TREATMENT FOR SPECIAL WEEDS IOO, 



In response to circulars of inquiry sent out by the Iowa 

 Experiment Station, the majority of correspondents 

 recommended shallow plowing, disking, and harrowing, 

 and continuing cultivation and hoeing as long as the 

 thistles make their appearance. Some report successful 

 treatment with salt when scattered thickly about the 

 thistles, especially if cattle or sheep are given access to 

 it. Some report success with carbolic acid where it is 

 applied directly to the stem. Tarred paper in a few 

 instances gave success, as did also the method where the 

 thistle was covered thickly with straw or manure. The 

 depth of covering was not, however, given. 



Milkweed. Milkweed, like the morning-glory, is a 

 deep-rooted perennial, and where abundant in small grain 

 fields it is rather difficult to remove. The plowing here 

 should always be shallow, as the roots are deep seated 

 and new plants spring up from where the roots are cut 

 off. The plowing should be followed by disking and 

 harrowing to expose as many of the roots as possible and 

 it should be turned into pasture as soon as possible. It 

 is seldom that milkweed becomes injurious to pastures, 

 as the plants lose their vitality. It is by continuous 

 cropping of one crop that the weed becomes pernicious 

 in its character. 



In response to a query sent out one correspondent 

 recommended oats one year, clover one year, corn two 

 years, saying the weed is not troublesome in the pasture 

 after the second year. Some have advocated pulling the 

 weed by hand. This is not practical. 



Horse Nettle. In southern states north to Iowa the 

 horse nettle is one of the most troublesome weeds to deal 

 with. Like morning glory and milkweed, it is a deep- 

 rooted perennial. The roots are known to extend into 

 the soil as much as three to four feet. The cultivation 

 here should be shallow. When the weed is common, disk 

 thoroughly and harrow, exposing the roots. When a 



