MAPLE PETIOLE BORER damage; CANKERWORMS AND LOOPERS in trees;
ORIENTAL FRUIT MOTH flight; STRAWBERRY CLIPPER damage;
REDBANDED LEAFROLLER flight will continue through apple bloom;
swarming HONEY BEES, now is a good time to renew contacts with local beekeepers
who may be willing to collect swarms; CARPENTER BEES tunneling in wood.
Captures of true armyworm moths in the UK-IPM program's pheromone-baited traps at the Princeton Research and Education Center are on the way back up! The two traps there captured 290 and 252 moths, respectively during the week ending 06 April. These are unusually large numbers compared to the past four years, and very similar to trap captures during the armyworm outbreak year 2001. While these moth numbers cannot be directly translated to outbreak levels of the damaging larval (worm) stage, they certainly indicate that scouting for this pest is necessary.
In the outbreak year of 2001 our greatest first generation peak trap captures were about 400 moths per-trap-week during the middle of April. Our current capture for this first week in April could indicate that record numbers of moths are in the offing during the normal middle-of-April peak flight time.
In 2001 Kentucky producers saw outbreaks in hay and pasture fields, as well as in small grains. Corn is also a target host of this pest. It is too early to try any control measures, and high trap counts do not necessarily mean that a larval outbreak will occur. Armyworms are a major food source for many natural enemies. Natural enemies (predators, parasites and disease) usually control armyworm populations. However, large trap counts do indicate that producers, scouts and consultants should be watching for the worms to appear. Additionally, if an outbreak does occur, it will not be uniform across our production area or crop type. Each field will have to be evaluated individually for the presence / absence and relative number of worms.
Because we are depending upon a relatively small sample, only two traps in one county, I cannot tell you IF or WHERE an outbreak may occur. However, we can use a basic IPM tactic to estimate WHEN an outbreak might occur. Since the rate of insect development is almost completely dependent on temperature, we can use the pheromone trap captures as a starting point and forecaster daily temperatures to estimate when the damaging stage (caterpillar aka worms) might appear.
Insect development can be measured in degree days (DD). This is simply a mathematic measure of how temperature affects insect growth (See: Entfact-123). Generally, armyworms do not grow when the temperature is below 50oF. So, each day the average temperature is one degree above 50oF is one degree day. Through many years of experimentation by many entomologists the number of DD's needed for the insects to go from one stage to another for a large number of insect species has been determined. In the case of true armyworm it takes about 239 DDs for moths to mate, lay eggs and the eggs to mature and hatch into larvae.
If we use our current trap captures as beginning points and historic temperatures and insect models (See: Agricultural Weather Center) as estimates of current temperatures and DD calculators, we can estimate when the worms may appear. Obviously, there are lots of unknown variables here so don't expect an exact date. However, we should at least know about when to scout for the pest.
Projecting forward from our first trap captures on 17 March (Ave. 89 moths), and using 239 DD's as our estimate of worm appearance one might expect armyworm caterpillars as early as Apr 18-19. However, these would be very small numbers of worms and likely below our ability to scout for them using any reasonable amount of time. Additionally, due to a cold snap, moth flight was stopped / reduced for the following two weeks thus further reducing likely worm numbers. However, it does provide the beginning of a time frame to begin scouting.
By projecting forward from the 07 April trap catch (Ave. 271 moths), we might expect to reach the 239 DD mark on 27-28 Apr. This date is more likely to indicate worm populations that are detectable.
If in fact our trap catch numbers are still climbing and the situation is similar to what occurred in 2001, we might expect our peak trap catches to be on or about 14 Apr. In this case the major portion of the population should begin about 02 May.
Also, true armyworms require about 498 DD to complete larval (worm) development, so we might expect a large disappearance of the larvae on or about 29 May.
Checking KPN articles from 2001 (KPN #919) the period of time when most people noticed the armyworm outbreak, was 07-20 May. Additionally, undetected populations were certainly present before and after the "outbreak" dates. Again this fits pretty well with our current estimates.
I think it likely that if the "outbreak" does occur it will likely begin near the first week in May and disappear in the final week of May. Of course there will be worms present both before and after the major occurrence.
Certainly these predictions are full of estimates of temperatures, moth flight, numbers of moths captured, appearances etc. So, the estimate of when the damaging stage (worm) will appear, and how long the worms will be around have a fairly large error range. However, these estimates do provide a pretty good estimate of when to scout and when the greatest potential for damage will likely occur.
Agricultural Weather Center. Ag/Wx Calculators http://wwwagwx.ca.uky.edu/calculators.html Note: "True armyworm" is currently not one of the choices but "Black cutworm" may be used as a substitute.
Johnson, D., R. Bessin and L. Townsend. Predicting Insect Development Using Degree Days. Entfact-123. http://www.uky.edu/Ag/Entomology/entfacts/pdfs/entfa123.pdf
UC-IPM Online. Research Models: Insects, Mites, Disease Plants and Beneficials.
http://www.ipm.ucdavis.edu/MODELS/index.html
With the possibility of large "true armyworm" populations occurring over the next month, perhaps we should review when there is a need for rescue control in the standing small grains crop.
True armyworm is a common pest of many grass species. Generally speaking, this pest can be found in every small grain field every year. However, it is unusual for it to become a pest of economic importance. The only economically important population in recent memory occurred in 2001. However, it does appear at this time, that the numbers of moths being captured in pheromone baited traps in Princeton, KY run by the UK- IPM program are very similar to the numbers captured in 2001. Though not an absolute indicator, this similarity does indicate that field scouting for this pest will be necessary this year.
Larvae (worms) are greenish brown with a narrow, middorsal (middle of the back) stripe and two orange stripes along each side. The yellowish head is honeycombed with dark lines. Armyworms are about 1-1/2 inches long when full grown.
Armyworms are primarily leaf feeders. However, the will feed on awns and tender kernels and may clip off the seed heads. Infestations are more common in barley than wheat. Armyworms may also feed on oats, rye and grass forages.
Scout each field at least once each week. You may first want to examine the field margins especially in lodged / luxuriant grain. This can often be an early indicator of worm activity. If worms are present, sample the entire field, checking about 5 locations for each 50 acres in field size. At each location check all the foliage in four square feet of area, for the presents of true armyworm. It is best to scout in early morning or late afternoon as armyworms will avoid the direct daylight. If you sample during midday be sure to check the ground. You should also note worms that look waxy or fuzzy as they are diseased. Additionally, you may find worms with small eggs just behind their heads. These are the eggs of fly parasites and the worms that carry them will die. Do not include diseased or parasitized worms when counting for the economic threshold. Though they may still be moving they are essentially dead.
If on average you find 16, ½ to ¾ inches long armyworms per four square foot sample you should consider an insecticide application.
If pesticides are needed you can find a list of common products in ENT-47, Insecticide Recommendations for Small Grains - 2006. http://www.uky.edu/Ag/PAT/recs/crop/pdf/Entfact-47.pdf
There is a wide variety of products available and armyworms are not particularly hard to control with proper application technique.
You can find more information on scouting and control of armyworm as well as other insects and other pests of small grains in IPM-4, Integrated Crop Manual for Field Crops - Small Grains, available from the IPM website at: http://www.uky.edu/Ag/IPM/manuals.htm
The armyworm, or true armyworm, is a common, early-season pest that can cause occasional losses in corn and should be monitored through late May. No-till fields planted into a small-grain cover crop, pastures, and weedy fields all have higher risk for armyworm infestations. Cool, wet, spring weather usually favors armyworm development. This spring we have had exceptionally high numbers of moths captured in pheromone traps in Princeton. Armyworms usually migrate from small grains starting in late May.
The full-grown 1-1/2 inch armyworm has a greenish brown body with a thin stripe down the center and two orange stripes along each side. The head is brown with dark honeycombed markings. Armyworm over winters as a partially grown larva in pasture or small grain fields. When warm spring temperatures return, armyworm feeding resumes. Armyworms may move into corn during this period, and movement from small grains or pasture to corn is common. Feeding is usually confined to leaf margins, but occasionally they may strip the entire plant leaving only the midrib of the leaves. During the day, armyworms are found in the soil or underneath ground cover. Corn can usually recover from light to moderate feeding by armyworm without significant yield loss. However, severe damage, particularly if the growing bud is injured, can cause significant loss in yield.
Scouting is used to determine if armyworms are present (identify hot spots) and to evaluate if they are worth treating. Survey field edges that border small grains or large grassy areas, and watch for damaged plants. If the characteristic armyworm damage is observed while scouting, look on the ground for armyworms or their black pepper-like droppings littering the ground. To sample for armyworms, examine 20 consecutive plants in each of at least 5 random locations in the field. Note the number of plants with the characteristic damage and the size of the larvae.
In conventional tillage, infestations usually begin around the field margins adjacent to small grains or grassy strips. These areas should be scouted first. If armyworms are present, then determine how far the infestation extends into the field. Entire fields are rarely infested and armyworms can be controlled by treating just a portion of the field.
Before deciding whether to treat for armyworms with an insecticide, there are a few things to consider. First, what sizes are the armyworms. If the armyworms are longer than about 1-1/4 inch they have completed most of their feeding. Controlling larvae of this size is not profitable because the damage is already done. Control actions in corn are recommended when armyworms average between 1/2 and 3/4 inches and the entire field averages 35% infested plants or 50% or more defoliation is seen on damaged plants.
Preventive treatments for armyworms are not justified. Keep in mind that majority of fields will have some armyworms in most years, but the chance of encountering a infestation that economically justifies the cost of treatment is small on a field by field basis. Only rescue treatments are recommended for armyworms in corn. Spot treatments can usually provide effective control of field-margin infestations.
Bt Corn - YieldGard and Herculex 1 hybrids suppress true armyworm activity, particularly against small larvae. However, large infestations or large larvae moving from small grains to corn may still cause economic injury. These fields will still need to be monitored.
Seed Treatments - Many growers are using seed treatments (Poncho, Cruiser, Gaucho, or Prescribe) for control of insects attacking seedlings. These treatments are not likely to provide any noticeable control of armyworm on early-whorl stage corn.
Armyworms damaged some pastures and hayfields during the 2001 outbreak. Usually, infestations were discovered late, after the larvae were large and had completed most of their feeding. If large numbers of armyworms are present in some areas this year, then scouting of highly managed pastures and lush or lodged areas of pastures can help to identify places that may benefit from an insecticide application.
Insecticide alternatives for armyworm control in pastures and hay fields are limited to Bt products, malathion (Cythion) and carbaryl (Sevin). Early detection will be the key to successful control because small larvae will be more vulnerable to an application than large ones.
Producers around Kentucky have seeded quite a bit of tobacco over the past 3-4 weeks in preparation for the 2006 season. Temperatures have been a little on the cool side, and we have had no reports of disease to date. Given the age of the transplant crop, however, we can expect the risk of disease development to increase as the temperatures outside begin to rise in the coming weeks. This week, we'll discuss the most serious disease in the float system, Pythium root rot (PRR), and review its epidemiology and management.
The float system that is used to produce the bulk of Kentucky's tobacco transplants creates ideal conditions for Pythium root rot. Several species of Pythium, a fungus-like organism belonging to the Oomycota (or water molds), are known to cause root rots and damping off of tobacco seedlings. The first symptoms of PRR are usually yellowing and stunting of transplants in a localized area in a float bay. Many times symptoms will be limited initially to individual trays. As the disease progresses, wilting and decay of the root system is common on affected plants. Lower stems and roots of plants with PRR take on a darkened, necrotic appearance, and roots may be slimy. Infected roots will eventually slough off and some re-growth may be observed; however, newly emerged roots will become infected over time. Damping-off and seedling death can occur in severe situations.
Pythium spp. require water, a readily available resource in the float system, for reproduction and dispersal. For the majority of Pythium spp. found in float systems, water temperatures greater than 72 °F favor development of disease. Oospores, the principle resting and survival structure of Pythium spp., are the primary source of initial infections. Swimming spores, or zoospores, are released from zoosporangia produced on germinated oospores and will move toward plant roots due to their attraction to chemicals exuded from the roots. After encountering host tissue, zoospores encyst and enter the root system to establish an infection. Multiple cycles of zoospore production and infection will occur afterward.
Infested soil and water are routes by which Pythium spp. enter the float system. Introduction of the pathogen can occur when soil is introduced into float bays on feet, implements, or trays that have been in contact with soil. Water from creeks, ponds, and rivers is likely to carry Pythium spp. and can be a source of inoculum if used to fill float bays. Contaminated Styrofoam trays (Todd trays) are another important source of Pythium spp. Tobacco roots penetrate Styrofoam float trays during the production cycle and Pythium spp. can survive on these roots, providing a source of inoculum when the trays are re-used.
A good management program for PRR should be based upon sanitary production practices during the production cycle. The goal is to reduce the likelihood of an accidental introduction of Pythium into the float system. If at all possible, avoid the use of surface water (creeks, ponds, and rivers) to fill float bays or mix pesticides and other materials that will be applied to tobacco transplants. Don't allow soil to get into float water - clean and sanitize trays, tools, and even boots before they enter the float bed. Place boards or gravel on dirt walkways to keep down dust and minimize dispersal of potentially contaminated soil.
Terramaster 4EC, the only formulation of etridiazole labeled for use in float systems, is a very effective tool for the management of PRR. Terramaster should be used preventively for best results. "Rescue" applications of Terramaster in systems with active PRR are permitted by the product label and will halt further development of disease. Symptomatic seedlings will likely recover following this type of treatment; however, the higher rates of Terramaster used in rescue treatments increase the risk of phytotoxicity AND recuperating plants may still harbor Pythium that can weaken them and neighboring plants later in the season (and increase their susceptibility to black shank and Fusarium wilt). Refer to PPAFS-AG-T-8, the 2006 Fungicide Guide for Burley and Dark Tobacco, for more information on Terramaster. The link to this publication is: http:/www.ca.uky.edu/agcollege/plantpathology/ext_files/PPFShtml/ppfsagt8.pdf. As with all pesticides, refer to the product label for specific use directions and rates.
For the latest blue mold status and other tobacco disease information, check the KY Blue Mold Warning System online.
http://www.uky.edu/Agriculture/kpn/kyblue/kyblue.htm
For more information about tobacco pests, visit "Insect Management Recommendations".
This past winter has been mild and has favored higher than normal corn flea beetle survival. Flea beetles are important in corn for two reasons, first, they are leaf feeders and large infestations can kill small seedlings, particularly when growing conditions are poor. Flea beetles are also vectors of Stewart's Wilt, also known as bacterial leaf blight. I expect to begin receiving reports of large numbers on corn just spiking through the soil. Feeding by these beetles results in scaring of the leaf surface and evidenced by a frosted appearance to the leaves. Serious damage can occur on plants less than six inches tall.
Fields with a history of Stewart's Wilt should be scouted carefully. Most field corn varieties are not as susceptible to this disease as sweet corn.
With most hybrids under good growing conditions, the corn seedlings will recover from flea beetle damage, so control is not recommended unless some plants are killed or taking on a whitish cast. Control is rarely justified, unless damage is extensive and growing conditions remain poor. The seed treatments that are very common with corn will protect the seedlings from corn flea beetle, at least through the four-leaf stage. The fields likely to be at the greatest risk are early-planted fields without seed treatments, using hybrids with low seedling vigor.
For information about corn pests, visit
"Insect Management Recommendations".
Infestations of cowpea aphids on alfalfa in Barren and Logan counties were reported in the March 20 (1084) issue of KPN. Weather immediately turned cold and slowed development of this insect for several weeks. Infestations have been spotted again recently in Logan and Marion counties and is something to watch up until the first cutting. The distinctive dark aphids can occur in heavy infestations on alfalfa.
See Insect Recommendations
for more alfalfa pest recommendations.
Fusarium head blight (FHB) of wheat, and deoxynivalenol (DON) accumulation in harvested grain, are periodically very serious problems in Kentucky. There was minimal FHB in 2005, but a 2004 FHB epidemic was very severe, and many producers experienced significant yield and grain quality losses.
On April 6, 2006 the Environmental Protection Agency (EPA) granted the Kentucky Department of Agriculture's section 18 request to allow applications of Folicur 3.6F to suppress FHB/DON in Kentucky during 2006. This is the third year in a row that EPA has granted this request.
Folicur is manufactured by Bayer CropScience. The proper use of Folicur will reduce the risk of FHB and DON when used with other FHB/DON management tactics (see http://www.ca.uky.edu/ukrec/newsltrs/news03-2.pdf).
Let me say up front that Folicur is not a "silver bullet" for managing FHB/DON. A great deal of research suggests that about 30-40% reduction in FHB symptoms and DON accumulation is a reasonable expectation for winter wheat. Sixty percent control or more has been achieved in rare field studies in the U.S., but these are atypical results. In other words, do not expect Folicur to provide the same level of FHB/DON control as you have come to expect when fungicides are used to control other wheat diseases. The key is to think in terms of disease suppression, not control. Nevertheless, a 30-40% reduction in FHB and DON could have a significant economic impact locally, and state-wide, if FHB is moderate to severe in 2005. But be advised that significant losses due to FHB and/or DON may occur even where Folicur has been applied if weather conditions favor severe FHB this spring,
The section 18 label allows for a single ground or aerial application of 4 fl oz/A of Folicur 3.6 F to wheat through very early flowering (Feeke's stage 10.51) or May 30th, whichever comes first. Applications cannot be made within 30 days of harvest. A copy of the section 18 label must be in your possession at the time of application.
Excellent fungicide coverage on wheat heads is crucial to achieve the greatest possible FHB/DON suppression. This is no small challenge since most spray systems used in wheat were developed to deliver pesticides to foliage (horizontal structures). In order to maximize coverage on heads (vertical targets), significant changes may need to be made to the sprayer boom system. Also, discipline must be exercised to ensure that proper sprayer pressure and volumes are used.
For ground application, research has shown that best head coverage is achieved with a double-swivel nozzle configuration of XR8001 flat-fan nozzles oriented forward and backward at a 45 degree angle. Acceptable coverage can also be achieved with a single nozzle configuration using TwinJet TJ8002 nozzles. When using either the double-swivel nozzle or the single TwinJet configuration, best head coverage is achieved when the boom is set 8 to10 inches above the heads, spray pressure is 30 to 40 psi OR 80 to 90 psi, fungicides are delivered in 15 or more gallons or water/A, and ground speed does not exceed 8 mph during application.
For aerial application, nozzles should be angled to direct spray 90 degrees to the direction of travel. Spray droplet size should range from 300 to 400 microns and Folicur should be delivered in no less than 5 gallons of water/A. It is best to spray early in the morning or at other times when heavy dew is present. This will facilitate fungicide coverage on heads.
Regardless of the method of application, be sure to tank-mix the lowest rate of a spray surfactant with Folicur to enhance coverage and optimize treatment effectiveness.
Folicur must be applied at a specific time, early flowering, in order to be effective. The optimal time for application is 25% of primary heads, scouted at several random sites in a field, showing anthers (pale, yellow-green structures about 1/8-in-long). Much beyond 25%, and it may be too late. The flip side - applying Folicur before full head emergence/early flowering can seriously compromise FHB/DON suppression. This brings up a point of tension that wheat producers may face this spring. Delaying application of Folicur to achieve FHB/DON suppression could allow for excessive build-up of other fungal diseases. Conversely, application of other labeled fungicides before full head emergence will control other diseases, but will have no impact on either FHB or DON. I would advise growers that foliar disease development should take precedence since little is to be gained by suppressing FHB/DON if serious losses are incurred by allowing fungal foliar diseases to develop.
One desire we all have is for fungicides to be used only when needed. Regular field scouting for foliar fungal diseases has been successfully used by growers for many years to determine if and when to spray fungicides. However, this is not possible with FHB since once symptoms are present it is TOO LATE to spray with Folicur. Below are some general guidelines to help you determine if you should spray Folicur for FHB/DON suppression this spring:
If most or all of the above conditions exist when the crop is at 10-15% flower, you should consider spraying Folicur within one or two days.
An exciting new tool that can be used to help determine the FHB risk is a new web-based, disease forecasting model recently made available by Penn State University, Ohio State University, and the U.S. Wheat and Barley Scab Initiative. This forecasting model, which is reported to be 80+% accurate in predicting conditions conducive for FHB epidemics, utilizes realtime weather data from numerous National Weather Service stations within each state. When you enter into the "Risk Map Tool" section of the FHB prediction center home page, you will be asked if you are growing winter or spring wheat and, if winter wheat, whether the field has corn residue that covers 10% or more of the soil surface, regardless of tillage system used. At that point you will come to US map and are asked to click on your state. This will bring you to the main FHB Risk Management Tool page.
The FHB Risk Management Tool page will have a map of Kentucky showing the locations in the state where the weather data are being retrieved. In the upper left corner of the page is a calendar section labeled "Flowering Date". This section needs a bit of explaining. You will note right away that the model will only let you input a "flowering date" as late as the current day. It also covers the preceding 7 days. So, if you estimate your crop will flower on May 7, but it is only May 3, the best you will be able to do is to determine if the weather on May 3 is favorable for FHB, and establish what the FHB risk has been for the preceding 7 days (April 26 to May 2). Of course, since your crop is not flowering, the real FHB risk is zero, no matter what the forecast model says. Nevertheless, that information will tell you if FHB is brewing or not. My advice is to begin determining the FHB risk using this model several days out from crop flowering. Keep checking your wheat and keep checking the model every 1 to 2 days. By the time your crop reaches 10 to 15 % bloom, you will have a good feel for the FHB risk in your area. If the forecast model says the FHB risk is high (medium if you are not a risk-taker), and the forecast matches your local weather reality, then you might consider spraying Folicur within 1 to 2 days.
The web address for the FHB Prediction Center is http://www.wheatscab.psu.edu/. Check it out. Once you actually see it and play around with it, what I have said above will make much more sense. The model does have several practical limitations in predicting final FHB levels; these are clearly discussed within the Prediction Center web site. Perhaps the greatest limitation of the model is that it does not account for weather conditions during flowering and grain fill. This is where the model failed us in 2004. Specifically, disease-favorable weather occurred during late flowering and grain fill and greatly impacted final FHB/DON levels. As I said earlier, the forecast model is 80+% accurate, so final FHB/DON conditions will not always be reflected by the model's risk output. The authors of the model discuss this limitation under "Reality Check" in the "Model Details" section of the Prediction Center.
We all hope that FHB is non-existent this spring and that growers achieve record yields and grain quality as they did in 2005. However, if this is not the case, wheat producers now have an additional tool to consider, and possibly use, to minimize FHB and DON development this spring.
See "Insect Management Recommendations" for more wheat pest information.
Bacterial blight (bacterial leaf spot, bacterial stem rot, bacterial wilt) is capable of destroying geraniums in Kentucky landscapes. Spring and summer warm weather interrupted with daytime thundershowers (while stomata are open) favors rapid spread of this disease. Although geranium bacterial blight has appeared in Kentucky landscapes before, it is hoped that Kentucky gardeners will not experience a serous outbreak of the disease this year. So far, in the U.K. Plant Disease Diagnostic Laboratory, bacterial blight-contaminated commercial greenhouse geraniums have not been observed. The causal bacterium (Xanthomonas campestris pv. pelargonii) attacks geranium leaves and stems in the greenhouse and in the landscape.
Some homeowners may not notice the disease until the plants begin to collapse and die. However, the disease appears first as circular or irregular, brown, sunken spots. The spots are well defined, rarely coalescing. This stage is followed rapidly by necrosis and wilting of the leaf. Infected leaves either fall off or droop and hang on the plant for a week or two.
In certain varieties (e.g. Sincerity) symptoms begin as a wilting of the leaf margins. Infected areas rapidly die in angular patches bounded by the veins. Later, the smaller veins will appear dark due to systemic infection. Several other problems (e.g. Botrytis blight) can also cause angular leaf necrosis, however, the additional presence of the limp condition of the leaf generally signifies that this is a bacterial infection. In the laboratory, geranium leaves with brown streaks along the veins are examined for evidence of bacteria. Observations of large numbers of bacterial cells are made via microscopic examination.
The disease then progresses to a decay of the stem. The vascular bundles and pith in the stems and branches become brown to black and the stem rapidly discolors and rots. Leaves wilt and then drop off as the stem rot progresses. The roots become blackened but not decayed. Infected plants may be stunted, however there are several root rot diseases that cause stunting, but not necessarily death of geraniums.
Infected plants cannot be cured. The bacterial blight organism may be spread from diseased to nearby healthy plants in the bed by contact, splashing water and contaminated cutting tools. The bacterium is extremely infectious and may survive long periods in moist soil. Control measures in the landscape are based on establishing disease-free plant beds and practicing strict sanitary measures:
Why do greenhouse growers use culture-indexed cuttings? Bacterial blight can be transported into a geranium crop by an infested cutting. The cutting may appear normal and healthy, but it contains tiny amounts of bacteria that later grow and cause disease in the contaminated plants and spread throughout the crop. Growers reduce the likelihood of getting infested cutting material by purchasing "cultured" or "culture-indexed" cuttings. These cultured cuttings are the end result of a complex and meticulous program to develop and produce pathogen-free geraniums.
Cuttings that survive rigorous testing for pathogens become "mother" plants that are used to increase the number of plants of the disease-free cultivar. From these cuttings, large groups of production plants are produced. Growers who purchase culture-indexed material get plants from these production blocks. Growers will have best success with purchasing culture-indexed cuttings from the company that manages the original steps in the program (or a licensed propagator). These companies have their reputations to uphold and take care not to allow their stock to become contaminated.
Kentucky bedding plant producers also have their reputations to uphold and will want to invest in the culture-indexed plants so that their customers have the best quality geraniums possible. Thus, to reduce the possibility of bacterial blight in flower beds, landscapers and homeowners will want to purchase the culture-indexed plants even though they may be a bit more expensive. Be aware that when these plants are being sold, these more expensive plants are often displayed at the outdoor retail garden centers side-by-side with less expensive and possibly diseased plants. Exposed to splashing rain, a group of healthy plants can become contaminated from diseased plants nearby. Where possible, growers need to observe how their geraniums are being marketed so that disease-free plants are not becoming contaminated.
A variety of holes and excavations, ranging from mole runs to insect and earthworm diggings can show up in turf at this time of year. The large fresh mounds and runs from mole activity are relatively distinct but there smaller holes can be from a variety of different creatures.
Here are some signs that may be seen over the next few weeks:
The majority of samples received in the PDDL this past week were greenhouse ornamentals and vegetable transplants: Pythium root rot on lettuce, sweet potato vine, and calibrachoa; Botrytis blight on Gerbera daisy; powdery mildew on African violet; Sclerotinia stem rot on petunia; and thrips infestation on verbena. Other samples included double blossom on blackberry and black knot on plum.
UKREC-Princeton, KY, March 31 - April 7, 2006| True Armyworm
| 271
| Black Cutworm
| 1
| | |
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