44 



This disease is of special .significance since there is no external evidence 

 of the malady on the nuts before they are cracked. When cracked 

 the kernels are seen to be jjartly shrivelled or otherwise badly de- 

 formed andi quite worthless. It would be impossible to keep this 

 disease from being imported into the U. S. as long as we allow any 

 filberts to be brought in from Italy or other countries where it occurs. 

 A very similar disease occurs on Lima beans in this country. It has 

 been found in Northern Illinois and Virginia and is probably rather 

 wide spread. I am of the opinion that the fungi are identical^ although 

 they have been given different specific n imes. If this proves to be 

 true, we may expect trouble from this disease in the future. 



Discussion 



The one outstanding jihrase in the previous discussion of nut dis- 

 eases is "It is probable." I think I have scanned the literature on the 

 subject of nut diseases with reasonable thoroughness. Nmnerous 

 isolated facts are known but these facts do not give us sufficient knowl- 

 edge to outline definite methods of control. It will be necessary for 

 northern nut growers t^ obtain knowledge of their diseases much is 

 the southern pecan growers have secured information on pecan scab 

 or California walnut growers on bacterial blight. In other words the 

 life histories of the fungi causing our common and destructive northern 

 nut diseases must be carefully worked out. This is necessary before 

 control measures can be satisfactorily applied. Then spray schedules 

 must be tried over a series of years until the number and kinds of 

 spray applications are established. Also, the life history studies will 

 point the way to essential sanitary measures. It will in other words, 

 eliminate much of the uncertainty which now exists and make nut 

 growing as a whole less of a gamble. 



We are fortunate here in the north in having the experience of 

 the Southern pecan growers to g;uide us. We have a reasonably cer- 

 tain knowledge of what sprays can be applied to nut trees with safety 

 and which spray mixtures will probably be most satisfactory. The 

 fact that Bordeaux mixture can be used on nut trees is in itself of 

 great significance since few fungi can escape when this fungicide is 

 applied in the proper manner at the proper time. \Vliat we must 

 learn now is when to apply the sprays. The nut industry is not yet 

 profitable enough to permit the application of ten or fifteen sprays 

 a year without knowing that these sprays are absolutely necessary. 



