24 BULLETIN 742, U. S. DEPARTMENT OP AGRICULTURE. 



secure a better development of. the lower fruiting branches, those 

 that contribute to the production of an. early crop. 



This new method of delayed thinning and of closer spacing of the 

 plants has resulted in a much earlier development of the crop, as well 

 as in making the picking much easier and cheaper. The time and 

 manner of thinning are so important that they merit the closest per- 

 sonal attention of the grower, the more so as.it is impossible to lay 

 down general rules which will be equally well' suited to each type of 

 soil and to each season. 



UNDESIRABILITY OF RATOONING EGYPTIAN COTTON. 



The winters of southern Arizona and California are often mild 

 enough to allow many of' the old cotton stumps to remain alive in the 

 ground, and it is possible to grow a. second crop from them. This 

 has suggested the ratooning of Egyptian cotton, a practice which 

 has recently had some advocates in the Salt River Valley. Ratoon- 

 ing was formerly practiced in Egypt, but the system was discon- 

 tinued in that country because of the poor quality of the fiber pro- 

 duced. The practice has also 'been thoroughly tested with Durango 

 cotton in the Imperial Valley, where the results were unsatisfactory. 



While ratooning saves the labor of spring planting and results in 

 the earlier maturity of the crop, it has no other advantage. A perfect 

 stand can rarely be had, and the seedling plants with which the gaps 

 must be filled ripen later than the ratooned plants and produce fiber 

 of different length and quality, making it impossible to obtain a uni- 

 form product from the field. It is questionable whether the very early 

 ripening of the ratooned cotton is really a benefit, since it necessitates 

 picking during the hottest season of the year. It would also be 

 difficult to keep the land from becoming weedy if this method were 

 followed. Finally, the practice of leaving the old stumps in the 

 ground would favor the increase of such injurious insects and fungi 

 as might gain a foothold in the locality. The advisability of re- 

 planting the fields each year with the best seed obtainable can not 

 be too strongly urged. 



ENEMIES OF THE CROP. 



Fortunately, no very serious diseases or insect enemies of the crop 

 have yet appeared in the Salt River Valley. A weevil, very closely 

 related to the Mexican cotton boll weevil and capable of feeding 

 upon and depositing its eggs in the bolls of cotton, is native to the 

 mountains of southern Arizona, occurring on a wild plant somewhat 

 nearly related to the cotton plant. 1 Neither this weevil nor the true 

 Mexican boll weevil has as yet been observed in the cotton fields 



1 Cook, O. F. A wild host plant of the holl weevil in Arizona. In Science, n. s., v. 37, 

 no. 940, pp. 259-201. 101.1. 



