118 Maine Agricultural Experiment Station. 1918. 



ferences were slight, or within the limits of experimental error. 

 The writer has no explanation to offer as to cause of these 

 unexpected results. It is true that the dates of application in 

 1917 were much later than in 1913 and 1916, but they were 

 made at a corresponding stage of the development of the flowers 

 and fruit. 



LIME-SULPHUR VS. BORDEAUX MIXTURE. 



There has been, perhaps, little excuse to continue to in- 

 clude a plot sprayed with bordeaux mixture in these series of 

 experiments. It was omitted in 191 7. In the past it was re- 

 tained solely for the purpose of serving as a check, along with 

 the one sprayed with lime-sulphur and the unsprayed plot, for 

 a standard of comparison with the other spray combinations. 

 Regardless of seasonal conditions bordeaux mixture has invari- 

 ably caused much damage to the Ben Davis variety on this 

 farm, both by leaf injury and fruit russeting. Although almost 

 perfect scab control has been secured, the per cent of perfect 

 apples has been so reduced on account of russeting that spray- 

 ing with bordeaux mixture has actually resulted in a loss rather 

 than a gain. This is well illustrated when the record of plots 

 7 and 9 in 1916, Table I, are compared. Only a little more 

 than half as many merchantable apples were obtained on plot 7 

 as on the one where no sprav whatever was used. 



In 191 6, as in the past, lime-sulphur combined with ar- 

 senate of lead gave efficient scab control, as is shown by com- 

 parison of plots 9 and 1 where the amount of scab was reduced 

 from nearly 39 per cent to less than 1 per cent. On the other 

 hand the large amount of russeting which occurred where the 

 lime-sulphur and arsenate of lead was used reduced the per- 

 centage of merchantable apples to less than was obtained on 

 the check plot. In 191 7, while scab control was far from effi- 

 cient, the percentage of merchantable apples, as shown by com- 

 paring plots 5, 7 and 9, Table III, was increased approximately 

 29 and 49 per cent respectively by the lime-sulphur and arsenate 

 of lead treatment. 



The records over a series of years indicate that in most 

 seasons, even on a variety like the Ben Davis where the skin 

 of the fruit is easily injured, spraying with lime-sulphur com- 

 bined with moderate amounts of acid arsenate of lead is profit- 



