No. 7. DEPARTMENT OF AGRICULTURE. 305 



not to use stable manure upon the potato ground, but I have ceased 

 to teach that way, chiefly because it is not in accord with practical 

 experience. It is true that stable manure will induce some potato 

 diseases in some soils, but, as a matter of fact, our successful grow- 

 ers, as a rule, are depending quite largely upon stable manure where 

 they do not have a natural potato soil. You have some potato soils 

 in Pennsylvania that need potash and you have a great many more 

 acres that need phosphorus rather than potash. 



We are told that fertilizers should be scattered through the 

 ground, over the entire surface, and yet we do not teach that any 

 longer, where it is a potato soil, because the potatoes require the 

 largest amount of soluble plant food. We give the land a little bit 

 of top tillage in order that we may loosen up the soil. We give a 

 little top tillage to it when the potato is appearing from the ground. 



I think that the failures right here in Pennsylvania are due to 

 poor seed more than anything else. Now, you can tell whether you 

 have good potato seed or not. You know that the tuber in the 

 ground is going to show its character by the vine above ground. It 

 is only an underground branch, and if you have a spindling vine 

 above, I do not care how much that potato may get under the soil, 

 you don't want it for seed. The potato that has a strong vine above 

 ground will have a good potato for planting beneath, even if it has 

 not reached a greater size than a hen's egg. 



I have heard it taught not many years ago, from the view of the 

 botanist, that mature seed is not the best, and yet we have learned 

 there is no seed better than that which is mature. I do not believe 

 that it is our business to advertise machinery of every sort at insti- 

 tutes, and yet I do not hesitate to tell this truth that no automatic 

 potato planter will do perfect work; an automatic corn planter is all 

 right, but with potatoes you have pieces of uneven size and the au- 

 tomatic planter will skip some of the hills and put too much seed 

 in other hills. I want a planter that will require two men to 

 operate, one man making it his business to see that a proper amount 

 of seed goes into every hill. 



We make this mistake sometimes in speaking of tillage as a 

 means of retaining moisture, and say that tillage is a means of 

 controlling moisture in the soil, and then if we have a dry season 

 we will till the surface only, and that will retain the moisture. If, 

 on the other hand, we have packing rains, soaking rains, and the 

 ground is water-logged, we can loosen it, we can stir the ground, 

 loosen it up, so that enough moisture in the sub-soil will rise to keep 

 the plants growing. 



Occasionally we are asked whether it pays to thin potatoes. Now 

 I believe that notwithstanding the fact that one extensive grower in 



20—7—1904 



