674 IOWA DEPARTMENT OF AGRICULTURE. 



above ground. You may accomplish this by covering the plants so densely 

 and heavily with some kind of mulch as manure, straw in various condi- 

 tions, or any other refuse or any coarse material, but the coarser it is the 

 thicker it must be to shut out the air and heat, thus absolutely preventing 

 growth. This same process of starvation may be accomplished by thor- 

 ough, persistent cultivation in fields, which also makes a good opening 

 for "the man with the hoe" in connection with the cultivators. No slop- 

 shop haphazard work here. It will not answer to do this for a month or 

 so, and when you get busy putting up hay, etc., forget about your thistle 

 patch. It must be as regularly and thoroughly done as the milking or 

 your cows, though not quite so often. The vital principle operative here 

 in all these ways, is that a plant cannot grow without leaves. A plant 

 derives the greater portion of its food from the soil in the shape of ignor- 

 ganic materials held in solution by what we term the sop of the plant. This 

 sop ascending upward through the cell structure of the plant to the leaves, 

 and by them through a process of evaporation and elaboration become 

 associated with or changed into organized compounds similar to starch and 

 sugar celulose, etc., and then used in the repair and growth of every part 

 by deposits to each, leaves, stem and roots to their uttermost significance. 

 Thus we may see how largely the growth of roots and roots only but 

 the entire structure is determined by the amount, health and vigor of 

 the leaf system and its consequent ability to supply this elaborated food 

 in sufficient quantities. Deprive a plant of this leaf structure, starvation 

 begins, make this deprivation continuous and death by starvation inevit- 

 ably follows. Of course we all know there is a vast difference in the in- 

 herent, organic vitality of the different plants, but it is simply a question 

 of degree, and the Canada thistle must succomb when its uttermost de- 

 gree is reached as well as others, but you must expect a stubborn resistance 

 until that limit is reached. 



NEW MACHINERY. 



Henry Wallace, before the Fremont County Farmers' Institute. 

 It isn't always best for the small farmer to buy every new machine 

 that comes along. The farmer on forty or eighty acres must go slow. His 

 capital is small and his investments must be made on a corresponding 

 scale. But there are some new machines which most farmers can buy 

 with profit. 



disk prows. 

 The profits of corn growing are pocketed by the man who produces 

 at the least cost. There has been a great improvement in plows in recent 

 years. I well remember the old long-nosed plow with the long handles. 

 Now and then it would strike a boulder and one handle would take you 

 under the fifth rib, and for a little while you wouldn't know whether you 

 were dead or alive. 



