Pest Management Program
Common Pests…………………………………………………….. 2
Damage on Plants…………………………………………...3
Mites………………………………………………………...3
Thrips………………………………………………………..5
Whitefly……………………………………………………..7
Aphids...……………………………………………………..7 Fungus Gnat/Shore Fly…………………………………….. 8
Powdery Mildew…………………………………………… 9
Integrated Pest Management…………………………………….. 10
Scouting……………………………………………………..10 Cultural/Mechanical Methods of Pest Control…………….. 10
Beneficials………………………………………………….. 11
Type of Pesticides………………………………………….. 11
Spray Notices………………………………………………. 12
Rotation and Additives…………………………………….. 13
Pesticides for Cassava Rotations……………………………13
Signage……………………………………………………... 14
Measuring and Tank Mixing……………………………... 14
Personal Protective Equipment…………………………….. 16
Emergencies………………………………………………...17
Sprays………………………………………………………17
Spotting…………………………………………………….. 18
Restricted Entry Intervals………………………………….. 18
Cleaning the Tank………………………………………….. 19
Disposal……………………………………………………. 19
Record Keeping……………………………………………. 20
Preventative Systemic Treatments…………………………. 21
Licensing and Inspections…………………………………………23
Pesticide Room Etiquette………………………………………… 23
Phytotoxicity……………………………………………………… 25
Phytotoxicity Log………………………………………….. 27
Pesticide Record Application Page Example…………………… 30
Definitions of Pesticide Spreadsheet Terms……………………...31
Chemicals for Specific Pests ………………………………………32
Common Pests
Aphid Whitefly
Spider Mite Thrips
Shore Fly Fungus Gnat
Damage on Plants
Even a small quantity of pests can cause damage to a plant. Often this damage is the first indication of their presence and is seen before the pests. Look for pest presence/damage vs. looking for actual pests.
Mite Damage
Mite damage on cassava- Mites are often found on the bottom of leaves and at the highest point of the plant. Leaves are marked with yellow spots (“stippling”), lose their normal green color, and develop a mottled appearance. Leaves may become deformed or drop. Plant growth may be stunted with high populations.
Mite damage on soy- Usually the first symptom of leaf damage is on the top surface where yellow or white spotting occurs. Mites are then found on the underside of the leaf. As populations increase, the spotting spreads over the entire leaf and causes leaf-drop, webbing, and yield loss.
Mites on strawberries Mites on peanuts
Mites on sweet potato Mites on Brachypodium
Thrips Damage
Tiny, linear yellow-to-white lines appear on the top of the leaves. Thrips are usually found on the underside of the leaf or on leaf veins. When populations increase, the lines form a mottled appearance between the veins. The leaf may become crinkled.
Thrips also will be in the flowers on a plant, especially if the flowers are yellow. High populations will cause flowers to become distorted. Often the damage done to both flowers and leaves is when they are still in the bud stage and the injury doesn’t show until they start to open. Their ability to hide in buds makes them difficult to treat. Thrips may also cause the buds to abort, cause pollen loss, and transmit viruses.
Thrips on Camelina Damage to Camelina flower
Thrips damage to peanut Thrips damage on sweet potato
Thrips on lettuce Thrips on potatoes
Thrips on soy Thrips damage starting on soy
Whitefly Damage
Whiteflies will cause chlorotic lines on the leaves. New growth may appear wilted or distorted and new leaves may look curled or yellow. Fruit may then ripen unevenly. Whiteflies can transmit viruses.
Whitefly on tomatoes
Aphid Damage
Large populations can cause yellowing, curling, or distortion of leaves. They excrete honeydew, which causes plants to become sticky and potentially grow sooty mold. Aphids will also transmit viruses.
Aphid on corn leaves Aphids on corn tassels
Fungus Gnat/Shore Fly Damage
Both of these pests’ larvae live in the soil and eat the roots, which may cause plants to be stunted. This impacts young plants, seedlings, and cuttings the most. They leave black droppings called frass and may produce holes or yellowing of leaves.
Shore flies do not cause as much damage and are more of a nuisance. Cutting back on watering or throwing out pots without plants will help decrease their populations.
Fungus gnat damage to Arabidopsis Shore fly with frass on Arabidopsis
Powdery Mildew
This fungus is the most common one seen in our greenhouses. It can infect many different plants, but is most common for us on Arabidopsis, Camelina, and soybean. Whitish-gray patches or spots will appear on the topside of leaves. As the fungus spreads, it will cover the leaf and will also move to the underside of the leaf and stem. Infected leaves will turn yellow and fall off. If it is on the buds, they may not open. Spores will germinate with higher humidity, so air circulation is important in prevention. Powdery mildew is host specific. For example, powdery mildew on cucumber will not spread to Camelina, even when it is next to each other.
Powdery mildew on Camelina Powdery mildew on Arabidopsis
Powdery mildew on cucumber
Integrated Pest Management
This type of pest management uses a combination of techniques to control pests. It may involve using alternative control measures in addition to or instead of spraying. The focus is on producing plants with vigor that are healthy and can help combat pests, taking inventory and scouting for pests before spraying, and using biological and environmentally sound methods. Beneficials are used when possible and chemicals are rotated to prevent resistance. Mix only the amount of chemical needed to prevent waste.
You should be very familiar with any chemical you use. Always read the labels of chemicals you are going to be spraying so you will understand how it works, what you are targeting, what its requires to properly work, and to make sure that it is the best option for what needs to be done. “The label is the law.”
Scouting
Crop monitoring involves regular, systematic inspection of an area. It involves looking for crop uniformity, symptoms of plant stress, abnormal growth, discoloration, and presence of pests. This is done for the purpose of making a decision: to spray, to wait, or to use a preventative measure. To manage pests, it requires information that you gather, hear about, or infer. Good information leads to good decision-making.
The focus is on the plants vs. the insects. Some amount of pests will always be present, but their presence should not be high enough to cause damage to the plants and interfere with the research. Because of the high value of the crops grown here, a presence/absence method is used for scouting instead of looking solely at insect counts. A 1-5 scale may also be used for pest density if you want to track populations. Usually, if a pest population is low, they are easier to control. Often the preventative pesticides used will help keep their numbers more manageable and for a longer period of time than without their use.
Weekly scouting and monitoring is done for early detection of pests. High value plants and the potential uniqueness of each plant call for this constant monitoring. Start at one end of each house and work around to each bench to look for severity and density of any pests present. Different ways of scouting may help find different pests. In addition to just looking for the pests or damage visually, you can use yellow sticky cards, microscopes, or white paper that you tap a plant onto to find the pests. This will determine which houses need to be sprayed and when.
Often, spotting pest damage on a plant is one of the first indicators that a pest is present. Different pests are found on different areas of the plant. Mites are often on the underside of the leaves or at the highest point of the plant. Thrips will be on the leaves, but will also be in the flowers. Aphids usually are on the stems and bottom of the leaves. Shore flies and fungus gnats are on the leaves, flying around the plants, or crawling on the soil. Whiteflies may be seen flying when the plant is brushed against or on the bottom of the leaves. Therefore, it is important to inspect all parts of the plant for pest presence when scouting.
Cultural and Mechanical Methods of Pest Control
1. Culturally, good sanitation is one of the best ways to help keep pests under control. Benches should be kept free of leaf debris. Floors should be regularly swept and sanitized. Trash cans lids should be kept in place and trash bags emptied regularly.
2. Plants that are heavily infested should be discarded if possible.
3. If pruning a plant or part of a plant is an option, then this should be done prior to spraying the plant.
4. All plants coming into our greenhouses from other facilities should first be inspected by Danforth Greenhouse staff and placed in the quarantine chamber for observation. Once they are free of pests, they may be moved to their designated greenhouse.
5. Whenever a house is empty, all benches, walls, and floors should be cleaned and sanitized. The house can then be heated for several days to help kill any lingering pests.
6. Plants that are ready to be harvested should be done so in a timely matter so that plants cycle through the greenhouses in as short a time as possible.
Beneficials
Currently, we are using beneficials in the chambers with sweet potatoes and Arabidopsis. We apply Amblyseius cucumeris for thrips, Hypoaspis miles for thrips and fungus gnats, and Phytoseiulus persimilis for spider mites. Sprinkle over plants monthly. We also are applying the beneficial nematode Steinernema feltiae to chambers once every 2-3 weeks. This helps with controlling the fungus gnats by eating their larvae.
In the greenhouses, beneficials are used on cassava that cannot be sprayed and on Camelina for the first 1-2 months.
Types of Pesticides
Any chemical used to kill a living pest is considered a pesticide. This includes fungicides, insecticides, miticides, herbicides, and bactericides including household cleaners. Plant growth regulators are also classified as pesticides and are subject to similar regulations.
What type of pesticide you are spraying and the method by which it works will determine how you spray. If a contact-only spray is used, the chemical must come into contact with the pest for it to be effective. If it is systemic, a soil drench will be taken up by the roots and transported through the plant, or taken in through its leaves when a foliar spray is applied. A translaminar pesticide will move from the tops of leaves to the undersides.
Pesticide Spray Notices
Spray notices should be sent out at least 24 hours before the start-time to allow researchers ample notice. Additional verbal reminders will need to be given if they are still working in the greenhouses as the spray time approaches.
At minimum, the following information needs to be included in all spray notices:
- Date and time of application
- Locations to be sprayed
- REI / time reentry will be allowed
- Warning to not access sprayed locations until after REI has passed
- Information on emergency facilities
- Previous spray information for the past month
Below is an example of a spray notice:
The following pesticide sprays have been scheduled for this week:
Tuesday March 3: A-range and 7C
Wednesday March 4: 9A, 3C, 4C, 6C, and all B-range houses
These greenhouses will close at 2:30 pm and will re-open the following mornings.
Please be aware that pesticide application equipment will be present and in use in the greenhouse corridors at this time. This will limit access to other ranges until the sprays have been completed.Once the signs have been removed from corridor entrances, you may pass through the corridor again.
Following the completion of the spray, doors will be locked on the greenhouses listed above. Entry will remain restricted until the following morning when the re-entry interval of 12 hours has expired. Do not attempt to enter the treated greenhouses until that time.
Information concerning upcoming pesticide sprays and locations, chemicals previously sprayed over the past month, and an emergency medical facility location are located on the pesticide-room door.
Let us know if you have any questions.
Rotation and Additives
Chemicals need to be rotated to avoid insect resistance. Each pesticide is grouped into a class depending on its mode of action (MOA). Do not to use a chemical in the same MOA class repeatedly. Check labels for how frequently a particular chemical may be used. Pesticides that are oil-based and contact-only can be used more often since no resistance is built up. Generally one chemical for mites is used every week. If other pests are present, an additional chemical will be added for that pest. Always verify compatibility if multiple pesticides are mixed together.
An adjuvant such as Capsil may also be added to help improve the performance of the pesticides, especially when spraying on plants with waxy leaves (corn, cassava, etc.). This will help the chemical stick to the leaf more and prevent it from rolling off. Most of the chemicals are compatible with adjuvants and can be used most of the time.
Another additive that may need to be used is one that will regulate pH. Some chemicals are effective only within certain pH ranges. The chemicals that have specific requirements will be listed on the pesticide information spreadsheets. The pH of the water to be used should be checked at the time of the spray to determine if it needs adjustment.
Pesticides for Cassava Rotations
Because of the sensitivity of cassava leaves, and because pesticide damage may mimic virus damage, a limited number of chemicals are available to use for these plants.
Avid Pylon Sirocco
Floramite Shuttle Sultan
Judo Tetrasan Triact
Ovation Kontos
Signage
EPA-designated “Do Not Enter” signs are placed at each entrance to the area (and door locked if possible) of the greenhouse range being sprayed. These signs contain the name of the chemicals being used, the date and start time, and the date and time that re-entry is allowed. Each individual greenhouse will also have a sign placed on it and its door locked once the spray in that house has been completed. Once all the houses in that range have been sprayed, the corridor entrances may be unlocked and those signs removed. Signs on greenhouse compartment doors must be left until the REI has expired.
All signs need to be removed and doors unlocked for the researchers as soon as REI has expired.
Measuring
Wear gloves and eye protection while measuring and mixing. There are disposable long sleeves in a cabinet above the counter. Only mix the amount of chemical needed. Base your decision on how many gallons to mix on what you and others have done in the past. When measuring out chemicals, only pour one chemical in each cylinder so that if you over-pour, you will not end up having to discard chemicals. Pour chemicals below eye level.