DEVELOPMENT OF WILT-EESISTANT TOMATOES. 7 



fore was not fully measured in the Red Majestic and the Enormous 

 by the percentage of dead plants. It was more closely related to the 

 appearance of the crop and quantity of fruit produced. The per- 

 centage of dead plants in the other varieties corresponded fairly 

 closely with the degree of infection. 



Table 1. — Comparative susceptibility to icilt of different varieties of tomatoes 

 when grown on uniformly wilt-infested soil at the Arlington Experimental 

 Farm, Va., in 1915, 1918, and 1919. 



[1= infected; K= killed.] 





Comparative susceptibility. 



Variety. 



Field 1. 



Field 2. 



Field 3. 





1915 



1918 



1919 



1918 



1919 



1918 



1919 





I 



K 



I 



K 



I 



K 



I 



K 



I 



K 



I 



K 



I 



K 





P.ct. 

 87 

 92 

 92 

 98 

 84 

 100 

 94 

 92 

 100 

 100 

 98 

 99 

 100 

 100 

 100 

 100 



P.ct. 

 1 



6 



6 



6 



8 



12 



16 



24 



24 



28 



34 



35 



38 



40 



44 



100 



P.ct. 



P.ct. 



P. ct. 



P.ct. 



P.ct. 



P.ct. 



P.ct. 



P.ct. 



P.ct. 



P.ct. 



P.ct. 



P.ct. 



Duke of York 















































































































100 



63 







100 







































100 



65 







100 



88 































100 



72 







94 



25 



68 



10 



69 



44 



Texas Bell 



























































































96 



57 



9ij 72 







81 



44 



88 



31 







Willis 













2 

 40 

 43 

 • 53 

 ' 75 

 100 

 100 

 100 





 

 

 

 

 25 

 68 

 94 



81 

 97 



87 

 89 





 3 

 

 



40 











6 







25 

























42 

 60 





 



66 



67 





 



15 

 35 

 60 





 

 



19 



25 

































































75 







































81 

 91 

 97 

 94 

 96 

 100 

 100 

 100 

 100 

 100 









 

 6 

 4 

 13 

 

 38 

 63 

 69 









































27 



75 

 100 







































































100 

 100 

 100 



6 

 31 

 50 



































































100 



3S 







































56 



69 











100 



75 







































100 

 100 



56 



81 



100 

 100 



93 



81 







88 

 89 



38 





















41 













94 



75 



















1 



100 

 100 



88 

 100 





















ioo! 94 



100 100 











94 



56 

















94 



38 





























In 1918 and 1919 the Marvel, Columbia, Norton, 3 and Arlington, 

 wilt-resistant varieties developed by the writer, the Louisiana Red 

 and Louisiana Pink, wilt-resistant varieties developed by Edger- 



3 The Norton, as will be explained later, was developed in cooperation with Mr. J. B. S. 

 Norton, of the University of Maryland. 



