2 BULLETIISr 1102, U. S, DEPARTMENT OF AGRICULTURE. 



under natural conditions. He gave no method of possible means of 

 control. However, he suggests in a footnote that affected nuts should 

 be gathered and burned, in order to lessen the chances of further 

 spread of the disease. 



Turner (6) reports a severe outbreak of kernel-spot throughout 

 central and southern Georgia during the season of 1916. He, as 

 well as several growers, observed that orchards having an abundance 

 of kernel-spot were planted to cowpeas ; also that these same orchards 

 had a severe infestation of the southern stinkbug (Nezara viridula 

 L.). He at first considered this to be possibly only a coincidence. 



However, Turner conducted a preliminary experiment the following 

 season to test the possibility of an association of pecan kernel-spot 

 with punctures of sucking insects. His work, though conducted on a 

 small scale and apparentlj^ with no check except nuts growing upon 

 the tree not confined with bugs, indicated very strongly that these bugs 

 bore either a -direct or an indirect causal relation to the disease. Xo 

 attempt wa^s made at that time to determine what part the fungus 

 C omothyrviiTn caryogenumti'Ra.Tid played in the cause of pecan kernel- 

 spot. 



Since one of the investigators above cited conducted his work 

 entirely in a laboratory and from a pathological standpoint and the 

 other did field work only, ,and from an entomological standpoint, 

 and the two results were in a way contradictory or, at least, not cor- 

 roborative, the growers were considerably confused as to the true 

 cause of the disease and, therefore, as to the adoption of possible 

 remedial measures. Consequently, the writer was urged to con- 

 duct an experiment combining both field and laboratory work to 

 definitely determine which of the above-named investigators arrived 

 at the correct conclusion regarding the cause of pecan kernel-spot. 



ECONOMIC IMPORTANCE. 



It is difficult to estimate the amount of damage and the extent 

 of the prevalence of kernel-spot, owing to the fact that the evi- 

 dences of the disease are not discernible until the shells of the nuts 

 are removed. 



Pecans from planted orchards do not ordinarily go to cracking 

 establishments, but are widely distributed in small quantities in the 

 shells to consumers, adding greatly to the difficulty of accurately es- 

 timating the proportion of nuts affected. While the nuts in some 

 orchards will be entirely free from the trouble, in other orchards 

 such a large percentage of the nuts will be spotted that the crops 

 will be unmarketable. 



The most serious losses have been reported to the writer by grow- 

 ers in southern Georgia, northern Florida, and Texas. The trouble 



