This disease is more likely to develop during periods of heavy rains in relatively poorly drained soils. June started out dry for many areas of Indiana, however recent rains increase the likelihood of Phytophthora diseases. Phytophthora fruit rot of watermelon causes large, soft areas to develop on mature watermelon fruit. These lesions can be several inches…Read more about Phytophthora Fruit Rot of Watermelon[Read More]
Watermelon
White mold of watermelon – Usually when I write about a vegetable disease it is because the disease may cause important economic loss. Once in a while, however, a disease I find is more a curiosity than a real problem. So, go ahead and read this article about white mold of watermelon. But please don’t worry about…Read more about White Mold of Watermelon[Read More]
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Last week, we received calls from several watermelon growers who reported that their newly planted watermelon seedlings had died (Figure 1). After closely inspecting the affected plants, we did not find any pathogens. This reminded us of what happened to our cucumbers back in early April in our high tunnel. We will review the cucumber…Read more about Establishment Failure of Watermelon and Cucumber Transplants Because of Low Soil Temperatures[Read More]
The cool, wet weather we are experiencing is perfect for the root and seed maggots, namely cabbage maggot, onion maggot, and seedcorn maggot. One way of avoiding damage from these pests is to wait until the soils warm up to 70o F before planting, but that is not always possible. The use of row covers…Read more about Root and Seed Maggots[Read More]
Gummy Stem Blight – this fungal disease causes dark brown leaf spots, however, the diagnostic feature of this disease is the water soaked lesion that is often formed under one of the seed leaves (cotyledons). Such lesions often start at the point where the seed leaf joins the stem (hypocotyl) and do not extend to…Read more about Cucurbit Transplant Diseases[Read More]
Every year since 1980, we have conducted watermelon and cantaloupe variety trials at Southwest Purdue Agricultural Center. In 2016, our variety trials include 44 standard seedless watermelons, 12 cantaloupes, 4 mini-sized seedless watermelons, and 5 seeded watermelon varieties. Seeds have already been planted in the greenhouses and our target date for transplanting in the field…Read more about 2016 Watermelon and Cantaloupe Variety Trials at Southwest Purdue Agricultural Center[Read More]
I have never had as many questions about how to use MELCAST as I did in 2015. The interest in this program is growing both here in Indiana and nationally. Read on to find out how to apply fungicides according to the weather and perhaps save money in the process. MELCAST (MELon disease foreCASTer) is…Read more about MELCAST 2016[Read More]
Late in the 2015 season, I observed some unusual symptoms of anthracnose on watermelon fruit. I wanted to discuss these symptoms, but first a little background of cucurbits. An extension bulletin on this subject may be found at https://www.extension.purdue.edu/extmedia/bp/bp-180-w.pdf. Anthracnose of cucurbits, caused by Colletotrichum orbiculare, is responsible for lesions on leaves, stems and fruit. Crops affected…Read more about Symptoms of Anthracnose of Watermelon on Fruit[Read More]
Downy mildew has been confirmed on jack-o-lantern pumpkins in Daviess and Jasper Counties and on acorn squash in LaPorte County. These are the first confirmed reports of this disease on Cucurbita pepo in Indiana in the 2015 season. There are unconfirmed (but reliable) reports of downy mildew on pumpkins in Parke, Washington, and White Counties. This disease has…Read more about Downy Mildew of Cucurbit Update[Read More]
On July 22, I announced that downy mildew had been observed on watermelon in Knox County in southwestern Indiana. This article in the Vegetable Crop Hotline issue 603, https://ag.purdue.edu/hla/Extension/VegCropsHotline/Pages/Latest-Articles.aspx?article=118, describes the outbreak and management options. Downy mildew has now been reported on cucumber and cantaloupe in Knox and cucumber in La Porte County Indiana and pumpkin in Jasper County….Read more about Downy Mildew Update[Read More]