56 
IOWA ACADEMY OP SCIENCES. 
CHANGES THAT OCCUR IN RIPENING CORN. 
BY C. P. CURTISS. 
The great importance of corn as a forage and grain crop has 
induced the writer to record some observations in noting the 
successive changes that occur in the ripening process of this 
plant. These observations have been confirmed and empha- 
sized by the generally unsatisfactory experience of the present 
season in the use of forage made from the immature corn plant. 
It is well known that the corn plant in the process of ripen- 
ing undergoes rapid and important changes. In order to note 
some of these changes equal areas, comprising one-fifth of an 
acre each, of uniform well- grown corn on the Iowa experiment 
station grounds, were cut and shocked in successive stages of 
growth at intervals of a week extending from September I7th 
to October 13th, 1892. This period took the corn in what is 
commonly termed the “dough stage” of the kernels, with stalks 
and leaves entirely green, and ended with the fully ripened ear, 
and stalks and leaves nearly all dead or dry, in the natural 
process of ripening without killing frost. These plots of corn 
were put into large, well-built shocks of 144 hills each on the 
dates named, and allowed to stand until the middle of Decem- 
ber, the usual time of storing corn fodder under practical farm 
conditions. This was purposely included as one of the features 
of the investigation. To have been more scientifically accurate 
would have required immediate analyses at the time of cutting; 
however, all plots were treated alike, and the comparison undis- 
turbed. The chemical work of this investigation was done by 
Prof. G. E. Patrick. 
The yield of husked ear cornranged from 53.6 to 64.3 bushels 
per acre. At the time of the first cutting the ear corn consti- 
tuted 48 per cent by weight of the total crop; at the second, 49 
per cent; at the third, 52 per cent; at the fourth, 53 per cent; 
and at the fifth, 54 per cent. There was then a steady increase 
of the proportion of corn to stover as ripening progressed. The 
