No. 7. DEiPARTMENT OF AGRICULTURE. 541 



PROF. STEWART : About three or four inches ; if you do cut off 

 a great many of the old roots the efifects will show increased yield, 

 and that is all the argument that is necessary, I should say. If the 

 orchard is doing well, however, it would not be advisable to make 

 any radical changes. We can over-till orchards as well as under-till 

 them, in my opinion. 



MR. HALE : What is the risk ? 



PROF. STEWART : It aids fire-blight, for instance. And in trees 

 just coming into bearing, our present records seem to show that it 

 delays fruiting. In such orchards, in our experiments, the sod-mulch 

 system shows an advantage of 30 per cent, over clean tillage. 



MR. GOSSARD: Do you think that apple trees that are treated 

 with stable manure are more subject to twig blight than those that 

 are treated with commercial fertilizers? 



PROF. STEWART : That simply resolves itself into this, it seems 

 to me; twig blight is caused by bacteria, which are largely trans- 

 ferred by insects during the blooming period and during other periods 

 of succulent growth. The insects become inoculated by visiting the 

 gummy masses that exude from active blight cankers on the limbs 

 or trunks of trees, in which the bacteria pass the winter. Many 

 twigs become inoculated in this way every year, but it is only those 

 of succulent growth that are badly injured. Therefore, the fertilizer 

 that does most to produce the succulent growth is the one that does 

 most to spread the blight. Barnyard manure as shown by the Mas- 

 sachusetts records, already presented, will produce a somewhat greater 

 growth than commercial fertilizer, hence, it is likely to be a litt'e 

 more conducive to blight. 



A Member: I would like to know w^hether there is any material 

 difference between cultivating three inches deep in an old orchard 

 with a spring tooth harrow, or a three-inch cultivation with a plow. 



PROF. SURFACE : I doubt whether you could get a three-inch 

 cultivation with a spring-tooth harrow. 



I'm afraid some of us are inclined to be too tender on these old 

 roots, and we often fail to do things we should. I sometimes think 

 that fear of injuring the apple roots is simply an excuse for not get- 

 ting out and doing the work. I have recently made a study of costs 

 and profits in fruitgrowing. I have noticed a most interesting re- 

 lation between the cost of production and net returns. Of course, 

 you know the man who does nothing for his orchard and gets nothing 

 back from it In that case, the cost of production is zero, the return 

 is zero. Up in Orleans county, N. Y., the records from the 15,000 

 acres of which I spoke a while ago show that the average annual cost 

 for five years in producing and marketing the fruit is about |50 per 

 acre, about |35 of which went into barrels, packing and so on. The 

 average net return is |61.40 per acre. I have the figures from an or- 

 chard here in Pennsylvania, the exact figures, where |116 per acre 

 has been put out for cost of production and marketing, and the net 

 returns are $274 per acre. In an Oregon orchard, where the cost of 

 production and marketing was -f380 for an acre, the net returns were 

 $900. Notice that the higher the cost of production the higher the 

 net returns were. We must remember that there are several essentials 

 in fruit growing, and in order to succeed we must look after them all. 

 The neglect of any one may reduce returns from the whole orchard. 



MR. HALE : The orchard is simply a factory in which a man 

 invests his capital, and the finished product must be so regulated 



