Ute PowWow this Saturday

Colorado State University Extension is hosting a mini-powwow this Saturday from 9:00 to 4:00 at the Ute Learning Garden on the Mesa County fairgrounds. Tours of the garden, which features plants used by the Utes, will be given through the day. You'll have the opportunity to visit the nugan (the Ute word for tipi), view the wickiups and cooking hearths, and see demonstrations of flint knapping and corn grinding.




Ute Indian Students at the 2010 CSU PowWow.

 At 11:00 and 2:00, there will be traditional Ute singing and dancing courtesy of members of the Ute Indian Nation. There is a silent auction of six works of art by Ute artists Kessley LaRose and Robert Colorow; proceeds go to support the Learning Garden.

Admission is free; donations are gratefully accepted. Please plan to join us for a fun and informative day!

Preventing Bird Damage in Peas

 Birds love peas. They eat the leaves and flower buds.

The leaves on this stem have been
stripped by birds.


If enough leaves are eaten or damaged the yield may be reduced. "Research has shown that 30 percent leaf loss prior to bloom stage will not result in reduced yield or quality. In addition, these plants can tolerate up to 15 percent leaf loss during bloom and pod-fill stages without significant drops in yield or quality."

Damage to the blossoms, however, will reduce yield.



This flower is fairly unscathed other than
some damage from thrips.





Note where a bird took a bite out of this flower.

Covering the row with insect barrier cloth keeps the birds away and doesn't hinder the yield very much.

Peas are self-pollinating so they don't need insects to carry pollen from one plant to another. That was why Mendel choose to do his genetics research using peas. Even when there is a neighboring row of peas it is highly unlikely pollen will be transferred from one row to the next. Bees and other insects, however, will increase pollination and yield.



Four different potato cultivars are in the fourground.



The insect barrier also reduces the temperature of the plants and their flowers enhancing the yield.  Most nurseries and garden centers carry insect barrier.  Pin the fabric to the ground with sod staples or use bricks or boards to hold it down. 

Fruit Tree Pest Update for Mesa and Delta Counties, western Colorado

The following information is provided by Dr. Ramesh Pokharel, Western Colorado Research Center, Orchard Mesa Station.

Mesa County:
Codling moth is active, and you need to protect your crops from this pest by pesticide applications. (Please remember not to repeat the same chemistry of pesticides more than twice).

Peach twig borer moth (PTB) was captured in our trap on May 25 at WCRC-OM site. June 15-18 is the recommended period for the first cover spray for this insect.

Western Cherry fruit fly (WCFF) should be flying in the area by now  and you need to spray your cherry to protect from WCFF.



Delta County
At Rogers Mesa, Delta County: Codling moth (CM) biofix occurred at about May 7. This is the right time to put your first cover spray for CM management.

At Rogers Mesa site, we have no record of other insects in our traps. However, you need to watch for PTB moths and western cherry fruit flies as this is the right time to observe these insects flying according to our DD model. If it is so, schedule your spray at around June 17-18 for PTB and June 5-6 for WCFF.

For more details on these fruit tree pests and sprays needed check out :
http://www.ext.colostate.edu/pubs/garden/02800.html and
http://www.ext.colostate.edu/pubs/garden/02804.html




For Cedaredge, the biofix for codling moth (CM) was projected at around May 17-18. Then the first cover spray for CM should be scheduled for June 5-6 if you are scheduling to spray at 150 DD days, and the spray date should be June 10-11 if you are spraying at 250 DD of biofix. PTB is expected to fly from June 8 then you need to schedule your first cover spray at around last week of June or early July. Western cherry fruit fly is expected to start flying from June 11, and the first cover spray should be done around June 13-14.

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.

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
sunscald.

 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

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.