252 



COTTON 



COTTON 



part their lodging places and food supplies. A 

 thorough dusting with Paris green will control the 

 webworms and cotton-square borers. Plant-lice 

 are destroyed by plowing under their host plants 

 in late fall or winter. When it becomes necessary 

 to take some other course, spraying with whale- 

 oil soap, kerosene emulsion or tobacco solution is 

 effective. Cutworms are controlled by placing 

 about the fields bunches of grass or weeds im- 

 mersed in Paris green. The better method, how- 



Fig. 361. 

 Mezican cottonboll- 

 weevil. Enlarged. 



Kg. 362. 



Larva of Mezican cotton- 



boU-weevil. More enlarged. 



ever, is to kill them by thorough winter cultiva- 

 tion, and keeping down all vegetation in the early 

 spring. 



The cotton-worm (Aletia argiUacea), boUworm 

 {Heliotkis armiger) and Mexican cottonboU-weevil 

 {Anthonomus grandis) are not so easily controlled, 

 and their ravages have been costly. The cotton- 

 worm is now more easily controlled than formerly. 

 It is a blue-green caterpillar, with black spots and 

 stripes on its back. It is most severe in late sum- 

 mer, but is present the entire summer. There are 

 several generations each year. The common method 

 of combating it is to apply dry Paris green to the 

 plants. 



The cottonboU-worm is a common garden pest, 

 attacking various crops, as corn, tomatoes, peas 

 and squash. The caterpillar is somewhat darker 

 than the cotton-worm, but otherwise the two are 

 very similar in their early stages. This, too, has 

 several generations in a season. It is most eifec- 

 tively controlled by the planting of an early trap- 

 crop. Sweet corn is much used. As soon as the 

 corn is infested it is removed and destroyed or 

 fed to stock. Lantern traps for the moths and 

 arsenical sprays for the worms have given limited 

 success. 



The most serious problem confronting the cot- 

 ton-grower today is the control of the Mexican 

 cottonboll-weevil, which is threatening the de- 

 struction of the industry. The weevil is small, 

 three-eighths inch, or less, in length, of a dark 

 brown or black color. The eggs are laid in the 

 young bolls, and the larvse begin their work by 

 eating the inside of the bolls. No very effective 

 direct method of combating the weevil has been 

 found. Its control depends on strict attention to 

 many details in the culture of the crop, and to a 

 modification of the farm practice. It is very 

 important to mature the crop early, and then to 

 clean up the plantation as soon as the cotton is 

 picked, burning or plowing down all stalks and- 



refuse ; this will largely control the weevil, at the 

 same time that it improves the cropping practice. 

 The seed should be fumigated with carbon bisulfid 

 to be sure that the pest is not introduced in this 

 way. Early trap-crops may be planted about places 

 where the weevils are likely to hibernate, as about 

 cotton-gins, and sprayed with arsenical poisons ; 

 later the crops are destroyed. Sometimes the 

 weevils are jarred from the trap-crop into pans, 

 and destroyed. Volunteer cotton-plants must be 

 destroyed. Attention must be given to the picking 

 and destroying of infested squares. All rubbish, 

 infested squares that have dropped, stalks remain- 

 ing at the end of the season, weeds and litter 

 should be gathered and burned. 



Among the diseases attacking the cotton-plant, 

 wilt is controlled by planting disease-resistant 

 seed, the burning and careful destruction of all 

 infested plants, and the rotation of crops. Sore- 

 shin, or damping-off, is checked by liming the soil 

 and cultivation to keep the surface mulch dry. It 

 is caused by excessive dampness. No remedy for 

 anthracnose is known. Red-rust is not serious. 

 Vigorous plants will withstand it. It is usually 

 localized in its attacks. Crop rotation is the most 

 effective means of controlling the root-knot fun- 

 gus (see article on "Soil Diseases," Vol. I, page 

 450). Angular leaf -spot attacks the plants in June 

 and July, forming watery spots on the leaves. The 

 growing of vigorous plants is the best insurance 

 against infestation by it. Leaf-blight is common 

 but not very serious. It forms a tan or light spot, 

 surrounded by irregular reddish spots, on the older 

 or less vigorous leaves. No remedy has been sug- 



Fig. 363. Cotton boll infested with three boll-weevil larvse. 

 Figs. 361-3 adapted from Yearbooks. 



gested. Mildew is not serious and no treatment 

 has been found. 



Shedding of the bolls is common in unfavor- 

 able seasons. Extremes of rain and drought, or 

 their alternation, are the probable causes. The 

 trouble is to be prevented to some extent by 

 maintaining good soil conditions and employing 

 hardier varieties. 



Manufacture. 



The manufacture of cotton consists of the 

 various processes in the production of thread or 

 yarn and woven fabrics from the fiber. The spin- 

 ning of yarn and the manufacture of coarse cotton 



