44 HORTICULTURAL SOCIETY OF NEW YORK. 



was greatly injured. Some of them planted beside the Rivers cotton during 

 the present season have proved to be equally as resistant to wilt as that 

 variety. These strains of Sea Island cotton were developed in practically the 

 same way as the Rivers cotton — by selecting as parent stalks very vigorous 

 and healthy plants found in the worst infected fields. The seed from each 

 of these was picked separately and planted the next year on land known to 

 be thoroughly infected with wilt. Under such conditions their resistance was 

 put to a severe test. Those that failed to withstand the disease were dis- 

 carded at once, and others were thrown out because they were deficient in 

 yield or in length or quality of staple. It was found that the progeny of 

 most of the selected plants were all resistant in the second generation, and 

 only such were preserved. Where many of the individuals grown from one 

 parent plant were affected the whole selection was discarded as lacking the 

 quality of prepotency, or transmitting power. In the third generation the 

 quality of resistance was still retained, with only a few reverting individuals 

 showing disease. They were destroyed, and it is believed that with proper 

 care in selection these strains can be kept resistant indefinitely. 



The development of strains of Sea Island cotton resistant to wilt is so 

 easy that it can readily be done by the planters themselves. In fact, several 

 of the more progressive Sea Island planters are already doing this, with en- 

 couraging results, and land once abandoned because of the wilt disease is 

 now being taken under cultivation agam. 

 3. The Sensation Cotton. 



An interesting instance of the origination of a wilt resistant variety is 

 found in the history of the Sensation, a local strain of Sea Island cotton 

 grown on Edisto Island, S. C, by Messrs. M. M. and E. M. Seabrook. The 

 cotton planters of this section have been accustomed for many years to keep 

 up the quality of their product by a rigid system of selection, the funda- 

 mental principle being the annual selection of a single superior plant, which 

 becomes the parent of the strain.* 



The above mentioned strain was originally selected for its length and 

 fineness of staple, without reference to its wilt resistance, which was not ob- 

 served until about the fifth generation, when it was planted in a field where 

 some spots were known to be infected with wilt. This cotton made a healthy 

 growth on these wilt infected areas, and thus attracted the notice of the 

 growers. The writer made an examination of the field at this time and found 

 evidence of the presence of the fungus in the soil in the occurrence of tufted 

 roots on some of the resistant plants.** Later and more extended trials of 

 the Sensation cotton have verified these observations and demonstrated the 

 important fact that it is thoroughly resistant to wilt. The explanation of this 

 is not difficult to find. It will be remembered that, as previously stated, there 

 are in almost every field some plants that resist infection by the wilt fungus. 

 The parent plant of this variety undoubtedly possessed this quality, though 

 the field in which it grew was not infected by the wilt fungus, and all its 

 descendants have inherited its wilt resistance. It is encouraging to note that 



*For a full account of this method of selection see Webber, Yearbook U. S. Dept. 

 of Agric, 1898, p. 358. 



"See Bui. No. 27. Div. Veg. Phys. & Path. U. S. Dept. of Agric, p. 8. 



