31 articles tagged "Corn".

(Photo by John Obermeyer.)

​Fall armyworms have completed their annual trek from the Gulf Coast to the Midwest. Fall armyworm larvae will feed on all aboveground parts of the sweet corn plant, during all stages of growth. The damage to the foliage is much more severe than with European corn borer. Larvae will feed from within the whorl of the plant until the tassel starts to emerge, at which time they will move to other plant parts, including the ear. Larvae will enter the ear either through the tip, similar to corn earworm, or they may come through the husk into the side of the ear. The best time to control fall armyworms is during the late whorl stage, before they tassel emerges and they start to move. Pyrethroid insecticides such as Warrior®, Brigade®, Mustang Max® and Hero® will provide excellent control. Most growers will want to save their more expensive Coragen® or Radiant® treatments for earworm control[Read More…]


(Photo by John Obermeyer.)

​I have seen more green stink bugs this year than at any time in my career. I have no logical explanation for their abundance. It was thought that as the invasive brown marmorated stink bug became established, it might outcompete the native stink bugs such as the green stink bug, causing numbers to decrease. However, this year, brown marmorated stink bugs have been relatively uncommon, and green stink bugs seem to be everywhere. Stink bugs feed with their sucking mouthparts and are likely to feed on a wide variety of vegetable crops, including cabbage, sweet corn, cucumber, bean of all types, okra, mustard, peas, peppers, and tomato. Check the Midwest Vegetable Production Guide (ID-56) for your particular crop for insecticide recommendations.


QR code linking to registration for August 13 event.

​Pinney Purdue Vegetable Field Day and Sweet Corn Sampler. Thursday, August 13, 2015. 4:00 p.m. – 8:00 p.m. CDT. Pinney Purdue Ag Center, 11402 S. County Line Rd., Wanatah, IN. Plot tours include soil health management and disease suppressive soils, tomatoes and peppers in high tunnels, and sweet corn varieties. Private Applicator Recertification (PARP) Credit available. To register, visit http://tinyurl.com/no6tosr or contact Lori Jolly-Brown, ljollybr@purdue.edu, or 765-494-1296. Beginning Farmer Tours. Free farm tours and networking events sponsored by Purdue Extension and Local Growers Guild. For more information and to register contact the Purdue Extension Education Store at www.edustore.purdue.edu or 888-EXT-INFO. August 18: Redbud Farm, home of Caprini Creamery, Spiceland, IN. Breakfast, networking, lunch and tour. September 8: Growing Places Indy, Indianapolis, IN. Lunch, networking session, tour. Urban produce farm with raised beds, u-pick, and greenhouses. September 14: Morning Harvest, Palmyra and Hardinsburg, IN. Breakfast, networking session, lunch and tour. Developing[Read More…]


​We are again seeing a lull in pheromone trap catches of corn earworms. However, I caution sweet corn growers to remain vigilant in checking their traps. Populations can increase rapidly, especially if carried north on storm fronts from the Gulf Coast. It is also important to watch the development of the field corn around your sweet corn fields. If the field corn is not yet silking, use a threshold of 1 earworm moth per night to determine if you need to spray when your sweet corn is silking. If the neighboring field corn starts to silk, it will draw a lot of earworm moths away from your sweet corn and the treatment threshold goes up to 10 moths per night. Particularly during this lull in moth flights, this is an opportunity to save money and time by avoiding spraying silking sweet corn.


Sweet corn ready for sampling.

​Pinney Purdue Vegetable Field Day and Sweet Corn Sampler. Thursday, August 13, 2015. 4:00 p.m. – 8:00 p.m. CDT. Pinney Purdue Ag Center, 11402 S. County Line Rd., Wanatah, IN. Plot tours include soil health management and disease suppressive soils, tomatoes and peppers in high tunnels, and sweet corn varieties. To register, contact Lori Jolly-Brown, ljollybr@purdue.edu, or 765-494-1296.


​In years past, the European corn borer was the most important pest of sweet corn, as well as being a pest of peppers and other vegetables. Since the advent of Bt field corn, the overall population of corn borers has been dramatically suppressed, so far that we often forget about it being a pest of sweet corn. However, occasionally the corn borers like to remind us that they are still around and can still be damaging to our crops. These outbreaks usually occur in the northern part of the state, often in areas where the landscape is not dominated quite as much with field corn and soybeans. Corn borers have a broad host range, so diverse habitats provide them with a choice of suitable foods. Management of corn borers in sweet corn is relatively easy. As your sweet corn approaches tasseling, look for corn borer feeding and confirm that borers[Read More…]


After a brief lull in pheromone trap catches, we have resumed catching earworm moths all around the state. Although most of the counts are relatively low (less than 10 per night), remember that for early planted sweet corn that silks before the neighboring field corn silks, the threshold for treatment is 1 moth per night. So, if you have sweet corn that is in the vulnerable stage, green silks present, treatment is justified if you are catching any earworm moths in your trap.


​2015 marks the 40th year of my career as an entomologist and I still am surprised on a regular basis by how insects behave. I put out a corn earworm pheromone trap on May 14 and immediately caught 7 moths that night. Over the next three nights, I caught 36 moths. Typically, the few earworms that we would expect to overwinter here in west central Indiana would emerge about June 20. It has not been an unusually warm spring, to say the least, so it is unlikely that those moths emerged locally. The other possibility is migration from southern areas. Earworm moths often migrate in on storm fronts from the south. However, when moths are blown hundreds of miles on storm fronts, their wings usually get a little tattered. The moths I’ve been catching look pristine, as if they just emerged. So, the bottom line is that I have no[Read More…]


​The cool, wet weather we have been having is perfect for the root and seed maggots in early planted vegetables. I have already received calls about onion maggots. If you are planting early vegetables, check out the article in the March 19 issue of the Hotline for 2015. So, how do we define early planted vegetables? With regard to root and seed maggots, anything that you plant before the soil temperatures reach about 70°F is subject to attack from the flies. Of course, not every field will suffer damage but the potential is there. The use of black plastic mulch will heat up the soil more quickly and may help to reduce root and seed maggot damage.


One way insects communicate with individuals of the same species is with pheromones. Pheromones are volatile chemicals released by an insect that usually can be detected only by individuals of the same species. There are a number of different types of pheromones, but the most common type is the sex pheromone. Usually the females will emit a tiny amount of a chemical that attracts the male to her and increases the likelihood of mating. Because the chemical is volatile, air currents carry it. The male detects the pheromone in the air with receptors on his antennae. He then flies upwind to find the source of the pheromone, a prospective mate. The chemical compositions of pheromones for a number of pest species have been identified and synthetic copies can be produced in the laboratory. Synthetic pheromones can be used in conjunction with traps to catch male insects. Listed below are some, but[Read More…]


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