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9 articles tagged "Root, Tuber, and Bulb Crops".

Seedling Damage by Maggot Pests

May 6, 2020 - From Issue:
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Fig. 2 Maggot in young onion transplant with a penny referenced for size. Photo by John Obermeyer.

Each and every spring we get reports of poor seed emergence, seedling and transplant damage in early planted crops of all sorts. Most recently in untreated sweet corn, home gardens and transplanted onions. Lucky for us, we got to dive right into this pest and see them in action, but not so lucky for the growers who weren’t expecting it! While we don’t have a lot to offer in terms of a rescue for these crops affected this year, we hope to help you plan for this in the future and understand what the threat looks like for the remainder of the season. There are two different species to blame: the Onion Maggot (Delia antiqua) and the Seed Corn Maggot (Delia platura). There is a third species that attacks brassica crops referred to as the Cabbage Root Fly (Delia radicum). All three are nearly identical to the naked eye but[Read More…]

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Anthracnose of Garlic a New Disease to Indiana

July 22, 2019 - From Issue:
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Anthracnose of garlic, a new disease to Indiana, may cause sunken, orange lesions on scapes.

Earlier this summer, sunken lesions were observed on garlic scapes on a small farm in east central Indiana. Lesions started out a cream or tan color (Figure 1), however under rainy or humid conditions, spore production caused lesions to turn orange (Figure 2). Larger lesions resulted in the collapse of the scapes. It is estimated that 45 to 50 percent of scapes were affected. Lesions ranged from ¼ to ½ inch long. Samples of these scapes were sent to the Purdue Plant and Pest Diagnostic Laboratory in West Lafayette where they were diagnosed as anthracnose of garlic, a new disease to Indiana. This new disease is caused by the fungus Colletotrichum fiorinae. This fungus has also been reported on elephant garlic in New York. Reports from New York suggest that onion is unaffected. In the US, C. fioriniae has also been reported as an Apple post-harvest decay, causing bitter rot on[Read More…]

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Cercospora Leaf Spot of Beet

August 31, 2017 - From Issue:
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Figure 1: Cercospora leaf spot of garden beet causes bray/brown lesions with reddish margins.

This disease was observed in southern Indiana recently. Cercospora leaf spot affects table beets and swiss chard. Symptoms include circular leaf spots that may have a reddish margin. The center of the lesions may start off a light brown and turn to gray after the fungus (Cercospora beticola) begins to sporulate. Under conditions conducive to disease, the lesions can coalesce and result in loss of foliage. Yield and quality of the crop can be reduced. Cercospora leaf spot is favored by rainy weather or overhead irrigation and temperatures from 77 to 95°F.  The spores are readily dispersed in rainy, windy weather. Resistant cultivars are available. Fall tillage and crop rotations of 2 to 3 years should help to lessen disease severity. Several fungicides are listed in the 2017 Midwest Vegetable Production Guide for Commercial Growers including copper compounds, some of which may be allowed in organic certifications. Synthetic fungicides include:[Read More…]

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Daikon Radish

January 24, 2017 - Veggie Extras Article
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Daikon radish is a member of Brassica family. It forms a large white tap root like a giant carrot. The tap root (12 to 20 inches long and 2 to 4 inches in diameter) penetrates into the soil leaving 2 to 6 inches protruding above ground.  Radishes are cool-season crops. They are best grown with air temperatures in the range of 50 to 65°F. They grow fast, forming a dense canopy in the fall.  They are winter killed when temperatures drop to low 20s °F for a few consecutive nights. Daikon radish is a common and popular vegetable consumed in the southeast and Eastern Asia (Figure 1). The large and white roots have a favorable mild flavor, very low calorie content and rich in vitamin C. Fresh or picked diced daikon roots are important ingredients in a variety of dishes and soups in Asia cooking. Leaves are also consumed as[Read More…]

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Alternaria Leaf Blight of Carrot

November 15, 2016 - From Issue:
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Last fall, my lab received a carrot sample with disease-like lesions (Figures 1 and 2). There are at least 3 carrot diseases that may appear similar. These diseases are: Alternaria leaf blight (late blight), Cercospora leaf spot (early blight) and bacterial leaf blight. Often an examination in the laboratory is necessary. My examination revealed the characteristic spores (conidia) of Alternaria dauci, causal agent of Alternaria leaf blight. Figure 1  shows a stand of carrots with several leaves that appear chlorotic (yellow) and necrotic. A closer examination reveals small lesions on the leaves (Figure 2). Loss of leaves may lead to fewer or smaller carrots. Sometimes severe infections can lead to the premature separating of the leaves and root. Alternaria leaf blight can be rapidly spread between plants by the conidia that are produced on the plant surface. I could easily find these spores on the surface of the carrot leaves brought to my lab. The conidia may[Read More…]

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Seed and Root Maggots

March 14, 2016 - From Issue:
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Three species of seed and root maggots attack vegetables in Indiana. The seedcorn maggot (Figure 1) feeds on seeds and seedlings of sweetcorn, 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.[Read More…]

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​Potato Leafhopper

July 9, 2015 - From Issue:
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I’ve seen some substantial populations of potato leafhoppers recently. Leafhoppers can be a significant pest of a number of vegetable crops, with potato and snap beans being particularly affected. Look for adults flitting off the plants when they are disturbed and for nymphs feeding on the underside of the leaves. It is important not to wait until you see symptoms (hopper burn) before you take action. Scouting is the best way to avoid leafhopper injury.

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Root and Seed Maggots

April 27, 2015 - From Issue:
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​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.

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Seed and Root Maggots

March 17, 2015 - From Issue:
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​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…]

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