Pecan Diseases y and Spraying Outfits 183 



greatest damage is with the nuts. Early in the season it is 

 not nncommon for the entire crop of nuts to become so badly 

 damaged that they fall to the ground. Infection late in the 

 season is likely to cause the nuts to be undersized and to leave 

 a large percentage of mere empty shells. 



Pecan scab is very generally distributed over the south- 

 eastern states and to some extent over the entire pecan belt- 

 It is most severe along the Atlantic and Gulf coasts where 

 there is an abundant rainfall and a humid atmosphere 

 throughout most of the growing season. The severity of the 

 disease diminishes as the distance from the coast and the 

 elevation of the land above sea level are increased. Scab does 

 comparatively little damage to pecans 150 to 200 miles from 

 the coast, except on certain varieties known to be decidedly 

 susceptible.^ 



Scab is apparently carried over winter on the small diseased 

 spots on the twigs. The severity of the disease fluctuates from 

 year to jear somewhat according to the weather conditions. 

 Frequent rains and a constant humid atmosphere during the 

 spring and early summer produce conditions favorable to 

 severe infections of scab. In west Texas, where the rainfall is 

 light and the atmosphere less humid and where the elevation 

 is above 800 feet, scab is of minor consideration in the com- 

 mercial orchards and native groves. However, when some of 

 the west Texas varieties of pecans, the San Saba for example, 

 are planted in the coast country of the southeastern states, 

 they are very susceptible to the scab disease. 



*The entire crop of Beveridge pecans was destroyed by scab for a 

 period of several years at the Georgia Experiment Station which 

 IS more than 200 miles from the Atlantic Coast and has an ele- 

 vation above sea level of 046 feet. 



