WEEDS 



Resvdta of spraying with iron sulfate — Continued 



With the exception of the application to the poison ivy, the iron 

 sulfate was ai^pUed as a 20 per cent solution, using it at the rate of 

 100 to 150 pounds per acre. 



At the South Dakota Station the following weeds were entirely killed 

 Ijy the u.se of iron sulfate: — 



Wild mustard (Brassica arvensis) ; ragweed (Ambrosia artemiscefolia) ; 

 king-head or greater ragweed {Ambrosia trifida) ; bindweed {Convol- 

 vulus Sepium) ; marsh elder (Iva xanthifolia) ; milkweed (Asckpias 

 sp.) ; pepper-grass (Lepidi urn Virginicum) ; pigweed { Am,arantus sp.) ; 

 sweet clover (Mclilotus alba and M. officinalis). Those that were 

 more or less badly injured : Russian thistle (Salsola Kali) ; sunflower 

 {lidianthus sp.) ; dandelion; dock (Rumex crispiis) ; thistle (Carduus) 

 sp.); white clover {Trifolium repetis) ; red clover (Trifolium pratense) ; 

 alfalfa (Mrdicago saliva). The following were but slightly injured: 

 plantain {Plantago major) ; sheep sorrel {Oxalis violacea) ; prairie 

 rose; lamb's quarters {Chenopodium album). Grasses in general, 

 including the grains (wheat, oats, corn, barley, and speltz were sprayed 

 in our experiments) were none of them seriously injured. 



According to the Ohio Station, salt has thus far proved the best spray 

 tested for Canada thistle, poison iv}'', yarrow, and horse-nettle. In the 



