75° Jo/inial of Agrui/ltiirc, Victoria. \^o Dec, 1912. 



Table V. 



The sites for the plots were selected witli due regard to the raiiilall and its effect on the crops maturing 

 at different seasons ; Nos. 1 and 2, for the early Spring rains on the first early crcp ; No. 3 for early Summer 

 rain on the mid-season^crop, and No. 4 for the late Summer and Auliimn rains en the late crops. The 

 following table will show the number of wet days and total rainfall during the growing period at each 

 station : — 



and Koroit was hard spring-water, highly mineralized, and required 

 a much larger quantity of soda than the standard formula to preci- 

 pitate the copper. On applying the litmus and cyanide test, the solu- 

 tion contained too much copper, and instead of the standard 

 6 — 7I/2 — 50, it required 6 lbs. soda-copper, 12 lbs. soda, to 50 gallons of 

 water. At "Warragul, with soft water, the proportions were 6 lbs. soda- 

 copper, 8 lbs. soda, to 50 gallons of water. It is a question for the 

 future whether it would not be better to use the lime-water prepara- 

 tion, which has proved quite as effective, and much cheaper. The 

 latest formula is as follows : — 



Copper-sulphate — 10 ounces. 



Lime-water — 8I/2 gallons. 



Add water to make up 50 gallons. 



When considering the results of these experiments, it must be re- 

 membered that the season w^as an abnormally dry one, consequently 

 the results are no indication of the benefit to be derived from early and 

 systematic spraying, in such a season as 1910-11. The actual benefit 

 to be derived from spraying every season is far from settled. In other 

 countries, the results are not conclusive ; in some seasons they are 

 slightly in favour of the sprayed sections ; and in others it is in favour 

 of the unsprayed. But, allowing that the decreased yield in these ex- 

 periments is due to the effect of the mixture on the plants, it amounts 

 only to about 15 per cent., whilst the loss from the Blight in 1910-11 

 ranged from 25 per cent, to a total loss. As many fields were not 

 harvested, it is safe to assume that if spraying had been imdertaken 

 early, and persistently followed up, many of these abandoned fields 

 would have given a fair percentage of sound tubers. It is most de- 

 sirable that those growers w^ho have a spraying plant should be on the 

 alert for any appearance of an outbreak in the coming season, and 

 in carrying out the work are advised to have one or more unspraj^ed 

 control sections. 



