-3- 



highly poisonous metal on fruits and vegetables, the material must be used 

 in such a manner as to preclude any mercury residue on the harvested crops. 

 Analyses made of apples spra^'^ed by Puratized in 1944 and 1945 indicate a 

 detectible residue of mercury when the spray was used throughout the season, 

 but none when the spray was discontinued after the first cover spray. If 

 Puratized is used on fruit crops, it should not be included in the schedule 

 later than the oalyx or first cover spray. 



The supply of Puratized is still limited, and the manufacturers 

 indicate that it will be plentiful in 1946 only for limited use under care- 

 ful supervision. It vjill be sold as Puratized Agricultural Spray, and the 

 stock solution v/hen diluted in the spray tank at the rate of one pint to 

 loo gallons will give a concentration of the active ingredient of 1:15,000'. 



Isothan Q-15 (Lauryl isoquinolinium bromide). This is one of the 

 recently developed quartenary ammonium derivatives that has given consider- 

 able promise in the control of apple scab and the leaf and fruit spots of 

 pears. It, like Puratized, is vifater-soluble ; it possesses a high degree 

 of inherent vretting and spreading qualities, and it is not supposed to be 

 poisonous to higher animals. In tlie spray test at the College this year, 

 (^-15 fell dovm badly in apple scab control, and when combined with lead 

 arsenate the spray mixture caused considerable fruit russet and pronounced 

 late season leaf burn characteristic; of arsenical injury. Isothan Q-4 is 

 a close relative of '<i-15, is a stronger fungicide generally, but it also 

 causes too much injury to be considered practical. 



Phygon or ^604 (2 .3-dichloro-l ,4-naphthoquinone). This promising 

 nevj- fungicide has been tested rather exteiisively on a number of crops, in- 

 cluding a dry or dust treatment for vegetable seeds, and has proven gener- 

 ally highly fungicidal i However, its chief handicap is a tendency to burn 

 the plant when applied in sufficient concentration to give satisfactory 

 disease control. Dithane and Methosan are tv;o other new organic fungicides 

 likev/ise still in the experimental stage of development as regards their 

 use on fruit crops. 



~ 0. C. Boyd 



t'EADCTT MIC E_C01^ITR_OT. 



Surveys of representative orchards in the Ilashoba area of Massa- 

 chusetts during the latter part of November indicate moderate infestations 

 of meadow mice this year. Only one instance of early damage was observed, 

 but signs of mouse activity were abundaait in several localities. 



Field observations show that most orchardists have secured ade- 

 quate control through use of poisons, but there was evidence tliat some 

 grov/ers have not seriously considered the following factors: 



1. Infestations are spotted or localized and not general throughout 

 orchards. Some gi-owers have unnecessarily magnified the task of control 

 operations by placing the poison at every tree. Baits must be placed along 

 active trails to be effective. Such trails are most numerous in relatively 

 smn.ll areas v;hich are low. rough, wet. and covered by thick grass or mulch. 

 Check such locations carefully and don't worry too much about the rest of 

 the orcharcl. 



