The illustrations and discussion in this publication represent an adapted midseason hybrid in central lowa. Each plant develops 20-21 total leaves, silks about 65 days after emergence, and matures about 125 days after emergence. Plants and plant parts are displayed at identifiable stages of morphological (form and structure) development. All plants except figures 5 and 6 (which were greenhouse grown) were field grown and photographed in the laboratory.
All normal corn plants follow this same general pattern of development, but the specific time interval between stages and total leaf numbers developed may vary between different hybrids, seasons, dates of planting, and locations. For example:
- An early maturing hybrid may develop fewer leaves or progress through different stages at a faster rate than indicated here. A late maturing hybrid may develop more leaves or progress more slowly than indicated here.
- The rate of plant development for any hybrid is directly related to temperature, so the length of time between the different stages will vary as the temperature varies, both between and within growing seasons.
- Environmental stress such as nutrient or moisture deficiencies may lengthen the time between vegetative stages but shorten the time between reproductive states.
- The number of kernels that develop, final kernel size, rate of increase in kernel weight, and length of the reproductive growth period will vary between different hybrids and environmental conditions.
Familiarity with the names and locations of some corn plant parts is helpful in understanding how the plant develops. Thus, the labeled illustrations of a corn seedling, lower stalk, corn ear, and corn kernel are introduced first as a reference, figures 1-4.
figure 1 |
figure 2 |
figure 3 |
figure 4 |
Next page - Identifying Stages || Previous Page - Introduction || Table of Contents