The Black Rot of the Grape axd Its Control. 



399 



many of the shoots did not train to the wires but simply hung from the 

 crowns. An idea of the density of the foliage may be obtained from 

 Figs. loi and 102, which are photographs of the same vine. From the 

 appearance of this vine, the physical impossibility of spraying every 

 cluster even with a trailer can be seen. 



Very fortunately, however, certain peculiarities in the life habits 

 of the fungus make the later sprayings of less importance. In the 

 vicinity of Romulus during the past two seasons the following observa- 

 tions have been made. Although about August ist, or even a little earlier, 



Photo. Ang. 31, igo8 



Fig. 102. — Same vine as shown in Fig. 10 1 aiid frofn the saine position, but with 

 leaves stripped off. Shows average yield of vines. Notice presence of too many 

 short spurs with a leafy shoot, especially at the lower crown. This increases the 

 difficulty of spraying 



some berries rot and becom.e covered with the minute black receptacles 

 of the fungus, an examination of these receptacles with the microscope 

 reveals the fact that these bodies do not contain propagative spores 

 for the further dissemination of the fungus; they are for the most part 

 filled up with resting ceils, packed with food material, and to all appear- 

 ances are preparing for a period of rest. Receptacles containing summer 

 or propagative spores can be found occasionally, but there is no doubt 



