Every year, fields of corn are different from other years. This year, in the USA, it is more different than usual. Most of it is related to extreme delays in planting time and some by soil moisture extremes. After the first 10 days after pollination, kernels begin to absorb carbohydrates at about 2% of their final total per day. This rate continues for the next 40 days, drawing on the new photosynthetic production plus reserves stored in the pith cells of the stalk. Genetics and environments before and after pollination contribute to the amount transferred each day to the kernels. The number of kernels on the plant affect the total being transferred.
Uneven environments associated with late planting and extreme wet soils results in wide differences among individual plants, resulting in uneven numbers of pollinated ovules, and plant to plant differences in numbers of kernels per plant within a field. Individual plants that emerged later than adjacent plants may have same number of kernels as adjacent plants but will not have same photosynthesis rate because of shading from adjacent plants. Competition for uptake of minerals will probably also be inferior. Hybrids that have high number of pollinated ovules, despite this early stress, may have a larger draw of carbohydrates to the ear but the delayed emergence plants of these hybrids may deplete supply stored in stalks, developing early death of roots, leading to stalk rot.
2019 corn production in the USA will be different. Biology is the same, the environment is different.
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About Corn Journal
The purpose of this blog is to share perspectives of the biology of corn, its seed and diseases in a mix of technical and not so technical terms with all who are interested in this major crop. With more technical references to any of the topics easily available on the web with a search of key words, the blog will rarely cite references but will attempt to be accurate. Comments are welcome but will be screened before publishing. Comments and questions directed to the author by emails are encouraged.