BOLL-WEEVIL COTTON IX TEXAS. 15 



The precaution of thinning rather late, when the plants are from 

 6 to 10 inches tall, is in order when conditions favor luxuriant 

 growth and the farmer wishes to use rather wide spacing, 10 to 12 

 inches or more. This tends to suppress the vegetative branches and 

 to reduce the risk of injurious crowding later in the season If close 

 spacing is to be used, 8 inches or less in the rows, or if two plants 

 are left in a hill with 10-inch. 12-inch, or 15-inch spacings, there is 

 no object to gain by deferred thinning, since the vegetative branches 

 are not likely to be troublesome with such close spacings under nor- 

 mal conditions that do not force rank vegetative growth of the 

 plants. The possibility of suppressing the vegetative branches and 

 the importance of doing so were recognized first in Arizona, in con- 

 nection with Egyptian cotton, which often grows too rank, so that 

 ; the vegetative branches are recognized as a distinct menace to the 

 crop, even to the extent that some farmers have considered it worth 

 while to cut off the vegetative branches in order to keep the lanes 

 open. 



Close-spaced plants may grow too tall and become too spindling 

 if the conditions are such that an excess of vegetative growth can not 

 be avoided, but if single-stalk plants can not be grown to advantage 

 the results are worse with large, spreading plants. Some lands are 

 too rich and moist to raise cotton to the best advantage. Even 

 though large crops may be produced in favorable seasons, there may 

 be complete failures in other years, and the planting of cotton is not 

 justified where failures are too frequent. 



Since the use of deferred thinning is only to suppress the vegeta- 

 tive branches under conditions of too luxuriant growth, where the 

 production of many vegetative branches is a danger to the crop, it 

 is a mistake to extend this precaution to other conditions where no 

 restriction of the growth of the plants is needed. Good understand- 

 ing and practical judgment of spacing questions are not to be ex- 

 pected unless the vegetative branches are taken into account. If 

 plants that are spaced, for example, at 12 inches develop many vege- 

 tative branches, they become too crowded, and the lanes are closed 

 between the rows, so that the yield may be smaller than with plants 

 of the same general size and number of vegetative branches but 

 spaced farther apart. Though most of the experiments reported in 

 former years show larger yields for 12 inches than for wider spac- 

 ings. cases probably occurred where early-thinned plants produced 

 vegetative branches and became too crowded at 12 inches, while tire 

 wider spacings with more room could produce bolls on secondary fruit- 

 ing branches when the period of setting the crop was longer, before the 

 boll weevils came. Such cases of larger yields secured occasionally 

 from 16-inch or 18-inch spacings would explain why 12 inches was 

 looked upon as the practical minimum of close spacing before the 

 existence of the two distinct kinds of branches and the possibility of 

 suppressing the vegetative branches were recognized. 3 



CLOSE SPACING NECESSARY WITH LATE THINNING. 



Apart from the intentional use of late thinning to suppress vege- 

 tative branches under conditions that require this precaution, the 



s Cook, O. F. Dimorphic branches in tropical crop plants : Cotton, coffee, cacao, the 

 Central American rubber tree, and the banana. U. S. Dept. Act., Bur. Plant Indus. 

 Bui. 108, 64 p.. 9 fig., 7 pi. 1911. 



