496 articles


Cucurbit downy mildew has been observed on cucumber in La Porte County and LaGrange Counties, Indiana. Downy mildew of cucurbits has also been reported in southern and central Kentucky. All cucurbit growers in Indiana should be scouting and managing for downy mildew. The organism that causes downy mildew of cucurbits doesn’t overwinter in Indiana. It has to be blown in every year. It is common for downy mildew to start the season in the Gulf States and migrate north with the cucurbit crops. Downy mildew apparently overwinters in northern Michigan/southern Ontario in greenhouses where cucumbers are grown year round. Therefore, downy mildew is often found in Michigan before it is found in Indiana. Many cucumber varieties have some resistance to downy mildew. For susceptible cucumber varieties or other types of cucurbits, specialized systemic fungicides will help to reduce the severity of downy mildew. Unfortunately, many of the most effective systemic fungicides for downy mildew are not[Read More…]



Many years ago, I was told that to successfully use fungicides on vegetables, one must use high spray pressures and hollow cone nozzles. However, I had trouble finding any research on this topic, just rumors. So, I did my own research. Dennis Nowaskie, Superintendent at the Southwest Purdue Agricultural Center (SWPAC) built a single row sprayer that could be used to vary nozzle types between flat fans and hollow cones and spray pressures from 30 to 150 PSI. We used the sprayer to conduct experiments on Alternaria leaf blight of cantaloupe during three years of field tests. The fungicide we used to try to manage this disease was the contact product chlorothalonil (trade names include Agronil®, Bravo®, Echo® and Terranil®). Phillip Harmon, now a professor at the University of Florida, was my co-author on this paper. Try as we might, we could not find any statistical differences in disease severity[Read More…]


Since there is an article about the application of insecticides in this issue, below I list 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[Read More…]


thumbnail image

Daviess Co. Produce Production Meeting Date: Aug. 14, 2018 6:30 pm – 8:30 pm Location: Daviess Co. Produce Auction, LLC, 5567 N 900 E, Montgomery, IN 47558                           Small Farm Education Field Day Date: Aug. 30, 2018 Location: Purdue Daniel Turf Center (1340 Cherry Lane, West Lafayette, IN 47907) and Purdue Student Farm (1491 Cherry Lane, West Lafayette, IN 47906)                             Greenhouse and Indoor Hydroponics Workshop Date: Sept. 5, 2018 Location: 625 Agriculture Mall Drive, West Lafayette, IN 47907                          


It’s not uncommon for us to get calls from growers who are expressing concern about a particular insecticide product that is not working as well as the growers would like. Often, growers will suggest that Product X is no good or that the target insect has now developed resistance to that particular insecticide. Before we jump to conclusions, we need to consider a number of possible causes for poor performance by an insecticide. Here are some questions to consider if you are not getting the control you would like. Are you using the right product? Every fall, a group of vegetable entomologists from throughout the Midwest thoroughly revise the insecticide recommendations in the Midwest Vegetable Production Guide (ID56). The products we list in the guide are the ones that we believe work for a particular pest, based either on research trials or through our experience with growers. That’s why we[Read More…]




blah

Bacterial spot of tomato has been observed across Indiana this summer. Leaf spots are usually 1/16 inch, and dark. Where lesions are numerous upon a leaf, the tissue may be chlorotic (yellow) (Figure 1 & 2).  (In contrast, each lesion of bacterial speck is often accompanied by chlorosis whether lesions are numerous or not.) Lesions of bacterial spot on fruit are dark, raised and up to 1/3 inch in diameter (Figure 3). The disease prefers warm, wet weather. Overhead irrigation will also spread this disease. Although much of Indiana has been dry recently, rainy weather earlier in the year has increased the severity of bacterial spot. Bacterial spot is much more common in field tomatoes than in greenhouse or high tunnel tomatoes. This is because bacterial spot requires leaf wetness for infection to take place and rain to spread the bacteria from leaf to leaf and from plant to plant.[Read More…]


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

© 2018 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.