66 



CORN 



TABLE NO. 11 — Continued 



Rainfall 



A close Study of the two tables will reveal several very striking 

 points. In the increase of growth there is a gradual rise in the number 

 of inches per day as the plants near forty inches in height. That is, 

 when the plants are smaller the root system has not developed suf- 

 ficiently to secure an abundance of plant food which will push the 

 plant along. It will be seen that this rapidity of growth is kept up 

 until the tassel begins to appear in August; then a decided slackening 

 occurs. 



A relative study of the second table with the first shows more rapid 

 growth during the days of the highest temperature. However, the 

 greater factor is the amount of precipitation during these warmer 

 days. The period from July 15th to 25th inclusive, the amount of 

 rainfall was 3.5 inches. With the high temperature plants at that 

 age utilized this excessive moisture and rapid increase in height 

 ensued. 



LIGHT. In 1779, Ingenhouss discovered that oxygen gas is given 

 off from foliage and carbon deposited in the structure and tisrues of 

 plant due to the influence of light upon the absorbed carbon dioxide. 

 Partial darkness decreases to a certaiH|^<extent the assimilation of 

 carbon dioxide, besides eliminating tl^%reen chlorophyll entirely. 

 Absolute darkness even causes the plant to lose in weight and deter- 

 iorate in structure. The yellow corn plant growing in a shaded place 

 or under a clod is a practical example of a lack of sunlight. This is 

 often seen also in the listed furrow. Corn which is drilled thickly for 

 fodder purposes, shows long, slender internodes, and very often has 

 short narrow leaves. The cells of the plant are elongated and require 

 a large amount of moisture to maintain their turgidity. In cold, 

 cloudy seasons, crops are always late in maturing. 



