132 Diseases of Truck Crops 



fungus also seems able to pass from year to year as 

 viable mycelium in the late infected leaves of the 

 spinach. 



ANTHRACNOSE 



Caused by Colletotrichum spinacia Ell. and Hals. 







This disease is apparently limited to New Jersey 

 and Virginia, although it probably occurs also in 

 other States where spinach is grown. 



Symptoms. It appears as minute round water- 

 soaked spots on the leaves. These quickly enlarge 

 and become gray and dry (fig. 21 d). In the spots 

 will be found evenly scattered minute dark tufts; 

 these are merely fruiting pustules which also contain 

 minute black bristles or setae (fig. 21 e). The onset 

 is not limited to any particular part of the plant. In- 

 fection may take place anywhere on the foliage, 

 stems, or petioles. The spore pustules may be formed 

 on the upper as well as on the lower surface of the 

 leaf. In wet moist weather the pustules take on a 

 salmon tinge, indicating that there is an abundance of 

 spores formed at that time. The spores may be 

 carried from leaf to leaf and from plant to plant by 

 insects, wind, or rainwater. In badly infected fields, 

 picking should never be done during wet rainy 

 weather, neither should spinach from infected fields 

 be allowed to be shipped long distances, as in this 

 case the product may rot before reaching its destina- 

 tion. 



