kentucky pest news august 10, 2010

8/9/2019 Kentucky Pest News August 10, 2010

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Online at:www.uky.edu/KPN

Number 1242 August 10, 2010

CORN

-Southern Rust Prognosis

-Producing Late-Season Sweet Corn

-Brown Spot of Corn

SOYBEAN

-Watch for THESE Stinkbugs in Your

Soybeans!

FIELD CROPS

-Late Summer Caterpillars in Field Crops

CORN

Southern Rust PrognosisBy Paul Vincelli

Last week I toured a number of corn fields in

Mclean County (and enjoyed excellent

interactions with a group of Extension agents

and fellow industry representative; thanksfolks!). Southern rust was found but only in

localized hotspots. In other areas of the state,

Extension agents continue to scout for the

disease and have not yet seen it (although it hasbeen found also in Caldwell Co. and Graves

Co). Thus, southern corn rust appears to still be

at a relatively low prevalence in Kentucky.

Many corn crops in Western Kentucky are wellinto the dent stage, because of the combination

of early to timely planting, rapid accumulation

of heat units), and very dry weather during grainfill. Between the low prevalence of southern

rust and the rapid maturation and drydown of the

crop, it appears that many crops have escaped

the threat of significant damage from southernrust.

SHADE TREES & ORNAMENTALS

-Fall Webworms

-Walnut Thousand Cankers Disease A

Potential Threat

-Spruce Fungi Causing Needle Loss

LAWN & TURF

-Summer Patch of Kentucky Bluegrass

DIAGNOSTIC LAB HIGHLIGHTS

INSECT TRAP COUNTS

Of course, late-planted fields should still be

scouted for the disease. And all fields should be

checked for stalk strength as they dry down.

Producing Late-Season Sweet CornBy Ric Bessin

Producing sweet corn late in the season can be

one of the more challenging crops to produce

without insect damage. Insect management

techniques used to produce sweet corn for sale

in July are often insufficient for crops maturingin mid August and later. The problem is corn

earworm. During this time period, it is not

unusual to find 80% of the ear tips damaged by

this insect even when the plants were regularly

sprayed.

Lexington, KY 40546

Figure 1. Corn earworm larva in tip of corn ear.
http://www.uky.edu/KPNhttp://www.uky.edu/KPNhttp://www.uky.edu/KPNhttp://www.uky.edu/KPN


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There are a couple of reasons for this. First, by

midsummer, much larger populations of corn

earworm are present and egg laying increases

proportionally. There are several generationsper year so by midsummer populations have had

a chance to buildup. By midsummer migratingpopulations are also arriving from southern

states.

Heat is the other reason why corn earworm is

more difficult to manage in midsummer. Heat

makes the corn silks grow faster and the corn

earworm eggs develop quicker. As new silk

emerges from the ear more rapidly, insecticides

may need to be reapplied more often to protect

the ears. Higher temperatures may reduce spray

intervals from 5 to 3 days with some

insecticides. Heat also has a negative influenceon pyrethroid insecticides, the most common

insecticide class used on sweet corn. The higher

the temperature, the less effective they are.

When examining sweet corn ears, keep in mind

that there can be a few different kinds of insect

larvae that can be found. Corn borers, both

European and southwestern will attack the ears.

Unlike corn earworm that attacks only the tip,

corn borers can damage the base and side of the

ear as well as the tip. Both of these larvae are

smooth and without the microspines found onthe corn earworm. Corn borers also have very

dark head capsules rather than the lightercolored head capsule of the corn earworm. Fall

armyworm will also attack the ear. The brown

fall armyworm has a dark head capsule with a

light colored inverted Y on the front of the

head.

Management of corn earworm in the

midsummer is not easy, but it is possible. First,

producers should think about how they are

applying their sprays. The only part of the plantneeding protection is the ear. So sprays should

be directed to the middle third of the plant.

Drop nozzles on ground equipment should be

angled toward the ear. Leaves can interfere withpenetration to the ear, so a nozzle angled

downward above the ear and one angled upward

below the ear on each side of the row can

improve coverage. Spray volume needs to besufficient to allow for through coverage.

Corn earworm management is preventive. We

must prevent it from entering the ear as onceinside we cant do anything to kill it. Generally

the first insecticide spray is applied when 50 to

70% of the ears first silk. Sprays are reapplied

at two to six day intervals based on pheromone

trap captures and temperature. With higher the

temperature and moth populations, producers

should shorten the spray intervals. Once the

silks dry, they are no longer attractive for egg

laying and insecticide sprays can be

discontinued.

Insecticides for corn earworm control includeAsana XL, Baythroid XL, Belt, Brigade,

Lannate, Larvin, Mustang Max, Pounce,

Proaxis, Radiant, and Warrior. Most of these are

pyrethroid insecticides (IRAC Group 3) and

some corn earworms in the Midwest appear tobe less sensitive than in the past. Belt, Lannate,

Larvin, and Radiant are from other non-

pyrethroid insecticide classes.

It helps to select the proper variety. Ears withgood tip coverage, tight husks, and long silk

channels help to limit kernel damage. Anothertool available to growers is the use of Bt sweet

corn. These varieties produce a protein that killsthe larvae and can provide up to 90% control,

but 90% control may not be enough when each

ear has a dozen or more corn earworm eggs.

Early-planted sweet corn may not need any

supplemental corn earworm controls, but by midAugust supplemental sprays are recommended.

Figure 2. Insecticide sprays need to begin at early silking.


3/11

Larvae that do develop on Bt sweet corn are

small and damage is often restricted to just a few

kernels.

Brown Spot of CornBy Paul Vincelli

Last week I visited a corn field with brown spotdisease, caused by the fungus Physoderma

maydis. This disease does not occur widely in

Kentucky, though it is not unusual to see it pop

up here and there.

Infection by this fungus produces chocolate-

brown spots on leaf midribs and leaf sheaths.

Infections of the leaf blade tend to be small and

yellowish to yellowish-brown in color (Figures3-4). Often, brown spot symptoms appear as

diffuse bands of disease. This is because

infections often occur in the whorl, where

moisture accumulates. Since environmental

conditions in the whorl fluctuate, so does the

occurrence of infections as the corn tissue grows

through the whorl.

Brown spot rarely causes yield loss. However,

the brown spots on the sheath can raise concern

about stalk heath. Keep in mind, however, that

these are infections of the leaf sheath, not thestalk. The underlying stalk is healthy. Prove

this to yourself by removing a brown-spotted

sheath, and youll see healthy stalk beneath.

SOYBEAN

Watch for THESE Stinkbugs in Your

Soybeans!By Doug Johnson

By now stinkbugs will have begun congregatingin soybeans. Generally attracted by blooms, they

actually do their damage by feeding on the pods.

In Kentucky, our beans will be infested by green

and brown stink bugs. Yes, those are the colorsbut also the common names, of two of the

species. We might occasionally see a southern

green stink bug but they are by far in the

minority. The green and southern green stink

bugs look very much alike and there is no easyway to tell them apart.

Figure 3. Symptoms of Physoderma brown spot of

corn on the leaf blade. Note band of diseased tissue,

indicative of an infection period when that leaf tissue

was in the whorl.

Figure 4. Symptoms of Physoderma brown spot of cornon the leaf sheath. Note diagonal "banding" pattern,

indicative of sequential flushes of infection.

Figure 5. Green stink bug (R. Ottens, Univ. of

Georgia, Bugwood.org photo).

Figure 6. Southern green stink bug

(M. Shepard, G.R. Carner, and P.A.C.

Ooi, Bugwood.org photo).


4/11

The brown stink bug complex is also usually

made up of two species, the brown stink bug and

the one spotted stink bug. You can sometimes

tell them apart by looking for a dark brown/

black spot on the underside of the rear end of themale one spotted stinkbug.

There are of course other species that might also

appear in much fewer numbers. At present wecount all of these species of stink bugs the same

for purposes of making a control decision. That

may change with the introduction of newspecies.

In addition dont forget that there are predatory

bugs around that may look like the brown stinkbug. Common predatory bugs are the spined

soldier bug and the spined assassin bug. These

are a good guy working for you. Dont count

these bugs with the pest stink bugs when making

a treatment decision!

So much for what has been, now what will the

future bring? There are three stink bug species

that are quite literally on our borders and could

change how we handle this insect pest complex.At present we are unaware that any of these

species have been captured in Kentucky, but

they could be close by and we are on the lookoutfor them.

Perhaps the most important is the red banded

stink bug. This pest originally from South

America, has been making life difficult forsoybean producers in the deep south for several

years. It often requires multiple insecticide

applications to obtain control. They are known

to occur as far north as southeastern Missouriand west Tennessee. This stink bug is rather

distinctly different in coloration from the greens

and browns that we normally find. They have

red coloration across the upper back and

sometimes along the sides of the back.

Fortunately, just because you find a stink bug in

your beans with red coloration, does not mean

that it is the redbanded stink bug. We also have a

redshouldered stink bug that naturally occurs in

Kentucky, though it not known to be a pest of

soybeans. Nevertheless if you find such a stink

bug in your beans it would be a very good ideato send the specimen(s) in for identification.

Figure 7. Brown stink bug (R. Ottens, Univ. of Georgia,

Bugwood.org photo).

Figure 8. Spinded shoulder bug (Clemson Univ.-USDA

CES Slide Series, Bugwood.org photo).

Figure 9. Spined assassin bug (W. Cranshaw, Colorado

State Univ., Bugwood.org photo).

Figure 10. Redbanded stink bug (R. Ottens, Univ. of

Georgia, Bugwood.org photo).

Figure 11. Red shouldered stink bug (W. Cranshaw,

Colorado State Univ., Bugwood.org photo).


5/11

States to our immediate north and Tennessee are

known to have the brown marmorated stink bug.

The adults might have entered the United States

as stowawaysin packing crates from Asia.This

insect is a know pest of many fruit and pod

producing crops, including soybeans; in its

native China, South Korea, Japan, and Taiwan.However, it is likely to be most problematic as

an invader of buildings. Once inside it is very

difficult to control, and produces an extremelyoffensive odor. This pest will be somewhat

difficult for the untrained eye to differentiate

from our normal complex of brown stinkbugs.

The last two antennal segments have alternating

light and dark bands.

A little bit farther afield we find the latest

invasive stink bug the bean plataspid. This pest

was discovered last fall (2009) in northeastGeorgia. In 2010 its range has expanded within

Georgia and into South Carolina. They have

been observed feeding on soybean, but like the

brown marmorated stink bug, the bean

plataspids major impact is likely to be the

invasion of structures. This is an odd lookingcritter, that is easily identified once seen. Unlike

our normal stinkbug complex, when in soybeans

this pest appears to prefer feeding on stems and

petioles as opposed to pods.

Because of their differential damage potential

and difference in ease of control, it is important

for us to know which of these stink bugs are in

our soybean fields. To that end entomologist at

the University of Kentucky and our county

extension agent colleagues are involved in amonitoring program for these and other invasive

species. We are interested in establishing two

items: 1.) What is the current make of thestinkbug complex in our soybeans. 2.) Are any

of these invasive stinkbug species already

present in Kentucky? The former provides an

important baseline with which we can compare

future populations, particularly when theinvasive species arrive. The latter will help us

understand when, where and how these invasive

stinkbugs may affect our crop production

systems. We are looking first at soybeansbecause it is a common host, but these stink

bugs are pests of many other crops.

When you are sampling soybeans you may wish

to send samples of stinkbugs to the University of

Kentucky for identification. If so, you may take

samples to your county extension office or send

the stink bugs directly to Dr. Doug Johnson,

UK-REC, 1205 Hopkinsville St. Princeton, KY

42445. These samples will help us establish our

base line of species and to detect them early

should one if the new stink bugs arrive!

FIELD CROPS

Late Summer Caterpillars in Field CropsBy Lee Townsend

Several species of caterpillars can be found now

on alfalfa, corn, soybean, and tobacco. Many are

distinctive and easy to recognize. Begin by

looking at the numbers of pairs of fleshy legs onthe underside of the abdomen. These can be seen

most easily if you look at the caterpillar from the

side. Most have 5 pairs with 4 on consecutive

segments and a 5th pair on the last segment.Other features such as head and body coloring,

hairs, and spines on the body also help with

identification.

_____

Figure 12. Brown marmorated stink bug (D.R. Lance,

USDA APHIS PPQ, Bugwood.org photo).

Figure 13. Bean Plataspid (D. Suiter, Univ.

Georgia photo).


6/11

Loopers or inchworms have adistinct crawling motion

because of the reduced

numbers of prolegs (2 or 3

pairs) on the abdomen.1 2 3

A

common

looper inKentucky

soybean

has a

purple-

brown band along the center of the back. It is

about an inch long when full grown and may be

found on a variety of crops, plants, and trees

from June to October.

_____

1 2 3 4

The green

cloverworm

can be very

abundant in

alfalfa and

soybean.

There are 4

pairs of

fleshy abdominal legs, the last pair extends backfrom the end of the body. This lime green

caterpillar has thin white stripes running thelength of the body. It moves with a looping

motion and thrashes violently when disturbed.

_____

Most caterpillars have 5 pairs of flesh legs andmove more smoothly

than the looping crawl of

the previous types.

1 2 3 4 5

The alfalfa

caterpillar has a

velvety greenbody with a

narrow white

stripe along each side; there is a fine red line inthe white stripe. They are about 1.5 inches long

when full grown. It is found on legumes.

The silverspottedskipper is easily

recognized by thepair of orange

spots on its dark

brown head and anarrow black

neck behind the

head. The larvae

use silk to form

leaves into aretreat or protective shelter. It feeds on legumes.

The yellow bearcaterpillar is

very common in

crop fields.

These woolly

caterpillars are

covered with

soft fine hairs.

They vary from

almost white to

yellow to nearly black. Mature larvae are about

1.75 inches long.

The saltmarsh

caterpillar also

is a woolly

species but can

be recognized

by the distinctbumps or warts

on the body.

Coloring of this species can vary from blonde to

black. They will feed on many plants, crops, and

trees. Full grown larvae are about 2 inches long.

The thistle

caterpillaris a spiny

caterpillar

with

variable

Figure 14. Common looper.

Figure 15. Green cloverworm.

Figure 16. Alfalfa caterpillar.

Figure 17. Silverspotted

skipper.

Figure 18. Yellow bear caterpillar.

Figure 19. Saltmarsh caterpillar.

Figure 20. Thistle caterpillar.


7/11

colors. They feed on many plants includingsoybeans and live in a loose nest of silken

webbing. Mature larvae are about 1.75 inches

long.

Three stripedcaterpillars can

be present in

crop fields inlate summer:

fall armyworm,

corn earworm

(soybean

podworm), and the

yellowstriped

armyworm. The

fall armyworm and

corn earworm aremost similar but

can be

distinguished by

looking at the head.

The head of the

corn earworm is yellow-brown with nomarkings. The head of the fall armyworm has

mottled or net-like markings and two distinct

light bars that converge in a V at the top of the

head. Fall armyworms feed on corn, grasses, and

legumes. They can destroy late summer seedings

of grasses and forages.

The

yellowstriped

armyworm has

the yellow-

brown head of

the corn

earworm but

can be

recognized by the yellow stripe running along

each side and a distinct black spot on each sidebehind the last pair of segmented thoracic legs.

These larvae are about 1.25 inches long when

feeding is complete.

SHADE TREES & ORNAMENTALS

Fall WebwormsBy Lee Townsend

The light

gray silktents of fall

webworm

caterpillarsare showing

up now at

the ends of

branches of

over 100species of forest and shade trees. The worms are

covered by pale green or yellow hairs and have

rows of black spots along their backs. Groups of

these caterpillars can be found in webbing at theend of branches on caterpillars feed on leaves

inside the webbing and expand the "tent" as they

require more food.

Usually, the infestation is limited to a branch or

two on a plant and the impact is aesthetic rather

than a plant health threat. Removal and

destruction of the web and caterpillars is an

effective control measure.

Walnut Thousand Cankers Disease A

Potential ThreatBy John Hartman and Lee Townsend

Thousand Cankers Disease (TCD) is a recently

recognized disease of walnuts (Juglans spp.).

The disease results from the combined activity

of the walnut twig beetle (Pityophthorus

juglandis) and a canker producing fungus called

Geosmithia. TCD has been active in the western

United States for a decade but the cause was

only recently described. TCD has been involvedin several large scale die-offs of walnut,

particularly black walnut (Juglans nigra),

growing in the west. In the past few weeks,

investigators in Tennessee may have found the

first case of TCD in an eastern state. If TCD is

present in Tennessee, it surely represents a threat

to black walnut plantings in Kentucky.

Figure 21. Three striped caterpillars.

Figure 22. Yellow striped

armyworm.

Figure 23. Yellow striped armyworm.

Figure 24. Gray silk tent.


8/11

Symptoms. Trees infected with the causalfungus first develop yellow leaves and

eventually twig and branch decline and dieback

(Figure 25). The fungus causes a canker, visible

by peeling back the bark, corresponding to theactivity of the insect vector in the branch or limb

(Figure 26). When multiple cankers develop onthe limbs (Figure 27) the vascular system is so

disrupted that the limb dies. The combination of

disease-causing fungus and insect vector is alethal combination for walnuts.

Disease vector. The walnut twig beetle

(Pityophthorus juglandis), the vector of

Thousand Cankers Disease (TCD), is native toNew Mexico and Arizona where its distribution

follows that of Arizona walnut, the likely nativehost. This 1.5 to 1.9 mm long yellow brown bark

beetle aggressively attacks black walnut and

carries the pathogens associated with TCD.Contrary to its common name, beetle attacks are

not confined to twigs; tunneling is most

commonly seen in branches greater than 0.7

inches in diameter and sometimes in trunks.

The adult female begins to tunnel in walnut by

early May to form a nuptial chamber with 1 or

more radiating egg galleries. The small, white

legless larvae develop below bark. A generation

from egg to adult takes a little less than 2

months. However, adults can be present from

mid-April through early October.

Urban and parkland trees have been infected

with TCD. Kentucky arborists, homeowners,

and woodlot owners need to be alert to thepossibility of TCD and report suspicious cases

of walnut decline to local County Extension

Agents and foresters.

Figure 25. Walnut yellowing dieback caused

by thousand cankers disease (Photo by W.

Cranshaw, Colorado State University).

Figure 26. Canker on walnut limb caused by

the fungus Geosmithia (Photo by N. Tisserat,

Colorado State University).

Figure 27. Multiple coalescing cankers on walnut

limb illustrate destructive potential of thousand

cankers disease (Photo by N. Tisserat, Colorado

State University).

Figure 28 & 29. Dorsal and lateral views of the

walnut twig beetle, the head is completely

hidden from view, a characteristic of many bark

beetles (Photo by J. LaBonte, Oregon Dept of

Ag).
http://www.ipmimages.org/browse/detail.cfm?imgnum=5406089http://www.ipmimages.org/browse/detail.cfm?imgnum=5406096http://www.ipmimages.org/browse/detail.cfm?imgnum=5406045


9/11

Spruce Fungi Causing Needle LossBy John Hartman

During recent weeks, numerous samples of

spruce twigs and branches shedding yellow or

brown needles have been observed in the Plant

Disease Diagnostic Laboratory and in severallandscapes. Symptoms have included

yellowing, browning and shedding of current

and especially last years needles resulting intwig and branch dieback.

Normal needle drop. Spruce and fir trees

typically retain their needles for several years.

In most years, needle drop is hardly noticeable

without careful examination of the inner

branches where a few scattered needles may turn

yellow and drop in late spring or early summer

of their third year. Normal needle drop is aseasonal occurrence and can vary from tree totree and from year to year. Sometimes these old,

yellow needles can harbor saprophytic fungi, but

these fungi are unlike the parasitic fungi that

appear on younger needles.

Two needle cast diseases. The fungi

Rhizosphaera kalkhoffii and Stigmina lautti are

the causes of needle cast being seen now on

spruce trees in Kentucky.

Rhizosphaera needle cast symptomsconsist of yellowing first-year or olderneedles in summer which later turn

brown and drop (Figure 30), perhaps 15

months after initial infection. Thus,

needles dropping now could be the

result of infections that occurred last

summer, 2009 (a wet season here in

Kentucky). Diseased needles contain

fungal signs in the form of dark

spherical pycnidia which typically

emerge from the needle stomata and are

thus lined up in rows (Figure 31). These

rows of pycnidia protruding through thestomata can be seen with the aid of a

hand lens, and are pretty diagnostic for

this disease. Damage typically starts on

the lower branches and moves up the

tree. After 3 to 4 years of severe

infection the lowest branches may begin

to die. Colorado blue spruce, Picea

pungens, is highly susceptible to this

disease. White spruce, P. glauca, is

intermediate in susceptibility and

Norway spruce, P. abies, is relativelyresistant. Trees that are stressed from

drought, poor planting practices, or

other factors are more likely to suffer

from Rhizosphaera needle cast. Stigmina needle cast has also been

observed on shedding spruce needlesthis year (Figure 32). Stigmina is

associated with spruce needle symptoms

and signs almost identical to those of

Rhizosphaera. Stigmina produces dark

spore-bearing structures in the needle

stomata (Figure 33), but under a hand

lens or a dissecting microscope, they

appear bushy compared to the

compact pycnidia ofRhizosphaera.

Without some magnification, the twodiseases appear to be very similar.

Figure 30. Spurce needles; brown needles

have symptoms of Rhizosphaera needle cast

disease (P. Bachi photo).

Figure 31. Close-up ofRhizosphaera

pycnidia lined up in rows corresponding to

spruce needle stomata (P. Bachi photo).


10/11

Other causes of needle cast. Another spruceneedle drop is caused by a newly identified

fungus, Setomelanomma holmii. This needledrop disease has not been found in Kentucky as

far as can be determined. Yellow, sickly needles

can also result from an infestation of spruce

spider mites. Although spider mites are found

on spruce in Kentucky, they have not beenobserved as frequently as the Stigmina and

Rhizosphaera needle casts this year.

Improving the health of landscape spruce trees.

Spruce health is enhanced by providing goodgrowing conditions.

Provide one inch of water per weekduring times of drought. Be sure the

water is applied over the root zone and

avoid getting the foliage wet.

Mulch underneath the trees to retainmoisture. Grass competes very well and

can actually contribute to water stress on

trees.

Prune out diseased and dying branches(only under dry conditions) and take

them away for burning or burial.

Pruning tools should be sterilized with

70% alcohol between cuts. If needle cast disease has been

diagnosed, a spring treatment with a

chlorothalonil-based fungicide may

provide protection. Timing of the

treatment should coincide with needleemergence and be repeated as necessary

until full needle emergence has

occurred.

Avoid unnecessary trunk or branchinjuries.

LAWN & TURF

Summer Patch of Kentucky BluegrassBy Paul Vincelli

Summer patch was diagnosed several weeks ago

on a Kentucky bluegrass athletic field in Central

Kentucky. This disease commonly appears as

circular or crescent-shaped dead patches

measuring a few inches to two to three feet(Figure 34). When the disease is most active,

the margins of affected patches can have a

slightly bronze color as the plants die. This

bronze color is evidence of active disease

progress. Tufts or patches of healthy turfgrass

tillers sometimes appear in the center of affected

patches.

Figure 32. Spruce needles fading and

turning brown due to Stigmina infection.

Note that the foliage appears to be thinned

out (P. Bachi photo).

Figure 33. Close-up ofStigmina emerging

from spruce needle stomata (P. Bachi

photo).

Figure 34. Summer patch of Kentucky bluegrass.

Note bronze margin indicating the zone of active

root infection.


11/11

This is a root disease (Figure 35), caused by a

common fungus in our soils. The rather early

appearance of this late-summer disease is due to

the hot conditions the turf has experienced this

summer.

Management of the disease is difficult if the

variety is susceptible to summer patch. For

severely affected sites, renovation to tall fescue

or a resistant variety of Kentucky bluegrass isrecommended. Information on the best-

performing turfgrass varieties can be found at

http://www.uky.edu/Ag/ukturf/Top%20Turfgras

s%20Varieties.pdf.

Management on sites with low to moderate

levels of disease should include the following:1. Make sure the mowing height is 2.5-3.0

inches. Avoid scalping the turf.

2. If choosing to irrigate, irrigate deeplyand infrequently. Avoid irrigating

lightly and frequentlythat helps to

promote the fungal infections of the

roots.

3. Regular use of ammonium sulfate,ammonium chloride, or sulfur-coated

urea as a nitrogen source can reduce the

severity of summer patch. Avoid nitrate-

containing fertilizers for these sites.

More information on the biology and

management of summer patch can be found in

the UK Extension publication, Patch Diseases

in Kentucky Bluegrass Lawns, available at

http://www.ca.uky.edu/agc/pubs/id/id122/id122.

pdf.

DIAGNOSTIC LAB HIGHLIGHTSBy Julie Beale and Paul Bachi

Recent agronomic samples in the PDDL have

included crazy top and boron deficiency on corn;Rhizcotonia and Fusarium stem rots on soybean;

Pythium root rot on alfalfa; brown stripe onorchardgrass; black shank, blue mold, soreshin,

Pythium stem rot, frogeye leaf spot, bacterial

soft rot and frenching on tobacco.

On fruit and vegetable samples, we have

diagnosed Phytophthora root rot on raspberry;

black rot and flyspeck on apple; bacterial spot

on peach; Fusarium crown rot on asparagus;

southern rust on sweet corn; Microdochium

blight on pumpkin; anthracnose, early blight,

Septoria leaf spot, root knot nematode and

Fusarium wilt on tomato.

On ornamentals and turf, we have seen southern

blight on rudbeckia; black root rot on holly;

Phytophthora root rot on itea, rhododendron and

sassafrass; Botryosphaeria canker on blackgum

and lilac; bacterial leaf scorch, Actinopelte leaf

spot, powdery mildew, anthracnose and

Phytophthora root rot on oak; Pythium root rot,

brown patch and heat injury on bentgrass; spring

dead spot on bermudagrass; and brown patch on

fescue.

INSECT TRAP COUNTS

July 30-Aug 6

Graphs of insect trap counts for the 2010 season are

available on the IPM web site at -http://www.uky.edu/Ag/IPM/ipm.htm.View trap counts for Fulton County, Kentucky at -

http://ces.ca.uky.edu/fulton/InsectTraps

Location Princeton,

KY

Lexington,

KY

Black cutworm 9 64

Armyworm 21 3

Corn earworm 51 29

European corn

borer

3 4

Southwestern

corn borer

4 0

Fall armyworm 7 0

Figure 35. Microscopic view of the surface of a

Kentucky bluegrass root, showing the dark

filamentous growth of the summer patch fungus.
http://www.uky.edu/Ag/ukturf/Top%20Turfgrass%20Varieties.pdfhttp://www.uky.edu/Ag/ukturf/Top%20Turfgrass%20Varieties.pdfhttp://www.uky.edu/Ag/ukturf/Top%20Turfgrass%20Varieties.pdfhttp://www.ca.uky.edu/agc/pubs/id/id122/id122.pdfhttp://www.ca.uky.edu/agc/pubs/id/id122/id122.pdfhttp://www.ca.uky.edu/agc/pubs/id/id122/id122.pdfhttp://www.ca.uky.edu/agc/pubs/id/id122/id122.pdfhttp://www.ca.uky.edu/agc/pubs/id/id122/id122.pdfhttp://www.uky.edu/Ag/ukturf/Top%20Turfgrass%20Varieties.pdfhttp://www.uky.edu/Ag/ukturf/Top%20Turfgrass%20Varieties.pdf

kentucky pest news august 10, 2010

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