Environmental Factors Influencing Fruiting of Cotton 373 



avoidance; therefore, each helps to de- 

 termine the amount of the crop which 

 will be matured by a certain date in 

 the autumn. 



THE QUESTION OF HEREDITY 



"In our attempt at an analysis of the 

 hereditary factors concerned in earli- 

 ness all these factors have been studied 

 independently and in their combined ef- 

 fects. It now remains to record in de- 

 tail the differences which have been 

 found in fruiting activity of the sev- 

 eral varieties studied. 



"These studies have not included any 

 observations on the growth of the plant. 

 Our attention has first been centered 

 on the (juestion of the time of opening 

 of the first flower in the several varie- 

 ties planted and grown under as nearly 

 identical conditions as is possible with 

 the usual methods of variety testing. 

 With the appearance of the first flower 

 in each variety the daily counting of 

 all flowers produced by each variety 

 was started. The number of plants 

 of each variety studied was one hun- 

 dred. These were divided equally among 

 two rows of adjacent series, the varie- 

 ties being planted in multiple series, 

 each series consisting of as many par- 

 allel rows as there were varieties. Thus, 

 in 1914, ten varieties were studied, and 

 these were grown in twenty parallel 

 rows, one thousand plants in all, one 

 hundred of each variety, fifty to a row. 

 This flower census was continued each 

 day throughout the principal flowering 

 season, each 3rear from 1911 to 1914. 

 The differences found in the flowering 

 characteristics of the several varieties 

 have reappeared rather consistently in 

 the different years. 



"During four seasons, 1911 to 1914, 

 statistical studies have been made of 

 the various fruiting process, but, as has 

 been stated, the data obtained in 1913 

 have not been used for comparing va- 

 rieties. In each of the other three 

 years we have compared varieties of 

 three groups : First, the so-called Early 



group, represented by such varieties as 

 King and Simpkins, in which we have 

 included the Trice variety; second, the 

 so-called Big Boll group, of which Tri- 

 umph and Cleveland are typical repre- 

 sentatives; and, third, the Long Staple 

 group, to which Columbia and Sun- 

 flower are referred. This grouping is 

 that devised by Duggar (7)^ and elab- 

 orated by Tyler (15),^ and generally 

 followed by agronomists working on 

 American Upland cotton. No system 

 of grouping, without an almost indef- 

 initely large number of groups, can be 

 made to include at once certain varie- 

 ties and to exclude all others. This is 

 due to the fortunate circumstance that 

 certain of the dominant characteristics 

 of the several groups are not so cor- 

 related as to be mutually exclusive. For 

 instance, there is nothing necessarily to 

 prevent a variety from combining the 

 distinctive qualities of both the Big Boll 

 type and the Long Staple type ; in fact, 

 Columbia and a few other varieties 

 might qualify for either of these groups. 

 Likewise it appears that a variety may 

 be early in its fruiting habits and at 

 the same time produce a long staple, 

 although it has generally been believed 

 in the past that Long Staple varieties 

 were necessarily late in maturing their 

 crop and slow in setting their fruit. The 

 Express variety is one which resembles 

 the Early group in its fruiting charac- 

 teristics, and at the same time its lint 

 is long enough to qualify for the Long 

 Staple group. Cotton breeders are en- 

 deavoring with some success to break 

 down negative correlations as far as 

 they tend to oppose the combination of 

 certain useful qualities. 



"Obviously no variety combines all 

 the good qualities in a high degree. 

 Varieties are strong in some respects 

 and weak in others. In choosing from 

 the available varieties for the best cot- 

 ton to grow, one can only take the kind 

 that possesses the most advantageous 

 combinations of qualities, but any va- 

 riety selected necessarily will have some 



1 Duggar, J. F. : Description and Classification of American Upland Cotton, Alabama 

 Experiment Station Bulletin No. 140, 1907. 



2 Tyler, F. L. : Varieties of American Upland Cotton, U. S. Department of Agriculture 

 Bureau Plant, Indiana, Bulletin 163, 1910. 



