178 Mortier F. Barrus 



varieties. Of course the yield in such a case will be reduced below that 

 obtained when a greater amount of seed is used, but not proportionately. 

 It is impracticable, however, to plant hills at a distance sufficient to 

 keep the vines of one hill from touching those of others during the latter 

 part of the season. Just what. distance apart the hills of any variety 

 should be planted in order to secure a satisfactory yield and protection 

 from infection has not been determined. Whatever has been said on 

 this subject should be considered also in the light of present knowledge 

 concerning the possibility of spore dissemination by spattering. 



Good land drainage 



The relation of drainage to bean anthracnose is obvious. Poorly drained 

 soil is cold, and bean seed planted in such soil starts slowly or not at all. 

 If the seed is diseased, the fungus develops rapidly and usually destroys 

 the seedling before it appears above ground. During a wet season poorly 

 drained soil tends to produce a moist condition about the base of the 

 plants, which should be avoided. Galloway (1889) notes that the disease 

 is worse on moist soil. Cobb (1894:383) and Querner (1908), in recom- 

 mending control measures for the disease, suggest draining the land, and 

 others suggest not choosing low, damp ground. 



Removal of affected seedlings 



Affected seedlings serve as a source of infection to healthy plants in 

 the field and the garden. An early removal of them would aid in lessen- 

 ing the amount of disease should favorable weather for infection follow. 

 The practice of removing affected plants was early recommended. 

 Berkeley (1880) suggests that diseased plants be pulled and burned, and 

 many other writers on the subject have recommended this. Whetzel 

 (1908:433), however, has pointed out that this method is absolutely 

 impracticable except in short garden rows. It is, of course, out of the 

 question to attempt to remove affected seedlings from a field. However, 

 in the seed plot and in the garden it is worth while to remove and 

 destroy such plants, as- is explained later. If the weather remains dry 

 following the appearance of the seedling, the diseased cotyledons will drop 

 off before further infection of the seedling takes place, as already noted 

 (page 161). In such a case the field would be as free from disease as 

 though every diseased seedling had been removed. Appel (1916) has 



