WILT RESISTANT VARIETIES OF 



COTTON 



By 



E. V. ('ai THHN, Ass()ci;i(o Agriculliirisl. 



Sum mar v. 



Cotton wilt and root-knot occur more frecjuently in 

 tlic soullu'i-n lliird llian in any ollu-r i)art of Alabama, 

 llowcver. llusc diseases are also to be found in tbc 

 central lliird, and on small widely separated areas in 

 certain otlier coiudies slill farlber nortli. Cotton wilt 

 is found most freciuenlly in loose sandy land; it rarely 

 occurs in heavy clay soil. 



In total money value of lint and seed jjer acre 

 a non-resistant strain of Cook, used for comparison, 

 averaged in fifteen experiments '*}^26.78 per acre; while 

 the wilt-resistant varieties averaged as follow^s: Mo- 

 delhi .^2<S.1)(); Wood ^'XU9; Dixie .^33.22; Cook No. 

 307-0 .t31.17; Covington-Toole -^31. 42; Tri-Cook .1^40.53 

 per acre. 44ie range of gains from resistant varieties ex- 

 tends from 8.1 perctnl with Modella to 51.3 percent 

 with 4"ri-C()ok. 



An average of the i)ercentages of yearl}^ loss of cot- 

 ton plants in each variety from wilt is as follows: Cook 

 (check), a non-resistant strain, 40.3 percent; Wood 

 IT).! percent; Modella 14.7 percent; Covington-Toole 

 lO.") ])ercent; Cook 307-() 9.3 percent; Dixie 8.5 percent: 

 4ii-Cook 7.3 })ercent; Dillon 5.4 percent. In the two 

 experiments in which Dix-Atiti was planted, it lost no 

 ])lants. 



14ie wilt-resistant varieties of cotton used in these 

 experiments differ slightly in their relative earliness. 



In comparison with standard varieties like Cleve- 

 land, Cook and I'riumph, most of them must be regard- 

 ed as somewhat later in time of opening. 



Among the resistant varieties tested, (hose ranking 

 highest in total money value of seed and lint per acre 

 are the earliest and turn out about 40 percent of lint. 



4'his Station reconvmends to farmers who have cotton 

 wilt and root-knot in their land that they employ, as 

 a means of controlling these diseases, a simple rota- 

 tion of crops (see page 88) in which are excluded 

 those crops that have a tendency to increase these dis- 

 eases. In this rotation, which includes cotton, only 

 wilt-resistant varieties should be planted. 



