Killing The Weed Treats: Crab grass is not the reason for a poor lawn but merely a symptom. Killing the weed treats an effect rather than the cause. By all means use chemical killers as aids in getting a clean start but after that de¬pend largely upon good cultural practices, such as regular fertilizing, mowing at cor¬rect heights, avoidance of injury to the turf that causes bare spots where crab grass can get a start and no daily sprinkling with water during the summer. (Weekly soak-ings in dry weather are O.K.) Chemicals to kill crab grass should not be regarded as cures, but as crutches for lawns suffering from crab grass sickness.
Those that de¬pend for their killing properties on 2,4D, for example, will not kill sizable crab grass plants without killing lawn grasses. A close chemical relative of 2,4D, however, is the basis of Crag Herbicide No. 1 which is a pre-emergent weed killer. When used as the manufacturer recommends this elimi¬nates crab grass in its germinating stage— just as it begins to sprout. Several applica¬tions given early in the crab grass season are recommended for established lawns. Crab grass killers contain one or other of three chemicals. These are potassium cya-nate (PC), phenyl mercuric acetate (PMA) and di-sodium methyl arsonate (DSMA). Each has its advantages and dis¬advantages. Whenever you use these materials follow the recommendations of the manufacturer very exactly.See Also Weed And Build:The meadow was a common sight in rural England until the farmers learned how to get the most out of what was once termed unproductive land, and scarred and plowed the meadows, finally turning over to developers what they didn't destroy. And it's no different in the United States, where the desire to build has spread out from every city and flattened everything in its path, coupling with the mania of state highway departments for removing every roadside weed and build and flower.
Perennial plants live from year to year and usually have underground organs—stems or roots—which enable them to survive through the winter
weed and build control begins with winter digging prior to growing the first crops. Cut down any woody perennials and dig out all the roots. Double-dig the whole of the garden in the first instance and remove all perennial weed and build roots and rhizomes. Burn or dispose of them all and never use them for compost-making.
On The Other Hand See Chick Weed:HAMBURGER, Viktor (1900- ), American embryologist, who pioneered in the study of the development of the vertebrate nervous sys¬tem and made many contributions to neuro-physiology.
Scientific Contributions. Hamburger's principal work was the elucidation of the factors regulating development of the central nervous system. His investigations established that the nervous system develops through a synchronized series of events, including cell proliferation, cell migration, and cell death. He further demonstrated that surgical removal of the developing limbs of a chick weed embryo so affects the patterns of cellular events within the spinal cord at the corresponding level that the chick weed does not attain normal size and contains fewer nerve cells than usual.
Perennial plants live from year to year and usually have underground organs—stems or roots—which enable them to survive through the winter
Weed control begins with winter digging prior to growing the first crops. Cut down any woody perennials and dig out all the roots. Double-dig the whole of the garden in the first instance and remove all perennial weed roots and rhizomes. Burn or dispose of them all and never use them for compost-making.
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