244 CORN 



that the plants have made a very weak growth. It could not be 

 expected that they would produce more than nubbins. The amount 

 of nourishment which the roots have furnished these plants has been 

 necessarily so small that even a fair sized plant has not been pro- 

 duced. Some of the plants present an erect appearance, because there 

 was not sufHcient weight in the stalk to cause them to topple over. 



This shows that the best results cannot be had by continual crop- 

 ping with corn. They may be obtained only by practicing a proper 

 system of rotation. After the ground has been in corn for the second 

 year it is subject to serious ravages by the corn-root worms, which 

 result in a very noticeable weakening in the corn plants and a very 

 material decrease in the yield of corn per acre, due to the lacerating 

 and decaying of the root system. 



The injury done by the corn-root worm becomes very apparent 

 after a wind or heavy rain, especially in fields which have been in 

 corn for 3 and 4 years or more. 



Cuts on pages 245 and 246 represent ground in corn for the first, 

 second, third, and fourth years, respectively, and also the fields from 

 which the representative hills were taken, as shown in preceding 

 pages. 



From 125 to 161 corn-root worms were found to the hill. The 

 roots were badly lacerated and decayed, causing the whole plant to 

 fall. The stubby ends of the roots could be seen protruding from 

 the dirt about them. 



Yield. It is to be expected that the. yield of corn per acre would 

 necessarily vary in fields where continuous cropping of corn had been 

 practiced. The following contrast will be noted in the yield of corn 

 per acre on ground in com for the first and fourth years, respectively : 



First year, from clover sod, 72.4 bushels 



Fourth year, from alfalfa sod* 45.1 bushels 



From the above it will be seen that the difference in the yield of 

 corn on ground in corn for the first year from that of ground in corn 

 for the fourth year, was 27.3 bushels per acre, or 60 per cent more 

 corn in favor of the former. 



Remedy. — Rotation of Crops. Nothing can be done to help 

 corn that is attacked by the corn-root worm, but due to the fact that 

 this worm lives entirely upon the roots of the corn plant, 

 it is simple to combat them, a rotation of crops being sufficient. The 

 ground which is infested with the corn-root worms which hatch out 

 next spring will die — simply starve to death. The best results will 



* Alfalfa, a legume, euriches the soil the same as clever. 



