THE MONTHLY BULLETIN. 57 



and found to be ('fHeiont. It iniisl he rciiiciiilx'i-cd thai a iiiucli laryer 

 area than that inuuodiately occupied by the plants )imst be covered, 

 otherwise sprouts will be found springing up Ix'voiid the covering. 

 Straw, manure, boards, tar paper, and old sacks have been used. The 

 object is to exclude the light as much as possible. 



Morning glory can also be absolutely eradicated by constant cutting. 

 Experiments by the University of California and the State Commis- 

 sioner of Horticulture have demonstrated this beyond a doubt. Plow- 

 ing is not the best method of cutting this weed. Use a horizontal blade 

 weed cutter and set the knife to pass about six inches below the surface 

 of the ground. Repeat the cutting every six or ten days, according to 

 the rapidity of growth. Keep all green leaves down. If the green 

 leaves are allowed to appear they begin to manufacture more food for 

 the underground rootstoeks, and the work expended is wasted. Irri- 

 gate the land where possible, as this stimulates the dormant roots and 

 hastens their final exhaustion. 



Under this method if the morning glory is in the field it is possible 

 to grow a crop before the weed cutting begins. Plow in the .spring and 

 sow to grain. After harvest plow again and then commence to use the 

 weed cutter. 



CHEMICALS. 



Experiments with chemical weed killers have demonstrated that 

 morning glory and many other weeds can be controlled. "We hope 

 before long to complete experiments which will prove that morning 

 glory and Johnson grass can be completely eradicated by the use of 

 chemical sprays. 



Spray with iron sulphate, 100 pounds to 50 gallons of water, or use 

 arsenite of soda, 1 part to 60 parts of water. The time to spray morning 

 glory is in the dry season, when the plants will absorb the spray readily. 

 Experiments tried in 1915 by Geo. P. Gray, of the University of Cali- 

 fornia, showed killing of the roots to the depth of three feet. Arsenite 

 of soda was used in this test. A high pressure sprayer should be used, 

 preferabl,y a power machine. 



Wild Mustard. (Brassica arvensis). — Spraying with iron sulphate is 

 the most practical and economical method of ridding large farms of 

 mustard and other weeds. Experiments have been conducted at several 

 agricultural experiment stations, to determine the practicability of 

 sprays as a means of weed control, and the results have amply justified 

 the work. Thousands of dollars can be saved the large grain grower by. 

 eradicating weeds from his fields. Iron sulphate Avill kill or control 

 mustard, cocklebur, ragweed, dandelion, daisies, wild lettuce, morning 

 glory, thistles, kinghead and many other broad leaved plants, without 

 harming the grain in the least. 



The method of preparing the solution and the application are taken 

 from Bulletin 179. University of Wisconsin Agricultural Experiment 

 Station, entitled ''Eradication of Weeds with Iron Sulphate." 



Empty 100 pounds iron sulphate into a 52 gallon cask and fill with 

 Avater. Kerosene and vinegar barrels are usually gauged at 52 gallons. 

 If tank of unknown size is used, put in ^ iron sulphate to f water by 

 Aveight. One hundred pounds of iron sulphate is sufficient to make 

 enough solution to treat one acre, and the sprayer should be so regulated 



