Onions planting

Chan-Jung L, Jong-Tae L, Jin-Seong M, In-Jong H, Hee-Dae K, Woo-11 K, Mi-Geon C (2007) Effects of solar heating for control of pink root and other soil-borne diseases of onions. Plant Pathol J 23 295-299... 

Many of the culinary seasonings we use, like black pepper, chili pepper, dill, ginger, paprika, and red pepper, owe their hot stuff to capsaicin, a compound shown to repel insects. Researchers have found that as little as M ounce of capsaicin sprinkled around an onion plant reduced the number of onion maggot eggs laid around the plant by 75 percent, compared to untreated plants. 

The underground bulb of the onion plant is the sixth leading vegetable crop of the world. It is distinguished by its pungency when raw and the appetizing flavor it imparts when cooked with various other foods. The odor is due to an oil, which readily forms a vapor and escapes into the air when onions are peeled or cut It affects nerves in the nose connected with the eyes, and makes tears flow. 

C7H6O4. Crystallizes with IH2O m.p. 199" C. It occurs in the free state in the onion and other plants is a constituent of one group of tannins, and is a product of the alkaline decomposition of resins. 

Exceptions to the simple definition of an essential oil are, for example, gadic oil, onion oil, mustard oil, or sweet birch oils, each of which requires enzymatic release of the volatile components before steam distillation. In addition, the physical process of expression, appHed mostly to citms fmits such as orange, lemon, and lime, yields oils that contain from 2—15% nonvolatile material. Some flowers or resinoids obtained by solvent extraction often contain only a small portion of volatile oil, but nevertheless are called essential oils. Several oils are dry-distiUed and also contain a limited amount of volatiles nonetheless they also are labeled essential oils, eg, labdanum oil and balsam oil Pern. The yield of essential oils from plants varies widely. Eor example, nutmegs yield 10—12 wt % of oil, whereas onions yield less than 0.1% after enzymatic development. 

Zwieback, m. biscuit, specif, rusk, zwieback. Zwiebel, /. wi, bulb, specif, onion, zwiebelartig, a. bulbous alliaceous, zwiebelfdrmig, a. bulbshaped, bulbar. Zwiebel-gewachs, n, bulbous plant, -linse, /. biconvex lens, -mannor, m. cipolin, -bl, n. onion oil. 

Other compounds include the plant-derived sterols (phytosterols) and other sulphur-containing compounds found in onions and their relatives. Only a few of the more important examples will be discussed in the following sections. 

It has been suggested that in cell walls other than those of onions, different types of pectic matrix are present in different parts of the wall (17). This work clearly demonstrates the existence of at least two spatially separate pectic matrices with polymers having at least two conformational forms and three distinct mobilities. It suggests pectins are more than just pore fillers within the plant cell wall. 

J. Manthey, B. Tisserat, and D. E. Crowley, Root responses of sterile grown onions to plant iron deficiency. J. Plant Nutr. 79 145 (1996). 

Leaves and flower plants Cabbage, Chinese cabbage, Japanese radish (leaves), broccoli, komatuna, soybeans (immature), field pea, kidney beans (immature), onion, garlic, scaUion, hops... 

Apple, cereals, citrus, corn, cotton, grapevine, peach, peanut, pear, potato, sorghum, soybean, sugar beet, tea, tobacco, cabbage, onion, turf grass, woody plant, water, soil and air... 

After use, herbicides decompose slowly, and so affect cultivated plants for many years. In 1990, investigations in many regions of the USSR detected herbicides phytotoxic effects, especially among the si/m-triazine class, on different cultivars in many varied situations [13]. These sym-triazine herbicides, such as protrazin, simazin, atrazine, metazin, and prometrin, were used in different oblasts of the Ukraine, Kirgizia, Kazakhstan, Russia and Moldavia in previous years, especially on corn. Residual herbicide aftereffects led to the suppression and death of crops such as winter wheat, oats, barley, rye, potatoes, beets and sugar beets, linen, onions, watermelons and other melons, and sunflowers. 

Concentrations of lead (wet weight basis) in samples of eleven raw edible plants have been reported for growing areas in the United States that are uncontaminated by human activities other than normal agricultural practices (Wolnik et al. 1983a, 1983b). Results are as follows plant (mean pg/g wet weight) lettuce (0.013) peanut (0.010) potato (0.009) soybean (0.042) sweet com (0.0033) wheat (0.037) field com (0.022) onion (0.005) rice (0.007) spinach (0.045) tomato (0.002). 

For the characterization of compounds extracted from plants, wool and dye baths, acquisition in the NI mode is used. The main signals in the mass spectra of each colourant are attributed to deprotonated molecular ions [M H]. More detailed studies can be performed by ESI MS" with a quadrupole ion trap mass analyzer, and such a set-up was used e.g. for the investigation of photo-oxidation processes of components of weld and onion skins.[29]... 

Acrylonitrile is a colorless, liquid, man-made chemical with a sharp, onion-or garlic-like odor. Acrylonitrile is used mostly to make plastics, acrylic fibers, and synthetic rubber. Because acrylonitrile evaporates quickly, it is most likely to be found in the air around chemical plants where it is made. Acrylonitrile breaks down quickly in the air. It has been found in small amounts in the water and soil near manufacturing plants and hazardous waste sites. In water, acrylonitrile usually breaks down in about 1 to 2 weeks, although this can vary depending on conditions. For example, high concentrations of acrylonitrile (such as might occur after a spill) tend to be broken down more slowly. In one case, measurable amounts of acrylonitrile were found in nearby wells 1 year after a spill. Further information on the properties and uses of acrylonitrile and how it behaves in the environment may be found in Chapters 3, 4, and 5. 

Plants of the genus Allium, e.g. garlic Allium sativum), leek Allium amp-eloprasum), and onion Allium cepa), produce a bewildering variety of sulfur compounds. Selenium analogs for some of these have also been found (Section 11.1.3.6). Much work has focused on garlic (contains more than 100 such materials) and onion.56,66,67 Key compounds for formation of the Allium sulfur-containing secondary metabolites are sulfoxides of cysteine derivatives,... 

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