560 THE Monthly bulletin. 



"The natural program, therefore, in every pine and oak mixture, is 

 so to eliminate the oak as to afford the pine a better opportunity to take 

 possession of the ground. How this may best be accomplished depends 

 entirely upon the individual characteristics of any particular wood lot. 

 And, furthermore, it is strictly a problem in applied forestry and one 

 for the forester, not for the entomologist, to solve." 



To those who have witnessed the devastation of the New England 

 forests through the gypsy moth during the past twelve years, Mr. 

 Fiske's message will be most welcome. While in the light of the work 

 done the remedy seems simple enough, the idea is a big one, really the 

 result of genius, and the Bureau of Entomology is to be congratulated 

 on having placed so able a man as Fiske on this important Avork. 



TEAR STAINING OF LEMONS. 



(Due to the fungus ColletotricJium gloeosporioides Penz. ) 



By H. S. Fawcett, Plant Pathologist, State Commission of Horticulture, Whittier, 



California. 



A faint, reddish stain has often been noticed on lemons, as if formed 

 in a drop of dew, or as if a drop of water had run down over the 

 surface of the fruit, leaving infection in its track. It sometimes covers 

 a large part of the fruit. Usually this stain only slightly injures the 

 appearance of the fruit, but since it is set in the surface of the rind 

 and cannot be washed off it is sometimes troublesome. 



This faint staining of the surface is not to be confused with "red 

 rot" (see Fig. 57, Bui. 218, California Experiment Station), in which 

 a large area on one side is highly colored and somewhat hard and 

 shrunken, nor with "red spot," a reddish pitting in which small red 

 sunken pits are formed. (See description and Fig. 18 by E. 0. Essig, 

 in Pomona College Journal of Economic Botany, Vol. I, page 33, and 

 see also illustration in California Plant Diseases, Bui. 218, Fig. 55, 

 California Experiment Station.) Considerable doubt has existed as 

 to whether the faint, reddish discoloration on lemons in California, 

 known as tear stain, was due to the same cause as the tear stain of 

 Florida fruits attributed by P. H. Rolfs to the wither tip fungus 

 Collet otricliuni gloeosporioides. 



Some recent experiments by the writer indicate that it is the same. 

 The results of the experiments are also confirmed in an unpublished 

 manuscript report by C. N. Jensen in 1910 at the Whittier Laboratory, 

 that a reddish stain of this kind can be produced on uninjured lemons 

 in California with spores of this fungus. Lisbon lemons of various ages 

 were picked and placed at once into a glass jar on March 14, 1913. 

 The spores from a culture of wither tip fungus isolated from a lemon 

 tree at Santa Paula were shaken up in water and poured over these 

 fruits. The jar was then covered to keep the fruit moist. In two 

 weeks the faint reddish stains in blotches and in lines where the water 

 with spores had run down were quite prominent. In four weeks they 

 were still more pronounced. They appeared to develop on green, 

 half-grown fruit, as well as on mature fruit. Other fruits picked at 

 the same time and kept in a moist jar without the application of the 



