132 articles tagged "Cucurbits".

Figure 3. Cucumber cultivar Taurus were grown in the front, cultivar Corinto was grown in the back.

Supported by NC SARE (LNC17-390), we are continuing research for improving high tunnel cucumber production. One of the biggest challenges for growing cucumbers in high tunnels in the summer is two-spotted spider mites. Dry and hot environments featured in high tunnels allow two-spotted spider mite populations to increase rapidly. The mites cause leaf yellowing, necrosis, and defoliation that interfere with plant photosynthesis. Yield can be significantly reduced. The pest also causes direct damage on cucumber fruit, resulting in a sandpaper-like texture to the rind (Figure 1). Early detection is the key for controlling two-spotted spider mites. As soon as two-spotted spider mites are detected, control efforts need to be taken. In the early stage, yellowish specks on the upper side of the leaves may be noticed (Figure 2). Turn the leaf over, on the other side of where the yellow specks are, you may find the presence of two-spotted spider[Read More…]


Figure 1: A cantaloupe plant surrounded by striped cucumber beetles that have died after feeding on a plant treated with an imidacloprid product.

I know this may not come as a surprise to most of you, but it is rare that we get to observe the effectiveness of insecticides in such a dramatic way as we encountered when visiting a melon grower in southern IN recently. And in this case, the decision to apply an insecticide at transplant was a good one. In the photo below (Figure 1), one can see an accumulation of dead striped cucumber beetles that have fed upon a cantaloupe seedling that was treated with an imidacloprid soil drench (Trade names include: Admire Pro®, Macho®, Midashe Forte®, Montana®) at transplant 14 days prior to the photo being taken. The beetles are dead because they fed upon the cantaloupe plant and ingested the imidacloprid. Therefore, the plants were protected from defoliation by the beetles, but what about bacterial wilt? Did the act of feeding, however brief, cause bacterial wilt to[Read More…]


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Finally the time has come to plant warm season crops. Zucchini is a popular summer squash grown throughout Indiana and the United States. It always delivers a bounty of fruit. Yes, technically zucchini is a fruit (botanically classified as a modified berry) but as per the USDA it is listed under the ‘Vegetables and Vegetable Products” food group. Zucchini have a multitude of fruit colors and flavors. Therefore, this makes a great vegetable to present to consumers. Characteristics of zucchini – Typically, zucchini is non-vining and bushy but some varieties could have a creeping habit. Some varieties have prickly trichomes on both the stems and leaves. Male and female reproductive structures are produced on the same plant but in different flowers. The large yellow-orange unisexual flowers (a flower that possesses either stamens or carpels but not both) attracts bees, beetles and other insects to pollinate the flowers. The pollen is[Read More…]


Seed Corn Maggot in cucurbit stem. Photo credit John Obermeyer.

In addition to delaying much of our fieldwork, the cool set spring has wreaked havoc on some of the plants we have been able to squeeze in during brief dry periods. We have received reports of damage caused by seedcorn maggots (Figure 1) and wireworms (Figure 2). In preparation of this article I browsed the Vegetable Crops Hotline archives and came across eight articles published by Rick Foster. What do they have in common? Associations with weather and limited strategies for control. Capture LFR® remains the only product labeled and for wireworms only. Rick Foster did some work with this product and had some promising results. Seedcorn maggots typically lay their eggs in organic matter and feed on seed in the soil, however, they can also cause damage in cucurbit transplants. The adults are active in April and May laying eggs in the field. When soil temperatures reach 70°F the[Read More…]


Figure 1. Watermelon seedlings planted in a week

In the past week, we have observed a few cases where newly planted watermelon seedlings were severely damaged or dead (Figure 1). In some fields, we observed rotted roots and lower stems caused by fungal pathogens. However, such diseases were in response to the cold soils and would not normally cause problems in warm soils. Most of the dead plants had intact stems, although growers did report seedcorn maggot and wireworm in the stems of a few dead plants. The same thing happened in May 2016. Coincidentally, rain, cloudy days, and lower than normal temperatures were observed in the same period in both years. Since early May, We have had consecutive days with the lowest temperatures in the 40s°F. There was no risk of frost damage, however, this temperature was low enough to cause chilling injury on young cucurbit plants.  This article ‘Protect Early Planted Warm-Season Vegetables from Low Temperature’[Read More…]



Ever year, I put together fungicide schedules for cucurbits. These may be found at purdue.ag/pumpkinfs and purdue.ag/melonfs. They may be downloaded as PDFs on legal sized pages.  Please use these tables along with the MW Vegetable Production Guide and the fungicide label.  If you have trouble with accessing the tables or have other questions. please let me know.


Figure 3: Fusarium wilt symptoms on watermelon transplant.

A recent observation of gummy stem blight on a watermelon transplant has reminded me to remind growers to inspect seedlings. Whether one is growing transplants or receiving transplants for delivery, seedlings should be inspected for possible disease problems. If one is uncertain of the cause of the symptoms, an official diagnosis can be obtained by sending the sample to the Plant and Pest Diagnostic Clinic. Below I will describe several common transplant diseases of cantaloupe and watermelon as well as management options. I have had similar articles in the Hotline in the past, however, I will use new photos here. Gummy stem blight on transplant seedlings may be recognized by the water-soaked area of the stem near the seed leaves. In this article, I will show a leaf with a lesion of gummy stem blight (Figure 1). A closer look (one may need a 10X hand-lens) at any gummy stem[Read More…]


Figure 2. Beetles are attracted to the color yellow and to the lures within the jugs. Once they find their way inside, they have difficulty finding their way out, eventually falling into the soapy water to die.

Have you ever wondered how striped cucumber beetles manage to find your cucurbits every year? Striped cucumber beetles rely on sight and smell to find food. They are particularly attracted to the color yellow and to scents produced by cucurbit flowers and male striped cucumber beetles. This summer we studied how we could use lures that imitate cucurbit flowers and live beetles for mass trapping with yellow gallon jugs. On one farm, 16 traps captured 2,363 striped cucumber beetles from late May through early September (Figure 1). The vast majority of these beetles were captured in May and August. In May, the beetles were most attracted to the control jugs, but in August, beetles preferred jugs containing live beetles and floral lures. If you place traps early in the season—before or as striped cucumber beetles begin to emerge—we recommend using only yellow jugs without any lures or live beetles. If[Read More…]


On Friday, April 12, the FDA and CDC announced an outbreak of Salmonella Carrau in pre-cut melon products distributed by Indianapolis-based Caito Foods. While an Indiana company has been implicated in the outbreak, the melon product used to create the pre-cut products were not from Indiana and were likely imported from outside of the United States. Indiana growers are currently preparing to plant Indiana’s 2019 cantaloupe and watermelon crops in Southwestern Indiana and other parts of the state. Growers are anticipating a safe, bountiful harvest. Indiana melon growers take food safety very seriously and implement many on-farm practices aimed at reducing the risk of a foodborne pathogen contaminating the crop. “Indiana growers use a variety of practices that reduce the risk of contamination at the farm level. Among these are testing of irrigation water, use of sanitizers in wash water, and employee training programs”, said Scott Monroe, Food Safety Educator[Read More…]


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