352 r.LLi,i;Ti-\ S2 



Ix\TERPRETAT10X OF RESIXTS 



In figuring gain or loss in tlie above tables actual profits were not 

 reckoned since no charge was made for interest on investments, depre- 

 ciation of implements, etc., taxes, and shares of general supervision 

 costs which should be divided among the fields. Accordingly, actual 

 losses were sustained both by fields E and fl and actual profits were 

 materially lower on the other fields than figures represented as gain 

 indicate. 



field C : The hardest blow given to Johnson grass on Field C was 

 the dry plowing of August, 1915. Leaving this ground rough through- 

 out the succeeding winter also assisted materially. The plowing in 

 April of 1916 made the remainder of the fight easy. In addition, actual 

 profits were swelled materially by the abnormally high prices of grain 

 in 1917. 



Field D : In spite of the fact that this field did not return a great 

 deal of profit we are led to favor the control of Johnson grass by 

 means of close pasturage. Much greater profits should be realized 

 when such a field is allowed to grow grain in winter and when hogs 

 are turned in to feed upon the rootstocks ttirned up by plowing. A 

 combination of winter grains and pasturing with both sheep and hogs 

 in the summer is one of the most practicable methods of quickly and 

 svtrely bringing Johnson grass into subjection. 



Fields E and F : The results from Field E appear to be inconsistent 

 with those of Field F. The only difference in treatment of the fields 

 has been the planting of cotton in Field E in 1916 followed by corn 

 the succeeding year, and the reversal of this rotation in Field F. How- 

 ever similar the treatment may appear to have been there is a material 

 advantage in following corn with cotton for the following reasons : 

 Since corn is not usually planted until late in June or early in July, 

 the most rapid growth of the Johnson grass, which takes place earlier 

 in the season, may be combated by clean cultivation with weeders and 

 results can be obtained more cheaply than with row cultivators and 

 hand hoes. If this early cultivation is carefully done the Johnson grass 

 will be fairly under control by corn planting time and the work neces- 

 sary to keep it in subjection is much less than that demanded earlier in 

 the season. Furthermore, corn can be cultivated later than cotton, and 

 even after it is too large to cultivate with horses the few remaining 

 Johnson grass plants can be easily handled with hoes. In this way 

 plants from seed brought in by the irrigating water of late summer 

 may be destroyed before the}- have reached the stage where the root- 

 stoc!cs are formed. This makes the fight against Johnson grass much 



