166 THE MONTHLY BULLETIN. 



the soil under the trees in summer and covering it in winter with a straw 

 or a green cover crop. Thick Bordeaux mixture sprayed on the ground 

 under the trees in winter aids in controlling the disease. Lemons are 

 most liable to contract the rot in the tank of the washing machine w^here 

 the water becomes filled with spore-infested orchard soil. Disinfect 

 wash water with copper sulfate. See Bulletin 190, California Experi- 

 ment Station. 



Apple and Pear Scab. 



Attention has been called to this fungus which produces the scabby 

 patches on the fruit and leaves of these two fruits." Bordeaux mixture 

 5/5/50 formula is used just before the buds are opening ; a second or 

 third spraying is sometimes applied at later intervals. Conditions will 

 determine number of applications of the fungicide. 



Brown Rot of Stone Fruits. 



Brown rot is another important disease of a fungous nature which 

 attacks the stone fruits in localities where suitable moisture conditions 

 prevail. Georgia peach and plum growers lost approximately $600,000 

 in 1900 from an attack of the brown rot. Preventive measures consistin 

 destroying mummied diseased fruits or bliglited twigs and spraying with 

 a fungicide. R. E. Smith recommends for trial self-boiled lime-sulfur 

 just a"s the fruit is setting, and again after the rains are over. See 

 Bulletin No. 203, page 39, California Experiment Station. 



Apple Mildew. 



Apple mildew causes a dwarfing of the tips of new shoots and covers 

 them with the characteristic whitish growth.. Some growers have used 

 the caustic-soda-sulfur spray, 10 pounds of dry sulfur being added 

 to each fifty gallons of the spray; others iron sulfide, spraying 

 frequently throughout the early part of the season, beginning just 

 before the buds open. 



Cherry Gummosis. 



The formation and exudation of gum by an abnormal condition of 

 the cherry is commonly termed "Cherry gummosis." Often death of 

 the tree results. The work of F. L. Griffin of the Oregon Agricultural 

 College has demonstrated that gumming in the sweet cherry may result 

 from the attack of a certain species of bacteria. These same organisms 

 rriay also cause the blight of the cherry buds, gum may or may not exude 

 from the affected portions. The Mazzard cherry as a resistant stock, 

 the cutting out of diseased parts of the tree, sterilization of the wounds 

 thus made by the application of a solution of corrosive sublimate, 1 to 

 1000, when dry, the coating of large wounds with walnut-grafting wax 

 as a' protection against the entrance of rot fungi, have been recom- 

 mended as control factors. 



Rose Mildew. 



Last year many sfmiples of rose leaves and shoots affected Avith a 

 w hitish thick growth came to the office of the Commission. This diseased 

 condition of the rose results from the attack of the powdery mildew 

 fungus. The most eft'ective treatment consists in thoroughly spraying 



