BULLETIN No. 212. 



ORCHARD SPRAYING EXPERIMENTS IN 1912. 



W. J. ^lORSE AND G. A. YeATON. 



At this Station the first tests of lime-sulphur as a substitute 

 for bordeaux mixture in spraying apple orchards was made in 

 1908. This was an experiment jjlanned and conducted by the 

 Department of Plant Patholog}-, the results being reported in 

 Bulletin 164. In this work self-boiled lime-sulphur was pre- 

 pared by using both hot and cold water and was compared with 

 bordeaux mixture to test its efficiency in the control of apple 

 scab. Five varieties of apples were used, including the Fameuse 

 and the ^^Iclntosh, both of which are quite susceptible to scab. 



Although three applications of the sprays were made, the 

 first when the leaves were unfolding, the second just after the 

 petals fell, and the third about three weeks later, considerable 

 scab developed on all of the spra3-ed trees. While the results 

 from the self-boiled lime-sulphur showed that it had materially 

 reduced the amount of scab the bordeaux mixture showed much 

 m.ore efficient control of the disease. However the test was a 

 severe one and 99 per cent of the apples on the unsprayed trees 

 were scabbed. 



The same experiment was repeated in 1909 in the same or- 

 chard but, on account of weather conditions, that season scab 

 failed to develop even on the unsprayed trees, consequently the 

 results were inconclusive and were not written up for publica- 

 tion. Neither in 1908 nor in 1909 was there any spray injury 

 to be observed on foliage or fruit, even where the bordeaux- 

 mixture was used. 



Highmoor Farm came under the management of the Maine 

 Agricultural Experiment Station on July i, 1909, and the or- 

 chards, which now consist of over 2300 trees, furnished the 



