Spraying for Black Spot of the Apple. 



855 



TABLE [. — RESULTS OF SPRAYING AT DONCASTER. 



t Note. — All Bordeaux mixtures in Doncaster experiments made 

 on the 6- 4- 50 formula. 



From the forgoing table it will be seen that while the iinsprayed 

 plot gave only lU per cent, of absolutely clean fruit, the worst of the 

 sprayed ])lots, that is Bordeaux with nitrate of soda, returned 77 per 

 cent., and with the latter the total yield was more than three times as 

 great as that from the unsprayed plot. The cleanest fruit was from 

 the Bordeaux and salt plot, 9U'6 per cent, absolutely free from spot, 

 followed closely by Bordeaux alone, 90"4 per cent. Bordeaux, with 

 Paris Green, was distinctly inferior to Bordeaux alone, as only 8o per 

 cent, was qifite clean, and as these results were corroborated at 

 Killara, it would seem that Paris Green reduces the efficiency of 

 Bordeaux mixture as a fungicide, and does not increase it, as has 

 often been supposed. But, of course, where Codlin moth and similar 

 pests have to be fought, it may be that the mixture of Paris (4reen 

 and Bordeaux may be the best to use. 



If we turn to previous experiments in this line, and compare them 

 with the present, it is found that the addition of salt has been highly 

 satisfactory. At Pakenham, in 1901, which was a remarkably bad 

 season for black spot, the addition of 3 lbs. of salt yielded 100 per 

 cent, of marketable fruit, and altliough the ordinary Bordeaux 

 mixture did the same, yet the addition of salt yielded 67 per cent, of 

 absolutely clean fruit, as against 57 per cent, in the other. 



In the preparation of the various modified Bordeaux mixtures, 

 the added substance was dissolved in the copper solution ; but in the 

 case of the salt it was added to the milk of lime. The results 

 obtained from the Copper-soda solution are worthy of note. It was 

 tried at Killara as well ; but unfortunately the weight of the clean and 

 spotted fruit was not accurately ascertained, so that for the past 

 season only the one record is available. It is considerably behind 

 the Bordeaiix mixture in effectiveness, the proportion of absolutely 

 clean fruit being as 8(5 to 90'4. It is prepared similarly to Bordeaux 

 mixture, the washing soda replacing the lime, and the forniula 



