2 BULLETIN 279, U. S. DEPARTMENT OF AGRICULTURE. 



The period during which conditions are favorable for the setting 

 of bolls in the region of San Antonio, Tex., is usually less than two 

 months and frequently less than 30 days. In order to secure a good 

 crop of cotton it is necessary, therefore, to practice the system of 

 culture that will promote the production of the greatest number of 

 bolls in the least time. For this reason the single-stalk system of 

 culture has been looked upon as most nearly meeting the require- 

 ments of local conditions. To compare the merits of the common 

 practice of wide spacing and the new single-stalk system, a series of 

 tests was conducted in 1914 on the United States experiment farm 

 at San Antonio. The results of these tests showed striking differences 

 in favor of single-stalk culture. 



In spite of the fact that the season was somewhat out of the ordi- 

 nary, hi that two months of excessively wet weather were followed 

 by two months of drought, it was even more favorable for the pro- 

 duction of cotton than ordinary seasons. Yields higher than the 

 average were secured from rows grown according to the ordinary 

 method of culture, even though the period during which bolls were 

 set was shorter than normal. Whether the results in a normal 

 season would have been more or less in favor of the single-stalk cul- 

 ture can not be definitely stated, but results of previous experiments 

 indicate that even if the season had been normal the differences in 

 the two methods of culture would have been comparatively the same. 



COTTON PRODUCTION IN THE SAN ANTONIO REGION. 



In the San Antonio region the development of cotton seedlings is 

 frequently retarded because of the low temperatures that prevail 

 often as late as the middle of May. As a result of exposure to low 

 temperatures the plants are variously affected with the disorder 

 known as leaf-cut, 1 some only slightly, others so seriously that the 

 terminal buds abort. From the middle of May to early July the 

 plants usually develop normally and constantly, June being espe- 

 cially favorable for their growth. Flowering commences from the 

 first to the middle of June and reaches the maximum early in July. 

 About the middle of July a drought usually ensues and continues 

 until some time in August. This droughty condition causes the 

 flowers to fall from the plants and only a very small percentage of the 

 flowers that open in that period develop into bolls. By the end of 

 July the plants cease to grow and very few flowers open. Rains 

 usually fall during the latter part of August, and if the succeeding 

 two months continue warm and the weevils are not numerous a "top 

 crop" is sometimes produced. 



1 For a detailed explanation of the nature of this disorder, see the paper entitled •' Leaf-Cut, or Toniosis, 

 a Disorder of Cotton Seedlings," in Circular 120 of the Bureau of Plant Industn . 



