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UNIVERSITY OF CALIFORNIA EXPERIMENT STATION. 



tree. The season of blooming for 1908 was about three weeks later than 

 that of 1907. During the period that this experiment was taking place 

 there was no natural infection developing on the nuts of this tree or in 

 the orchard. The climatic conditions were decidedly unfavorable for 

 blight development. From these inoculations a fair percentage of the 

 nuts became diseased, while from those that dropped no accurate data 

 was secured. 



It should be remembered that the season of 1908 was one in which the 

 nuts were practically free from blight, and yet from our atomizing 

 experiments the blight could be produced when the germs were placed 

 on the nuts, although the percentage was somewhat less than that of 

 1907, because of the less favorable conditions. The small amount of 

 blight for 1908 was due largely to a lack of foggy weather, which is one 

 of the chief ways in which the germs are distributed to the nuts from the 

 old natural sources of infection on the branches. 



Table showing source of culture and tests of puncture inoculation on young shoots. 



