Last year’s hot, dry weather is rearing its ugly head! From spruce to yews to maple trees — it is evident we experienced an extreme 2011. I continue to receive reports of trees and shrubs being slow to leaf out, losing branches or not leafing out at all.
The cause in most of these cases appears to be stress-related. Last summer was very hot and dry and placed a number of plants under stress. This was followed by a warm, dry, open winter which further stressed root systems. Trees that lose individual branches should have those branches cut out. Trees slow to leaf out need to be given some extra care so that further stress is avoided.
We may see more damage as we transition into summer weather. Plants may wither seemingly overnight. These trees may have died earlier but had enough food reserves to put out leaves and even to grow for a period of time. When the food reserves become depleted, the plants die suddenly. Another possibility is the root system was damaged last summer and winter from drought. The tree has enough roots to keep up with moisture demands now but may collapse when the weather turns hot and moisture demands rise.
Before any tree is cut down, check the twigs. Dead trees will have brittle, dry stems that snap. Live stems may break, but they won’t be dry. If the tree is still alive, give it time to put out a new set of leaves. If you suspect you have plants under stress, try to water them once a week during hot weather if we do not receive rainfall. Watering every two weeks should be adequate during cool weather for established trees. Trees should be watered to a depth of 12 to 18 inches if possible. Water from the trunk out to the edge of the branches.
If you use a soaker hose, connect it to a Y-adapter so that both the beginning and ending of the hose are connected to the Y-adapter. This will equalize pressure. Though this will not reach all the roots of a tree, it will reach enough of them to make a difference. Trees normally have at least 80 percent of their roots in the top foot of soil. Shrubs should be watered to a depth of 8 to 12 inches. Check the depth of watering by pushing a wooden dowel or metal rod into the soil. It will stop when it hits dry soil.
Scott Eckert is a Kansas State University Research and Extension agent of Harvey County, specializing in horticulture.
Cutworms and armyworms are the caterpillars of several species of night-flying moths. Cut-worms are plump, smooth and often, greasy-looking. Typically, cutworms curl up tightly when disturbed. They have greenish, brownish, grayish, or striped bodies, up to 1 3/4 inches long. Although about the same size, the armyworms differ in appearance. True armyworms are plump, sparsely-haired, generally green to brown larvae, with dark stripes running down the sides and back. These caterpillars feed on the aboveground plant parts of many grasses and is a pest of many garden and field crops.
Life History: Cutworm larvae may be noticed early in the growing season or not until later in the summer when subsequent generation begin feeding. Adult cutworm and true armyworm moths first appear between April and July. Females lay about 500 eggs on the lower leaves of grasses over a 2- to 3-week period. The caterpillars usually remain hidden during the day and feed at night. A second or third generation of cutworms may emerge in the summer and early fall. Cutworm larvae stop feeding and seek concealed areas to spend the winter during mid-fall. In contrast, many of the armyworms are not successful in over-wintering in Kansas.
Cutworms feed on grass blades and cut plants off near the soil surface. Grasses appear ragged and may turn brown from the feeding of any of these larvae. Damage is more likely to occur if the lawn borders cropland or large untended fields. Armyworms, in particular, seem to be attracted to areas of lush vegetation. Inspect lawns more frequently when vegetation in these nearby source zones is destroyed, forcing the caterpillars to seek out new food. If cutworms are suspected, check the damaged areas a couple of hours after dark. Depending on the species involved, larvae may be feeding up on the plant foliage or down near the crown of the plant. Damage near the crown should be considered much more serious than simple foliar feeding.
Recommendations for control: Active ingredients (and products thereof) registered for the control of armyworms and /or cutworms include: *acephate (Acephate, Systemic Insect Killer); *Bacillus thuringiensis var. kurstaki (various products); bifenthrin (Talstar, Rose and Flower Insect Killer); *carbaryl (various Carbaryl and Sevin products); cyfluthrin (Tempo, Multi-Insect Killer); fluvalinate (Mavrik); fonofos (Crusade) lambda-cyhalothrin (Scimitar, Spectracide Triazicide); and trichlorfon(Dylox, Proxol). *Active ingredients are contained in various product lines commonly sold through various retail outlets and, therefore, are the most readily available to the general public.
Scott Eckert is a Kansas State University Research and Extension agent of Harvey County, specializing in horticulture.
The Wheat is showing some sign of drought stress in parts of the county and Western Kansas South of I-70 is really affected. Stressed wheat is generally showing some combination of the following symptoms: * White heads, which developed very quickly over a large area. * Curled & dried up flag leaf * Tillers that have sloughed * Loss of one or more small developing kernels in the spikelet * Poorly developed kernels * Chlorotic leaves due to poor root development This stress has come in quickly and is a result of poor subsoil moisture due to 2011’s drought. We need a good rain for this not to occur more in Harvey County.
Field bindweed produces an almost delicate-looking vine with arrow- or shield-shaped leaves. Until its trumpet-like flowers bloom in pink or white, it’s adept at blending in with lawn or shrub.
The vine’s No. 1 talent, however, is its ability to multiply. Field bindweed is a non-native that spread to smother or out-compete millions of acres of Kansas crops before it ever reached town, according to Ward Upham, K-State Research and Extension horticulturist.
“You’d be telling the truth if you said that in Kansas – as elsewhere -- it’s officially noxious,” Upham said. “Fortunately, this year homeowners have another weapon in their arsenal of controls.”
Bindweed can form tangled mats, run along the ground, twist-twine around other plants, plus climb up and over all kinds of things, he explained. Each plant can produce up to 500 seeds that remain viable for 50 years.
But, bindweed’s real strength is underground, where the vine’s roots grow deep into the ground, while also extending out far enough to reach from one landscape into neighbors’ yards. Any break in or bud on those lateral roots can produce another plant.
“This isn’t a weed you can control by hand-pulling unless you’re willing to devote years to the task. Trying to hoe it up simply helps bindweed spread,” Upham said. “The recommended control has always been glyphosate – a nonselective herbicide that kills any green plant tissue it touches. In shrub borders, for example, you have to spray on a still day. You probably should put up cardboard shields, too, to protect the shrubs from any drift.”
Recently, however, a selective herbicide for use on lawns has come onto the market and sold under the trade name Drive (active ingredient: quinclorac). Drive is also an ingredient now in such combination herbicides as Ortho Weed-B-Gon Max + Crabgrass Control (one name), Fertilome Weed Out with Q, and Bayer All-in-One Lawn Weed and Crabgrass Killer.
“Drive is very stable on grass clippings. You can let treated clippings fall into the lawn. If you bag them, though, you should discard them, not add them to your compost pile,” the horticulturist warned. “You’ll be making a big mistake if you assume that because it won’t harm turf, Drive can’t harm other plants.
“If you were to convert an area of treated lawn into a vegetable garden, Drive could still damage any tomatoes you planted there within the next 24 months. Drive can injure exposed tree and shrub roots, too. In fact, to help homeowners avoid possible damage, I recommend not spraying beneath the leaf canopy of any trees.”
For instructions on how to control bindweed as well as other pests without chemicals, Upham suggests homeowners look at the photo series and instructions for No. 15 in the University of Illinois Extension program called “57 Ways to Protect Your Home Environment.” That page is on the Web at http://www.thisland.illinois.
The rain this spring has been great! However, problems can be caused by the timing of rain and temperatures.
Sycamore anthracnose is the most serious of the anthracnose diseases in Kansas. The most conspicuous symptom of the disease in early spring is death of twigs and new shoots. Small black fruiting structures of the fungus break through the dead bark of blighted, one- year-old shoots. Repeated killing of young twigs results in abnormal branching and gives the tree a ragged appearance.
After bud break, sycamores show a scorching and wilting of new shoots and leaves. Later, fully expanded leaves develop elongated tan to brown lesions parallel with the midrib and veins. This should not be confused with summer scorch of sycamore (also a common problem), which causes a burning of the leaf margins. Infected leaves scorch and shed. In exceptionally cool, wet springs, sycamore trees leaf out and then can defoliate heavily.
Anthracnose fungi overwinter in leaf debris on the ground and/or dead areas of the bark on the tree, called cankers. In early spring, spores of the fungus are produced in fruiting
structures and are dispersed by splashing rain. These spores infect expanding leaf buds, shoots or in some cases young leaves. The infection process is favored by relatively cool temperatures and prolonged periods of leaf wetness. Therefore, the disease tends to be more severe during wet, cool springs. After infection, the anthracnose fungus colonizes leaf
tissue and begins to produce new fruiting structures and spores capable of reinfecting expanding leaf tissue.
These diseases tend to be less of a problem during hot, dry summer weather. As temperatures increase, the disease becomes less active and the trees releaf. Anthracnose rarely causes significant damage to shade trees in Kansas; consequently, specific control measures generally are not required. Nevertheless, the disease may be unacceptable in certain high visibility landscape settings.
The disease also can increase susceptibility to other disease or insect problems in areas where trees are attacked year after year.
Several cultural practices can reduce the severity of anthracnose. Remove dead leaves in the fall to help limit the amount of fungal inoculum present for infection of new leaves the following spring.
This practice really eliminates the problem, especially for those anthracnose fungi that may also survive in blighted twigs on the tree. Proper tree spacing and placement to promote good air circulation reduces the number of hours leaf surfaces remain wet, and decreases the likelihood of fungal infection.
Many trees recover rapidly from anthracnose if they are maintained in a vigorous condition. Water and fertilize trees regularly. Nitrogen fertilization may increase the tree's tolerance or resistance to anthracnose, but avoid overfertilization. Chemical sprays normally are not necessary to control anthracnose except on those trees that have had a history of the problem. Several fungicides are labeled for anthracnose diseases including thiophanate and Bordeaux or other coppers. Thorough coverage and proper timing of the sprays are essential for adequate control.
Anthracnose isn’t exclusive to just sycamore trees. I have seen it several times on Maple trees as well.
Scott Eckert is a Kansas State University Research and Extension agent of Harvey County, specializing in horticulture.
Everyone is invited to learn about the latest news on wheat varieties in our area. Once again K-State Research and Extension, Harvey County, has joined forces with DeLange Seed to have a single wheat plot tour.
The joint wheat plot tour will be at 6 p.m., May 17 at Camp Hawk. Camp Hawk is located at 1801 SW 36th St. This is one mile west from the intersection of Old 81 Hwy and 36th St. at the Newton Outlet Mall.
Doug Shoup, KSU Crops and Soil Specialist, and Steve Ahring, the Delange Agronomist, will provide information on the wheat variety comparisons. A meal will be served at 6:00 p.m. at Camp Hawk, and the tour will begin at approximately 7:00 p.m.
This year our field cooperator is Darren Hughes, and the plot is located south of 48th and Hoover, 2 miles west of Camp Hawk and 1 mile south on Hoover.
This is an excellent opportunity to study new wheat varieties and compare the established varieties. Mark your calendars and plan on having an enjoyable and educational wheat plot tour. Please call the Harvey County Extension Office 284-6930, to reserve your spot for the free dinner.
Joni James is a Kansas State University Research and Extension agent of Harvey County, specializing in agriculture.
Conditions are right for cedar-apple rust to appear. Cedar-apple rust appears as large, bright orange, jelly-like, tendril covered balls on cedar trees. These rust galls release millions of spores that can infect apples and crabapples with the disease. There is a related disease named cedar-quince rust that infects hawthorn trees.
Unprotected, susceptible apples, crabapples, and hawthorns are likely to become infected. Though not yet visible, it is impossible to cure what is already there. But many of the newer crabapples are naturally resistant. Though they may show some signs of the disease, they wont defoliate like susceptible varieties. Even susceptible varieties that defoliate will develop a new set of leaves if they were healthy before infection. Significant damage to crabapples is rare. But fruiting apples, which pour a great deal of energy into the fruit, may be stressed more severely.
It will be important to pamper them this summer by keeping them watered. It is also recommended to prevent further infections by applying fungicides through Memorial Day. Several fungicides, including Banner, Systhane, Rubigan, Funginex and Bayleton, applied on a 14- to 21- day interval are effective in controlling rust. However, most of these products are only available to commercial applicators. Homeowners may use triadimefon (Green Light Fung Away), propiconazole (Fertilome Liquid Systemic Fungicide) or myclobutanil sold as Immunox (same active ingredient as Systhane). Chlorothalonil is also labeled for rust, but it is not as effective as the other products listed and cannot be used on apples. Only myclobutanil can be used on fruiting apples. Fungicide applications to the leaves of hawthorn, apple, and crabapple must continue as long as the cedar galls remain active (jelly-like). If you don't want to mess with fungicide applications, use flowering crabapple or apple varieties that are resistant and avoid the use of any hawthorns in areas where cedar-quince rust has been a problem.
Scott Eckert is a Kansas State University Research and Extension agent of Harvey County, specializing in horticulture.
They move in unison like a synchronized swimming team at the Olympics when startled and make a clicking noise when feeding. What in the world could I be referring too? The answer: the European Pine sawfly.
We are now seeing sawfly damage to pine trees. If you have had a problem with this insect before, check your pines for the beginning stages of damage. When these worms are small, they cannot consume a complete needle, so they rasp off the top layer of cells. This leaves individual needles brown and twisted. Look for this damage to pinpoint where sawfly larvae are feeding.
The larvae are gregarious, so a number of larvae will be found close together. As the larvae mature, they will consume whole needles and can virtually strip a tree. This happens before new needles expand, so the tree is rarely killed. The pine sawfly prefers Scotch and Mugo pines.
A number of insecticides can be used for control including spinosad (Captain Jack’s Deadbug Brew; Fertilome Borer, Bagworm, Leafminer and Tent Caterpillar Spray), acephate (Hi-Yield Acephate Systemic), cyfluthrin
(Bayer Lawn and Garden Multi-Insect Killer), malathion and permethrin (numerous trade names). Horticultural oils and insecticidal soaps also are effective because of the soft skin of sawfly larvae.
Scott Eckert is a Kansas State University Research and Extension agent of Harvey County, specializing in horticulture.
Research from K-State indicates that a single fungicide application made to susceptible wheat varieties, when risk of the disease is high, will often result in an average yield increase of 10 percent relative to wheat that remained untreated. A lower yield response is likely if the disease remains at low levels or is absent.
Fungicides need to be applied between full extension of the flag leaves and when the male flower parts begin to emerge. Always consult the label before applying and pay close attention to any pre-harvest intervals.
According to Dr. Erick DeWolf, K-State Plant Pathologist, he has diagnosed stripe rust in Kingman county and Sedgwick county. Deciding to apply the fungicide is not an easy decision. Producers should scout their fields to see the stage their wheat is in, and if any sign of the disease is present, and should also consider their wheat varieties tolerance to the rust diseases. My advice currently is for the fields that have the potential to raise 40+ bushel/acre it would probably pay or break even to apply the fungicide.
For those fields producing less than 40 bushel/acre, it likely will cost more to fly the fungicide on than it will save in yield. Based on recent calls, the average price to apply the fungicide is $27 per acre. If producers are able to get it applied for less, then it may pay off for those lower yielding fields as well. Remember on average you gain a 10 percent yield advantage.
We have a new publication on this topic that can be downloaded off our website ( www.harvey.ksu.edu ) or picked up at the office. It is titled Foliage Fungicide Efficacy Ratings for Wheat Disease Management 2012.
Joni James is a Kansas State University Research and Extension agent of Harvey County, specializing in agriculture.
The most common aquatic vegetation problems occur in impounded waters (ponds, lakes, and reservoirs). Abundant vegetation affects the fish populations in these bodies of water. Small fish hide in the vegetation making them unavailable to predators. This often results in overpopulation and stunting of certain species. Excessive vegetation interferes with fishing, swimming and boating, and dead, decaying vegetation produces offensive odors. A more serious problem results from the oxygen deficiency caused by the decaying vegetation. The solution is to control problem weed species.
Cattails are a common weed problem. The best method of control is to spray with an aquatic round-up herbicide. Usually it takes at least two applications to obtain good control. The first application usually causes the plant to die back, and the second application usually results in its death. Be diligent with this weed.
Algae weeds can be controlled by applying a copper algaecide. Be sure to follow the label to prevent any fish kills. If a heavy growth of algae is present treat only one-third or one-half of the pond at a time at weekly intervals. This prevents depleting the oxygen when the mass of dead organic matter decomposes.
Grass carp are often chosen to control submersed or floating aquatic vegetation. These fish originate from china and will not reproduce in ponds or lakes since they require large fast flowing rivers for reproduction. Grass carp at the rate of 20 fish per acre are needed if at least half of the area is normally covered by vegetation. Some submersed plants are not well controlled by grass carp due to the plants growing habits. For instance, coontail, once bitten in half by a fish, has the ability to sprout new roots. It is best controlled by the herbicide sonar.
Properly identify any problem weed before selecting a control method. If you are unable to identify the weed, bring a sample in to the Harvey County Extension office or call them at 316- 284-6930 for help with the identification. Once identified control options can be discussed. Also available is a great publication targeting aquatic weed control. Remember to always follow the label when applying any herbicide.
Joni James is a Kansas State University Research and Extension agent of Harvey County, specializing in agriculture.
Extension notes is written by K-State Extension of Harvey County extension agents Scott Eckert and Joni James. They focus on horticulture and agriculture.
