24 Growing Sea Island Cotton Under Florida Conditions 



until frost. The summer migration of the weevil is nothing- 

 more or less than an exodus from fields where the cotton has, 

 for one reason or another, become unattractive to it. Perhaps 

 it is because weevils have become so numerous that all squares 

 and bolls have been punctured, forcing the females to seek 

 clean squares and bolls elsewhere for laying purposes. It may 

 be because the cotton has ceased to square, and has shed all 

 its tender bolls. This is frequently the cause of a migration 

 from upland cotton. Heavy early summer migrations are to 

 be expected in communities where a considerable acreage of 

 unpoisoned upland cotton is found. In such communities, mi- 

 gratory weevils are often so numerous around July 25 that it 

 is almost an impossibility to control them. 



Florida conditions, however, do not in general produce ex- 

 cessively heavy summer migrations of the weevil until rea- 

 sonably late in the season, because the acreage planted to cot- 

 ton is comparatively small, and well scattered. Under such 

 conditions, slinging can be expected to pay best. If slinging 

 were tested by the small plat method, whereby an acre of 

 weevil-infested cotton is divided into, say, tenth-acre plats, 

 with the small slung plats located adjacent to unpoisoned cot- 

 ton, it, no doubt, would make a very poor showing. Numerous 

 reports have been published where the mopping method of 

 control, tested in this manner, failed to control the weevil. 

 Yet mopping has, four years in succession, satisfactorily con- 

 trolled the weevil on Sea Island cotton in Madison County, 

 which had never ceased to grow upland cotton, and therefore 

 had a good supply of weevils on each of the four years. In 

 our opinion, the small plat method of testing weevil control 

 methods is not a reliable indication of the worth of a control 

 method when it is to be used on a field-wide basis in more or 

 less isolated plantings such as are commonly found in Florida. 

 It would follow that it would be a still poorer indication of 

 the worth of a control method when used on a county-wide or 

 state-wide basis, although, of course, the small plat method 

 of testing has much to commend it as a means of evaluating 

 a control method that is to be used in communities where no 

 isolation from unpoisoned cotton is possible. 



We feel, further, that considerable injustice has been done 

 the mopping method of control by publishing "averaged" re- 

 sults, wherein some of the plats included in the average were 

 under conditions inherently unfavorable to the mopping 

 method of control. Perhaps some of the test plats were located 

 where an abnormally late emergence of the weevil was to be 

 expected, and poisoned an insufficient number of times to 

 take care of this unfavorable factor. The most common unfa- 



Librar5r 

 N. C. State Collesre 



