Herculex RW has received EPA approval and USDA deregulation to begin
marketing for the 2006 season. Corn hybrids with the Herculex RW
trait are resistant to larvae of western, northern and Mexican corn
rootworms. Dow AgroSciences LLC and Pioneer Hi-Bred International,
Inc are the developers of the Herculex RW trait.
Unlike other Bt corn currently on the market, Herculex RW produces binary Bt endotoxin proteins. This means that there are two active ingredients that act together in the rootworm larva's midgut to provide control. Independently, the toxins are not active in the larvae. The active proteins are Bacillus thuringiensis Cry34Ab1 and Cry35Ab1.
In Kentucky, western and northern corn rootworm larvae can be with continuous corn production. Where corn is rotated with other crops, corn rootworm damage is rare. This is in contrast to states to our north where in some regions, serious rootworm damage can occur in first year corn. While damage by corn rootworm larvae is possible in second year corn, it usually takes a few to several years of continuous production to build economic levels.
As with YieldGard Rootworm corn, the resistance management plan for Herculex RW is different than the resistance management plan for Bt hybrids that control corn borers. Growers are allowed to plant up to 80 percent of their acreage with Herculex RW hybrids, but at least 20 percent must be in a corn rootworm refuge. The refuge must be immediately adjacent to the Herculex RW fields (may be separated by roads or ditches but not by other fields). The refuge may be treated by insecticide (soil or seed applied) for rootworm control. If adult rootworm beetles are controlled on the refuge, then the fields with the Herculex RW trait need to be treated as well. The refuge needs to be planted at the some time.
There are some restrictions on rotation with the refuge and the Herculex RW fields. If the refuge is planted on rotated ground, the Herculex RW corn must be planted on rotated ground. However, if the refuge is planted on continuous corn ground, then the Herculex RW corn can be planted on either continuous or rotated ground. It is suggested that growers use the same field for the refuge year after year. More information on managing Herculex RW corn can be found on the web at: http://www.pioneer.com/usa/agronomy/insects/hxrwpug06.pdf.
For information about corn pests, visit
"Insect Management Recommendations".
Sclerotinia crown and stem rot (SCSR) is a serious disease of fall- seeded alfalfa. Alfalfa-whether spring-seeded or fall-seeded-is highly susceptible to infection for the first 10 weeks or so of its life. Spring-seeded alfalfa stands escape significant damage because the fungus, Sclerotinia trifoliorum, produces its fruiting bodies from the last week or two of October until early December. However, during this time, the fall-seeded stands are still in a highly susceptible stage, so they can get "whacked" if levels of the fungus are high in the field.
The fruiting bodies of S. trifoliorum are visible to the naked eye but you have to look hard for them. They look like tiny, flat mushrooms, light brown in color, 1/8 inch to ¼ inch in size, and held 1/16 inch or so above the soil surface by a slender stalk. They tend to be most abundant when they first appear, usually when the soil surface is moist and the average soil temperature drops to around 50°F. Hard freezes kill many of these fruiting bodies, but a new, smaller crop emerges, and this cycle is repeated until the soil gets too cold in December.
Some of the risk factors for SCSR are:
1. History of forage legumes in or around the field.
2. Mid-September seeding vs. earlier in the fall-seeding window.
3. No-till seeding. (No-till protects important soil resources, but
be aware that it increases the SCSR risk, if the fungus is present in
the field).
Sowing alfalfa in late summer poses a risk from SCSR, and few varieties have significant levels of resistance. Over the past decade we have seen in our research that the use of certain varieties can provide a degree of protection against stand loss, should SCSR be active on the farm. It would be wise to monitor new seedings for disease activity in the spring when the damage from the disease becomes obvious. Damage shows up in one of two ways: as the failure of a good stand to survive the winter, or as wilting, yellowing, and dying plants during March and April.
There are only two varieties currently available that have shown
partial resistance to high pressure from SCSR under Kentucky
conditions: Cimarron SR and WL 338 SR. Encouragingly, FFR
Cooperative has a breeding line which has performed significantly
better than Cimarron SR, with stands of over 60% under high disease
pressure, so another commercial variety with partial resistance may
be on the horizon. No variety with partial resistance will provide
complete protection against high pressure from SCSR. However, if the
disease is active on your farm this fall, it seems sensible to rotate
away from forage legumes on those fields for a time, and to consider
sowing varieties that have been proven to provide some protection
against SCSR under the high disease pressure possible in Kentucky.
Raspberry crown borer can be a devastating pest of blackberry and
raspberry in Kentucky. While not as obvious as Japanese beetle or
green June beetles attacking the fruit, raspberry crown attacks the
roots and crown of the plants which results in killed or weakened
canes. Symptoms of raspberry crown borer attack include canes
prematurely dying, spindly cane growth, sawdust-like frass at the
base of the canes, tunneling in the base of the canes noticed during
pruning, or noticeable swelling at the base of the cane.
The raspberry crown borer adult is a clearwing moth that resembles a
medium-sized yellowjacket. It has similar yellow and black bands on
the abdomen. The cream colored larva is the stage that causes the
damage and is very similar in appearance to other clearwing borer
larvae (such as the squash vine borer, dogwood borer, peachtree
borer, and grape root borer).
Sanitation and control of moisture are two very important strategies for disease control in the greenhouse. Few fungicides are labeled for use in greenhouses, and a limited number of resistant varieties are available. Efforts should be focused on excluding pathogens from the greenhouse and on maintaining an environment that doesn't favor development of disease.
Sanitation is extremely important in the greenhouse. Every effort should be made to keep greenhouses and the areas around them clear of debris and weeds. Benches and implements need to be cleaned routinely with a sanitizing solution, such as a 10% solution of household bleach. Sterilize transplant trays if they are to be re- used, or purchase new ones. Don't recycle old growth media, as this can result in the introduction of pathogens into a crops.
In between seasons, solarize the greenhouse by closing it tightly for several weeks during the hot and sunny parts of summer so that air temperatures reach 140°F. This will reduce populations of many pathogens. Maintain high relative humidity/moisture to encourage microbe activity during this solarization period; this will make microbes more sensitive to being killed by heat.
Foliar diseases in most greenhouse crops can be suppressed if relative humidity is kept below 90%. Manage the heat and temperature and keep the air circulating with fans and tubes. Consult a greenhouse specialist for more information on how to best manage the greenhouse environment. To avoid virus disease problems, do not produce vegetable transplants in greenhouses together with ornamental plants.
The following table summarizes the fungicides and bactericides registered for use on greenhouse-grown vegetables (including transplants). Exotherm Termil is no longer labeled for use on greenhouse-grown tomatoes. Consult product labels for crops covered by each material and for application instructions.
| Product | Rate | Target diseases | Comments |
|---|---|---|---|
| Armicarb | 2.5-5 lb/100 gal water | powdery mildew, Botrytis | apply on 5-14 day schedule |
| Botran 75W | 1 lb/100 gal water | Botrytis | direct spray at stems; limit 4 applications per crop |
| Kocide 101 | 4-8 tbsp/1000 sq. ft | bacterial diseases, early blight, leaf spots | Apply on a 7-14 day schedule. Other fixed coppers are registered; check product labels. |
| Dithane DF | 1-3 lb/100 gal water | early blight, leaf spots, bacterial diseases (+ Kocide 101) | Apply on a 7-day schedule. Other formulations of mancozeb are registered; check product labels |
| Maneb 75DF | 1-3 lb/100 gal water | early blight, leaf spots, bacterial diseases (+ Kocide 101) | Apply on a 7-day schedule. |
| Turfcide 10G | 1-1.5 lb/ cubic yard of growth medium | root/stem rot; damping-off (Rhizoctonia) | For use on cabbage, cauliflower, broccoli, Brussels sprouts, pepper, and tomato plants grown in containers. |
Dry weather this summer and fall has created difficult times for mature landscape trees in many areas of Kentucky. The dry weather was in contrast to the past two growing seasons which saw plenty of rain. In oaks, bacterial leaf scorch disease is widespread, placing additional stress on urban trees. Branch breakage from previous winter storms and periodic high winds have left wounds that allow ingress of weak parasites and even aggressive saprophytes that are often indicators of the final stages of tree decline. The fungus Hypoxylon atropunctatum and to a lesser extent relatives, H. mediterraneum, and H. punctulatum are fungi that attack injured oaks and other trees growing in stressful conditions such as drought and disease.
Hypoxylon canker is commonly seen on oaks as patches of brown, gray, silvery gray or black fungal stromata in the cambial zone of affected trees. These smooth, hard patches are revealed when the tree bark is loosened and sloughs off the affected trunk or limb. By the time the patches of fungal stromata are revealed, the fungus has decayed much of the adjacent inner bark and outer sapwood. Discoloration and decay are often accompanied by black zone lines in the sapwood, similar to that seen for other sapwood decays. Leaves on dying limbs wilt or turn yellow, an indicator that this serious canker disease is active and that the tree is stressed.
Hypoxylon fungi are quick to colonize weakened bark and wood, and stromata may develop within a few months after infection. Oaks and other trees are very quickly attacked because it seems that in some instances, the fungus may already be present as a latent colonist of even healthy trees. Injuries of any kind, and warm, dry weather or diseases such as bacterial leaf scorch favor the fungus and rapid decline of branches attacked by Hypoxylon can be expected. Tree trunks and major limbs with Hypoxylon canker and dieback should be considered as posing a risk of falling and need to be removed where they represent a danger to people and property.
Look for Hypoxylon canker and limb dieback on all oaks, especially
those in the red oak sub-group, sycamore, linden, hickory, maple,
beech, dogwood, hornbeam, elm, and willow. Although in some cases,
the fungus is pretty much saprophytic, attacking trees already
declining, the fungal stromata are sure indicators that the tree or
tree parts will not recover. These fungi are most active in summer
under our warm growing conditions, but fall is a good time to observe
this fungal disease when the cankers are not completely hidden by
foliage.
Phytophthora ramorum is a fungus-like organism that can infect woody trees and shrubs, herbaceous plants and ferns, causing diseases like Ramorum leaf blight and Ramorum shoot dieback, on mature oak trees it causes sudden oak death. An updated list of host plants and plants associated with Phytophthora ramorum is available on the USDA-APHIS- PPQ website. The last revision was dated September 14th 2005, when eight plants were added to the list of P. ramorum hosts and plants associated with P. ramorum , bringing the total to 85. There are 40 plants listed as proven hosts and these are regulated in whole or in part, the other 45 plants are referred to as plants associated with P. ramorum and are regulated as nursery stock. The complete list can be viewed at: http://www.aphis.usda.gov/ppq/ispm/pramorum/pdf files/usdaprlist.pdf.
The USDA Forest Service and collaborating states are conducting surveys for detection of P. ramorum in general forest areas and nursery perimeters in several states. Surveys have been completed in 28 states and to date no confirmed positives have been found outside of California and Oregon. The purpose of the National Forest Surveys is early detection of P. ramorum in forests because this quarantined pest may have been inadvertently introduced to states outside the regulated areas in California and Oregon on infected nursery stock during the years of 2003, 2004 and 2005.
In Kentucky, in 2005 the forest survey was carried out for the first time as collaboration between the USDA Forest Service, the Kentucky Division of Forestry and the Plant Pathology Department of the University of Kentucky. The survey was performed according to a protocol designed by Forest Health Monitoring of the USDA Forest Service, and sampling was based on a risk polygon map developed by Forest Health Monitoring. The risk map was developed based on the following factors: presence of oak species in the overstory and presence of the target host genera in the understory; locations of trace forward nurseries (nurseries that received camellias from a contaminated West coast nursery in 2004); length of the period of moist weather and mild temperatures; and area outside the temperature extremes that limit the establishment of P. ramorum . Target host plants were plants in genera that are relatively abundant in forest settings, exhibit distinctive symptoms when infected with P. ramorum , and have been shown in other places to develop the disease when exposed to this disease causing organism. For the eastern United States in 2005 there were eleven target hosts.
The survey locations in Kentucky were chosen based on the criteria above and in each location four 100 meter transects were installed in the four cardinal directions from a central point. The width of each transect was determined by how far the surveyors could see from the transect line. GPS readings and other host and terrain data were taken and samples were collected from target host plants showing suspicious symptoms and found in the transect area. Suspect samples were placed in double bags with a zip closure, labeled and maintained at low temperature until they were analyzed in the laboratory. Tools used for sample collection were disinfected after each sample was taken to avoid spreading any disease to other plants. Replicate samples were shipped overnight to a collaborating laboratory for analysis and for confirmation of the results.
Thirty locations were surveyed in Kentucky and preference was given to high risk areas in predominantly oak forests rich in rhododendrons and mountain laurels. Because P. ramorum resistance spores are known to survive in soil that can be carried on hiker's boots and on bicycle tires, areas of high tourist traffic like national and state parks and some city parks were also sampled. The locations were distributed as follows:
1 - Six trace forward nursery perimeters: two in Jefferson Co and one
in each of the following counties Jessamine, Franklin, Laurel and
Pulaski.
2 - Four Kentucky State Forests: Pennyrille State Forest (Christian
Co), Tygart State Forest (Carter Co), Kentucky Ridge State Forest
(Bell Co) and Kentenia State Forest (Harlan Co).
3 - Privately owned forest areas in the following counties:
Muhlenberg, Clay, Jackson, Knott, Scott, Grant, Madison and Bullit.
4 - Forest areas in the following State Parks: Rough River State
Recreation Park (Grayson Co), Cumberland Falls State Resort Park
(Pulaski Co), Levi Jackson State Resort Park (Laurel Co), Jenny Wiley
State Resort Park (Floyd Co), Yatesville Lake State Resort Park
(Lawrence), Carr Creek State Recreation Park (Knott Co), Dale Hollow
Lake State Recreation Park (Cumberland Co) and Green River Lake State
Resort Park (Taylor Co).
5 - Other forested areas: Land between the Lakes National Recreation
Area (Lyon Co), Mammoth Cave National Park (Edmonson Co),
Tompkinsville City Park (Monroe Co) and Murray City Park (Calloway
Co).
From the thirty locations surveyed in Kentucky in 2005, 42 suspect
samples were collected, DNA was extracted from all samples and PCR
was performed to test for P. ramorum . No samples were found to be
positive for P. ramorum . A nursery survey was also performed in
Kentucky 2005 and no suspect samples collected during that survey
were found to be positive for P. ramorum .
Early detection and eradication of diseased plants are important to
protect Kentucky's forest resources and the forestry industry from
Phytophthora ramorum , and surveys like the Forest Survey and the
Nursery Survey are important in the effort to achieve this goal.
Clients soon will be calling about lady beetles congregating on the
sides of homes and infesting buildings. This phenomenon has become an
all-too-common autumn event throughout Kentucky and much of the
United States. The culprit is the Asian lady beetle, Harmonia
axyridis, in search of protected places to spend the winter. In
Kentucky, movement into buildings typically begins in mid-October,
continuing through mid-November.
Detailed information on this perennial problem is contained in ENT- 64, Asian Lady Beetle Infestation of Structures. Key points include:
1. Lady beetle flights are heaviest on warm sunny days when temperatures climb above 60 degrees F. They tend to congregate initially on the sunnier, southwest sides of buildings in mid- afternoon. Structures that are shaded and not brightly illuminated by afternoon sun are less likely to attract the beetles.
2. Once the beetles alight, they attempt to enter crevices and other dark openings in search of hibernation sites. These locations may be anywhere on the structure, but especially beneath exterior siding, around window and doorframes, soffits, fascia boards, and through weep holes and attic or crawl space vents. Sealing exterior cracks and openings with caulk, screening, weather stripping, etc., is the most effective long-term, prevention against beetle entry. (See ENTFACT-641 How to Pest-Proof Your Home.)
3. Once the beetles are indoors, the best way to remove them is with a vacuum cleaner. When brushed or handled the beetles often secrete a yellowish-orange fluid, making vacuuming a better option for indoor removal than brooms, mops, etc. Insecticides applied indoors tend to be ineffective and may stain or leave unwanted residues on walls, counter tops, and other surfaces.
4. While sealing exterior openings is the more permanent means of denying ladybug entry, pest proofing is time-consuming and impractical for many clients. If a household or business continues to be troubled by lady beetles, owners may want to enlist the services of a professional pest control firm. Some companies offer pest proofing services and many offer insecticide treatment of the building exterior, which helps to prevent pest entry. Fast-acting, "professional strength" pyrethroid formulations (e.g., Demand, Suspend, Talstar, Tempo) tend to be most effective, and can be applied around eaves, attic vents, windows, doors, underneath siding, and other likely points of entry.
Homeowners insistent upon applying exterior treatments themselves will usually get the most for their efforts using over-the-counter versions of these products such as Spectracide Triazicide or Bayer Advanced Powerforce Multi-Insect Killer. Purchasing the concentrated formulations of these products that can be diluted will enable the homeowner to mix up and apply larger volumes of material with a pump- up or hose-end sprayer. In order to have any benefit, exterior treatments must be applied before the beetles enter buildings to overwinter.
5. When all else fails, customers should be reminded that lady beetle
entry into buildings is a relatively short-term event which generally
runs its course by mid-November. The beetles sometimes emit a foul
odor, stain indoor surfaces, and occasionally give a "nip" if they
land on one's skin. They do not breed or reproduce indoors like fleas
or cockroaches, and constitute a nuisance mainly by their presence.
Wolf spiders are among the common household invaders that alarm and
frustrate homeowners in the fall. These brown to gray spiders, 0.5 to
2 inches long, have two oval body regions and relatively thick long
legs. The legs and body appear hairy and often are marked with light
to dark stripes.
Wolf spiders are speedy, wandering hunters that are most active at night when they move around in search of prey. They are common in lawns and around buildings so several may be found indoors soon after a drop in temperature. Individuals can be swatted and discarded. Sticky boards, placed near doors and along baseboards, can be used to trap wandering spiders if several are seen.
Wolf spiders can bite if handled. Their venom is not considered toxic
but reactions to bites can vary from person to person.
Recent samples in the Diagnostic Laboratory have included Fusarium stalk rot, anthracnose and Penicillium ear rot on corn; downy mildew, frogeye leaf spot and sudden death syndrome on soybean; and black shank, soreshin and frogeye on tobacco.
On fruit and vegetable samples, we have diagnosed sooty blotch/flyspeck on apple; anthracnose, Sphaerulina leaf spot and cane borers on bramble (blackberry and raspberry); downy mildew and Alternaria leaf blight on cucumber; Microdochium (Plectosporium) blight, powdery mildew and Fusarium fruit decay on pumpkin; and sour rot and yellow shoulders (physiological disorder) on tomato.
On ornamentals and turf, we have seen rust on daylily; symptoms
related to high soil pH on chrysanthemum; black root rot on pansy and
holly; Septoria leaf spot on azalea; anthracnose and spider mites on
maple; bacterial leaf scorch, Actinopelte leaf spot and powdery
mildew on oak; ozone injury on pine; Rhizosphaera needle cast and
Cytospora canker on spruce; Pythium blight and anthracnose on
bentgrass; Pythium blight and smut on fescue; summer patch on
bluegrass; gray leaf spot on ryegrass; and large patch disease on
zoysiagrass.
View Princeton trap counts for the entire 2005 season at - http://www.uky.edu/Ag/IPMPrinceton/Counts/2005trapsfp.htm
Fulton County trap counts are available at -http://ces.ca.uky.edu/fulton/anr/Insect%20Counts.htm
For information on trap counts in southern Illinois visit the Hines Report at - http://www.ipm.uiuc.edu/pubs/hines_report/comments.html The Hines Report is posted weekly by Ron Hines, Senior Research Specialist, at the University of Illinois Dixon Springs Agricultural Center.
NOTE: Trade names are used to simplify the information presented in this newsletter. No endorsement by the Cooperative Extension Service is intended, nor is criticism implied of similar products that are not named.
Lee Townsend
Extension Entomologist