Pecan Diseases, and Spraying Outfits 189 



most generally recommended. The dead and diseased twigs 

 are difficult to locate in winter. More effective w^ork can thus 

 be done if the trees are carefully gone over in the fall just 

 as the leaves begin to shed, and again in the spring after the 

 buds swell. In both operations the diseased twigs are cut off 

 well down below the juncture of the dead and the live wood 

 so as to make certain of removing all infected tissues. The 

 control of dieback depends very largely on keeping out dead 

 and weakened branches. Twigs injured by rosette or by at- 

 tacks of insects often afford harboring places for the dieback 

 fungus, and so far as possible should be pruned and destroyed. 



NURSERY BLIGHT 



{Pliylloticta caryce, Peck.) 



Pecan nursery blight is confined to the leaves and is prin- 

 cipally a disease of nursery stock. It is, however, sometimes 

 found on mature trees, especially those weakened by over- 

 crowded planting or ^Wth their vitality lowered by rosette. 

 In fact, attacks of the disease are favored by any condition 

 which may lower the vitality of the tree. 



The disease has about the same distribution as that of pecan 

 scab and is usually first observed in April soon after the 

 leaves reach full size. Eand found that the first indication 

 of infection of nursery blight appeared as ^^ Minute, roundish 

 spots, which are dark reddish brown on the upper leaf surface 

 and blackish on the lower. These slowly increase in size until 

 a diameter of two to five mm. is often reached in the indi- 

 vidual spots. "With increase in size the center of the spot 

 on the upper surface assumes an ashen-gray color, which is 

 usually bordered with reddish brown, while the lower surface 

 remains black throughout or with an occasional tiny ashen- 



