98 



The strength of the Bordeaux solution consisted of six pounds of copper sul- 

 phate, four pounds of lime and fifty gallons of water, while thiit of the ammoni- 

 acal copper carbonate consisted of one ounce of copj)er carbonate dissolved in 

 ammonia and diluted with nine gallons of water. The latter solution proved too 

 strong, some of the plants showing considerable injury two days afterwards. 

 Subsequent sprayings were made with a much weaker solution. 



The plats were sprayed quite frequently during June. In July, owing to the 

 absence of the writer during the early part of the month, and frequent showers 

 during the middle part of it, the sprayings were somewhat interrupted. The par- 

 tial failure of the fungicides in completely preventing the smut may be largely 

 attributed to these facts: 



On July 20th some injury to the plants from the liordeaux was noted, and for 

 the remaining sprayings the strength of the solution was reduced one-third. The 

 last spraying was made August 14th, the plants being then supposed to be too 

 mature for infection. 



The dates of spraying were as follows.- 



Just previous to harvesting the crop a careful record of the number of smutted 

 stalks was made and gave the following percentages of smutted stalks: 



Unsprayed plants 1.S.37 per cent. 



Those sprayed with Bordeaux 3.83 per cent. 



Those sprayed with ammoniat'al copper carbonate, 6.72 per cent. 

 It will be readily seen from the above figures that there is a marked dificrence 

 in the amount of smut between the sprayed and unsprayed plats. 



