44 



carbolic acid experiment, where the loss in number of stalks was 13 

 per cent and that in weight of the yield was only 7 per cent. The 

 losses from the other experiments of this series were too small for 

 such analysis. 



Our contract with the owner of this field provided that he should 

 be reimbursed for any net loss of yield attributable to our experiments, 

 and a comparison of the product of the experimental plots with that 

 of the checks showing a loss for the whole field of 60 bushels and 23 

 pounds of corn, a settlement was made with him on this basis. A tabu- 

 lation and analysis of the data from the earlier counts of hills, stalks, 

 ants' nests, ants, and aphids in the different plots simply confirm the 

 conclusion that no benefit was obtained from the treatment of the 

 seed-corn planted in this field in 1908. Parallel experiments carried 

 on in this field and intended to test the effect of deep cultivation and 

 repeated harrowing and to show the consequences of a rotation from 

 corn to oats will be described later in connection with other experiments 

 of the same character. 



Use of Repellents combined with Fertilizers 



The outcome of our repellent work of 1907 and 1908 evidently 

 called for a change of program. The amount of the repellent sub- 

 stances which could be held by the hard, slightly absorbent corn ker- 

 nel was so small that it was easily washed away by flooding rains and 

 yet was sufficient to injure much of the seed, if placed in contact with 

 it, whenever wet weather followed closely upon the planting. Either 

 the idea of protecting young corn for a time from ants and root-lice 

 by the use in the hill of substances offensive to the ants must be given 

 up, or some safer repellents or safer and more effective methods of 

 application must be found. As there is no possible advantage to the 

 seed itself to be derived from the application of repellents to it, the 

 corn kernels serving only as carriers of the repellent substances, it was 

 plain that some other carrier might be used to which the repellents 

 might be applied more freely and with less danger of injury to the 

 seed-corn or the plant; and as it was desirable that the use of this 

 carrier should be worth while in itself, a powdered fertilizer contain- 

 ing ingredients commonly needed on Illinois corn lands was selected 

 for the purpose. 



Experiments were begun along this line in 1910, by W. P. Flint 

 and G. E. Sanders on the farm near Galesburg used in the field work 

 of 1908. In traveling twenty and two-thirds miles behind the plow 

 Flint and Sanders counted in the furrow 604 ants' nests of the corn- 



