B. P. I.— ( 



RELATION OF DROUGHT TO WEEVIL 

 RESISTANCE IN COTTON. 



INTRODUCTION. 



An important relation between weevil resistance and drought 

 resistance has been recognized for several years past. Special ability 

 to resist drought is to be reckoned as one of the factors of weevil re- 

 sistance, because more drought -resistant varieties can be grown in 

 the drier regions of the Southwest, where the weevils are often 

 unable to propagate and do relatively little damage. A rapid exten- 

 sion of cotton culture is taking place in this part of the United 

 States. 



The farming public in Texas is coming to look upon dry weather 

 in the early part of the season as the most important factor in the 

 production of a good crop of cotton. At first it was supposed that 

 the fate of the weevils during the winter would determine the possi- 

 bilities of production in the following season. Measures for reduc- 

 ing the number of weevils in the fall and spring received much 

 attention, but it is now understood that dry weather makes it possible 

 to secure a crop, even in a season when the weevils survive the winter 

 in large numbers. In southern and western Texas the reduction of 

 weevil injuries by drought is a very definite factor of weevil re- 

 sistance, tending to place these regions more nearly on a basis of 

 equality with other parts of the State for purposes of cotton produc- 

 tion. In favorable seasons the same factor of dry weather becomes 

 effective over much larger areas, as notably illustrated in the last two 

 years, 1909 and 1910. 



In order to take full advantage of other measures for combating 

 the weevils, the relation of drought to the behavior of the growing- 

 plants must be considered, no less than the direct effect of the drought 

 upon the weevils. Questions of the value of early and late varieties 

 and of early and late planting require to be reconsidered and given 

 further study now that the effects of dry weather are more fully 

 appreciated. It is only by a careful study and full recognition of all 

 the factors that the true possibilities of cotton culture in the presence 

 of the weevils can be realized. 

 220 



