is known. Among the most important diseases due to physiological causes are those known as the mosaic disease or yellow leaf-blight, and the shedding of bolls. In the first, small areas of the leaves become yellow, giving to the leaf a peculiar checkered appearance. Later these areas turn brown and dry up, leaving the leaf in a more or less ragged condition. At this stage the disease is usually referred to as the black rust. Heavy applications of kainit or similar fertilizer are said to correct this evil. The shedding of the bolls, or their drying up while still attached to the plant, is often a serious trouble. Extreme dry or wet weather causes this disease by interfering with the proper supply of moisture and nutriment furnished the plant through its roots. Among the diseases due to parasitic fungi a few of the most serious and widely distributed may be mentioned. Damping off, soreshin, or seedling rot is caused by Pythium debaryanum and a number of other fungi. They attack the young plants at or near the surface of the ground, producing ulcer-like spots, and later rot the plant off. The sunken, ulcer-like spots can be readily seen on the affected stems. Another common disease is anthracnose, due to Colletotrichum gossypii. It is a widely distributed fungus that attacks the bolls, stems, and leaves. Upon the bolls small reddish spots appear which later become black. The centre then becomes gray or pink and the spots enlarge in a concentric manner with well-marked zones of color. The boll is killed outright or has its development checked so that the lint is worthless. Upon the stems the fungus is somewhat similar in its behavior, although the spots are not quite so definitely marked. Upon the leaves the disease is not very well characterized. A root-rot is very destructive in some places. Its behavior is so marked as to need no description. It is due to a rather widely distributed fungus that has been called Ozonium auricomum. It attacks a number of plants in addition to cotton. Rotation of crops is about the only method of relief known. A leaf-blight (Sphærella gossypina) and a mildew (Ramularia arcola) are common diseases in the cotton-field, but they seldom occasion much injury.
The most serious fungous disease to which the cotton-plant is subject is the wilt disease, or Frenching, as it is commonly known. It makes its appearance usually in May, when the plants are six or eight inches high. The plants are dwarfed, have an unhealthy appearance, the leaves turn yellow between the veins and their margins dry up. Sometimes plants wilt and die at once, while at other times the progress of the disease is slower and the plant may partly recover. A plant attacked by this disease will show a brownish stained color in the wood when cut across. The cause of the trouble is a fungus recently described as Neocosmospora vasinfecta, and the same or a closely related form occurs on the okra and watermelon. Some varieties and individual plants seem less liable to this disease, which attacks the plants through the soil, and it is thought the means for overcoming this trouble lies in resistant plants. This disease, as well as some others, is very much complicated by the presence in the roots of the cotton of nematodes (Heterodera radicicola), minute worms that enter the roots of cotton and a number of other plants, causing a large number of galls to be formed. The plant is injured by the nourishment taken from other parts of the plant to make the galls. This weakens the plant so it is more liable to fungous attack. When nematodes occur in abundance in the field no entirely efficient means of eradication is known as yet.
Production and Distribution. The oldest known cotton-producing country is India, where for thirty centuries the plant has been grown and its fibre manufactured. For four hundred years before the Christian Era cotton was well known in what was then the civilized world, the writings of the Greeks and Egyptians plainly indicating the knowledge of the value of this fibre. Columbus found it in the Western world, although not so extensively cultivated as in the East; but during the past fifty years its culture here has distanced in quantity and in quality the produce of the Old World. Down to 1800 the cotton-consumers of Europe depended upon the Indies and the Levant for their raw material; but by 1860, so far had the inventive genius, the superior farming, and the greater energy of the planter of our Southern States pushed the production of the fibre, that they furnished the greater part of the cotton used by Great Britain and the Continent of Europe. From 1858 to 1860 America furnished 79 per cent. of the cotton imported into Great Britain. During our Civil War this dropped to 3½ per cent., rising to 58 per cent. in 1871, and amounting to 80 per cent. in 1900. During the Civil War, when the price of cotton was abnormally high, attempts were made to grow cotton in many countries. The industry flourished there for a while, but it has ceased to be profitable in Europe, Australia, etc. Russia in her Asiatic possessions has developed cotton-growing greatly in recent years, so that the imports into the empire have fallen off 50 per cent. in the past decade.
Cotton Production of the World. This is difficult to more than approximate, as a large proportion and amount consumed is produced in uncivilized or in semi-civilized countries, where no accurate record is kept; and in many countries and districts absolutely no data are available—as in China, where soil and climate are favorable and the clothing of the population is largely of cotton, yet the extent of its cultivation is a close secret; and in some parts of India, where the production can be estimated only by the amount in sight and the known or assumed requirements for dress. The amount produced in the vast unknown continent of Africa is even more of a mystery, although native cottons form there a large proportion of the dress.
The commercial crop for the year 1898-99 was 13,110,000 bales of 500 pounds each. This includes the total crop of the United States and the known imports into Europe and America from other cotton-producing countries. The product was divided as follows: United States, 11,189,000 bales; Egypt, 1,243,000 bales; India, China, etc., 607,000; Brazil, 23,000 bales; Peru, West Indies, etc., 30,000; and Turkey, Asia Minor, etc., 18,000. The domestic consumption in those countries from which only the exportations are given would add very materially to the total production of the world. India leads in the domestic consumption of cotton among those countries not reporting, and in 1900 about 1,100,000 bales were consumed by the local mills. According to Latham, Alexander & Co., the total production for 1900 was: United States, 9,137,000
