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Richard Smith, Michael Cahn, Timothy Hartz, Patricia Love and Barry Farrara

( Lactuca sativa L.), the predominant crop in this region ( Bottoms et al., 2012 ; Breschini and Hartz, 2002 ; Hartz et al., 2000 ; Jackson et al., 1994 ). Less attention has been given to cole crops (broccoli, cabbage, and cauliflower), which are

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A.M. Clements and L.A. Weston

80 POSTER SESSION 12 (Abstr. 635-649) Crop Protection

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C. Stevens, V. A. Khan, J. Y. Lu, A. Y. Tang and A. E. Hiltbold

Vegetable Crops

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H.F. Harrison, J. K. Peterson and M. Snook

These studies were initiated to investigate severe growth inhibition observed when some vegetable crops were infested with corn spurry (Spergula arvensis L.). Interference by a natural population of the weed reduced the shoot weights of English pea (Pisum sativum L.) and collard (Brassica oleracea L.) by 93% and 72%, respectively. In a greenhouse experiment where light competition by corn spurry was prevented, broccoli (Brassica oleracea L.) shoot weights were reduced by corn spurry, but pea weights were not different from the controls. Homogenized corn spurry shoot tissue incorporated into a greenhouse potting medium inhibited the growth of both species, and a concentration effect was observed. Sequential hexane, dichloromethane, methanol, and 50% aqueous methanol extracts of corn spurry root and shoot tissue were tested for inhibitory activity using millet seed germination and broccoli seedling growth bioassays. Dichloromethane, methanol, and aqueous methanol shoot extracts were inhibitory to broccoli; whereas all shoot extracts inhibited millet germination. Shoot extracts were more inhibitory than root extracts. Further fractionation of the inhibitors using a combination of reversed-phase sephadex LH-20 and silicic acid column chromatographic procedures showed that a major portion of the millet germination inhibition was due to sucrose esters (SE). Preliminary characterization of the esters showed that there were four different SE groups. The major groups contained either octanoic or dodecanoic acid along with butanoic and petanoic acids. All groups inhibited seed germination at concentrations as low as 20 ppm. This is the first report of the SE class of defense chemicals in plant species outside of the solanaceae family.

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Greg D. Hoyt

The North Carolina Agricultural Research Service supported this research. Emeritus Professors Thomas R. Konsler and Frank L. Haynes provided leadership in cole crops and potatoes. Anthony D. Cole and George B. Cox provided technical

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William James Lament Jr.

The development of polyethylene as a plastic film in 1938 and its subsequent introduction as a plastic mulch in the early 1950s revolutionized the commercial production of selected vegetable crops. Throughout the succeeding years, research, extension, and industry personnel, together with growers, have documented the advantages of using plastic mulch as one component of a complete intensive vegetable production system. Although a variety of vegetables can be grown successfully using plastic mulches, muskmelons, honeydews, watermelons, squash, cucumbers, tomatoes, peppers, eggplant, okra, sweet corn, and cole crops have shown significant increases in earliness, total yield, and quality. Research continues on field evaluation of new formulations of degradable, wavelength-selective, and colored plastic mulches and on cropping systems to use best these specific improvements. The use of plastic mulches for the production of vegetable crops continues to increase throughout the United States and the world.

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Mark Farnham*, Glen Ruttencutter, Powell Smith and Anthony Keinath

Collard (Brassica oleracea L., Acephala Group) is a uniquely American cole crop adapted to the southeastern United States, and several lines of evidence indicate its closest relative is heading cabbage (B. oleracea, Capitata Group). These two cole crops have been grown in close proximity in the Southeast from colonial times. Today, the number of commercially available collard cultivars is limited, and the most popular ones are susceptible to diseases like fusarium yellows, something that numerous cultivars of cabbage are highly resistant to. We postulated that hybrids between cabbage and collard would look more like collard because heading of cabbage is recessive to the nonheading nature of collard, and that such hybrids might be directly used as collard cultivars that express disease resistance from cabbage. Cytoplasmic male-sterile (cms) cabbage inbreds were crossed with different male-fertile collard inbreds using bees in cages to produce hybrid seed. Resulting cabbage-collard hybrids were compared to conventional collard and cabbage cultivars in three replicated field trials in South Carolina. In all trials, collard-cabbage hybrids exhibited similar size and stature as conventional collard, and throughout most of the growing season the hybrids remained nonheading. In addition, the collard-cabbage hybrids were much more uniform than open-pollinated collard cultivars. Among the cabbage-collard hybrids there was significant variation with some more collard-like than others. Results indicate that select collard-cabbage hybrids could out perform certain conventional collards and serve as potential new collard cultivars

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E.A. Guertal, B.K. Behe and J.M. Kemble

The use of composted waste materials as an alternative source of potting media has received much interest in recent years. Our objective was to incorporate composted, ground poultry litter into a standard greenhouse potting mix, and evaluate the effect of the poultry litter on vegetable transplants grown in the greenhouse and transplanted to the field. Treatments consisted of potting mixes of 100% potting media or 50/50 media/poultry litter. Collards (Brassica oleracea L. var. acephala DC.), broccoli (Brassica oleracea var. italica Plenck.), cabbage (Brassica oleracea L. var. capitata L.) and three tomato (Lycopersicon esculentum Mill.) cultivars were utilized as test crops. A nutrient solution treatment of 8 oz of 8N-11P-7K fertilizer or 8 oz of water was added when transplants were set in the field. Plant weight and nitrogen content were measured weekly during the greenhouse production stage, and final crop yield was recorded at harvest. Any effect from the inclusion of poultry litter in the potting media on cole crop (collards, broccoli, cabbage) transplant dry weight had disappeared by the fourth week of sampling in the greenhouse, and final yield of cole crops was unaffected by either type of potting mix or presence or absence of starter nutrient solution. Dry weight of tomato transplants was not affected by type of potting media. Differences in tomato yield due to type of potting mix were observed, as plots with transplants grown in the 50/50 mix had greater nonmarketable yields (`Bonnie' and `Big Boy'). Yield of `Big Boy' tomato was increased by the addition of starter nutrient solution. It appears that composted, uniformly prepared waste materials are suitable for production of vegetable transplants.

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C. Stevens, V. A. Khan, A. Y. Tang and R. M. Cody

Vegetable Crops

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Astrid Newenhouse and Helen Harrison

The primary goal of this project is to introduce various citizenry groups within Wisconsin to new and potentially profitable alternative crops and production systems, and to acquaint them with crops and ornamental which may be common in Europe and Asia but which have not been extensively grown in our region. Approximately 50 new cultivars of gourmet vegetables, edible flowers, everlasting flowers, fresh cut flowers, and ornamental grasses were field tested 3 years for their adaptability for home and market gardens in Wisconsin. Cultivars were chosen for their unique flavor, color, shape, or texture. Greenhouse grown plants were transplanted onto black plastic mulch, with an annual rye–grass living mulch planted between crop rows. Aside from carbaryl and Bacillus thuringiensis used for cole crop insect control, no chemical pesticides or herbicides were used. Data taken includes notes on production, climate adaptability, disease and insect stress, maturation date, color, taste, and texture. Regional interest has been widespread from various groups including growers for gourmet restaurants, farmers market producers, garden clubs, youth organizations, and urban gardeners..