64 



IOWA DEPARTMENT OF AGRICULTURE. 



fertilized. As it was late and nearly all of the pollen had been shed, the 

 only supply left was that which had lodged on the leaves. This, through 

 age, had become weakened and when blown upon the already partly ex- 

 hausted silks failed to produce kernels of sufficient vitality to properly fill 

 out and mature. 



FIG. 



-SCRUB EARS — NUBBINS 



Late corn has usually more nubbins than that which matures earlier. 

 These ' 'scrub" ears are sometimes produced because the silks at the butt of 

 the ear appear so early that there is no pollen to fertilize them. As a result, 

 no kernels are formed on the butt of the ear. No. 4 is a good example of 

 this. No. 3 suffered from the same cause, but, in addition, lacked strength 

 and vitality and so produced very few kernels. No. 2, with its wide space 

 between rows, is a good illustration of a run out ear. While No. 5 appears 

 to be a medium ear it is, in reality, very poor. Note the peculiarly beaked 

 appearance of the crown of the kernels ending in a needle-like projection. 

 This is a sure indication of running out. The shallow kernels and the small 

 circumference in proportion to length are strong indications of lack of con- 

 titution. 



Ear 4 has sharp projecting points also. Barring the butt, it is a much 

 stronger ear. 



Fig. 10. 



