11 articles tagged "Cole Crops".

Bolting of crops overwintered in high tunnels is common in the spring. ‘Bolting’ refers to lengthening and blooming of the flowering stalk. Bolting is often a problem because the quality of the marketable part of the plant declines. Also, plants subject to bolting are programmed to die once they complete flowering and seed production so yield will decline in quantity as well as quality. Sometimes bolting is not a problem because the stalk, buds, and flowers can be sold as a new product while they last; this is often the case with kale,  mustards and related crops. Crops susceptible to bolting include those in the mustard family such as kale, mustards, tatsoi, bok choy (pac choi), mizuna, turnip, radish, etc.; carrots; beets and in some cases Swiss chard; onions; lettuce; and spinach. (Figure 1)   Bolting is triggered by environmental conditions. Some plant types are triggered to develop flowers by[Read More…]

Figure 3. Broccoli ready to harvest.

A fall broccoli trial was conducted in a high tunnel at Southwest Purdue Ag Center in 2016 to test the potential of growing broccoli in high tunnels after tomatoes. This article describes what we found from the trial. Broccoli is a cool-season, frost-tolerant crop. The harvest portion of broccoli is the compact, slightly dome-shaped head that is comprised by numerous immature flower buds. Broccoli that forms a single large head and thick stalks requires 50-70 days to harvest. Vegetative growth occurs over a wide range of temperatures, but high-quality head development requires temperatures in the range of 54-68 ºF. If temperatures are below 41ºF, plant growth is significantly reduced. In Indiana, fall production of broccoli in an open-field can be challenging because of the relatively long growing season. But with increased heat accumulation in high tunnels, it is possible to have a second crop of broccoli following tomatoes. Broccoli can[Read More…]

There are three important caterpillar pests of crucifers in Indiana, the imported cabbageworm, the cabbage looper, and the diamondback moth. Each of these caterpillars will feed on leaves and heads. All are capable of producing serious damage to most crucifers. The adult imported cabbageworm is a common white butterfly with black spots on the forewing that can be observed flying early in the spring. The larva is a sluggish green caterpillar (Figure 1), exceeding 1 inch in length at maturity, with a light yellow stripe running down its back. The larvae can consume enough leaf material to reduce plant growth; can feed on the head, making it unmarketable, and can foul the head with excrement. The cabbage looper does not overwinter in Indiana, but flies into the state each spring from more southerly locations. Larvae are light green with a white stripe along each side of the body. They reach[Read More…]

Many of our vegetable crops are attacked by one or more species of flea beetles (Figure 1). All species do similar types of damage, chewing small holes in the leaves. Damage is most important on young plants or transplants, so growers should watch young plants carefully. Fortunately, flea beetles are easy to control. Sevin®, the pyrethroids, and many other products will provide excellent control.

Crucifers such as cabbage, cauliflower, and broccoli are frequently attacked by a variety of caterpillars, with the most important being the imported cabbageworm, diamondback moth, and cabbage looper. The first caterpillar pest to attack crucifers is the imported cabbageworm. The adult stage is the common white butterfly that you will see flying around your field (Figure 1.). They lay eggs singly on the leaves. The larvae are velvety green and move very slowly (Figure 2.). They will consume large amounts of plant tissue and will also contaminate the heads with their feces. Your first indication of activity is when you see the daytime flying butterflies in your field. Once the butterflies are observed, you should begin watching your plants for signs of damage. Plants can tolerate a considerable amount of feeding damage on the leaves before heads begin to form. See the table on page 101 of the Midwest Vegetable[Read More…]

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…]

(Photo by John Obermeyer.)

​I have seen more green stink bugs this year than at any time in my career. I have no logical explanation for their abundance. It was thought that as the invasive brown marmorated stink bug became established, it might outcompete the native stink bugs such as the green stink bug, causing numbers to decrease. However, this year, brown marmorated stink bugs have been relatively uncommon, and green stink bugs seem to be everywhere. Stink bugs feed with their sucking mouthparts and are likely to feed on a wide variety of vegetable crops, including cabbage, sweet corn, cucumber, bean of all types, okra, mustard, peas, peppers, and tomato. Check the Midwest Vegetable Production Guide (ID-56) for your particular crop for insecticide recommendations.

​Cabbage is the crop most often affected by black rot, however, other crucifers such as broccoli, cauliflower, mustard, kohlrabi or Brussels sprouts may be affected. The first symptom one is likely to notice is a ‘V’ shaped lesion on the margin of the leaf (Figure 1). However, the symptom on Brussels sprouts observed recently are irregular, jagged lesions on leaves (Figure 2). The plants represented in Figures 1 and 2 are different varieties of Brussels sprouts. The differences may be due to differences in susceptibility of the two cultivars or the cultivar in Figure 2 may have been infected at an earlier age than the one in Figure 1. Figure 3 shows two severely affected plants next to a relatively healthy plant. Black rot is most severe in wet, warm weather. The emergence of this disease during a rather cold spring may mean that the disease started in a greenhouse situation. The bacterium that causes[Read More…]

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.

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

© 2019 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.