28 STATE HORTICULTURAL SOCIETY. 



of apple scab causes an injury similar to that which I am discussing. And 

 spraying with the arsenite sometimes causes such injuries, and spraying 

 with lime alone will sometimes produce russeted areas and cracked-open 

 fruit, as in the case of the real Bordeaux injury. So that there are other 

 agencies which may malform and injure fruit somewhat as does the Bordeaux 

 injury. But the real Bordeaux injury can be told by all who have once had 

 their attention called to it, it is so striking and so individual. Its character- 

 istics are so peculiar that, once it is known, one ever after recognizes Bor- 

 deaux injury. 



In our work it was found certain sorts were almost immune to this injury 

 — Northern Spies, Kings, Russets; the Alexander is still another, and Ave 

 were not at all troubled with many other varieties from spraying with Bor- 

 deaux, while other sorts were very susceptible. Unfortunately for us in 

 New York, the Baldwin and Greening are very susceptible to Bordeaux 

 injury, so it is almost impossible to spray and control apple scab and not do 

 considerable injury to those two sorts. 



As to the way in which the injury is caused, it is pretty difficult to say. 

 As I said in the beginning, Bordeaux mixture changes in its chemical com- 

 position, after being applied, under the action of the sun and water and 

 moisture, and it is hard to tell just Avhat chemicals are set loose and how 

 the action does take place; but it is supposed that the lime and the copper 

 sulphate are disassociated and the copper sulphate becoming an acid, eats the 

 tissues, kills the cells, and carrying these dead cells as the live cells grow about 

 them, the ej^idermis becomes ruptured and split open, and the russeting 

 comes from this dead tissue — the action of the growing tissue about 

 this dead tissue, just as, if you injure the tissue of fruit in any way; 

 for instance, rubbing of the fruit against a branch, or the action of frost 

 or any other agency Avhereby cells die and become centers from Avhich living 

 tissue must part, tearing open the epidermis, AA^e get this russeted appearance 

 of the fruit. 



Coming now briefly to the experiments carried on at our station last year; 

 we de\'oted ten acres in our experimental orchard to this Avork, keeping 

 several men at it nearly all summer. We were determined to find out just 

 exactly, as nearly as possible, what conditions, at any rate, caused the trouble; 

 and in order that we might have all conditions, we secured the cooperation 

 of 25 fruit groAvers in different parts of the State, hoping thereby to secure 

 the different effects of all Aveather conditions. 



In all these experiments AA^e had, Avithin the one large experiment, four 

 distinct experiments : 



First, to determine for a certainty \A-hether or not Bordeaux mixture does 

 cause this injury. So that one part of all the experimental plots was devoted 

 wholly to this one end; leaving checked trees to see Avhat the effects of Bor- 

 deaux mixture Avould be on neighboring trees, and the lack of it on trees not 

 sprayed. 



Second, part of the experiment Avas to determine what effect Avet AV'eather 

 had upon Bordeaux mixture; so that Ave devoted a considerable number of 

 the experimental orchards to plats in which the Bordeaux mixture Avas 

 applied either during or just before or just after a rain. 



The third part of the experiment Avas to determine the value of the excess 

 of lime. In my correspondence Avith horticulturists all OA^er the country 

 the preceding year I ascertained that a great number of fruit growers held 

 that by adding an excess of lime they could prevent any of this injury — 

 perfectly sure that one needed only to add double or treble the quantity 



