16 



BURNING SUIiPHTJR IN COTTON FIELDS. 



This appears to be a comparatively recent practice. Burning sul- 

 phur is hauled through the cotton fields between the rows on small 

 sleds. Considerable sulphur was used in this way during August of 

 the past year. Its advocates claim that the fumes of the sulphur drive 

 the boll worm moths out of the field. The experiments of the writer 

 with burning sulphur in cotton fields, in 1903, do not indicate any 

 possible benefit from its use. Bollworm and cotton caterpillar moths 

 are often frightened from the plants, but usually fly onl}^ a short dis- 

 tance before darting among the plants again. The simple walking 

 between the rows would disturb the millers almost as much, and the 

 recommendation has no valid foundation. 



RESISTANT VARIETIES. 



The idea of making a crop of cotton ahead of the bollworm by the 

 early planting of early varieties has, to a limited extent, been confused 

 with the idea of immunit}^ on the part of the varieties recommended. 

 It should be stated that, so far as known, there are no varieties of 

 cotton immune to attack by the bollworm. It will be remembered 

 that, in regard to its feeding habits, this insect is practically omnivo- 

 rous, and it is not likely that it would be deterred bj^ the slight differ- 

 ences occurring in the different varieties of cotton. 



FIELD EXPEEIMENTS IN 1903. 



The field experiments of the Division of Entomology with the boll- 

 worm during the past season were conducted along the following lines: 



(1) To determine the possibilit}^ of making a crop of cotton 

 before the period of greatest bollworm injur}^ by the earlj^^ planting 

 of an early-maturing variet}'^ of cotton, aided by thorough cultivation. 



(2) To determine the value in bollworm control of spra3dng or dust- 

 ing cotton with arsenical poisons. 



(3) To determine the value of corn as a trap crop in protecting 

 cotton from bollworm injury. 



Incidentally, tests were made of light traps, poisoned sweets, fumi- 

 gation of fields with sulphur, and methods of similar character. 



CULTURAL METHODS. 



The more or less general rains which prevailed in Texas during the 

 winter and early spring of 1902-3 delayed the planting season, which 

 was everywhere from about four to six weeks late, and in this 

 important respect conditions were unfavorable for the experiments 

 involving the early planting of cotton. 



The accompanying diagram shows the arrangement, treatment of, 

 and yield from the respective plats in the experiment acreage located 

 on the plantation of Capt. B. D. Wilson, at Hetty, Tex. The plats 



