Fairfield County
Fairfield County
Agriculture and Natural Resources
The Connection
May 4, 2001
Dear Fairfield Countian,
When spring finally arrived, it arrived with force with a series of nice days. Spring field work is now well ahead of normal.
Nitrogen supplies have not been a limiting factor. With the recent dry weather we have not had any concern about slug problems in no-till systems. Survey work shows that there are very few young slugs in area fields. However, there are plenty of eggs and the juvenile slugs will be pregnant soon. A period of cool damp weather could still set us up for slug problems any time after the next four weeks.
Bean leaf beetle overwintering adults will likely be present soon in soybean fields. However with the large acreage of soybeans likely to emerge in a few days period of time, we may not see the heavy feeding in the early planted fields.
Scouting of corn fields should begin shortly after emergence. Cutworms and common stalk borer problems can be a concern during the next few weeks.
With the warm rainy start to April, we are likely to see the brown spots symptoms of fungal apple
scab on on susceptible crabapple trees in our landscapes as well as on backyard apple trees.
These symptoms will appear as we move through the month of May.
Rainfall for April
Rainfall totals in April were above normal for the month. However we are still short of moisture for the calendar year. Timely rains will be needed as we move through the next three to four months.
We have some volunteers collecting rainfall across Fairfield County this summer. The totals that they registered for April were as follows:
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Aquaculture
The Piketon Aquaculture Program of The Ohio State University at Piketon, Ohio organizes several workshops every year. To be put on the mailing list contact Cindy at 1-800-297-2072. The center at Piketon has a working fish farm that demonstrates the four major production systems in aquaculture. Call the above number to schedule a tour.
The Ohio Aquaculture Association is a very active producer association working to promote
aquaculture in Ohio. For more information contact George Hood, President, 740-585-2401. The
most complete website for aquaculture is www.aquanic.org.
Managing for Woodland Wildlife
If you have made the decision to harvest timber, consider these management practices which help to support wildlife needs in the forest.
This concept of crop tree management was developed by foresters of the USDA.
Gypsy Moth Larvae Now Emerging
WOOSTER, Ohio - Gypsy moth larvae are beginning to emerge from egg masses throughout the state, and egg hatch will continue for the next couple of weeks, says an Ohio State University entomologist.
Dan Herms said larvae will hatch from egg masses over the next three weeks, then climb into the canopy of host trees and spend the next two months feeding on the leaves. "Mid-to-late June is when 80-90 percent of defoliation will occur," he said. "One caterpillar will eat 25-30 leaves in its lifetime. Generally, if you find one caterpillar per 25 leaves, there's the potential for 100 percent defoliation."
During early and mid-May, the Ohio Department of Agriculture will take steps to help slow the spread of gypsy moth outbreaks in Ohio by making aerial applications of a biological pesticide derived from the naturally occurring bacterium Bacillus thuringiensis, commonly known as Bt. Gypsy moth larvae are most susceptible to Bt when they are small, so applications will be made to susceptible trees in urban and forested areas of Ohio before damage becomes evident.
The gypsy moth, an invasive insect accidentally introduced to the United States from Europe in 1869, has spread to Ohio in recent years from Pennsylvania and Michigan. It feeds on more than 100 species of deciduous and evergreen trees, leaving them defoliated and susceptible to other stresses and diseases. Several years of defoliation will eventually kill a tree.
Oak trees are the insect's favorite host. Last year more than 20,000 acres of Ohio trees were damaged by the gypsy moth, and state agriculture and forestry officials fear this year's outbreaks could be more severe as the insect continues to spread through the prime oak forests that dominate much of eastern and southern Ohio.
A gypsy moth caterpillar is easy to recognize by the five blue dots and six red dots on its hair-covered back. After feeding in early spring, it pupates in late June or early July, and the adult moth emerges about 10 days later. The female moth, which cannot fly, lays its egg mass on any object it comes across, such as rocks, houses, recreational vehicles, trees or car tires. "That's how the moth can spread rapidly from one place to another," said Herms. "It's important to check your equipment and cars, if you going camping, for example, and destroy any egg masses you find."
Natural predators, such as birds and mice, have been found to have some impact on controlling the gypsy moth, but only in low populations. Entomophaga maimaiga, a natural fungal disease of the gypsy moth, substantially decreased gypsy moth defoliation in northeast Ohio in 2000. But its effectiveness is highly dependent on environmental conditions. The fungus, which affects the caterpillar stage of development, is easy to distribute and spreads rapidly under favorable conditions. But it is only effective during wet conditions in the spring.
Herms said that during gypsy moth outbreaks, the most effective means of preventing defoliation during outbreaks is to apply insecticides. Bt is the most environmentally friendly because it affects only caterpillars and is harmless to humans, pets and birds. But even Bt has met controversy because of toxic effects on native butterflies and moths.
"Bt can be very effective, especially if it's timed correctly," said Herms. "Studies have shown that Bt has very little impact on non-target organisms. It has less of an impact than other insecticides that would affect a much broader range of insects." Dimilin, a growth-regulating insecticide that interferes with exoskeleton formation during the molting process, is also used in the state gypsy moth suppression program, but to a lesser degree because it affects a wide range of immature insects and remains in the environment much longer than Bt.
The Ohio Department of Agriculture will begin spraying 38,000 acres in 19 state counties
beginning the week of May 7. Counties targeted for aerial spraying include Ashland, Ashtabula,
Coshocton, Cuyahoga, Franklin, Harrison, Holmes, Knox, Licking, Lorain, Lucas, Mahoning,
Medina, Richland, Stark, Summit, Trumbull, Tuscarawas and Wayne. Single property owners or
groups of property owners with at least a 50-acre block of trees can apply to the department each
year in September to have their property included in the state suppression program the following
year. There is currently no charge to the property owner for participation in the program.
Homeowners can also contract with private applicators to have trees sprayed from the ground or
the air, depending on the number and area of infested trees. For more information on the gypsy
moth, log on to www.state.oh.us/agr/Index.htm or
www.hcs.ohio-state.edu/ODNR/Health/Health.htm
Noise on the Farm Can Cause Hearing Loss - Thomas L. Bean, OSU Extension
What Are The Effects Of Excessive Sound Levels?
Loud sounds can cause a significant loss of hearing. The amount of hearing loss experienced is related not only to the loudness of the sound but also to the frequency (pitch) and to the length of time exposure. Higher frequency sounds are much more damaging than low ones. Thus, the ability of the ear to hear high frequencies is usually the indication of damage. People who are experiencing a hearing loss may first notice this as an inability to hear higher pitched sounds such as the notes of music. Eventually the ability to understand speech is affected. Some danger signals to be aware of are (1) your ears ring or you experience head noises a few hours after you get off the tractor following a day's work, or (2) your speech seems muffled when you talk after being around loud noises for extended periods.
How Can We Protect Ourselves Against Noise?
Noise reduction can be accomplished by either reducing the amount of noise produced or by placing some type of barrier between the noise source and the ear.
Generally speaking, reducing the amount of noise produced by machines is an engineering challenge. Progress is being made in designing machines that produce less noise. Yet, the sound produced may still exceed safe levels when operators are exposed for long periods.
Good maintenance practices are an effective way to reduce noise exposure because they reduce noise at the source. Examples are:
Tractor cabs may or may not provide protection from noise. Those isolated from tractors by vibration mounts, covered on the inside with sound proofing or deadening material, and tightly closed to prevent air-borne noises from entering do protect the operator. Noise level in cabs without these features may be higher than if no cab was used.
An effective and inexpensive method of protection is to reduce the sound level at the ear by using acoustical earmuffs. These specially designed earmuffs cover the ears and provide a barrier to noise. Properly designed earmuffs reduce the sound to a safe level but still permit sound to reach the ears for informational and safety purposes. Actually, you can hear conversation and sounds that might indicate trouble in the machinery just as well with earmuffs as without earmuffs.
Protective devices such as ear plugs, which are designed to fit in the ear, are effective if properly fitted. When purchasing ear plugs make sure to follow the directions for insertion so that a snug, tight fit is obtained. Plugs must be kept clean to prevent ear infection. Because of their size they are easily lost so consider purchasing those that have a carrying case. Cotton in the ears is practically worthless as a protective device.
Wise tractor operators consider the inconvenience of using ear protection such as earmuffs a small price to pay for protection of their hearing.
Obviously, the time to take action is before any permanent damage is done. Have your hearing
checked to determine your present condition, then avoid noisy situations...and protect your ear
from those you can't avoid.
Not So Dandy Dandelions - Source: Buckeye Yard & Garden Online
Dandelions are blooming in Central Ohio as well as many other broadleaf weeds and many
people want to treat now, however post emergent herbicides are not effective unless conditions
are conducive for the weeds to absorb and translocate the herbicide. Broadleaf weeds are
generally controlled with amine formulations when day time temperatures are between 55F and
60F, and soil temperatures 55F consistently. Dandelions are best controlled when they enter the
"puffball stage", when the seeds are formed, as at that time, carbohydrates are sent back to the
roots for storage, along with the herbicide. Although ester formulations work well at cooler
temperatures, they are more likely to volatilize and injure adjacent desirable broadleaf plants.
Foot and Mouth Disease Prevention - College Policy
The policies described in this notice are based on the current situation where the disease does not exist in the USA. Further restrictions will be imposed if the disease is diagnosed in the USA.
Following are the policies to be instituted immediately:
Alfalfa Weevil Alert - Mark Sulc and Bruce Eisley, OSU Extension
Alfalfa weevil activity has been reported in recent days, primarily in southern and southeastern Ohio. To date, only a few reports indicated that injury was severe enough to warrant insecticide treatment. The greatest activity was reported on south facing slopes. In most cases, larval counts have been well below economic thresholds. The cool weather of last week slowed weevil activity, but with the warm conditions over the weekend, activity could pick up quickly. Growers are advised to scout their alfalfa for this potentially damaging pest. Careful assessment of weevil activity and presence should be made before applying a rescue treatment.
In most years, biological control by a complex of beneficial parasites generally maintain weevil activity at sub-economic levels of activity. To minimize adverse impact on beneficial parasites of alfalfa weevil, treatments should ONLY be applied when justified by prior sampling of weevil abundance. In some years, such as in 2000, the parasites may not maintain weevil populations at sub-economic levels, and application of a timely rescue treatment may be warranted to limit economic losses from excessive defoliation.
When weevil activity appears to be above normal, tip injury and weevil larval counts in the alfalfa should be made. Select a number of stems AT RANDOM to determine the percent of tips exhibiting feeding injury. If tip feeding injury indicates a potential problem, then walk across the field and select an additional 30 stems AT RANDOM to determine the number of larvae per stem. Walk into the field at least 30 to 40 feet before collecting stems, as field margins often have inflated counts that are not representative of the majority of the acreage. This will confirm whether a serious problem exists and if corrective action should be taken.
Levels of tip feeding injury, weevil larval abundance, and alfalfa stand height that should trigger a need for corrective action are as follows:
Because environmental conditions and parasites can dramatically reduce alfalfa weevil larvae, the most important variable in making a decision to treat or not to treat is the larvae per stem count. Economic thresholds assume that a larvae counts is based on a random sample of stems, not just the stems exhibiting injury. Too often, attention is focused only on plants exhibiting injury.
If diseased larvae are readily observed on the foliage, it may be assumed that additional larvae are infected and that a decline in feeding activity is occurring. Treatment of a declining population will not likely achieve an economic return on the cost of an insecticide application, and will also kill beneficials needlessly.
The following OSU Extension Fact sheets provide important information on managing and controlling this pest:
Alfalfa Weevil, FC-ENT-0032-00 http://www.ag.ohio-state.edu/~ohioline/ent-fact/0032.html
Insect Pest Management on Alfalfa, FC-ENT-0031-00
http://www.ag.ohio-state.edu/~ohioline/ent-fact/0031.html
Disinfection in On-Farm Biosecurity Procedures - Dr. William Shulaw, OSU Department of Veterinary Preventive Medicine
In recent weeks the appearance of foot-and-mouth disease (FMD) in Europe, and its possible introduction into the United States, has caused many livestock owners serious concern. So much so that many are now looking more closely at their biosecurity plans or their efforts to keep the disease out of their herds. We have received many calls regarding which disinfectants to use on shoes, boots, tires, or other equipment in order to kill the foot-and-mouth disease virus. A few important points about disinfection should be made before choosing a disinfectant for routine farm use.
First, most disinfectants won't work if the surface to be disinfected isn't fairly clean before applying the disinfectant. Organic materials such as soil, plant debris (such as straw), milk, blood, pus, and manure often inactivate some disinfectants or protect germs from the disinfectant's active ingredients. Chlorine-based disinfectants are an example of this problem. Chlorine, the active ingredient in bleach, is relatively quickly inactivated by organic debris such as manure, and even milk, at the concentrations usually used on clean surfaces. In addition, even "hard" water can reduce or destroy the activity of some disinfectants. Likewise, some disinfectant solutions are only active for a few days after mixing or preparing. Failure to make a fresh solution of disinfectant after it has been prepared longer than a few days, or after it has become visibly contaminated by organic material like manure, may result in using a product that doesn't really work. Even worse, it may give a false sense of security. It is true that sufficient concentration and contact time can overcome some of these problems with certain classes of disinfectants, but often increasing the concentration or contact time makes use of the product impractical, costly, or caustic.
Disinfectants also vary considerably in their activity against the assorted germs (bacteria, viruses, fungi, and protozoa) that livestock producers are concerned about. For example, plain vinegar (4% acetic acid) will readily kill the foot-and-mouth disease virus, but it won't do much to Mycobacterium paratuberculosis, the cause of Johne's disease. Most commonly used disinfectants are not active against bacterial spores, the environmentally hardy life-form taken by the germs that cause tetanus, blackleg, botulism, and anthrax. Yes, formaldehyde is effective against most spores, but it is nor really a practical disinfectant and is now considered a potential cancer-causing compound. It is important to select a disinfectant that will be active across a wide spectrum of germs under the conditions in which it will usually be used; this includes hard water, contamination with organic material, and potential for toxicity or damage to environmental surfaces or skin or clothing. It is also important to keep solutions clean and freshly made as directed by the manufacturer. Lastly, disinfectants must have sufficient contact time with the surfaces to which they are applied in order to allow them to kill the germs with which we are concerned. Contact time needed varies with the product and the germ. A quick splash in a foot bath with a dirty boot is not likely to accomplish anything except to give a false sense of security.
The following chart of disinfectants has recently been made available by the USDA for field use in a foot-and-mouth disease outbreak**:
| Product | Dilution | Mixing Instructions | Notes |
| 5.25% Sodium
Hypochlorite (NaOCl) (household bleach) |
3% |
Add 3 gallons of chlorine bleach to 2 gallons of water, mix thoroughly | |
| Acetic acid* | 4-5% | Add 6.5 ounces of glacial acetic acid to 1 gallon of water, mix thoroughly | Vinegar is a 4% solution of acetic acid |
| Potassium
Peroxymonosulfate and Sodium Chloride (i.e. Virkon-S) |
1% | Follow label directions | Virkon-S |
| Sodium Carbonate (soda ash)* | 4% | Add 5.33 ounces of sodium carbonate to 1 gallon of hot water (or 1 pound to 3 gallons of hot water), mix thoroughly | The solution is mildly caustic, but can dull paint and varnished surfaces. |
| Sodium Hydroxide
(NaOH) (lye)* |
2% | Add 1/3 cup of NaOH pellets (2.7 ounces of the lye) to 1 gallon of cold water, mix thoroughly. | This solution is highly caustic. Use protective rubber clothing, gloves and safety glasses. WARNING:Always add the lye to the water. Never pour the water over the lye. |
*Section 18 application submitted and EPA approval is pending.
**From National Emergency Response to a Highly Contagious Animal Disease, Executive Summary, March 30, 2001
As you can see above, common household bleach would be an effective disinfectant for the FMD virus, but the recommended concentration (3% sodium hypochlorite) is 60% of full strength as it comes from the bottle. This concentration would damage clothing, shoes, and rubber goods, and is mildly corrosive to steel surfaces. It can be used on an infected premise for FMD, but probably wouldn't be a good choice as a general purpose disinfectant for equipment and foot baths. Vinegar will also kill the virus, but wouldn't be a good choice for general use because of its lack of effectiveness against many other important germs. Obviously, lye is too caustic for general use.
So, where do we go from here? On most farms, disinfectants will be used in foot baths or for cleaning equipment and livestock premises. The older quaternary ammonium compounds (Roccal DT) are good for some situations and relatively clean surfaces. They will not be particularly effective against FMD or M. paratuberculosis, the cause of Johne's disease, and have markedly reduced activity in the presence of organic material. Some of the newer quaternary ammonium preparations have improved activity. Chlorhexidine (NolvasanT) is a widely used disinfectant/antiseptic that is easy on skin surfaces but can be inactivated by organic debris and hard water. It is useful for clean surfaces and some instruments. For foot baths, boots, and some equipment the phenolic-based compounds, such as One Stroke EnvironT, OsylT, and AmphylT, have good activity in hard water and in the presence of organic material. They are considered active against the germs that cause tuberculosis and Johne's disease but are not very active against the FMD virus. Virkon ST is an organic acid/surfactant combination, and it appears to have a wide spectrum of activity against many kinds of germs (including the FMD virus). It is relatively stable in the presence of some organic material. It has a pH of around 2.6, when mixed as directed, but is labeled as nonirritating to skin. It is advertised as useful on many kinds of equipment, including saddles, brushes, buckets, and etc. Again the contact time needed for effective disinfection will vary with the product used and must be a consideration in your choice. Disinfectants are not to be applied to animals directly, and you should consult the label to make sure there are no warnings against using them around feeders and animal quarters.
In the event of a foreign animal disease outbreak, such as FMD, the type of disinfectant and
procedures used in the cleanup of infected farms and for routine prevention activities will be
selected by regulatory officials. For routine use in biosecurity programs at the farm level,
producers should consider the major risks they are concerned about, consider the type of surface
they wish to disinfect, the conditions under which it will be used, and then select a disinfectant
that best suits their needs. Information about activity in hard water or in the presence of organic
debris, contact time needed, what germs are reliably killed, human use and environmental
concerns, and other details are usually on the label or can be obtained from the company. Web
sites are often good sources of information about individual products. Above all, producers
should remember that disinfection is just one aspect of their biosecurity program.