Agricultural Plant Pest Control

Q. What is the most important step in dealing with an insect problem?
A. The most important step in dealing with an insect problem is identifying the pest or pests involved. Only then can an effective control program be designed.

Q. What two things do all adult insects have in common?
A. All adult insects have two things in common: six jointed legs and three body regions. To distinguish one insect from another, the most important parts to look at are wings and mouthparts.

Q. What are the four stages in the life cycle of insects having a caterpillar stage?
A. The four stages in the life cycle of these insects are the egg, caterpillar (larva), pupa and adult. The adults are moths or butterflies. Only the caterpillar stage causes damage.

Q. What are some common names for the corn earworm?
A. The corn earworm is also known as the cotton bollworm, tomato fruitworm, and soybean podworm, depending on the crop upon which it is feeding.

Q. What are some examples of sucking insects?
A. Sucking insects include aphids (plant lice), thrips, stink bugs, whiteflies, plant bugs, and leafhoppers.

Q. Describe the appearance of powdery mildew.
A. Powdery mildew develops as a superficial, white to light gray, powdery to mealy growth on leaves, stems and sometimes flowers. Affected leaves usually turn yellow, wither and die rapidly.

Q. What are the three elements of the Disease Triangle
A. All disease symptoms and signs are caused by an interaction between the host plant, the pathogen, and the environment. These three elements are often called the disease triangle.

Q. Name seven plant disease symptoms.
A. These are leaf spot, wilt, canker, blight, root rot, crown rot, and fruit rot.

Q. What are five common symptoms of viral diseases?
A. Five of the more common symptoms are:

• Mosaic patterns: a light green to yellow leaf mottling usually accompanied by abnormal leaf growth.
• Vein banding: a light green to yellow band around the leaf veins that may turn dark with time.
• Ring spot: rings of light green, yellow or tan alternating with the normal green of the leaf.
• Yellowing: uniform yellowing of the entire plant or parts of the plant.
• Stunting: is common with most of these diseases.

Q. Why is crop rotation a good pest management method?
A. Crop rotations allow changes in weed management programs; that is, changes in cultural practices and herbicide systems. One crop in a rotation may have a considerable competitive advantage over a hardto-kill weed, or another crop in the rotation system may be tolerant of a herbicide that is particularly effective on the problem weed. As a result, crop rotations frequently provide a means of improved control of troublesome species in a given field. Crop rotations can also greatly affect the amount of pathogens in the soil and some soil insects.

Q. Why is sanitation important for on-farm storage of agricultural products such as grains?
A. Grain residues from previous years' harvests provide a means by which stored grain pests survive until the new crop is placed into storage. Thorough cleaning of storage facilities can eliminate the primary source of infestation.

Q. What is the difference between selective and nonselective herbicides?
A. Selective herbicides are those which kill some plants while having little or no effect on others. Nonselective herbicides injure vegetation without regard to plant species.

Q. What is the difference between contact and translocated herbicides?
A. Contact herbicides are applied to emerged vegetation and affect only the plant tissues subjected to spray coverage. Translocated herbicides are absorbed by plant roots or foliage and readily move within the plant to a site of actively growing plant tissues.

Q. What precautions should be taken when handling soil fumigants?
A. Read the label. Fumigants are usually applied as liquids which later turn into gases. Use extreme care; fumigants are generally hazardous to the applicator. Do not breathe the vapors! Always familiarize yourself with label directions, symptoms of poisoning, and first aid treatments before using any pesticide. Follow treatment re-entry restrictions and keep other people and animals away during and immediately after application. Fumigants should be handled in places with adequate ventilation.

Q. What factors should you consider when selecting pesticide application equipment?
A. You should consider the time that the equipment will require for the application versus the time in which the application must be completed; the suitability of the equipment to the area, the conditions, and the pest; the frequency with which you will have to make applications; the buffer zone that the equipment needs to prevent damage to the environment surrounding the treated area; the relative economy of the equipment; and the possibility of pesticide drift.

Q. Why is it important to read the product label when using fumigants?
A. It is always important to read the product label of any pesticide because it contains vital information on use and safety. The label is the law. When using fumigants, it is especially important to read the label because some fumigants may react with certain metals to cause an explosion hazard. You must check to ensure that your equipment is appropriate for applying the desired fumigant. Also, different fumigants behave differently when they vaporize in the soil, so your injection spacing has to vary.

Q. What is an advantage and a disadvantage of airblast sprayers?
A. An advantage is that highpressure sprayers allow good surface coverage, as well as penetration of tree canopies. Drift can be a disadvantage with highpressure sprayers. You should monitor weather conditions and change application plans if necessary.

Q. How should air-blast sprayers be used to get more uniform coverage of an entire tree?
A. Considerably more spray should be directed toward the upper portion of the tree. Twothirds of the liquid should be placed in the upper half of the air stream and one third of the liquid should be placed in the lower half of the air stream.

Q. To calibrate your boom sprayer correctly, you should know the three variables affecting the amount sprayed per acre. What are they?
A. The three variables affecting the amount sprayed per acre are (1) nozzle flow rate, (2) ground speed of the sprayer, and (3) effective spray width.

Q. What types of equipment are available to do ground applications of pesticides using dry formulations?
A. Granular pesticides can be spread using drop (gravity) spreaders and rotary (centrifugal) spreaders. Dust formulations can be spread using dusters; however, dust formulations are used less in modern agriculture because they are hard to control and can easily drift.

Q. How are soil fumigants most often applied?
A. Soil fumigants are most often injected into the soil behind an implement that opens a furrow. The furrow is closed immediately to prevent loss of the fumigant through vaporization.

Q. What are some of the advantages and limitations of aerial pesticide application?
A. Advantages include rapid coverage of large areas, accessibility to crops when ground equipment or ground conditions are not suitable and reasonable cost when properly managed. Limitations to aerial applications can be imposed by weather, fixed obstacles, field size and shape, and field location relative to pesticide sensitive areas (e.g. schools and residences).

Q. How does the Worker Protection Standard impact farm worker safety?
A. The Worker Protection Standard covers workers in areas treated with pesticides as well as employees who mix, load, and apply pesticides. The regulations expand the requirements for issuing warnings about pesticides, use of protective equipment, field re-entry restrictions, and safety training.

Q. What is meant by phytotoxicity? How is it caused?
A. Some pesticides can burn or otherwise damage the plants to which they are applied. Phytotoxicity may occur because of drift onto non-target plants, excessive rates, or using low volume (highly concentrated) applications. Sometimes tank mixes of multiple chemicals (that may not be phytotoxic alone) can result in crop damage. Certain weather patterns, such as exceptionally bright, hot and dry conditions, may increase phytotoxicity. Emulsifiable concentrates may cause some phytotoxicity.

Q. What is the most common route of exposure for acute toxicity?
A. Dermal exposure through splashes and spills is the most common route of exposure.

Q. What are the most common causes of delayed toxicity?
A. Delayed toxicity is most often the result of contaminated clothing, leaky spray equipment, inadequate protective clothing and equipment, not properly cleaning spray equipment after each use and most importantly, not cleaning yourself.

Q. What are sources of oral exposure?
A. Oral exposure sources can be caused by accidental swallowing and is usually from carelessness. Eating, drinking, and smoking while applying pesticides or before properly cleaning hands can also contribute to oral ingestion of pesticides.

Q. What is the minimum requirement of protective clothing?
A. When working with pesticides, at least wear a longsleeved shirt, long pants, shoes, and socks. When handling pesticide concentrates or mixing and loading the sprayer, a liquid-proof apron and rubber gloves are suggested. Read the pesticide label carefully. The new protective clothing requirements may differ for workers and pesticide handlers.

Q. What kind of gloves should be worn when handling concentrates?
A. Gloves should be unlined and made of a waterproof material that does not contain any cotton, leather, or other fabric that will absorb chemicals. Sleeves should be worn on the outside of the gloves.

Q. What types of hats and boots should be avoided when applying pesticides?
A. Hats should be easy to clean or they should be disposable. Avoid hat fabrics that absorb liquids. Unlined rubber boots are a good investment for pesticide applicators because they are waterproof and easy to clean. Work shoes made of canvas or leather should be avoided, because they absorb pesticides and cannot be decontaminated.

Q. What kind of face protection should be worn whenever concentrate is handled?
A. Wear goggles or a face shield anytime concentrate is handled.

Q. According to the WPS, what information about pesticide applications must be displayed at a central location?
A. For the benefit of all employees, as required by the WPS, information must be posted at an easily seen, central location on each agricultural establishment. This information includes:

• facts about each pesticide application-the pesticide product name, EPA registration number and active ingredient(s); location and description of treated area(s); the time and date of the application and the restricted-entry interval (REI);
• the name, address and telephone number of the nearest emergency medical facility; and
• an EPA WPS safety poster.

Q. What is a Restricted Entry Interval (REI)?
A. The restricted-entry interval is the time immediately after a pesticide application when entry into the treated area is limited. During an REI, do not enter or allow members of your family to enter a treated area or contact anything treated with the pesticide to which the REI applies.

Q. What are three kinds of non-point source pesticide pollution?
A. The three kinds of nonpoint source pesticide pollution are run-off, runin, and leaching. Run-off occurs when rainfall or irrigation rates exceed the rate at which water can be absorbed into the soil. When runoff occurs, pesticide residues can be carried off the field and into surface waters. Run-in is the transport of pollutants to groundwater by a direct route, such as through a sinkhole or an abandoned well. Leaching occurs when contaminants are carried through the soil with excess water that percolates below the crop root zone and into the groundwater. Leaching is most common in sandy, permeable soils.

Q. What is the difference between threatened species and endangered species?
A. Plants or animals in danger of becoming extinct are classified as "endangered". Plants or animals of intermediate rarity are classified as threatened. Threatened means that the possibility of becoming endangered exists if the population declines.

Q. What type of pesticide containers are accepted for recycling?
A. Only empty, dry plastic containers that have been triple- or pressure-rinsed will be accepted for recycling.

Q. What are the two kinds of drift?
A. Two types of drift are associated with pesticides. The most common, drift of spray droplets or dust particles, is directly affected by spray pressure, nozzle opening size, wind velocity and pesticide formulations. Drift of a chemical with high vapor pressure is termed "vapor drift." Vapors or gases can drift in harmful concentrations, even without wind. Fumigants such as methyl bromide must be confined so they will not drift from the treated area.

Q. What are the four equipment requirements of a chemigation system?
A. The chemigation act requires growers to install four main safeguards on their chemigation equipment to prevent contamination of groundwater:

• An interlock, mechanical or electrical, must connect the chemical injection equipment with the irrigation pump. Thus, if the irrigation pump stops so will the chemical pump, preventing too much chemical from being pumped into the lines. In addition to stopping groundwater contamination, this interlock also prevents too much fertilizer or herbicide from injuring the chemigated crops or plants.
• A check valve must be installed between the irrigation pump and the point of injection of the chemical. This prevents water that has chemical mixed with it from flowing back into the well or other water source. Any system that does not have this provision is risking contamination of everyone's water.
• A vacuum breaker must be installed behind the check valve. This prevents back siphonage of the chemicals by releasing the siphon on the water line when the pump is cut off.
• A low-pressure drain must be installed behind the check valve and preferably behind the vacuum breaker. This prevents backflow into the well or water source when the system is not under pressure or when the check valve leaks slightly during pumping.