April, '10] 



HEADLEE : THE CORN EAR WORM 



155 



than plot No. 2 because they experienced less harm from hail and 

 wind. After ripening the corn was gathered into bags, keeping each 

 row separate, and the damage carefully determined. First the 

 average percentage of ears infested in each variety of each plot was 

 determined, then the average percentage of grains destroyed on 

 infested ears of each variety in each plot. The results are graphically 

 represented in charts Nos. 3 and 4. 



a 



UJ 



CD 



■< 



o 



UJ 



LjJ 

 O 



LiJ 



NO. 3 



PLO 



DATE 



© = LEAMING 



♦ = RE IDS YELLOW DENT 



* = BOONE CO. WHITE 

 a = M9AULEY 



«■ = KANSAS SUNFLOWER 

 X =H1LDRETH 



NO 



Chart No. 3. — Percentage of ears prod 

 infested by one or more larvae. 



OF PLANT NG 



uced by each variety in each plot 



Chart Xo. 3 clearly shows that the corn in plot No. 2, which was 

 planted May 1st, experienced the smallest percentage of infestation, 

 and that the infestation became constantly greater as the time of 

 planting grew later. Chart No. 4, while the curves are very irregular, 

 shows that in general the smallest number of grains destroyed on 

 infested com was to be found in corn planted May 1st. 



Thus it is seen that both the largest number of clean ears and the 

 largest number of sound grains per infested ear were produced in 

 corn planted May 1st. 



To be more exact it may be said that corn planted May 1st produced 

 6.1 per cent more of its total number of ears clean than that planted 

 April 15th, 14.6 per cent more than that planted May 15th, 30.5 per 



