14 



Egyptian and upland cotton grown by the writer on infected land at 

 Dillon, S. C, was not so marked here. The quality of the lint was 

 good, though not equal to the crop from which the selection was made. 

 It ishelieved, however, that by continued cross breeding and selection 

 in succeeding years the qualitj' of the cotton maj^ be improved with- 

 out loss of resistance to the wilt disease. Work along this line has 

 alreadj^ been started in a small way by the Department, Avhicli it is 

 hoped may be enlarged. 



It has been shown that much can be accomi3lished in the control of 

 the wilt disease of cotton by simply selecting seed from resistant 

 plants. It is very probable that better results will be obtained bj^ 

 cross-breeding these resistant individuals, for in this way the resist- 

 ant qualities of two plants will be combined and there will be added 

 the increased vigor wiiich usually comes from crossing. On the other 

 hand, if the flowers of a resistant cotton plant should be fertilized by 

 pollen brought by insects from a diseased plant, as may easily happen 

 in the field, plants grown from the resulting seeds will very likely be 

 less resistant than if they had been fertilized by pollen from another 

 resistant plant. On this account, in the selection of resistant races, 

 it will be desirable to cross by hand as many flowers as possible in 

 order to increase the chances of success. 



In connection with tlie M^ork of the Department a large number of 

 crosses between resistant plants have already been made. It has been 

 our aim to secure resistant strains from our common races by 

 cross-fertilizing plants of the same race, and at the same time to 

 increase the productiveness and improve the quality bj^ selecting the 

 best plants of each sort for breeding. 



The fact that the Egyptian cottons are resistant to the wilt disease 

 has led to the attempt to produce a resistant long-staj)le ui^land cotton, 

 by hybridizing resistant plants of the common upland races with the 

 Egj'ptian cotton. It is very desirable that ever3''one who undertakes 

 the breeding of resistant cotton should at the same time pay great 

 attention to securing a more productive race and a finer quality of 

 staple. 



CONTROL OF OTHER WILT DISEASES BY SELECTION. 



The indications are that other diseases similar to the cotton wilt 

 may also be controlled by the selection of resistant races. 



The wilt of the cowpea, which is a troublesome disease in many 

 parts of the South, is caused bj' a fungus closely allied to that pro- 

 ducing the cotton wilt {Neocomospora vasinfecta var. iracheiijliila). 

 In this case we already have a race, known as Little Iron, which will 

 grow on infected land. A fine crop of this pea was groAvn during the 

 past season by Mr. T. S. Williams, of Monetta, S. C, on fields where 

 the whole crop was lost last year and where other races planted 

 alongside it this year have been practically ruined. 



