21 articles tagged "Pests and Pest Management - General".

Figure 2. Media and roots properly secured for shipment

Samples in plug trays, as well as unrooted and rooted cuttings, and plants in pots require extra care when they are packaged for submittal to a diagnostic lab. Before you mail the next sample, please take a few minutes to review these suggestions for packaging and submitting samples. This will help preserve the integrity of the sample during shipment and increasing the likelihood of a more accurate diagnosis. Plugs – keep them in the tray If possible, do not remove the plugs from the plug tray. Submitting either an entire tray or cutting off a section of the tray helps keep the soil off the foliage where most symptoms are observed (Figure 1). Secondary decay often occurs when soil is allowed to come in contact with the foliage, interfering with accurate diagnosis. When possible, submit at least 5-10 cells with plugs. This provides the diagnostician with ample material for microscopic[Read More…]



Small vegetable growers may find pesticide applications with a tractor driven sprayers impractical. Such growers may turn to hand sprayers. In a separate article, I argued that garden sprayers are not appropriate for most commercial pesticide applications.  In this article, I will discuss the use and calibration of a backpack sprayer, an excellent alternative to a garden sprayer for small growers. The remainder of this article will discuss one method of calibrating a backpack sprayer. Most pesticides are labeled for use on an area basis, typically an acre. Therefore, the first task in calibration is to measure the area to be treated. Let’s say that tomatoes are grown in a greenhouse where the production covers 30 X 100 feet = 3,000 square feet. For our staked tomato example, we will use a volume-based method of pesticide measurement. For this method: Determine the volume of water required to cover the fully-grown crop[Read More…]


As part of a multi-state effort being headed by Dr. Ian Kaplan at Purdue University in the Department of Entomology, we are investigating how to best manage insect pests on cucurbits, in our case watermelons, while having the least possible impact on pollinators. The research is being funded through the USDA/NIFA Specialty Crop Research Initiative. The premise of this research is based on the fact that neonicotinoid insecticides, which are a versatile and powerful pest management tool, have been implicated as a factor contributing to pollinator declines. Thus, farmers growing pollinator-dependent crops—including watermelons—are confronted with a potential trade-off between two competing aspects of crop production: effective pest suppression and successful pollination. Our objective here is to identify insecticidal management strategies that simultaneously optimize pest suppression while minimizing non-target exposure to cucurbit pollinators. To achieve this objective, we are currently looking for producers to collaborate with members of the Entomology Department[Read More…]


Vegetable growers are familiar with pesticide labels that specify how much of a product may be applied. As commercial growers, we usually think about such instructions as telling us how much pesticide is the right amount to apply to a crop to be effective. While such an interpretation is correct, there is more to the labeled rates of a pesticide. While many researchers (including myself) are involved with experiments to try to manage pests with pesticides, others are involved in trying to determine the pesticide concentrations that may safely exist in the produce we all eat. The latter is known as the pesticide tolerance. Both efficacies of the pesticide and human safety are involved in determining the label rates and timing of each pesticide. Indeed, some pesticides are not labeled for certain crops for reasons of safety. There is mostly good news in the just released 2015 Pesticide Data Program. Each year, the USDA’s[Read More…]


Figure 1. Colorado potato beetle larvae found on high tunnel tomatoes.

Last week we had a report of an infestation of Colorado potato beetle larvae on tomatoes in a high tunnel (Figure 1). Potato beetles are a pest of most of the solanaceous crops (potato, tomato, eggplant, pepper), but they rarely become a serious problem on tomato in Indiana. In addition, we have not seen them in high tunnels before, so this is a new problem for us. There are a number of insecticides that are labeled for use on Colorado potato beetles, but that list gets much shorter when the problem is in a high tunnel. Remember that in Indiana, a high tunnel is considered a greenhouse, so insecticides that are prohibited in greenhouse cannot be used in high tunnels. The effective products that could be used in this situation are Admire Pro®, Intrepid®, Entrust® and Exirel®.


Figure 1. Aphids on tomatoes in a high tunnel (Photo credit Wenjing Guan)

We have begun to receive the first reports of aphid outbreaks in high tunnels on tomato, pepper, and cucumber (Figure 1). Aphids are a very common problem in high tunnels because the covering excludes rainfall, which is a major mortality factor for small insects like aphids. Some growers are interested in using biological control in their high tunnels because the ability to contain natural enemies within the tunnels increases the likelihood of achieving control. Based on our experience, we believe that lacewing larvae hold the greatest promise for successful biological control of aphids in high tunnels. Because they don’t fly, they are less likely to leave the high tunnel than many other biological control agents. There are a number of biological control suppliers who can provide lacewing larvae for growers. For growers interested in chemical control, some of the insecticides that could be expected to provide good control and are[Read More…]


I continue to catch low numbers of corn earworm moths in my pheromone trap. Although the numbers are low, growers with very early sweet corn that is in the reproductive stage should be alert for potential damage. The threshold for spraying sweet corn that matures prior to field corn silking is only one moth per night. My cooperators at the Purdue Ag Centers around the state are putting up their earworm pheromone traps today (June 6), so by the time you receive this newsletter, we should have data available on moth catches around the state, which you can access at https://extension.entm.purdue.edu/cornearworm/index.php. As I suggested in the last edition of the Vegetable Crops Hotline, I have found corn earworm larvae feeding in the whorl of my knee high sweet corn, planted April 18.


Purdue Extension publication PPP-110 ‘Options for Dealing with a Pesticide Drift Incident’ describes causes and effects of pesticide drift. It discusses actions a vegetable farmer (or anyone) might take if they suspect that herbicide drift may have injured their crop. The first step suggested is to find out what caused the symptoms. The publication explains that Purdue Extension educators can help in determining the cause of symptoms, but are not pesticide drift investigators. The Office of the Indiana State Chemist (OISC) investigates pesticide drift complaints. What happens once a complaint is filed is outlined step-by-step. There is also a list of the kind of information it is helpful to collect as soon as a problem is noticed. To order a free, single copy of the publication, call the Education Store at 765-494-6795. It may also be downloaded as a pdf at https://ag.purdue.edu/extension/ppp/Documents/PPP-110.pdf.

Leave a comment

The symptoms of lettuce drop include a white mold that covers much of the plant and the dark, irregular sclerotia that are observed here. (photo: Wenjing Guan).

Cool season crops such as lettuce are becoming a more popular crop among Indiana greenhouse/high tunnel growers. One of the most important diseases of lettuce is known as lettuce drop. The symptoms of lettuce drop are often noticed after the thinning stage, early in the crop development. The early symptoms may include browning of leaves. Later on in the crop development, the outer most leaves of the lettuce plant may wilt. As the disease become more severe, inner leaves may become infected. Eventually, the entire plant may collapse. The plant often has white mold on the leaves and dark irregular fruiting bodies may be observed (Figure 1). The dark fruiting bodies are known as sclerotia. Two different organisms may be responsible for lettuce drop. Sclerotina sclerotiorum and S. minor. Lettuce drop caused by S. sclerotiorum requires a chilling period (52 to 59° F) for the sclerotia to turn into mushrooms smaller than a[Read More…]


Vegetable Crops Hotline - Department of Horticulture and Landscape Architecture 625 Agriculture Mall Dr. West Lafayette, IN 47907

© 2017 Purdue University | An equal access/equal opportunity university | Copyright Complaints | Maintained by Vegetable Crops Hotline

If you have trouble accessing this page because of a disability, please contact Vegetable Crops Hotline at guan40@purdue.edu.