• Apple Spraying Experiments in 1916 and 1917. 119 



able. It is only in exceptional seasons where a large amount 

 of russeting occurs as in igi6, that there is little real gain, and 

 actual loss of merchantable fruit may occur. These observa- 

 tions apply only to the value of the fruit as influenced by the 

 use of lime-sulphur and do not take into account the effects 

 of the spray in improving the general health of the tree, which 

 cannot be overlooked in practical work. 



It should be understood also that the above statements 

 with reference to both bordeaux mixture and lime-sulphur refer 

 only to the selling value of the fruit of the variety under con- 

 sideration. With any variety equally subject to scab and less 

 susceptible to spray injury there is plenty of evidence that spray- 

 ing with either fungicide combined with acid arsenate of lead 

 is, as a rule, exceedingly profitable. As a matter of fact if 

 apples were sold on the basis of quality and not on the ap- 

 pearance of the skin, those obtained on the plots sprayed in 

 1916 with lime-sulphur and bordeaux mixture were nearly 100 

 per cent perfect. The only imperfections were the russeting 

 of the skin. The fruit on these sprayed plots was larger and 

 in every way more healthy than on the unsprayed check. 



The single trial in 1917 of the "T. P." arsenate of lead 

 combined with lime-sulphur indicates that as good or even better 

 results may be obtained with this material than with the acid 

 arsenate used in like manner. It will be seen on comparing 

 plots 7 and 5, Table III, that on account of more efficient scab 

 control approximately 20 per cent more merchantable apples 

 were obtained where the "T. P." arsenate was substituted for 

 the acid arsenate. It is interesting to note, however, that while 

 the difference was slight, less russeting was obtained by the use 

 of the acid arsenate. Compare also plots 1 and 2, Table III, 

 where these two forms of arsenate of lead were used alone, 

 double strength. 



THE EFFICIENCY OF THE FIRST SPRAY APPLICATION. 



The results here reported are for the fifth and sixth sea- 

 sons in which a plot has been included in these spraying ex- 

 periments whei'e the application of lime-sulphur when the 

 blossom buds were showing pink was omitted. It will be noted 

 on comparing the figures obtained in 19 16 on plot 4 with those 

 for plot 1, Table I, that scab control was only slightly better 



