192 MAINIC AGRICULTURAL EXPERIMENT STATION. I903. 



per acre at each application effectually protected the potatoes 

 from the ravajjcs of the Colorado potato beetle. From its use, 

 however, no laig'er crops were obtained than where Paris green 

 was used as the poison. Desirable as it would be to find some 

 method of controlling- the potato beetle without the use of poisort, 

 there seems to be no immediate prospect of its attainment. As 

 good crops, both as measured by total yield and starch content, 

 can be obtained by the use of Paris green as an insecticide as by 

 anything yet suggested as its substitute. Used in moderate 

 amount, one-half to one pound per acre, in connection with 

 Bordeaux mixture, there is no trustworthy evidence that the 

 potato, as measured by growth of vines and yield of tubers and 

 of dry matter, is injured by the use of Paris green. 



The ready prepared lime was more convenient to use than the 

 ordinary lump lime. The prepared lime does not carry as much 

 lime per pound as pure lump lime. Since lump lime always 

 carries more or less of impurities (sand, etc.) which are largely 

 removed in the manufacture of the prepared lime, 5 pounds of 

 the prepared lime is sufficient to use with 5 pounds of copper 

 sulphate in the preparation of Bordeaux mixture. In this trial 

 Bordeaux mixture made by the use of prepared lime was as 

 effective against blight as that prepared in the usual way. The 

 prepared lime costs more per pound than the lump lime but its 

 use saves time, and hence may not in the end prove more ex- 

 pensive. 



