lo Dec, 191^-] Results of Spraying for Irish Blighi . 



747 



plot a month later, the latter thus receiving the benefit of the Decem- 

 ber rain, which amomited to 393 points at Warrnambool. 



The amount of disease in the Crossley plot was insignificant, the 

 only indication of any benefit being a decrease in the percentage of 

 Blight as the number of sprayings increased, but the average yield was 

 in favour of the unsprayed sections by 13 ewt. 67 lbs. 



The results of the Wollaston plot were more satisfactory, showing 

 in a marked manner that spraying checks the disease even in a dry 

 season. It will be noted that both the unsp rayed sections have practi- 

 cally the same percentage of diseased tubers, viz., 4.3 and 4.7 per cent., 

 whilst that sprayed only once has the largest amount of disease in the 

 spi'ayed sections, viz.. 2.5 per cent. Another spraying reduced the 

 percentage to 1.4, the third to .5, and the fourth to nil. 



In the case of the Wollaston plot, it will be noted that the 

 yield showed an average increase of 12 cwt. 92 lbs. per acre in 

 favour of the sprayed sections. This increase, no doubt, appears 

 small ; but, taking into consideration the very dry weather experienced 

 during the growing period, it may be regarded as satisfactory, and 

 proves beyond doubt that spraying increases the quantity of sound 

 tubers. 



Table III. 



SPRAYING EXPERIMENTS, 1911-12. 



Plot 3. — Mid-seasok Crop. 

 Mr. S. Mackay, Warragul. 

 Variety — Carman. 



Plot 4. 

 Mr. Ibbott, Pootilla. 

 Varietj' — Snowflake. 



Reference to table 5 will show that at Warragul for the period 

 embracing December, January, February, December had seven- 

 teen wet days, resulting in 704 points of rain, and January had eight 

 wet days before the 11th, with 121 points, with only 5 points for the 

 remainder of the month. Such conditions were favorable for the de- 

 velopment of the disease, with the result that it made its appearance in 



•2 V. 2 



