^4 AGRICULTURE OF MAINE. 



included in the experiments, and the latter are planned to cover 

 an indefinite series of years. 



While Bordeaux mixture is a very satisfactory fungicide to 

 use on resistant varieties, it has been shown at Highmoor, in 

 conformity with the almost universal experience under like con- 

 ditions elsewhere, that it is very unsafe to use it on those 

 varieties which are particularly susceptible to spray injury. 

 It has given good scab control, but on account of russeting the 

 yield of merchantable apples has averaged less than where no 

 spray whatever was applied. 



Standard summer dilution lime-sulphur controlled scab nearly 

 as well as 3-3-50 Bordeaux mixture and produced very much 

 less fruit russeting. Slight leaf injury occasionally occurred 

 but this was negligible from a practical standpoint. Increasing 

 the strength of the lime-sulphur summer spray 20 per cent 

 increased the percentage of merchantable apples for three suc- 

 cessive years. 



Timely application of the so-called "pink spray" is impor- 

 tant and essential for safety, but its omission three years out 

 of four led to no increase of scabbed fruit. Decidedly con- 

 trary results were obtained one season. 



The use of arsenate of lead alone, slightly in excess of the 

 amount commonly applied as an orchard insecticide, has unex- 

 pectedly given very satisfactory scab control for four successive 

 years. These results are simply suggestive — it is still an open 

 question how far Maine orchardists should depend upon it as 

 a fungicide for scab. 



The discovery of the apparent fungicidal properties of 

 arsenate of lead suggested the following modification of the 

 usual spraying program: Use a relatively strong, well-recog- 

 nized fungicide combined with arsenate of lead, just before 

 the flower buds open, followed by the stronger arsenate of lead 

 spray alone for later applications. For two successive years 

 seasonal conditions have made the results from this part of 

 the work inconclusive from the standpoint of the primary 

 object. They do appear to confirm the tentative conclusions 

 regarding the value of arsenate of lead in combating scab. 

 Also from them it is apparent that Bordeaux mixture is ruled 

 out, even for the single, early application, on account of 

 increased russeting of the fruit. 



