Johnson: An Improved Strain of Wisconsin Tobacco 283 



budded and matured on an average of a 

 week or ten days later than the normal. 



It is assumed that strains 26 and 

 27 are "mutations" from the normal. 

 The reasons for this assumption lie 

 primarily in the fact that both types 

 differ from any other variety or strain 

 which has previously or since been 

 grown at the station, and hence their 

 occurrence in the Connecticut Havana 

 variety was presumably not due to an 

 intermixture of seed. On the other 

 hand, these strains have now been grown 

 for ten years and during this time have 

 shown no sign of segregation but have 

 remained remarkably uniform as to 

 type. 



Both strains 26 and 27 possessed some 

 commercial advantages over the normal, 

 as, for instance, the size of the leaf in 

 26 and the number of leaves in 27. On 

 the other hand, both possessed points 

 of lesser value than the normal, as, 

 for instance, the reduced number of 

 leaves in 26 and the reduced size of 

 leaves in 27. The quality of the leaf 

 in both seemed to be in no way inferior 

 to that of the normal, although the 

 time of maturity of 27 might, under 

 certain conditions, prove undesirable. 



It at once became evident that, if the 

 desirable qualities of the two strains 

 could be combined into one plant, a 

 considerable improvement over the nor- 

 mal might be expected. Accordingly 

 this cross was made along with a large 

 number of other crosses of varieties 

 and strains made during 1909 for the 

 same purpose. The first generation of 

 the cross 269 X 27d^ was given in 1910. 

 The cross showed to a very large extent 

 a very desirable intermediate condition 

 of the characters of the two parents, and, 

 in an unexpected manner, produced a 

 plant whose conformation very closely 

 approached the ideal in mind. This 

 type was given the number 38 as a 

 means of readily distinguishing it from 

 the numerous other types grown. The 

 second generation of the cross was 

 grown in small numbers in 1911, but 

 in 1912 and succeeding generations was 

 grown in large numbers, although data 

 were unfortunately not taken upon 

 large numbers in the second generation. 



Field observations upon a large number 

 of individuals, however, have convinced 

 the writer that there was no marked 

 segregation into types such as occurred 

 when certain varieties of tobacco were 

 crossed and grown under similar con- 

 ditions. Whether the segregation was 

 of such character that it could not be 

 detected or did not occur at all may be 

 regarded as an open question. The 

 writer is inclined to believe, however, 

 as a result of data and observations on 

 this and other crosses in tobacco, that 

 under certain conditions, where the 

 strains crossed are closely related, 

 "blended" inheritance only may occur, 

 segregation into parent types and in- 

 termediates being absent in the second 

 filial generation. Whether this assump- 

 tion, which has been noted in several 

 variety crosses of tobacco (together 

 with segregation in others) be true or 

 not, it is evident that differences in 

 habit and form of growth and in quality 

 which cannot be detected by careful 

 observation can have no significance 

 from a commercial standpoint, although 

 segregation in characters concerned in 

 quality may occur. No evidence of 

 such segregation has been found, but 

 it is exceedingly important that no 

 segregating strain, no matter how small 

 the variability may be, should be in- 

 troduced into cultivation. In order to 

 be further certain of this, therefore, the 

 new strain was grown for four years at 

 the station before being distributed to 

 growers and then the distribution was 

 limited to small amounts for experi- 

 mental purposes. Following fairly ex- 

 tensive distribution in 1916, however, 

 the writer was convinced that the 

 quality was sufficiently uniform to 

 warrant the general recommendation of 

 this seed to Wisconsin growers. The 

 strain has met with considerable favor 

 among the growers from the standpoint 

 of appearance and yield in the field 

 and from the standpoint of the cured 

 I^roduct on the part of the buyers. 

 The strain owes its value, not to its 

 being widely different from the best 

 varieties grown in the State, but rather 

 to its general similarity to these varieties 

 combined with the fact that it is a 



