l6 MAINE AGRICULTURAL EXPERIMENT STATION. I9I2. 



growth of the adjacent healthy tissue continued, it ultimately 

 tore apart the dead areas and prominent splits or clefts ap- 

 peared (Figs. 5 and 6). 



The discussion of sunscald and spraying is considered later. 



The table on page 17 gives the data according to the respect- 

 ive observations. 



Discussion. 



Calyx Injury. Only one instance of the calyx injury ob- 

 served quite generally in last year's plots was found the past 

 summer. This was seen in a few fruits of one or two Ben 

 Davis trees belonging to another experiment, and which are 

 and have been in sod for an unknown period. In this soil en- 

 vironment they have been naturally quite unthrifty, with poor 

 and small amount of foliage. Their fruits in 1911 were re- 

 markable for small size. Fully fifty percent were no larger 

 than the larger crab varieties. (Fig. 4). 



The fact that such injury was confined to these few unthrifty 

 trees, whereas none whatever was to be seen during the season 

 on several thousand trees of the same variety in vigorous con- 

 dition; and the further fact that the trees showing such injury 

 last year were in that year experiencing their first season of 

 renovation, and were to a large degree bearing good fruit in 

 1910 more in spite of preceding neglect than as the result of 

 any direct response to that year's treatment, raises the question 

 whether or not such calyx injury was not indirectly due as 

 much to the lack of vigor as indicated by the tissues of the 

 fruit, as to the caustic action of the spray. 



In a discussion of this calyx injury in an earlier publication * 

 the writer attributed it largely to chemical reaction between the 

 lead arsenate and lime-sulphur when combined. It has been 

 found that such combination tends to release arsenic in soluble 

 form, and this would in itself furnish the grounds for an ex- 

 planation of such injury. 



The fact, however, that the same spray materials were used 

 this year, would present the same conditions, so far as forma- 

 tion of soluble arsenic is concerned. Furthermore, on the basis 

 of Wallace's results, previously mentioned, we might expect a 

 more serious injury when lime-sulphur and lead arsenate were 



*Bu]. 189, Me. Agr. Exp. Sta. (1911). 



