94 



APPLE GROWING IN CALIFORNIA. 



POWDERY MILDEW OF THE APPLE. 



(Podospha'ra leucotricha and P. oxycantha.'.) 



The above disease and scab are the two worst fungous troubles of the 

 apple that occur in California. Mildew attacks the leaves and tender 

 twigs and is recognized by a whitish powdery appearance of the twigs, 



Fig. 50. Apple twig affected with mildew, showing 

 (After R. E. and Elizabeth H. { 



' characteristic appearance. 

 Imith) 



both in the summer and winter seasons. There is also more or less 

 curling of the leaves. According to Bulletin No. 120, recently published 

 by W. S. Ballard of the Bureau of Plant Industry and W. H. Volck, 



