192 Pecan-Growing 



Infections of anthracnose occur on both the leaves and the 

 nuts of the pecans. The fungus forms reddish to grayish- 

 brown blotches on the leaves, varying in size, sometimes 

 covering the entire leaf. On account of the reddish color 

 of the blotches the disease is often spoken of as ''rust'' by 

 pecan-growers. The blotches on the nuts are black, irregu- 

 lar, and slightly sunken below the surrounding healthy 

 tissue. 



In extreme cases infected young nuts and leaves may be 

 attacked so severely that they fall to the ground. Generally, 

 however, the infection is on the outer surface of the husks of 

 the nuts and on mature leaves, where very little damage is 

 done. The losses to growers from anthracnose have been so 

 small that specific control measures have been thought un- 

 necessary. 



PECAN CATKIN DISEASE 



(Microstrojim juglandis, (Bering.) Sacc, var, 

 robv^turn, Higgins.) 



The distribution of this disease is not well known. It is 

 found on the catkins of practically all the commercial varieties 

 of pecans in the early spring soon after the catkins reach full 

 size. Infected staminate flowers of catkins are somewhat 

 distorted and are of a paler green hue than normally. 

 Higgins found that ''The stamens and under-surface of sub- 

 tending bracts were covered with a white substance w^hich, 

 at first glance, gave the impression of white fly; but, which, 

 on examination, was found to be the w^hite spore-clusters and 

 basidia of a fungus belonging to the genus Microstroma. A 

 little later when the pollen was being shed, the contrast be- 

 tween healthy and diseased catkins was made more conspicu- 



