278 DISEASES OF TROPICAL PLANTS OH. 



mixed when needed. The mixture will not keep. The 

 mixture can be combined with insecticides and the two 

 used as a single spray. 



This mixture discolours the plants, and for that reason 

 cannot be used on fruits which are nearly ready for 

 market. Therefore, it is frequently necessary to use 

 some other preparation for the last spraying of certain 

 crops. 



Copper Sulphate. Copper sulphate may be dissolved 

 in water in proportions of one pound of the copper 

 sulphate to twenty-five gallons of water, and used on 

 trees when not in foliage to remove lichens and to kill 

 the spores and mycelium of fungi, but cannot be used in 

 trees in foliage without danger. 



Burgundy or Copper-Soda Mixture. This mixture 

 is recommended as a substitute for Bordeaux by 

 Mr. George Quinn, of South Australia. It consists of 



Copper sulphate ...... 6 Ibs. 



Sodium carbonate (washing soda) . 9 Ibs. 

 Water 50 gallons. 



It is made in the same manner as Bordeaux mixture. 

 This mixture has been recommended by the English 

 workers in Australia, who claim that it is efficient in 

 protecting many plants against their fungus parasites, 

 and that it is not so severe on young foliage as the 

 Bordeaux mixture. The writer is not familiar with 

 its use. 



Ammoniacal Copper Carbonate. 



Copper carbonate . . 5 oz. 



Ammonia ... 3 pints. 



Water . . . .45 gallons. 



Dissolve the copper carbonate in the ammonia. 

 This solution can be kept and diluted for use at any 

 time, but it spoils easily after dilution with the water. 

 It is a clear blue liquid, and is used as a substitute for 

 Bordeaux when fruit is near maturity, and also on green- 

 house plants. It is not so good as Bordeaux, but it 

 does not discolour the fruit, and thus reduce its market 



