67 articles tagged "Tomato".

(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.


Late blight can cause brown necrotic lesions on tomato leaves that may be surrounded by growth of the causal fungus under moist conditions (Photo: Tom Creswell).

​Late blight has been reported on potatoes and tomatoes in LaGrange County.Potato and tomato growers in northern Indiana should follow the management recommendations listed below and in the Midwest Vegetable Production Guide for Commercial Growers 2015 (ID-56). Late blight thrives under cool, wet conditions. The disease can easily spread from plant to plant. Under ideal conditions, the disease can spread rapidly, causing symptoms on all above ground plant parts (Figure 1). The lesions may be green to brown and under moist conditions may be ringed with white fungal growth. Affected tomato fruit may have large brown lesions. The fungus-like organism that causes late blight does not usually overwinter in Indiana. Therefore, the disease must be blown or brought into Indiana. All strains of the fungus-like organism that affect tomato will cause disease on potato. However, not all potato strains will affect tomatoes. It is best for tomato and potato growers[Read More…]


Vegetables such as this watermelon may become sunburned if lack of foliage cover exposes the fruit to excess sun and heat. (Photo by Dan Egel)

​Loss of foliage due to poor growing conditions or disease can cause fruit to be exposed to the sun. Hot temperatures and direct sunlight can lead to areas of the fruit that appear bleached or sunburned. Sunburned fruit may not be marketable. To reduce the probability sunburned fruit, every effort should be made to maintain foliage throughout the season. Early wet weather encouraged foliar disease and recent hot, dry weather may have restricted foliar development. Orienting vegetable plantings to minimize damage from the prevailing winds and providing windbreaks such as strips of rye or wheat may help to reduce sunburn. Several products are available that are labeled for use as a preventive for sunburn. These products may be broken into two groups: kaolin (clay) based products and calcium carbonated based products. Kaolin based products include Surround®. Some Surround® products are labeled for use as sunburn protection, while others are not. For example,[Read More…]


Leaf lesions of Botrytis gray mold are often a light gray or brown color and the sporulation of the causal fungus can be seen on the leaf margin.

​Gray mold of tomato is one of the more common diseases of greenhouse-produced tomatoes. Although it is often a minor problem, if left unchecked, gray mold can cause yield loss. Gray mold, or more properly, Botrytis gray mold, often causes a light gray or brown necrotic lesion on leaves (Figure 1). The lesions on leaves are sometimes wedge shaped on the margin of the leaf. Stem lesions are a similar color and may encircle the stem, causing the death of the upper portion of the  stem. Occasionally, gray mold may cause the rot of tomato fruit. Whether on leafs, stems or fruit, the gray fungal sporulation is often easily seen, thus the name. It is a rare symptom, but when fungal spores land on tomato fruit that is wet, the spores may germinate, causing a symptom known as a ghost spot (Figure 2). Botrytis gray mold can cause disease on many different host plants, enabling[Read More…]


Powdery mildew of tomato is easily recognized from the sporulation of the white fungus on the leaves.

​This disease has been reported near West Lafayette and in Wanatah Indiana. Powdery mildew of tomato can be recognized by the white fungal colonies on both leaf surfaces (Figure 1). Occasionally, stems may also be infected. Severely affected tomato plants may have leaves that turn chlorotic and necrotic. Fruit will not be directly affected. The causal organism has been tentatively identified as Pseudoidium neolycopersici, formerly Oidium neolycopersici. This fungus may survive as resting structures on host material. The spores are easily wind dispersed to additional tomato plants. Development of this disease is favored by temperatures below 86°F. As with most powdery mildew diseases, high humidity allows the disease to develop; leaf wetness is not necessary. Since high humidity favors powdery mildew of tomato, greenhouse environments often favor the disease. Reports of powdery mildew on tomato are not common in Indiana. There is no data on yield loss from this disease on tomato. Nevertheless, if this disease is present, management options should be considered. Several systemic[Read More…]


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.


​Yellowstriped armyworms continue to cause problems for tomato growers, especially in high tunnels. The populations are often spotty within a field or high tunnel, but can easily reach damaging levels. Most of the insecticides listed in the Midwest Vegetable Production Guide for control of caterpillars on fruiting vegetables (pages 135-6) will control yellowstriped armyworms. If spraying within a high tunnel, be sure that the label allows use in a greenhouse or high tunnel. Consult Table 16 on page 40 for available options.


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.


(Photo by Dan Egel)

​Bacterial spot of tomato causes lesions on foliage and fruit of tomato. On leaves, the lesions begin as small water soaked areas and turn into brown lesions with a yellow halo. Lesions on stems often lack a yellow halo. Fruit lesions, which are responsible for direct loss of marketable yield, are often scabby in appearance (Figure 1).  Bacterial spot of tomato is favored by warm, wet weather. The causal bacterium survives on crop debris and may be seed borne. Volunteer tomatoes and peppers may also carry the disease. Transplant greenhouses should be cleaned and sanitized after each generation of transplants is produced. Management of bacterial spot of tomato has been covered in more detail here https://ag.purdue.edu/arp/swpap/VeggieDiseasesBlog/Lists/Posts/Post.aspx?ID=31. The Midwest Vegetable Production Guide for Commercial Growers 2015, also has recommendations.  In this article, however, I would like to discuss a new product that has recently been labeled for this disease. Quintec® has been labeled for[Read More…]


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