391 articles

thumbnail image

In southern Indiana, we are between generations of striped cucumber beetles. That doesn’t mean there are none out there, but numbers are lower than they were and lower than they will be. The second generation should be coming out soon. Northern areas are a little behind. The biggest concern we have with the first generation or overwintering cucumber beetles is their ability to feed on seedlings and to transmit the pathogen that causes bacterial wilt to cantaloupes and cucumbers. For the second generation, we are less concerned about bacterial wilt and more concerned about feeding damage to the fruit, particularly watermelons and cucumbers. If you are seeing beetle feeding on fruit, you should probably apply an insecticide to protect the fruit. If not, you are probably safe not spraying. For later planted pumpkins, the biggest concern is feeding on the plants in the seedling stage. Once the plants get larger,[Read More…]


Figure 3. Webbing produced on heavily infested cucumber leaves by two-spotted spider mite.

It is that time of year again, when the two-spotted spider mites (Tetranychus urticae; TSSM, Figure 1), and other mite species, show up in full force and wreak havoc on fruit and vegetables. These pests are very inconspicuous and often go unnoticed until the resulting damage appears. For TSSM this includes the webbing produced on heavily infested leaves or to the more trained eye, the characteristic yellow speckles or mottled symptoms on the upper surface of the leaves (Figure 2 and 3). The mites can be found on the underside, feeding with their sucking mouthparts. Cucumber, especially in organic production, can be the most susceptible. However, this pest feeds on a wide range of plants including tomatoes, melons, peppers, strawberries, apples, pears and grapevines, as well as flowers and field crops. Regardless of your production technique, an intervention is almost always necessary to control TSSM. In high tunnels in particular,[Read More…]


Figure 1. Corn Earworms

The first generation flight of corn earworm moths continues throughout the state. Heaviest populations as evidenced by pheromone trap catches have been in the northwest. This first generation flight should be ending soon. Then we will likely have a lull in catches for a while (several weeks) until the second generation emerges or we get a migratory flight from the southern US. To check moth catches in your area, please visit https://extension.entm.purdue.edu/cornearworm/index_doc.html. Remember that sweet corn that silks prior to silking in the dent corn near your sweet corn field is much more vulnerable to egg laying from the moths. That’s why we recommend spraying if your sweet corn is silking and you catch any moths in your trap. Once the neighboring dent corn begins silking, that corn will be just as attractive to moths for laying eggs as your sweet corn, so the amount of egg laying is diluted.[Read More…]


Figure 1. Hornworm feeding on tomato leaves in a high tunnel.

One of the most impressive insect pests that we deal with on vegetables are the hornworms (Figure 1 and 2). These two species, tomato and tobacco hornworm, can reach up to 4 inches long and consume massive quantities of foliage and fruit. In recent years, we have seen damage in high tunnels that is more serious than we normally see in field situations. The good news is that despite their size, hornworms are relatively easy to kill. A wide variety of insecticides will control them. See pages 143-44 in the Midwest Vegetable Production Guide for choices. As with most pests, it is better to treat when the hornworms are small because they are easier to kill and because you can avoid most of their damage. Hornworm damage is usually fairly easy to see, either because of the defoliation or the frass (insect poop) that they leave behind. So, scout regularly[Read More…]


Figure 2. Squash bug nymphs (photo credit John Obermeyer)

Squash bug is the most consistent insect pest of squash and pumpkins and is the most difficult to control (Figure 1 and 2). The key to management is early detection and control of the nymphs. The adults are extremely difficult to kill. Foliar insecticides should be applied to control the nymphs when you have more than an average of one egg mass per plant. When you find egg masses, mark them with flags and check every day or two to see when they hatch. When many of the egg masses are hatching, that is the time to begin application. Since eggs are laid and hatch over an extended period of time, several applications may be required. Brigade®, Mustang Max® and Warrior® have provided excellent control.


thumbnail image

Dr. Steve Weller, professor and extension weed scientist in the Dept. of Horticulture and Landscape Architecture is retiring from Purdue. I’m sure many readers share the Purdue Vegetable Extension team’s appreciation for all the work he has done to help vegetable growers with weed management and wish him the best in life’s next adventures. Thanks from all of us, Steve! You will be missed.


thumbnail image

Purdue Extension and Indiana University are collaborating to offer a series of field days featuring high tunnels. The events will be hosted July 18 at the Meigs Horticulture Research Farm in Lafayette; Aug. 10 at the Southwest Purdue Agricultural Center in Vincennes; Aug. 15 at the Pinney Purdue Agricultural Center in Wanatah; and Sept. 27 at the Hamilton County Extension Office and Full Hand Farm in Noblesville. Meigs Horticulture Research Farm High Tunnel Field Day Date: Tuesday, July 18, 10 a.m.-1 p.m. (EDT) Location: Meigs Horticulture Research Farm, 9101 S. 100 E, Lafayette, IN, 47909 Registration: Visit http://tinyurl.com/yc5lqvez or call (765) 494-1296 For more information, contact: Lori Jolly-Brown at (765) 494-1296 or ljollybr@purdue.edu The field day at Meigs Horticulture Farm will focus on high tunnel production of cucurbit crops. It will feature tours of conventional and hydroponic high tunnel cucumber and melon production. The use of insect-exclusion screens to control cucumber[Read More…]


thumbnail image

We are looking for sweet corn growers to participate in our 2017 Vegetable Field Day and Sweet Corn Tasting. Our field day on Aug. 15 at Pinney Purdue Ag Center in Wanatah, will feature tours of tomato production in moveable high tunnels, using both conventional and organic management systems. The event also will include walking tours of sweet corn and pumpkin variety trials, an overview of research findings about the opportunities available through high tunnels, and information about the NRCS program. Attendees will learn about managing pollinators; low-cost high tunnel structures for the home gardener; irrigation solutions; site and structure considerations for new high tunnel users; and finding, preserving, and preparing fresh produce. Private applicator recertification credits (PARP) are anticipated. This event includes a dinner and sweet corn variety tasting. If you would be willing to donate 2 ½ dozen ears of corn, please contact Lyndsay to arrange pick-up/drop-off arrangements. Lyndsay Ploehn, Purdue[Read More…]


Since we are well into fungicide application time, below I have listed 10 rules that will help vegetable growers apply fungicides effectively and safely. Apply fungicides prior to the development of disease. Although many fungicides have systemic (“kick back”) action they will not completely eradicate diseases after they have started. And by the time a single disease lesion is observed in the field, many more lesions too small to observe are already working at your crop. Most systemic fungicides move less than an inch toward the tip of the plant or may just move from the upper to the lower side of the leaf. Use shorter spray intervals during weather conducive to plant disease. Each plant disease has its own “personality” and thus prefers different weather. However, most plant diseases require leaf wetness. Therefore, during periods of rain and heavy dews, more frequent fungicide applications are a good idea. The normal[Read More…]


I have received some reports of Colorado potato beetles damaging both potatoes and tomatoes, including tomatoes in high tunnels. Both the adults and larvae are voracious feeders. As with most pests, it is best to get potato beetles under control before the populations get too high. Also, killing small larvae is easier than killing large ones, so spraying earlier will provide better control. We have had numerous reports of resistance to the pyrethroids in Indiana, so I generally don’t recommend those products. If you try one and it works, then you probably don’t have a resistant population at this point. For most of the state, I recommend one of the following products, Admire Pro®, Agri-Mek®, Assail, Coragen®, Exirel®, Radiant®, and Rimon®. Note that Coragen® and Radiant® cannot be used in high tunnels.


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.