20 APPLE BLOTCH IN SOUTHERN ORCHARDS. 



disease. The results of the demonstration in the Kodgers orchard are 

 shown in Table III, of which Plot 4 was given the demonstration 

 treatment. The sprayed block yielded 92.9 per cent of sound fruit, 

 and the checks only 44.6 per cent. 



The spraying not only protects the fruit but the twigs as well, thus 

 preventing the formation of cankers, the chief source of infection for 

 the fruit. The value of one season's treatment in this connection 

 was shown in experiments conducted in the orchard of Mr. H. W. 

 Gipple, at Bentonville, Ark. Trees left unsprayed in 1906 and 1907 

 had 64.6 per cent of the 1907 crop affected with the disease, while 

 trees sprayed in 1906, but left unsprayed in 1907, had only 27 per cent 

 of diseased fruit. As shown by an examination of the trees, very 

 few new cankers were formed on the trees sprayed in 1906, which 

 undoubted^ accounts for the smaller amount of fruit infection in 

 1907. It would seem, therefore, that a few years' thorough spraying 

 might exterminate the disease from an orchard. 



STRENGTH OF BORDEAUX MIXTURE FOR APPLE BLOTCH. 



In the experiments reported in this paper Bordeaux mixture com- 

 posed of 5 pounds of bluestone and 5 pounds of lime to 50 gallons 

 of water was used. In several other experiments conducted by the 

 writers various strengths were used, and it was always found that 

 the weaker mixtures were uniformly less effective against both apple 

 blotch and bitter-rot. However, the mixture containing 4 pounds of 

 bluestone controlled these diseases almost as well as the stronger one 

 and has the advantage of being slightly less injurious to the fruit 

 and foliage. It also developed from these experiments that an excess 

 of lime in the Bordeaux mixture was slightly advantageous in respect 

 to injury, the 4-4-50 mixture causing somewhat more injury than 

 the 4-6-50 mixture. All things considered, the following formula 

 is perhaps best for general use : 



4 pounds of bluestone. 



4 to 6 pounds of stone lime. 



50 gallons of water. 



To this should be added 2 pounds of arsenate of lead or 6 ounces of 

 Paris green for the control of the codling moth and other insects. 

 If a good lime which will entirely slake into a smooth paste is used, 



4 pounds are sufficient, but if the lime is poor or partially air-slaked 



5 or 6 pounds, or even more, may be required to get the least possible 

 injury. 



The usual directions for preparing Bordeaux mixture by dissolving 

 the bluestone in one vessel, slaking the lime in another, and diluting 

 each with half the required quantity of water before pouring them 



