THE BOTANY OF THE APPLE TREE. 3 



must be sprayed with the ammoniacal carbonate of copper solution, 

 and it may be advisable to watch the red cedar trees, also, pretty 

 closely in the spring of the year for cedar apples. Spraying these 

 trees, also, might be useful. 



Brown Spot. In some of the eastern states the leaves of apple 

 trees are sometimes destroyed by a minute fungus (Phyllosticta pirina). 

 While I have not myself seen the work of this parasite in Nebraska, 

 specimens were collected at Lincoln three or four years ago by Mr. 

 H. J. Webber, then assistant in the Botanical Laboratory of the State 

 University, who makes the following record regarding it : " On ap- 

 ple leaves. Abundant and frequently destructive. November 12. 

 Lincoln."* It is therefore certain that it is in the state, and it is prob- 

 ably only a question of time when our orchards will be seriously 

 troubled by it. 



Professor Alwood of Virginia describes it as follows : f 



" The external appearances are, in the early stage, more or less nu- 

 merous quite minute spots on the leaves, circular in outline, and of a 

 brick-red color. These grow rapidly larger, maintaining a nearly cir- 

 cular form, and show at the center a pale, circular spot of straw-like 

 color. Occasionally several spots coalesce and show a large area of 

 diseased tissue. The first attack occurs here [in Virginia] shortly 

 after blooming, about the first of May, and by June 20, the foliage 

 first attacked is falling. About this later period the foliage becomes 

 very seriously spotted from a second attack, and a third outbreak oc- 

 curs about the last of July. Thus this disease develops three succes- 

 sive outbreaks in the course of the summer, and unless promptly 

 treated in its early stages, promises to be the most serious disease of 

 the foliage orchardists have had to contend with." 



It is suggested that the careful burning of the leaves which fall 

 from the trees may be useful in checking the rapid spread of this 

 disease. Spraying the foliage with Bordeaux preparation J at the 

 time the tree is in bloom is recommended also. 



* Appendix to the Catalogue of the Flora of Nebraska, Second Edition, p. 16. 

 t Bulletin No. 17 of the Virginia Agricultural Experiment Station, 1892, p. 62. 

 JThe Bordeaux preparation is made as follows for this use: 



Sulphate of copper , 4 pounds. 



Fresh lime 5 pounds. 



Water 50 gallons. 



Dissolve the copper and the lime separately and then mix the solutions. This is 

 what is known as a weak solution; it is usually made two or three times as strong. 



