Capture of "true" armyworm moths in a
pheromone baited trap on the REC in Princeton
continues to drop. Last Friday (08 Jun) we reported
126 moths per trap week, which was a drop from
the 2nd generation peak of 220 (which occurred on 01
Jun). Counts continues to drop with this weeks
count of 79 moths per trap week (15 June). This
pretty well assures us that the peak of 2nd generation
moth flight was indeed the week of 01 Jun.
Last week using year 2000 temperatures we predicted that you should be seeing worm pressure this week (09-10 Jun) if problems were going to develop, and they would be disappearing about 28- 29 Jun. We now have 2001 temperatures through 14 Jun. Substituting these for the 2000 estimates our model predicts peak egg hatch on 11-12 Jun. Adding in 2000 temperatures for the future dates we would calculate peak worm disappearance at 29-30 Jun.
Though there is certainly considerable variation in our ability to predict when worms will be present, if you are going to see a problem with the 2nd generation you should be seeing the evidence by now. It certainly appears that the armyworm as reverted to its "normal" activity level.
The armyworm is still here and will be all summer but probably poses little problem for our field crops. My guess is that the predators, parasitoids and pathogens that usually keep this armyworm under control have caught up with the population. Certainly producers should continue to watch their crops for this and other insect pests; AND remember we still have fall armyworm yet to go!
To see recent armyworm trap counts,
click here.
(Frankfort) The U.S. Environmental Protection Agency has granted special registration for two insecticides to combat armyworms in pastures and hayfields in Kentucky, the Ky Department of Agriculture has announced.
The insecticides are Pounce 3.2 EC (FMC Corp.) and Confirm 2F (Rhom and Haas Co.). Both are Restricted Use pesticides. Cattle can be present during application, if necessary, when Pounce is applied and they may graze fields after treatment. However, pastures sprayed with Pounce cannot be cut for hay during the remainder of the season. Pastures sprayed with Confirm 2F can be harvested for hay after a14-day wait.
Applicators must have a copy of the appropriate state (24-c) label for Pounce or the Crisis Exemption label (Section 18) for Confirm. These are available from the pesticide dealer when the products are purchased.
Most readers who work with perennial ryegrass are aware of the emergence of gray leaf spot in the past decade as one of the most destructive turfgrass diseases known. Those of you with experience against gray leaf spot know how rapid and destructive the disease can be.
Fungicides remain our first line of defense against gray leaf spot, because all commercial varieties are susceptible and cultural practices can provide only limited control under high disease pressure. Because of the high cost of fungicides, many turf managers are interested in ways to use these important products more wisely and economically. My opinion is that at this time, there is no better way to optimize the use of fungicides than to scout your own swards for the disease and to microscopically verify the presence of the causal fungus in diseased tissues. Experienced turfgrass pathologists agree that microscopic verification is important because it is often not possible to positively identify this disease based on symptoms alone.
Proper scouting can help you decide:
The University of Kentucky Cooperative Extension Service will hold a workshop for turf managers and other interested professionals on microscopic identification of gray leaf spot of perennial ryegrass. Details are as follows:
Date & Time: June 20, 2001, from 1:00-5:00
Location: The University of Kentucky campus in Lexington
Cost: $900, Registration must be received by
Monday, May 7
While the cost may seem high at first glance, registrants
will actually be getting a lot for their money. Each
registrant will receive a high-quality compound binocular
light microscope (40-1000X magnifications, with halogen
illumination and high contrast lenses), which you will
learn to use during the workshop. In addition, each
registrant will receive dissecting kits, lense cleaning
supplies and other laboratory materials, a notebook
including color images, a 2X desk magnifier with built-in
illumination, and a field magnifying glass.
Learning Objective: As a result of this workshop, you will be able to detect Pyricularia grisea (the causal fungus of gray leaf spot) in diseased turfgrass tissue. This skill will provide the foundation for a scouting and monitoring program for gray leaf spot.
If interested in attending, please contact Pat Yancey
at
pyancey@pop.uky.edu
pyancey@pop.uky.edu for a registration form.
Registration is limited in order to provide a high-
quality learning experience for those who attend.
Interested Kentuckians should act soon, since out-
of-state registrants will be accepted on April 20.
Registration and payment must be received by
Monday, May 7.
Situation:
Active blue mold was confirmed again over the
weekend in Clark and Mason counties of Kentucky,
and Brown County, Ohio. These counties have all
been placed under a blue mold warning.
Observation reports from the sites support that
these new reports involve only new outbreaks, but I
hope to get into the northern outbreaks on Monday
to determine if that is the case. I urge all growers in
central and northern Kentucky, and southern Ohio
to reassess the situation, because some secondary
spread probably did occur from the late May
episode in central Kentucky. Consequently, I am
expanding the areas under a blue mold watch to
include: all tobacco production in southern Ohio,
and in Kentucky to include the Bluegrass, Licking
River, and Northeast Kentucky Extension Areas.
These are the areas initially placed under the watch,
which also included parts of the Ft Harrod Area but
I have not included it at this time, because the
evidence on the ground does not support my earlier
concerns for Ft. Harrod based on agent reports from
the area. With the cool temperatures experienced
this past weekend, expect blue mold to go systemic
in plants already infected.
Much of the state's tobacco has a poor root system and is not growing well, so it may be difficult to recognize blue mold even if it is present in some crops. By the way, growers need to keep the black shank-fungicide controls in place, especially the cultivation and layby applications of Ridomil Gold or Ultra Flourish. Some of the strains of blue mold involved will also be sensitive to those fungicides. So far, all reported cases of blue mold in Kentucky and Ohio have come from locations that had not been treated with mefenoxam.
Spray programs should be in place in all areas under either a watch or warning. Statewide, keep transplants protected with fungicides plus destroy them once transplanting is over, or if the plants become unacceptable to transplant.
For the latest blue mold status and other tobacco disease information, check the KY Blue Mold Warning System.
http://www.uky.edu/Agriculture/kpn/kyblue/kyblue.htm
Tomato spotted wilt virus (TSWV) has been recently
diagnosed on several samples of burley and dark
tobacco, tomatoes, and peppers. Greatest activity is
occurring mainly west of a north-south line from
Breckinridge County to Laurel County, Kentucky.
However, we are also finding a few cases in central
Kentucky. Very low levels of the disease are present
in many fields, less than one or two percent of the
plants in a field being infected and below the levels
of serious economic damage, but some cases have
involved greater than 15% incidence, with an
occasional planting exceeding 30% incidence.
Generally, if the tobacco plant is infected, and showing symptoms prior to layby stage, it will be killed or severely stunted. Fortunately, we seldom experience high levels of infection in Kentucky's tobacco (unlike the flue-cured production area) and there is little or no secondary spread (from one infected tobacco plant in the field to another in the field) in our tobacco fields, but primary spread may occur over a period of several weeks giving the impression of secondary spread.
Field reports again this year indicate there is a strong edge effect to the distribution pattern, and that most of the problem is with early-set crops. This is consistent with what we have seen in past years, which suggest the source vectors are coming from vegetation surrounding the edge of the fields. Some of our fields are so small that they are dominated by edge effects, especially the long narrow fields of less than 20 rows. But, the disease can also be transplant-borne.
This disease was first reported from Kentucky in 1986, when low level infections were scattered about 30,000 acres of tobacco, tomatoes, and peppers in south central Kentucky. Since then, it has occurred every year, and caused greater problems for the vegetable growers than the tobacco growers. Actual losses in tobacco from TSWV have been minimal to the state as a whole, but a few individual growers have experienced significant losses.
Spread of the virus is through thrips. The virus is spread by the thrips in a persistent fashion, which means that once the vector has acquired the virus, it can transmit for a long time. The juvenile thrips (nymphs) acquire the virus while feeding on infected plants, but these juveniles cannot spread it to healthy plants. Instead, only the adult stage can transmit the virus, which it can do for the remainder of its life. This causes a delay of 3-18 days between the acquisition of the virus by the nymphs and the time adults transmit the virus. Because the thrips move about the field in short flights, the distribution of infected plants from inoculations by the same insect usually leaves a clustered-pattern, where disease plants fit into small groups of 3-10 nearby plants. Such a random-clustered pattern with a strong edge effect in the field would suggest infection occurred after the plants were set, while a totally random pattern usually would suggest the transplants were infected prior to transplanting. With containerized transplants, we can see a strong tray-effect to the distribution, several plants clustered in the same row while adjacent rows are free of infection or with a very different rate of infection. Sometimes, a transplant source pattern is evident, also.
A wide range of symptoms are present on tobacco, which overlap with those caused by Tobacco Ringspot Virus, Tobacco Streak Virus, and Fusarium Wilt, so diagnosis requires special diagnostic tests in the lab. Moreover, TSWV-infected plants are weak and often infected by opportunistic fungi, such as Rhizoctonia, Pythium, Fusarium, and even Phytophthora (black shank). Initial symptoms of necrotic spots along the veins and concentric or zonate spots on the leaf, followed by obvious yellowing, stunting and wilt, are the most prevalent symptoms noticed in Kentucky. In time, necrotic lesions become very obvious on the stem and sometimes within the pith. TSWV symptoms in young plants are highly variable but often include darkened areas (which may appear wrinkled or sunken), decay, or brittleness. These symptoms are sometimes confused with soreshin, and the soreshin fungus will often move in to finish off the plants. Leaves often have necrotic (dead) spots, especially evident near major leaf veins. Symptoms usually appear first in the bud or on young leaves, which are often distorted. The vascular system is often stained brown, but not as extensive as with Fusarium wilt. The affected leaves often become distorted and may pucker due to unequal growth on one side. The apical bud droops or bends to one side and is followed by wilting of most of the foliage on that side of the plant, but unlike with Streak Virus, the bud does not recover. Many plants will not die; instead, they sucker and produce a very stunted and bushy growth with many spots on small unmarketable leaves. If soreshin or black shank are active at the site, TSWV-infected plants often are killed by these other diseases. Black shank resistant plants infected with TSWV act like susceptible plants!
Control of TSWV has been difficult in areas of the world where it is prevalent. The variables involved in Kentucky outbreaks of this disease, as well as many of those elsewhere in the U.S., are still not well understood. Several laboratories have taken on the task of unraveling this mystery. Evidence obtained from field observations over the past several years in Kentucky and research done in other states, suggests that annual broadleaf weeds in and around field borders are currently thought to be the main reservoirs for the virus-infected thrips. Also, most infections appear to result from heavy influx of virus-carrying thrips from outside the field, but setting of infected transplants is also involved in some cases. Planting date is an important but inconsistent factor in TSWV incidence and loss. In most seasons, early planted tobacco has experienced the highest incidences, but in some years, other planting times have been hit hard also. So, adjusting setting times for fields with a history of the disease may be justified. We have seen very little evidence to support secondary spread (from tobacco to tobacco) within the planting, although the possibility certainly exists if the thrips are able to complete their life cycle in an infected field. The issue is further complicated in that plants infected by the virus at different times, may all show symptoms at the same time, based on one of our studies. Several labs are studying TSWV management and they may provide new tools within a few years.
At this point, it is unclear as to whether attempts to
control thrips within the field planting will
significantly reduce disease activity in Kentucky's
tobacco fields. We see no benefit from rescue
insecticide options. However, we suggest normal
insect control programs be maintained, especially in
transplant production. Roguing out infected plants
should be considered where the plants were
introduced from other states to minimize the risk of
the virus becoming established locally, but we have
seen no benefits to the current crop. If the disease is
found in transplant operations, destroy the infected
plants as soon as possible. Do not grow tobacco and
ornamentals in the same operation. Do not grow
peppers adjacent to tobacco, especially if the
peppers are carrying TSWV.
For more information about tobacco pests, visit "Insect Management Recommendations".
The degree day model with the UK Ag Weather
Center indicates that the second flight of European
corn borer will begin sometime next week in much
of the state. Keep in mind that this is just the
beginning of the second flight and numbers will be
increasing over the next few weeks. The model
indicates that the earliest of the corn borer eggs will
be hatching in early July. Several commercial
producers are using pheromone traps in their fields
and can use numbers of captured moths to
determine the need to spray for corn borers, other
producers will need to protect their pepper plants
during this period of corn borer activity. First
generation numbers have been high in some areas,
low in others. It pays to monitor for this insect.
For more information about corn pests, visit "Insect Management Recommendations".
Managing eastern black nightshade is a full-season
job in soybeans. Monitoring fields and applying
postemergence herbicides in a timely manner is
important at this time of season. Information on
some of the postemergence that help in manage
black nightshade in soybeans is indicated below:
| Postemergence Herbicide | Rate | Nightshade Max stage/size | Soybean Stage |
|---|---|---|---|
| Cobra | 12.5 oz/A | 6 LF | Do not apply within 45 days of harvest or after R6. |
| Extreme (RR soybeans) | 3 pt/A | 12" | Before bloom and prior to 85 days of harvest. |
| Flexstar | 1 pt/A | 4 LF | Before bloom. |
| 1.5 pt/A | 6 LF | ||
| Pursuit 70 DG | 1.4 oz/A | 3" | Before bloom and prior to 85 days of harvest. |
| Raptor | 5 oz/A | 5" | Before bloom and prior to 85 days of harvest. |
| Reflex | 1 pt/A | 4LF | Before bloom |
| Roundup UltraMAX (RR soybeans) | 20 oz/A | 3" | Cracking through flowering. |
| 26oz/A | 6" | ||
| 40 oz/A | 12" | ||
| Stellar | 5 oz/A | 3 LF | Do not apply within 60 days of harvest. |
| 7 oz/A | 4 LF | ||
| Ultra Blazer | 1.5 pt/A | 2" | Prior to 50 days of harvest. |
Although Eastern lack nightshade often grows as an annual; there are a few isolated cases where it believed to have overwintered and exist as a perennial in Kentucky. The problem with these situations is that regrowth from the perennial roots occurs following an application of postemergence herbicides. It is not clear at this point what options will help in managing the black nightshade plants with perennial roots. A sequential spray program in Roundup Ready soybeans has been considered by some growers, but will be expensive.
In addition to using herbicides, cultural practices such as planting soybeans in narrow rows (< 15") and harvesting early will help limit harvesting problems associated with eastern black nightshade. Research has shown that shading from the soybean canopy helps limit berry production, but this benefit diminishes after soybeans senescence.
Kentucky grape growers face several major fungal
diseases, many favored by our moderate to hot,
humid weather. Black rot is the most common and
problematic of these diseases. Wet periods in late
May and early June were very favorable for
infections and new infections will continue to occur
just about any time there is more rain. Symptoms of
the leaf spot phase of black rot are now appearing
statewide. As the fruits begin to enlarge and
mature, there will be fruit spotting and decay on
them as well.
Black rot disease was first recorded on this continent in 1804 - in Kentucky. The pathogen, Guignardia bidwellii, infects leaves, and then fruits, generating the typical hard, black, shriveled mummies which produce crop losses ranging from 5 to 80%. Leaf petioles, pedicels, and shoots can also become infected. Management of black rot requires an integrated approach involving cultural practices and chemical controls.
Change the environment to reduce disease.
Increase grape resistance.
Reduce the fungal inoculum.
Fungicides for disease control. Leaf wetness requirements for black rot infections have been worked out. Fungicide sprays can be timed to coincide only with actual infection periods. However, even chemical controls need to be integrated because there are other fungal diseases in addition to black rot that need managing. Grape growers need to know the characteristics of the several available fungicides and what affect they might have on other important grape diseases such as powdery mildew, Phomopsis cane and leaf spot, downy mildew, bitter rot, and Botrytis bunch rot. Examples of fungicides follow:
More complete information about varietal susceptibility and timing and materials for grape disease control can be found in ID-94 Kentucky Commercial Small Fruit & Grape Spray Guide, available at County Extension Offices.
There have been a large number of reports of thrips
in vegetable and field crops this spring. While the
most serious problem associated with thrips is their
ability to transmit and spread plant viruses, most
notably, Tomato Spotted Wilt Virus. But in they can
cause direct damage to vegetable crops in some
instances. Tomato and pepper producers need to be
monitoring for thrips and for signs that they may be
damaging the quality of the fruit. Thrips feed in the
bud and flowers or the plants and often damage the
rapidly expanding cells in these tissues. This results
in scarred and misshapen fruit at maturity. A listing
of thrips insecticides can be found in
ID-36,
and
labelled insecticides that include pyrethroid or
SpinTor insecticides will help to reduce thrips
populations. Because thrips tend to be in protected
areas of the plant, spray equipment and gallonage
need to be adequate to provide thorough coverage.
Adult Japanese beetles and masked chafers have begun to emerge. As is usually the case, it's difficult to predict how serious a problem the beetles and grubs will be this year.
Japanese Beetle Adults - Detailed information on
this pest can be found in ENT-5,
Japanese Beetles in the Urban Landscape.
Options for protecting
landscape plants from foliage feeding adults are as
follows:
Plant Selection- The best way to avoid perennial battles with adult Japanese beetles is to select plant material that is less preferred. Publication ENT-5 lists species and cultivars of trees and shrubs that are less likely to be attacked by beetles.
Hand Picking and Exclusion- Removing beetles by hand may suffice for smaller plants and when beetle numbers are relatively low. Volatile odors released from beetle-damaged leaves attract more beetles. Thus, by not allowing Japanese beetles to accumulate, plants will be less attractive to other beetles. One of the easiest ways to remove beetles from small plants is to shake them off early in the morning when the insects are sluggish. The beetles may be killed by shaking them into a bucket of soapy water. Highly valued plants such as roses can be protected by covering them with cheesecloth, reemay, or other fine netting during peak beetle activity (usually late June to mid-July).
Insecticides- Various insecticides including Sevin, Tempo (= Bayer Advanced Lawn& Garden Multi- Insect Killer), Scimitar, Talstar, malathion, and Orthene are labeled for control of adult Japanese beetles. Sevin is very effective and is the product of choice for many homeowners. Foliage and flowers should be thoroughly treated. The application may need to be repeated at 7-10 day intervals to prevent reinfestation during the adult flight period, or after heavy rains. Follow label directions and avoid spraying under windy conditions. Insecticidal soaps may kill beetles that are hit by the spray, but they provide no residual protection. Botanical insecticides such as neem or pyrethrum are not very effective.
White Grubs - There is no reliable way to predict whether any given year will be a bad one for white grubs the immature, turf-feeding stages of Japanese beetles, masked chafers, and certain other beetles. Moreover, since grub infestations tend to be localized and sporadic, only a small percentage (generally < 10%) of Kentucky lawns require treatment, even in bad years for grubs.
Indicators of Infestation- White grubs and their resultant damage are not usually evident until August or September. Although sampling the turf is the only way to confirm that a problem truly exists, certain factors may indicate an increased risk of infestation later in the season. If your turf has a history of serious grub problems, there is a greater chance that adult beetles will return and re-infest the same areas. Sites with large numbers of adult beetles in June and July are more likely to have grubs in late summer. Early warning signs include swarms of brown, ½inch long masked chafer beetles skimming over the turf at dusk, or green June beetles buzz-bombing the turf by day in search of mates and egg-laying sites. Masked chafer and May beetle adults are also attracted to porch and street lights at night. Heavy infestations of adult Japanese beetles feeding in the area might also foretell subsequent problems with grubs of that species.
Rainfall and soil moisture are critical factors affecting the extent of grub damage during a season. Frequent irrigation in June and July may attract egg-laying female beetles to the turf, especially if surrounding areas are dry. High soil moisture also increases egg survival. If lawns are irrigated during June and July, be especially alert for signs of grubs later in the summer. Conversely, adequate soil moisture in August and September (when grubs are actively feeding) can help to hide root injury. Irrigated turf can sometimes tolerate 20 or more grubs per square foot before showing signs of injury.
Treatment Strategies - Two different strategies are available for controlling white grubs with insecticides: curative and preventive. Each approach has its own merits and limitations. With preventive control, the insecticide is applied as insurance, before a potential grub problem develops. Consequently, they are most suited for high-risk sites with a history of grub problems, or where heavy beetle activity is noted.
Preventive control requires the use of insecticides with long residual activity in soil. Both Merit® (sold to homeowners as Bayer AdvancedTM Season-Long Grub Control) and Mach 2® have sufficient soil persistence to be applied any time from late-May to mid-July and still control young grubs hatching from eggs in late July or early August. The optimum treatment period for these products is mid-June to mid-July.
Preventive treatments afford greater flexibility in application timing, and are easier to schedule and implement than are curative treatments. They often afford greater peace of mind to golf superintendents and lawn service companies because potential damage is avoided or minimized. The main drawback of preventive grub control is that the decision to treat must be made before knowing the extent of infestation. Grub outbreaks tend to be localized and sporadic, and only a small percentage of lawns require treatment in a given year. Thus, preventive control often results in areas being treated unnecessarily. Good record keeping and observation will help in pinpointing grub-prone areas, which are the most logical candidates for preventive applications.
With curative control, treatment is applied in late summer typically August or September after the eggs have hatched and grubs are present. This is an effective strategy when damaging grub populations are known to be present. Ideally, the decision to treat is based on site inspection and sampling, or past history of infestation. Since white grub infestations tend to be localized, the entire lawn often will not need to be treated. Grub "hot spots," which can be confirmed by sampling, are most likely to be full sun, south or west-facing slopes, lawns seeded with Kentucky bluegrass, lawns that were heavily irrigated during June and July, and turf areas that were damaged by grubs in previous years.
Proper timing of curative grub treatments can be tricky. Insecticides applied too early may degrade before the eggs have hatched, whereas if the product is applied late, the grubs will be harder to kill and severe damage to turf may have already occurred. Presently, granular Dylox is the fastest- acting, most effective insecticide for curative grub control. Diazinon is also an option for homeowners. Products containing chlorpyrifos (e.g., Dursban) are not very effective against grubs. There is little benefit in applying any of these short-lived, curative-type products for white grubs in June or July.
For a complete list of insecticides available for curative and preventive grub control, see Entfact-441, Insecticides for control of white grubs in Kentucky turfgrass.
A period of several days of hot, muggy weather allowed activity of Pythium cottony blight to develop late last week in susceptible turf swards receiving heavy and repeated irrigation and/or rainfall. The disease was found on creeping bentgrass, perennial ryegrass, and tall fescue. Although recent sunny, dry weather may arrest the disease, heavy irrigation or a return to hot, muggy conditions could allow new disease activity.
When the disease is active, look for dense, white, cottony mycelium on diseased tissues during early morning hours when the dew is still present. (Be aware that, on perennial ryegrass, very dense, cottony mycelium can also be produced by Rhizoctonia brown patch under certain conditions, so on that grass, have suspect cases confirmed by a diagnostic lab.) Diseased leaves have an olive- green, watersoaked appearance (the same color as frost-damaged plant tissue), and appear matted. As this tissue dries, it turns tan. Affected areas may follow drainage channels or mowing patterns.
The fungi that cause the disease are sometimes referred to as "water molds". Thus, the disease is favored by soil conditions that are frequently near saturation: heavy, repeated irrigation or rainfall. High nitrogen also favors the disease by enhancing plant succulence. New seedings are at greatest risk, since seedlings are succulent and easily infected by Pythium.
In tall fescue, a recently published study in Kansas showed that the combination of Heritage sprayed at a typical lawn-care spray interval (35 days) with daily irrigation promoted Pythium activity. In contrast, Pythium activity was not significant in plots irrigated daily without Heritage, or in plots sprayed with Heritage and irrigated on alternate days. Although Heritage provides about 10-14 days of protection against Pythium, a 35-day spray interval allows substantial Pythium activity to occur between sprays, and one reasonable explanation for the Kansas State results is that Heritage disrupted populations of naturally occurring antagonistic microorganisms of Pythium in the soil. The fungicide Prostar has also been shown to enhance Pythium activity in one research study, probably for the same reason.
As far as forecasting the disease, the best system is probably a variant of the one developed by Bill Shane when he was at Ohio State. Pythium cottony blight is favored by daytime highs of at least 82 F, nighttime lows of at least 68 F, and at least nine hours of wet leaves or high humidity (relative humidity above 90%). Several days of such weather provides a rough guideline as to disease activity, but understand that site management factors play a major role in determining how high the disease risk is, and therefore how important it is that a fungicide be applied.
Fungicides containing mefenoxam (Subdue), metalaxyl (Proturf Pythium Control), propamocarb (Banol), or fosetyl-Al (Aliette Signature, Prodigy) are the most effective choices against the disease.
Syngenta has recently obtained EPA registration for their new insecticide, Actara. This is a General Use insecticide that contains 25 % thiamethoxam and is formulated as a water dispersable granule. Thiamethoxam is a neonicotinoid insecticide with a mode of action similar to imadaclorid (Admire and Provado). Insecticides in this group are somewhat selective and often control sucking insects and some beetles. With thiomethoxam, there is an important label advisory regarding the potential for and prevention of surface water runoff.
Among the fruits and vegetables, Actara has been registered for use on cucurbits (0 day preharvest interval, PHI) for aphid and flea beetle control, fruit vegetables (0 day PHI) for aphids, flea beetle, stink bug, whitefly, and Colorado potato beetle control, tuberous vegetables (14 day PHI) for leafhopper and Colorado potato beetle control, and pome fruits (14 to 35 day rate-dependent PHI) for control of aphids, leafhoppers, plum curculio, pear psylla, and leaf miners.
Plenty of samples are arriving in the Diagnostic Labs--typical for mid-June. Among those diagnosed last week were herbicide injury, acid soil problems and zinc deficiency on corn; herbicide injury, nitrogen deficiency and Rhizoctonia root and stem rot on soybean; black root rot, black shank, systemic blue mold, cold injury, manganese toxicity and many cases of tomato spotted wilt virus (mostly in western KY) on tobacco.
On fruits and vegetables, we have seen black rot on grape; bacterial leaf spot on peach; Rhizoctonia root and stem rot on bean, okra, pea and pepper; bacterial wilt on cucumber and cantaloupe; bacterial spot on pepper; tomato spotted wilt virus on pepper and tomato; as well as bacterial spot/speck, bacterial canker, early blight, Septoria leaf spot, and root knot nematode on tomato.
On ornamentals, we have seen Pythium root rot on liriope, chrysanthemum and snapdragon, as well as Rhizoctonia root rot on snapdragon; take-all, dollar spot and red thread on turfgrass; rose rosette and black spot on rose; Phytophthora root rot on rhododendron; Pseudonectria canker/dieback on boxwood; eastern gall rust on pine; and Verticillium wilt on redbud and catalpa.
| UKREC-Princeton, KY, June 8 - 15, 2001 | |
| Black Cutworm | 0 |
| True Armyworm | 59 |
| Fall Armyworm | 2 |
| Beet Armyworm | 0 |
| Corn Earworm | 12 |
| European Corn Borer | 0 |
| Southwestern Corn Borer | 70 |
To see recent moth trap counts, click here.
Lee Townsend
Extension Entomologist
