U. v. I.-7:i,-). 



Tin- COXTROL.OF COTTON WILT AND 



ROOT- KNOT. 



INTRODUCTION. 



General attention should be called to the spread of two diseases 

 which seriously injure cotton, particularly on sandy land. These are 

 cotton wilt, or "black-root," and root-knot. They already occur in 

 scattered localities from North Carolina to Texas and are estimated 

 to cause an annual loss exceed- 

 ing 810,000,000. There are 

 thousands of acres of land 

 already so infested that ordi- 

 nary varieties of cotton can 

 not be grown, and the area 

 enlarges each year. 



In addition to the loss of 

 crops this land has depreciated 

 in market vahie; it costs more 

 to cultivate on account of the 

 weeds and grass that spring 

 up after tlie cotton dies, and 

 the farmer must often use it 

 for crops less profitable than 

 cotton. 



This situation is the more 

 unfortunate because it is un- 

 necessary. These diseases may 

 be controlled by the means 

 pointed out i'.i this circular. 



HOW TO RECOGNIZE COTTON 

 WILT. 



"When plants wilt suddenly 



,11 11 „ 1 £ 11 Fig. 1.— A young cotton plant dying from wilt. 



or the leaves yellow and fall ^ i . - 



without apparent reason, the wilt is to be suspected. (Fig. 1.) If 

 a freshly wilted ])lant is pulled and the inner wood of the stem or root 

 is found blackened (hg. 2), the disease is almost certain!}' wilt. 



Tlie trouble begins in May and June and continues to develop 

 throughout the season. Its first appearance in a fichl is Hkely to be 

 in small spots, whicli enlarge each season until considerable areas 

 [Cir. o-.'] 3 



