TYPES OF EARLINESS IN REI^TION TO WEEVIL RESISTANCE. 19 



One limitation must be recognized in all such efforts. It is possible 

 in some regions to stimulate the cotton into an excessive vegetative 

 growth, and thus defeat the object of securing an early crop. If the 

 plants make too rank a growth at first, fruiting is likely to be de- 

 ferred, the lower fruiting branches being replaced by vegetative 

 limbs.^ 



DIPFERENT TYPES OF EARLINESS IN RELATION TO WEEVIL 



RESISTANCE. 



The idenl form of earliness for varieties that arc to be grown in 

 humid regions is not extreme precocity in showing the first flowers 

 or the first ripe bolls, but the production of the crop as rapidly as 

 possible after fruiting begins. Even the early varieties are not so 

 early in humid regions as in dry, for abundance of moisture con- 

 duces to more vigorous vegetative growth and to the production of 

 vegetative limbs near the base of the plant instead of fruiting 

 branches. In a continuously humid region an early-fruiting variety 

 would have no advantage over one that began to fruit a little later 

 unless the later variety were attacked by weevils bred on the early 

 variety, in case both were planted in the same locality. 



If all the cotton in a humid district began to bud and blossom 

 somewhat later but had the rapid-fruiting habit, it would have two 

 advantages over an early-fruitmg variety in relation to the weevils. 

 A smaller number of weevils would survive until the late variety 

 began to fruit and the late variety would be able to set the same 

 amount of crop in a shorter period, after it had once begun to fruit. 

 Late varieties that differ from early varieties in completing a larger 

 amount of vegetative growth before they begin to fruit should be 

 able to produce fruit more rapidly after fruiting has once begun. 



Rapid fruiting, rather than early flowering or early opening of 

 bolls, represents the most effective foi*m of weevil resistance under 

 conditions of continuous humidity. Other things being equal, there 

 is more reason to expect fruiting to go on rapidly in varieties tRat 

 begin to bud and flower rather late than in those that flower very 

 early. A variety that begins to flower very early is likely to require 

 more time to produce the same number of bolls than a later flowering 

 variety. The relatively small size of the plants of all the early- 

 flowering types may be taken as evidence that the very early produc- 

 tion of fruit tends to check vegetative growth. In other words, 

 earlier flowering may lead to slower fruiting, if account be taken of 

 the total number of bolls or the quantity of cotton ripened within 

 a given period. 



1 See " Dimorphic Branches in Tropical Crop Plants," Bulletin 198, Bureau of riant 

 Industry. U. S. Dept. of Agriculture, 1911. 

 220 



