Abstract
Potatoes (Solanum tuberosum L.) normally are propagated vegetatively by tubers and produce a uniform, productive, high-quality crop. However, tubers accumulate systemic diseases, which greatly reduce their productivity and quality. Many countries control these diseases with complex and expensive seed certification programs. Such control methods are not available in many other countries where potatoes are an important part of the diet.
Abstract
The accomplishments of workers in the fields of horticulture and food technology during the last few decades are indisputable and impressive. The horticulturist has performed wonders in crop improvement and yields. The food technologist has brought an ever-increasing variety of foods to the consumer at reasonable prices. Together they have made our diet independent of season and location.
Abstract
Horticulturists' attention to the nutritional quality of fruits and vegetables has not been commensurate with the self-evident consumer interest in the contributions of safe and nutritious fruits and vegetables to the human diet. Consumers, regardless of their nutrition education, look upon fruits and vegetables as important foods for the maintenance of good health.
Feeding intensity of adult Japanese beetle (Popillia japonica Newm.) was compared among 27 taxa of Prunus host plants during 24-hour no-choice feeding trials conducted on individual leaves. Fecal dry mass per beetle, a measure of feeding intensity, varied from 0 mg·d-1 for Prunus padus L. to 20.4 mg·d-1 for P. sargentii Rehd. and P. tomentosa Thunb. Prunus padus, P. laurocerasus L., P. mahaleb L., P. serotina Ehrh., P. virginiana L., P. americana Marsh., P. ×yedoensis Matsum., and P. besseyi Bailey were resistant based on feeding intensities of <4.3 mg·d-1 (levels not significantly different from zero). Feeding intensity decreased exponentially as endogenous foliar cyanide potential increased. Evaluation of the cyanogenic glucoside prunasin in artificial diets showed a similar relationship with feeding being reduced by 50% (ED50) at 4.9 mmol·kg-1 in the diet. Prunus mahaleb was highly resistant to Japanese beetles despite having low cyanide potential. Two coumarin compounds known to exist in P. mahaleb, herniarin and coumarin, were tested in artificial diets and were effective feeding deterrents with ED50 values of 5.9 and 2.5 mmol·kg-1 in the diet, respectively. This research demonstrated a wide range of host plant resistance to feeding by adult Japanese beetles and further indicates that prunasin, herniarin, and coumarin are important factors in host plant resistance to this pest.
Every 5 years, the U.S. Department of Agriculture (USDA) releases dietary guidelines to help Americans choose nutritious foods to prevent chronic, diet-related diseases and promote better health. Nutrient-rich vegetables are a critical part of this
Resin glycosides extracted from sweetpotato skins were bioassayed for their effects on survival, development, and fecundity of diamondback moths, Plutella xylostella (L.). Glycosides were incorporated into an artificial diet (Bio-Serv, Inc.) and fed to diamondback larvae. Neonatals were individually fed artificial diet with 0.00, 0.25, 0.50, 1.00, 1.50, and 2.00 mg·mL-1. There were highly significant negative correlations between glycoside levels and survival as well as weight of survivors after 6 days. A significant positive relationship existed between dosages and development time. Lifetime fecundity was negatively affected at sublethal doses. The glycosides are viewed as contributors to resistance to the wireworm, Diabrotica and Systena insect complex.
This article examines the nutritional quality and human health benefits of melons, specifically, muskmelon or cantaloupe (Cucumis melo L. var. reticulatus Naud.) and honeydew melon (Cucumis melo L. var. inodorus Naud.) types. Melons are naturally low in fat and sodium, have no cholesterol, and provide many essential nutrients such as potassium, in addition to being a rich source of beta-carotene and vitamin C. Although melons are an excellent source of some nutrients, they are low in others, like vitamin E, folic acid, iron, and calcium. Since the U.S. diet is already high in fat and protein content, melons should be included in everyone's diet, along with five to eight servings per day of a variety of other fruit and vegetables, to ensure adequate nutrition, promote individual health, and reduce one's risk of cancer and certain other chronic diseases.
Abstract
Carotenes from vegetables and fruits are vitamin A precursors that contribute about half of the vitamin A in the U.S. diet (3) and two-thirds of the world diet (5). Carrots typically contain 65 to 90 ppm carotenes (1) and are estimated to be the major source of carotene for U.S. consumers (3). Few pro-vitamin A sources surpass the carotene content of typical carrots, although red palm oil can contain >825 ppm carotenes (2). Genetic selection for higher carotene levels in carrots could increase the dietary consumption of carotene and consequently vitamin A. A high carotene mass carrot population was developed for use in breeding, genetic, and biochemical studies of carrot (Fig. 1).
Abstract
Man has depended upon fresh commodities for proper nutrition. However, history reveals that early voyages stopped abruptly upon the exhaustion of the fresh food supply, armies starved as their rations spoiled and became depleted, and settlers died during the winter months due to an insufficient supply of nutritious foods. In order to provide an adequate diet the year around, deterioration of the perishable foodstuffs had to be eliminated. Thus, the beginning and justification of modern food processing.
Abstract
It is tempting to overemphasize the role of horticultural crops in man's diet. Horticultural crops rank a poor second after the cereal grains as an energy source (Table 1) (5). It is clear that roots and tubers, fruits, nuts and vegetables contribute less than a third of the dietary calories supplied by the cereal grains. There are several factors which deserve consideration in interpreting these data.