22 weevil-resisttnct adaptations of cotton. 



crop when in unfavoi'able seasons the earlier buds were lost, or when, as 

 occasionally happened in southern Texas, there was a liberal top croji. 

 or second period of bearin<>-. late in the autunui months. 



The presence of the weevil alters all these factors. The superlluous 

 buds become positively detrimental, for they furnish the breeding 

 grounds for successive generations of weevils and enable the pest to 

 attain in the latter half of the season such numbers that a top crop 

 Jiot only becomes utterly impossible, but a menace is prepared for the 

 cotton of the following year. For, although only a small proportion 

 of the weevils live through the winter, the number of survivors un- 

 doubtedly has a very jjractical relation to the snp])ly maintained at 

 the end of the previous season, and this again is merely a question of 

 this persistent production of buds, now much worse than useless. 



A short-season variety of cotton having a sufficiently determinate 

 habit of growth would by itself constitute a solution of the weevil 

 problem. The Department's entomological investigations in Texas 

 indicate that it is only the weevils hatched in the last month of the 

 growing season — in October or November — which have a prospect 

 of surviving the winter. A cotton which ceased to produce l^uds 

 after July or August would remove the chance of wintering over 

 from all the weevils except the few that might develop in the bolls, 

 an almost infinitesimal number compared with those that now attain 

 maturity in the squares. Much would be gained, of course, if all 

 planters would promptly pick their cotton and then pull up and 

 destroy the plants, being especially careful to collect the infested 

 bolls. But to carry out efficiently such a programme is difficult and 

 expensive. 



To what extent, if any, the Kekchi cotton will meet this need of a 

 short-season determinate variety, it is too early to form an opinion, 

 but the fact that it has these qualities to a higher degree than any of 

 the varieties hitherto known in the United States must be accepted 

 as evidence, at least, that the possibilities of this method of protection 

 have not been realized. In the latter part of the season the Kekchi 

 cotton ceases the upward growth of the main stem and its branches 

 and regularly drops the greater part of its buds before they are large 

 enough to be entered or fed ui)on by the weevils, and the analogies 

 to be drawn from the habits of other plants wnll justify persistent 

 ejBforts toward the development in this and in other stocks of the 

 habit of rejecting the buds still earlier or of not forming them at all 

 after the first crop of fruits has set. Many ]:»lants have, in fact, 

 exactly this habit so desirable in cotton; they continue to flower until 

 ])ermitted to set seed. 



