12 



to answer. It would go, I should say, all the way from 90 

 per cent down to perhaps 4 or 5, depending on the condition 

 of the tree. In our work in renovating we started in and cut 

 out dead wood, and if you have a particular tree in mind, 

 you will know how much will be left on the tree when you 

 get through with it. My boys have been working for the 

 last three weeks on renovating old trees, and they were in- 

 structed to cut out the dead wood. I was talking it over with 

 the class to-day, and we agreed that the cutting ran all the 

 way from 16 up to 50 per cent dead wood, so you see there 

 is considerable variation according to the tree itself. Then, 

 after you have got the dead wood out, the question comes up 

 what else to do; but after you have cut out, say, 60 per 

 cent, that is about the time you quit; there isn't much of 

 anything left. But in an ordinary tree of the type I have 

 seen renovated, I should think it would run somewhere 

 around 25 per cent. Of course, it is impossible to say with- 

 out knowing what the tree looks like. 



Mr. Brennan. I would like to ask the professor if I 

 understood him correctly when he said they were considering 

 fertilizing cover crops ? Is that fertilizing coming at a time 

 when it will introduce a growth of new wood ? 



Professor Sears. I am glad you raised that point. We 

 don't at that time put on any great amount of nitrogen to 

 start with, but the cover crop will use up most of the nitro- 

 gen. Then, you would not get very close to the tree with the 

 fertilizer. If you wanted to get it satisfactorily you would 

 keep away from the tree with the fertilizer. We have tried 

 it to a limited extent, but the dressing of nitrogen, or what- 

 ever we were using, would be relatively light. 



Mr. Hanson. I would like to ask what kind of fertilizers 

 will give color to apples. 



Professor Sears.. Why, I don't know. I doubt if any 

 one knows. The men here in this audience are better quali- 

 fied to discuss that than I am, but the latest evidence I have 

 heard seems to be rather against the view that any fertilizer 

 actually gives color. You can destroy it by the use of too 

 much nitrogen, but evidence seems to be lacking to abso- 



