RUBBER PLANTING 191 



trees with a brush. This remedy is found to be effective, 

 and the cost of application is small in comparison with 

 the value of the immunity obtained. Bordeaux mixture 

 is made by dissolving 5 Ibs. of copper sulphate in 

 25 gallons of water in a wooden barrel, and pouring 

 this solution into a large vessel simultaneously with a 

 like amount of milk of lime. The mixture must be 

 continuously stirred during the process. The milk of 

 lime is prepared by pouring water very gradually upon 

 5 Ibs. of quicklime, with constant stirring, the slaked 

 lime being finally made up to 25 gallons. Theoretically, 

 the amount of lime should be rather less than that 

 of the copper sulphate, but in practice perfectly pure 

 quicklime is not obtainable, so that some margin may be 

 allowed. 



Die-Back. 



A third disease which attacks the leading shoots of 

 Hevea is known as die-back. This expression describes 

 the nature of the disease with considerable accuracy. 

 The fungus responsible for the disease is known as 

 Gloeosporium alborubrum. This fungus is microscopic, 

 and its presence can only be recognised from its results. 

 These, however, are not generally serious unless the 

 dead shoots are attacked by another fungus, Botryodi- 

 plodia theobromae, which, as a rule, cannot by itself 

 attack living shoots. 



When only the first named fungus is present, the 

 dying back of the stem is confined to the leading 



