The Bulletin. 7 







cle organisms extreme care must be taken to avoid any field having this 

 or any other soil disease. While no positive statement can he made it 

 is very likely that the feeding of affected plants would lead to the 

 infection of stable manure, by means of which the disease would be 

 carried readily to new places. 



Infection. — Infection is favored by wet seasons, by high moisture 

 content of the soil, by mild winters, and by rank growth of the host 

 plants. 



Fig. 2 Stem Rot of Alfalfa. Note the white growth of the fungu3 and the selerotia or resting 

 ing bodies. Photo, by F. C. Stewart 



Control. — As soon as the disease appears adopt a rotation of crops 

 that will keep susceptible crops off the land for three to five years. 

 Guard against feeding affected plants to stock or distributing infected 

 soil in any way. Be sure before buying that clover or alfalfa seed is 

 free from contamination with the selerotia. In small plantings where 

 only a few plants are affected it may be worth while to put dry straw 

 on the spots, sprinkle with kerosene oil and burn. 



CORN EAR ROT. 



Distribution. — This trouble has been reported from all parts of the 

 State, but with most frequency from the mountain section. 



The only plant affected is corn. 



Symptoms. — Affected ears ripen prematurely, the husks are tight, 

 the ears light in weight, under sized, dark in color, and affected with a 

 dry decay. There is a moldy growth between the grains and over their 

 tips. The corn shelled from affected ears weighs only half as much as 

 that shelled from sound ears of the same dimensions. Very minute 

 black dots can be seen on the affected cobs. Old stalks also show such 

 dark dots just under the rind. 



Cause. — This condition is caused by the fungus Diplodia zeae. While 

 several other fungi may be responsible for other types of ear rot of 

 corn this is usually the most destructive one. Some of these can attack 

 the ears only when they are harvested before maturity and stored im- 

 properly. The fungus in question is an active parasite, and establishes 

 itself on the living corn plant. 



