EXPERIMENT STATION BULLETINS. 441 



1921 when codling moth injury was very severe late in the season, dusting 

 did not give as good results as spraying. This condition was found at Fenn- 

 ville in the experiment with Wealthy and in other experiments not reported 

 in detail in this bulletin. 



Experiments With Pears. 



Pear scab has caused serious losses in recent years in orchards in south- 

 western Michigan. Many of the best growers have complained that the 

 usual spraying schedule has not been giving the desired results. This 

 schedule consists of three applications as follows: 



1st. When buds are separated in the cluster. 



2nd. Just after petals have dropped. 



3rd. About two weeks after second application. 



Experiments were planned to determine if more spraying is necessary 

 under Michigan conditions to satisfactorily control pear scab. Information 

 was also needed concerning the efficiency of dusting materials when used on 

 pears, so a considerable portion of the experiments consisted of a comparison 

 of the dusting and spraying methods of application with particular attention 

 to the control of scab and the effect on the foliage. 



EXrERIMEXTS IX 1920. 



Experiments were conducted in two orchards at South Haven in 1920. 

 One was on the H. E. Hawley farm and the other on the farm of H. E. Merritt. 



EXPERIMENT ON THE MERRITT FARM. 



The work on this farm was conducted in a block of 250 ten-year-old Bart- 

 lett trees. The orchard in which this block is located stands almost on the 

 bank of Lake Michigan. The trees had produced little fruit in previous 

 years but most of them bloomed full in 1920. 



Materials and applications. The block of trees was divided into three 

 large plots and one small plot, the small one being left untreated as a check. 

 Each of the large plots was treated with a different material as here listed. 



1. Lime-sulphur solution, 1-50. 



2. Sulphur dust. 



3. Copper sulphate dust. 10 per cent dehydrated copper sulphate. 



4. Check. Untreated. 



Lead arsenate was used in combination with these materials when neces- 

 sary. 



The applications were made as follows except that part of each did not 

 receive the "pre-pink" application. 



1st. "Pre-pink" application. When buds first showed color but had not 

 separated in the cluster. 



2nd. Pink or cluster application. When buds had separated in the cluster. 

 All parts of every plot, except the check, received this and later applications. 



3rd. Calyx application. Just after the petals had dropped. 



4th. About two weeks after the third application. 



The spraying was done with a spray gun and with a sprayer which main- 



