Landscape and nursery
§ Black locust trees turning brown from leafminer
§ Basswood leafminer turning basswood trees brown north of Lansing
§ Asiatic garden beetle beginning to show in a few hot spots
§ Japanese beetle biocontrol field day
§ Research highlights from Southern Nursery Association conference
§ Chestnut growing in Michigan
Turfgrass
§ White grubs begin feasting on turf roots
§ Turf tips as autumn appears
Around the home
§ Foreign grain beetle: A fall invading insect that prefers new homes
§ Dogwood sawfly larva: a wood destroying pest?
§ Boxelder bugs: Looks like another bumper crop this year
§ Will we have good fall color this year?
Other news
§ Weather news
Driving between
Interestingly enough, at the same time the locust leafminer
is browning trees in southern
The basswood leafminer is about the same size as the locust leafminer (6 mm) but is a dark reddish-yellow color with wedge-shaped wing covers. The majority of the damage is also caused by the larvae tunneling mines in the leaves. The cycle of damage and natural control by parasites is the same as is described above for the locust leafminer. Basswood or lindens (all Tilia spp.) are the primary host trees, but these beetles may make mines in the leaves of apple, birch, cherry and maple, too.
Ken and Jan DeBruyn of DeBruyn Seed in
Asiatic garden beetle appears to love geraniums, a plant
that is toxic to most insects. The only way to prevent feeding damage is to
spray the geraniums with Sevin or Tempo in early July and again every week or
two until August. Another sample of Asiatic garden beetle came into Diagnostic Services last week from a
different location in southwest
A Japanese beetle bicontrol field day will be held on
Saturday, October 21, at the Binder Park Golf Course in
You should bring a flat shovel or sod-cutter, thin gloves, a plastic bucket for each person, and your sense of humor. (I mean, who is really going to believe what you are doing?)
Please let others know about this biocontrol field day. At
this time, only the Battle Creek-Kalamazoo area has the most important
pathogens. The rest of
Nursery researchers from throughout the country met at the
Proceedings of past SNA research conferences are available on-line at: http://www.sna.org/research/
Michelle McGinnis (NC State) followed the cumulative nutrient release of container media amended with either 10% or 40% vermicompost. Over the course of the study, the addition of vermicompost greatly increased nitrogen availability, but reduced P availability. McGinnis noted that the difference in the availability of the elements is due to the fact that nitrogen release is directly related to microbial activity, whereas phosphorus availability is a physical/chemical phenomenon with greater amounts of P adsorbed with increased organic matter.
The potential of a shortage (or at least escalating prices) of pine bark has spurred interest in developing alterative container substrates. Research in the South is focusing on two primary alternatives.
Southern nurseries continue to be concerned with availability of pine bark for container substrate. A growing body of evidence has shown the wood chip media can grow an acceptable nursery crop. Research at Virginia Tech examined effects of species and chip size on wood-chip media. Decreasing wood chip particle size from ¼ to 1/16” increased plant growth of container-grown plants. The benefit of reduced of particle size was attributed to increased water holding capacity and increased EC compared to the larger particle size.
Breanna Rau (Va Tech) examined growth of container-grown plants grown in wood chips from five different species. Growth varied depending on the species of trees used to produce the chips. The ranking of the species was (from most to least crop growth):
loblolly pine > sycamore > white pine > red maple > white oak
The effect of chip species was attributed to amount of extractable polyphenolics in the chips, which was negatively correlated to crop growth rates.
Jim Owens (
Cheryl Boyer (
Frank Henning (Univ. Of
Mid-season pruning reduced cold hardiness in five out of six Abelia cultivars in a trial conducted by Matt Chappell (UGA). Chappell recommends dormant season pruning to reduce potential for winter injury.
Ursula Schuch (
Cyclanilide, an auxin inhibitor, increased lateral branch density on Indian Hawthron at rates up to 50 ppm. Phytotoxicity was observed at 300 ppm.
The environmental impacts of nursery production – particularly the fate of phosphorus and nitrates – continue to be an active area of research. Container fertilizers commonly contain a Nitrogen Phosphorus ratio of 5:1. K.N. Walton (NC State) grew herbaceous perennials with varying ratios of N:P, maintaining N at 150 ppm and K at 50 ppm. Crop growth was unaffected even at the lowest P levels tested (N:P 32:1), suggesting significant reductions in P additions may be possible without adversely affecting crop growth.
My laboratory at
If you are interested in bringing back the American chestnut
tree, we have a research program on that, too. The center of activity for this
research is at the
Basically, there are three groups involved in the nut
industry in
I have seen lots of small European chafer and Japanese beetle grubs feeding in lawns and on golf courses. The grubs will be getting larger and eating more in September. Watch for grub damage to appear in late September and October, especially during dry periods when the turf is stressed and wilting.
Also, with the bumper crop of Japanese beetle adults this year, expect more grubs and more skunk and raccoon damage than usual. Merit and Arena will give some control of grubs in September, but not nearly the level of control that you get when it is applied in July. The only other products labeled for control of grubs in the fall are Sevin and Dylox, which work fairly well when watered-in immediately after application with a 1/2 inch of irrigation. Use a granular formulation when treating areas that are not irrigated. Sevin and Dylox degrade quickly in soils with a high pH (> 7.5).
It happened this morning on my drive into campus. I knew it was coming, the invasion of 40,000 students back to campus obviously gave me the first warning; the promise of another college football season that would be different than the past Spartan struggles was another sign. However, this morning when I saw that maple tree on the corner starting to show its crimson red colors, I knew autumn was officially right around the corner.
In the August 25 Landscape Alert issue, I covered the basics for reseeding damaged turf areas and touched on fall fertilization applications. Here is a wrap-up on turf issues you may want to think about in the next month.
One of the dangers of autumn is turning those new, white school sneakers to orange after walking through the lawn. After what was a sporadically sultry summer, the cool temperatures in autumn often result in rust showing up on lawns. Rust is very diverse; there is stem rust, crown rust, leaf rust and stripe rust. Don’t worry about what rust might be contaminating your lawn, as a general rule in almost all cases rust is considered a cosmetic turfgrass disease that although it may discolor the turf, it will not result in wide-spread death of the turfgrass. If you find yourself inundated with a bad case of rust, make sure to keep up on your mowing, and if you haven’t applied any fertilizer in a while, consider a fertilizer application to stimulate turf growth, which will help diminish the impact of the rust.
After a long summer of mowing turf, it would be a good idea to sharpen that mower blade as we head into the autumn. Sharp mower blades are essential for a good quality cut, and with leaf mulching season right around the corner, you want to ensure you have a sharp blade.
Just a reminder that all of those tough to control broadleaf weeds that you’ve struggled with all season long can be effectively controlled in the autumn with a well timed herbicide application in the latter part of September and first week of October.
For all of those compacted turfgrass areas, autumn is the perfect time to conduct core aeration. Core aeration will help alleviate compaction, can dilute out thatch over time, and can even be used as a method to create a seed bed for overseeding some damaged turfgrass areas. Make sure to have all of your underground wires or irrigation pipes well marked to avoid any unforeseen disasters.
There is a strange little bug that shows up about this time every year called the foreign grain beetle, Ahasverus advena (Coleoptera: Cucujidae). This tiny beetle is considered a stored product pest in the literature, although it feeds primarily on molds and fungi growing on damp grain, grain products and other materials. It is found throughout the world and is very common around grain processing facilities where damp, moldy grain is allowed to accumulate.
Little is known about its habits in "nature," however, it is reasonable to assume this beetle can occur in any damp situation where fungi persist. One odd thing about this beetle is that most of the specimens sent to this lab are collected from new homes. Possibly because the wood, plaster, concrete and other building materials in new construction may not be completely dry and will support a thin, invisible layer of fungi which attracts the beetles. These beetles can fly and are very small, so it is possible for them find their way into the house through screens and around loosely fitting windows and doors. These insects will stop coming in from the outside as colder fall temperatures arrive.
Not only is the dogwood sawfly a pest of dogwood trees, it can also be a problem to homeowners by boring into landscape timbers and other wooden objects in ground contact in the fall of year. It doesn’t eat wood, but instead it chews out little chambers in which to spend the winter.
There are three species of Macrempytus (Hymenoptera: Tenthredinidae) sawflies in the eastern
Sprays containing Sevin, cyfluthrin or Malathion will control them on dogwood. Their damage to wood can be controlled by applying residual insecticide, such as cyfluthrin, to the areas where the larvae are boring.
I had to cut down an old skaggy boxelder tree last week. There were thousands of the boxelder bug nymphs in the upper branches. For those us with boxelder trees growing near our homes, it looks like we are going to have plenty of company this winter.
As an Extension specialist, this is one of the calls I
dread. Newspaper reporters, school kids – everyone wants a prediction on fall
color. Although it doesn’t stop us from trying, a reliable prediction on fall
color in
While the intensity of fall color certainly varies from year-to-year, I contend that the duration of fall color and our perception of fall color vary more. Fall color is greatest when we have bright, clear days and cool nights. However, if conditions are too dry leading into the color season, leaves may begin to turn early and drop quickly. We may still have fairly intense color, but if the show doesn’t last long, we’re less likely to notice. This could be the case on the west side of the state, where the weather has been dry and some trees are already beginning to turn. Also, I believe weather during the fall influences how we perceive tree color. If you drive up north on a bright, clear day with a brilliant blue sky, we’ll perceive the color as more striking than if we saw the same trees on a drizzly, grey overcast day.
If you want to learn more about the development of fall color in trees and keep track of this year’s fall color, check out the USDA Forest Service Fall Color website at:
http://www.fs.fed.us/r2/recreation/fallcolors/chemistry
An upper air troughing feature will build into the Great
Lakes region by Saturday, September 9, bringing much cooler weather to
Medium range forecast guidance calls for the upper air
troughing pattern mentioned above to gradually give way to a more west to east
zonal pattern over the continental
Further ahead, the latest version of NOAA’s long lead outlook for the month of September calls for increased odds of above normal temperatures over northern sections of the state and for the equal chances/climatology scenario of near equal odds of above-, near-, and below-normal temperatures over southern sections of the state. The outlook also calls for the climatology scenario for precipitation statewide. Finally, the three-month seasonal outlook for the September-November period calls for increased chances of milder and drier than normal weather statewide.