorado

While this blog will mainly cover gardening, I wanted to send this announcement out as many gardeners also have horses. 

LAKEWOOD, Colo. – The Colorado Department of Agriculture is investigating two confirmed cases of Equine Herpesvirus (EHV-1) within the state. Two quarantines have been placed on two Weld County premises.

One horse was euthanized after showing severe neurological signs associated with the disease and the second horse is currently under observation in a biosecure location.

“The Department is taking quick and appropriate actions to control and mitigate this disease,” said State Veterinarian, Dr. Keith Roehr. “We will continue to trace the movement of these horses and those horses they came into contact with in order to protect Colorado’s equine industry.”

Both diagnosed horses had recently attended the National Cutting Horse Association’s Western National Championships in Ogden, Utah. The Colorado Department of Agriculture is working with the Utah State Veterina rian to investigate the location as a point of interest for the infection.

EHV-1 is not transmissible to people; it can be a serious disease of horses, causing respiratory and neurologic disease. It can even lead to death of the horse. The most common way for EHV-1 to spread is by direct horse-to-horse contact. The virus can also spread through the air, contaminated equipment, clothing and hands.

Symptoms include fever, decreased coordination, nasal discharge, urine dribbling, loss of tail tone, hind limb weakness, leaning against a wall or fence to maintain balance, lethargy, and the inability to rise. While there is no cure, the symptoms of the disease may be treatable.

Additional Resources can be found on the Colorado Department of Agriculture website at www.colorado.gov/ag

Wednesday, May 11, 2011

The Ute Learning Garden has New Signs

The Ute Learning Garden at the Mesa County Fairgrounds is a joint project with Colorado State University Extension, the Ute Indian Nation, the Bureau of Land Management, and Mesa County. To make this site more educational for school groups and others who visit, we have added some wonderful signs. Danielle Foushee was our graphics artist for the five signs we currently have installed at this site.

Danielle Foushee and Curtis Swift at the north entrance to the Ute Learning Garden.
 You can learn more about Danielle at http://www.daniellefoushee.com/ or by calling her studio at 970.314.7364 or her cell at 818.613.7459.

To learn how you can enjoy a tour contact Susan Rose at 970.244.1841. School classes make up the greatest number of visitors but others are welcome to visit.

In May, Clifford Duncan and Brock Chapoose, Ute Elder and member of the Ute Indian Nation respectively, will be building a ceremonial willow sweat lodge to complement the Wickiups and teepee already at the Ute Learning Garden. This will be another attraction for the powwow we will be hosting at this site on June 10th and 11th. Give Susan a call if you would like to be a vendor during the powwow or would like additional information on this educational project.

Monday, May 2, 2011

West Middle School Students visit Ute Learning Garden

Students from 6, 7 & 8th grades of Western Middle School enjoying a tour of the Ute Learning Garden.

Deborah and Mike talk to
the students
about native plants and
how they were
used by the Ute Indians.

Students continue their walk
 from the high desert
to the aspen ponderosa life zone

The Ute Learning Garden at the Mesa County Fairgrounds is designed to introduce students to the history of the Ute Indians of western Colorado.  Students of all ages are welcome to visit and learn about the Ute Indians and how their lives in western Colorado.  Signs are used to explain the plants for life zones from the high desert to the aspen ponderosa zones.  Wickiups, a teepee, and primitive cooking areas are also available for viewing.

To set up a guided tour contact Susan Rose at 244-1841 or Susan.Rose@mesacounty.us