89 articles tagged "Cucurbits".

Waterwheel transplanters are commonly used for vegetables on plastic-covered beds. (Photo by K. Freeman)

Getting seedlings from the transplant tray into the field is essential for a good crop (Figure 1). Healthy transplants treated well will quickly establish themselves in the field, setting the foundation for a productive crop.​  Here I offer some suggestions for successful transplant establishment. Harden transplants by exposing them to higher light, cooler temperature, and slightly drier conditions than during transplant production (Figures 2 and 3). One goal of hardening is to slow growth of the seedlings and increase their stored energy. A second aim is to acclimate the plants to the field environment. A properly hardened plant will recover from the stresses of transplanting more quickly and begin to grow sooner than a plant that has not been hardened. Seedlings are commonly hardened by putting them outside in a partially shaded and protected location, often on a wagon so they can be moved indoors if low temperatures or high[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.


​For most insect pests, we have some viable options to manage them organically. For years we have been looking for an organic solution for striped cucumber beetle and bacterial wilt on melons and cucumbers. It appears that we now have a viable option. There is a relatively new product, Cidetrak D, manufactured by Trece, which is sold as a gustatory stimulant. The active ingredient is buffalo gourd root powder, which contains a high percentage of cucurbitacin, which causes cucumber beetle to compulsively feed once they have tasted it. Years ago, there was a product available called SLAM, which contained buffalo root gourd and carbaryl, which we tested extensively and found to be quite effective. There were difficulties in applications, so the product never really took off with growers. More recently, my colleague in Kentucky, Dr. Ric Bessin, has tested Cidetrak D in conjunction with Entrust, which contains the active ingredient[Read More…]


​As you all know, many of our vegetable crops are dependent upon pollinators to move pollen from flower to flower. The cucurbits, muskmelons, cucumbers, watermelons, pumpkins, and squash, are completely dependent on insect pollination. Eggplant, okra, lima beans, and peppers will set fruit without pollinators but can have increased yield if pollinators are present. Honey bees are likely the most important pollinators for most of these crops, but other pollinators such as a number of species of native bees and other insects can also provide useful pollination services. In recent years, there has been a lot of attention given to larger than normal die off of honey bee colonies, commonly referred to as colony collapse disorder. There has been a great deal of discussion in the scientific community and in the public about the cause or causes of these colony deaths. Some of the suspected causes include new disease organisms,[Read More…]


In December 2014, I described the ‘Yearbook of Agriculture, 1928”. In that blog, I wrote about processing tomato production in 1925 and 2013 (the ‘Yearbook of Agriculture, 1928’ lists data back to 1925). Today, I would like to discuss cantaloupe and watermelon production. Unfortunately, yields posted in the “Yearbook” are in different units than in use today. However, I can compare acreage in 1925 and 2015. Cantaloupe production in Indiana in 2013 was at 2,100 acres. This compares to 4,820 acres in 1925. Part of the reason for the drop in acres might be that cantaloupe requires a lot of postharvest handling. Buyers want cantaloupe, also known as muskmelon, to be washed and cooled. Food safety concerns require growers to invest in specialized equipment and wade through reams of regulations. In 1925, Indiana was number 6 in the US in cantaloupe acreage, behind California and Arizona (of course) as well[Read More…]


​Three species of seed and root maggots attack vegetables in Indiana. The seedcorn maggot feeds on seeds and seedlings of sweet corn, cucurbits, lima and snap beans, peas, and other crops. Cabbage maggots can cause serious damage to transplants of cabbage, broccoli, cauliflower, and Brussels sprouts and make the fleshy roots of radishes, turnips, and rutabagas unmarketable. Onion maggots are pests of seedling onions, developing bulbs and onions intended for storage. Seedcorn maggot flies emerge in April and May and lay eggs preferentially in areas with decaying organic matter. Fields that are heavily manured or planted to a cover crop are more likely to have seedcorn maggot injury. Maggots burrow into the seed and feed within, often destroying the germ. The seeds fail to germinate and plants do not emerge from the soil, leaving gaps in the stand. When infested seeds germinate, the seedlings are weak and may die. Maggots[Read More…]


Lesions of bacterial fruit blotch on watermelon seedlings are easily confused with angular leaf spot. Check with a diagnostic lab to be sure. (Photo by Dan Egel)

Bacterial fruit blotch is a disease that can affect most cucurbits (see Figure 1). However, the symptoms are most often observed on watermelon. A brief description of this disease and some photos can be found here. This article will introduce new recommendations for this disease in Indiana. Details of these recommendations can be found in the Midwest Vegetable Production Guide for Commercial Growers 2015 (ID-56). Hard copies of the ID-56 are available from Purdue University now for $10. A free on-line version of the ID-56 will be available soon at mwveguide.org. Copper products such as those with copper hydroxide or copper sulfate are often recommended for management of bacterial fruit blotch (BFB).  However copper products applied too often can cause yellowing of leaves and even yield loss (phytotoxicity). Since BFB is mostly caused by rare contaminated seed lots, I have been reluctant to recommend copper products routinely for watermelon growers. However, the last few years I have[Read More…]


Bacterial spot of pumpkin often causes scab-like lesions on pumpkins. In this photo

The title of this article is pretty scary. But it isn’t entirely accurate. Pumpkins won’t really rot from the inside out. In this article, I will describe one way in which pumpkins can seem to rot from the inside out. Recently, I was asked to visit a field of pumpkins where the pumpkins were soft and rotting. Some of the pumpkins had already burst. Some were soft and when prodded, the insides flowed out. I set out to try to understand how this could happen. Although it seemed that the rotted pumpkins were healthy on the outside, upon closer examination, I found lesions of bacterial spot on the outside of affected pumpkins. More information about bacterial spot can be found in Vegetable Crops Hotline No. 586. Most lesions of bacterial spot on pumpkin are scab-like on the surface of the pumpkin (see Figure 1). Occasionally, however, such lesions will become[Read More…]


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Over the past few weeks, I have observed several watermelon fields with relatively large areas of wilted plants.There can be several reasons for such symptoms.In the article below, I will discuss late season Fusarium wilt of watermelon.In a separate article, I will discuss mature watermelon vine decline.In a separate article/blog I discussed root knot nematode.All of these diseases can cause wilt and decline of relatively large areas of cucurbits. Fusarium wilt of watermelon is often observed when the vines are just starting to touch each other within a row. Sometimes, however, Fusarium wilt of watermelon does not show up until later in the season when the plants are near maturity. Fusarium wilt at this point in the season may cause a few vines to wilt (Figure 1). The distribution of affected plants is due to the distribution of the Fusarium fungus in the soil. Often well drained areas of the[Read More…]


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