224 BOARD OF AGRICULTURE. [Jan., 



and going back in the other direction you get the other side of 

 the plant. If you go in the two directions you are sure to 

 cover them thoroughly. 



Question. Is it necessary to spray the under side of the 

 foliage ? 



Prof. Clinton. Of course. The fungus forms on the 

 under side of the leaves. If a spore gets there it seems to 

 hatch better. Then too, the underside spores of some leaves 

 will drop down on the upper side of leaves below them, and 

 most of them get in through that process. Of course, where 

 you get in and thoroughly cover the plant upon all sides, and 

 saturate the foliage, you will get better results. You cannot 

 do it too thoroughly. 



The President. How many sprayings does a crop need 

 in a season ? 



Prof. Clinton. It depends entirely on how thoroughly it 

 is done. Where you use some of these power sprayers you 

 should give as high as eight sprayings. My work has been 

 effective with from three to four sprayings with a hand 

 sprayer. 



The President. About what time ought the first to be 

 given ? 



Prof. Clinton. * From the tenth to the twentieth of July, 

 depending on the season. Just before the blight begins to 

 appear. In early potatoes the foliage is pretty well covered 

 by that time, and they think that this early spraying protects 

 them. One of the points that I want to make clear is that 

 these late sprayings are not the essential ones. If you have 

 the time and the opportunity, spray early. 



The President. How far advanced has this blight got 

 to be in order for the spraying not to do any good ? 



Prof. Clinton. That will depend on the condition of the 

 foliage. If it is matted to the ground it may not do good 

 because of the great difficulty in reaching the seat of the 



