DESCRIPTION OF PLATES. 



Plate I. {Frontispiece.) Three apples affected with bitter-rot and three mummies 

 which presumably furnished the infection. The twigs with these fruits and 

 mummies attached were cut from one of the uni^prayed trees in the experimental 

 orchard on July 10, and the photograph was made two days later. 



Plate II. The microscopic characters of the bitter-rot fungus ( Glomerella rufomacu- 

 lans (Berk.) Spaulding & von Schrenk): i.— Five asci, each containing eight 

 ascospores; also one probably immature ascus. X 900. ^. — A group of free 

 ascospores. X900. 3. — A group of ascospores germinating in a drop of water. 

 X 900. 4. —Spore-bearing hyphw springing from a mycelium growing in nutrient 

 agar: o, the mycelium giving rise to the fertile hypha?; b, a group of conidia, 

 or summer spores, newly born. X 600. 5.— A group of germinating conidia. 

 X 7-10. 6.— A section through a pustule showing the ruptured skin of the apple, 

 the spore-bearing hypha?, and the free conidia. X 200. 



Plate III. Fig. 1.— The crop picked from one tree of Plot 3, showing 33i bushels of 

 sound fruit on the left and 1 J bushels of rotten fruit on the right. Fig. 2.— Fruit 

 from an untreated tree (Check A). The only sound apple from the tree is 

 shown on top of the basket. 



Plate IV. Fig. 1.— Crop picked from one of the trees in Plot 6, showing 39 bushels 

 of sound fruit and less than a peck of rotten fruit in the half-bushel measure on 

 top of the pile. The fruit still shows a coating of Bordeaux mixture. Fig. 2.— 

 The crop from an unsprayed i,ree (Check D), showing only two sound apples, 

 Avhich are placed on a board on top of the heap of rotten fruit. 



Plate Y. Fig. 1.— Fruit from one of the trees in Plot 1, showing 13i bushels of 

 bitter-rot apples on the right, and 10 bushels of sound apples on the left; treat- 

 ment too early for best results. Fig. 2.— The fruit from Plot 12, showing 12 

 bushels of sound apples on the right, and 12J bushels of rotten fruit on the left; 

 treatment too late to save the crop. 



Plate VI. Fig. 1. — A yellow Newtown apple badly affected with bitter-rot, and 

 another recently mummified by the fungus. The specimen designated A shows 

 a typical case of bitter-rot on a Yellow Newtown ai)ple. The fruit was taken 

 from the tree in this condition. The apple marked B has been recently mum- 

 mified by bitter-rot, the entire fruit having become involved in decay. Fig. 2.— 

 Apples harvested from one tree in Plot 16, showing 28* bushels of sound fruit 

 above and to the left, and U bushels of rotten fruit in and near the baskets. 

 Plate YII. An unsprayed tree (Check A) with most of its crop on the ground at 



picking time, illustrating the destructive work of the bitter-rot. 

 Plate YIII. Fig. 1.— The platform and equipment used in preparing Bordeaux mix- 

 ture; also showing the spray tank receiving a supply of Bordeaux mixture. 

 Fig. 2. — The spraying outfit in operation. 

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