24 THE INDIANA WEED BOOK. 



suit has been that irmch of it has become impoverished and weed 

 ridden, and is therefore cultivated at a minimum profit. Feed the 

 crops and smother the weeds. 



11. TRY SPRAYING FOR SOME WEEDS. Within recent years it has 

 been proven that many weeds, especially those with comparatively 

 broad leaves, such as wild mustard, ox-eye daisy, white-top, horse- 

 nettle, wild carrot, yarrow, etc., can be practically eradicated from 

 timothy, wheat, oats and rye and from pastures by the use of 

 chemical sprays. The success of this method depends largely upon 

 the fact that cereals and grasses are narrow-leaved plants with a 

 single seed leaf, whereas the weeds mentioned and many others are 

 broad-leaved plants with two seed leaves. This fact enables one to 

 use the chemical for weed killing without much injury to the 

 cereals or grasses. 



The three spray solutions most used and the quantity applied 

 are: (a) Iron sulphate (copperas) solution, formed by dissolving 

 100 pounds of copperas in 50 gallons of water and used at the rate 

 of 50 to 60 gallons per acre. A granular form of iron sulphate can 

 at present be bought for $8 to $10 per ton. (5) Copper sulphate 

 (blue vitriol) solution, containing 8 to 10 pounds of blue vitriol 

 dissolved in 50 gallons of water and applied at the rate of 40 to 

 50 gallons per acre. The vitriol in barrel lots of 480 pounds costs 

 5 to 6 cents per pound, (c) Common salt solution, containing 3 

 pounds of salt to the gallon of water and used at the rate of 50 to 

 60 gallons per acre. A barrel of salt, 280-300 pounds, costs about 

 $1.15. 



For spraying large tracts a good spraying machine of consid- 

 erable force is necessary, while for small areas hand or knapsack 

 sprays may be used. Both should have good spray nozzles which 

 will deposit the solution as a fine mist upon the leaves of the weeds. 

 Special weed-spraying outfits are now on sale in almost any large 

 city. The following directions, as given by the Wisconsin Experi- 

 ment Station for spraying oat fields with a solution of iron sulphate 

 for the killing of wild mustard, will apply to the treatment of al- 

 most any grain or grass field : 



"The spraying should be done on a calm, bright day, after the dew 

 has disappeared, as the work is more effective if the solution is put on in 

 the warm sunlight. When rain follows the spraying within a few hours 

 the extermination of the mustard will not be complete. 



The grain fields: should be sprayed when the mustard plants are in the 

 third leaf, or before the plants are in blossom, in order to have the spray 

 do the most effective work. The day following the spraying the tips of 



