Leeks

Leeks are alliirms but do not btrib artd are less pungerrt than orriorrs. The crop can grow well atoimd the UK arrd is available from My to May. Leeks are sold with the leaves trimmed into an irrverted V, straight or stripped back. Leeks sold as prepack are usually smaller than those sold loose. Leeks can be harvested from the field over winter as they are tolerant of frosts. 

The varieties change over the season with mote rapid maturing varieties providing the early crops. Varieties that can hold well in the field ate suited to overwintering. 

Leeks can be grown on a wide range of soil types, but the most suitable ate sandy loam to sandy clay loam, silts and some peat based soils. It is best to avoid very light soils as these can spoil the crop if soil gets blown down into the leaves. Heavy soils may restrict access to the field in winter. 

The land should be ploughed, bed formed, destoned or declodded before planting. Capping soils should be avoided with drilled crops. 

Modules or blocks are machine planted and gapped up by hand. Blocks are bigger, giving an earher crop but are more expensive. Seed is drilled using a precision drill in 4 rows across a bed 45 cm apart. Spacings between plants are usually 7.5-15 cm for modules and 4-7.5 cm for seed. Leeks are smaller at matiuity at the higher density, being better suited to pre-pack crops. 

---

Praseodymium, Pr C. A. von Welsbach 1885 Greek rrpaoio -l-SiSup.o praseos -I- didymos, leek green -1- twin... 

Laub-holz, n. leaved trees, deciduous trees wood of deciduoiis trees, hardwood, -holz-kohle, /. hardwood charcoal, -holzzellstofff m. Paper) hardwood cellulose or pulp, laubverlierend, laubwechselnd, a. deciduous. Lauch, m. leek. 

Leek (Allium ampeloprasum porrum L.) Basil (Ocimum basilicum)... 

Comparison of the MHR with non-modified pectic hairy regions of apple cell wall, isolated in a mild and defined way, revealed great resemblance indicating that the modifications of the MHR during enzymic liquefaction were only minor. Analogous MHR fractions could be isolated from potato fibre, pear, carrot, leek, and onion tissue. 

D. Vetterlein and H. Marschner, U.se of a niicrotensiometer technique to study hydraulic lift in sandy soil planted with pearl millet (Penni.setiiin americanum L. Leeke). Plant Soil 149 215 (1995). 

R. C. Snellgrove, W. E. Splitstoesser, D. B. Strubket, and P. B. Tinker. The distribution of carbon and the demand of the fungal symbiont in leek plants with vesicular-arbuscular mycorrhizas. New Phytologist 69 15 (1982). 

Figure 6 Detail of the interface space (IN) between the fungal wall (U) of Glomuf versiforvte and the host membrane of leek (PL), as seen by electron microscopy. Xylo-glucan molecules are revealed by using a specific antibody and colloidal gold granules. P, host cell F, fungus, X 30,000.

Plants (cucumber, tomato, eggplant, French bean, deep root leek, strawberry, grape, apple, pear, cherry, peach, Unshu orange, Chinese citron, watermelon, persimmon, lemon, kabosu lime, sudachi, small beans and kidney beans), soil and water Gas-chromatographic determination... 

Vegetables Cucumber, tomato, eggplant, French beans, deep-root leek 0.1 82-102 <4.3 0.002... 

Rice (rice grain, rice straw), leek, lettuce, sugar beet (root), sugar beet (leaf), kidney beans, string beans and soil Gas-chromatographic determination... 

Untreated control samples were fortified with mepronil. The fortification levels were 0.05-0.25 mg kg for plant materials and 0.005-0.05 mg kg for soil. The following recoveries were obtained 93-95% from rice grain 93-99% from rice straw 86-96% from grape 99-103% from leek 90-110% from lettuce 96-106% from sugar beet (root) 92-100% from sugar beet (leaf) 91-96% from kidney beans 96-100% from string beans and 86-98% from soil. The limit of detection is 0.005 mg kg for plant samples, except for rice straw and soil materials, and 0.01 mg kg for rice straw. 

Citrus, cotton, melon, watermelon, banana, tomato, eggplant, onion, cabbage, carrot, chicory, leek, maize, hazelnut, potato, rice (straw, grain), air, sweet corn, soybean, French bean, sugar beet, flowers and ornamentals, sunflower, tobacco, soil and water... 

J. Rosen, M. Danish, M. Ragni, C. Lopez Saccar, S. Yaffe, and H. Leeks, Theophylline pharmacokinetics in the young infant, Pediatrics, 64, 248 (1979). 

J.H. Leek Pressure measurements in vacuum systems, Chapman Hall, London (1964)... 

Enantiomers of the same compound may have differing threshold values. This property was observed for a new, strong and high impact, flavor compound, 3-thio-2-methylpentan-l-ol, first detected in thermally processed materials but that is actually present in raw onions.54 First of all, there is a marked concentration effect at 1 ppm in 5% saltwater, the odor is described as sulfuric, burnt gum, sweaty, onion and at 0.5 ppb as meat broth, sweaty, onion, leek . Since there are two chiral centers (both dependent on carbon) there are four stereoisomers, all of which have been prepared 18a, 18b, 19a, 19b (Scheme 7). For this compound, enantiomers have the following marked differences in odor thresholds (but apparently all have the same general odor). 

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,... 

In structural terms, djenkolic has two units of L-cysteine joined through a CH2 group linked to sulfur atoms. It has also been found in seeds of Albizzia lophanta and Parkia speciosa32 and, as noted earlier, is the source of CS2 in Mimosa pudica (Section 11.1.2.2.2). An enzyme in A. lophanta seeds converted djenkolic acid to an unstable material with a leek-like odor, methylene dithiol 39.92 This was presumably an elimination of aminoacrylic acid 28 via intermediates 37 and 38 (Scheme 13). The methylene dithiol decomposed to H2S and possibly, thioformaldehyde, CH2S the latter might be a source for polysulfides. 

Takama F and Saito S. 1974. Studies on the storage of vegetables and fruits II. Total carotene content of sweet pepper, carrot, leek and parsley during storage. J Agric Sci (Japan) 19 11. 

Leek and Bagander [221] determined reduced sulfide compounds (hydrogen sulfide, methyl mercaptan, carbon disulfide, dimethyl sulfide, and dimeth-yldisulfide) in water by gas chromatography using flame detection. Detection limits ranged from 0.2 ng/1 for carbon disulfide to 0.6 ng/1 for methyl mercaptan. Hydrogen sulfide was determined at the 1 ng/1 level. 

Leek and Baagander [311] determined reduced sulfide compounds in seawater by gas chromatography using a flame ionisation detector. Substances determined include methyl mercaptan, dimethyl sulfide, hydrogen sulfide and carbon disulfide. Detection limits range from 0.2ng/l (carbon disulfide) to 0.6 ng/1 (methyl mercapton). 

---