In-Depth Primer ~ Cotton Botany 101
Each species of plant, like most of earth's life forms, has a similar starting point, the seed, and the cotton plant is no exception. Therefore, like most cash crops, cotton production starts with planting seed. Soon after planting, seedlings sprout and the plants begin to grow. "In How A Cotton Plant Grows", a reprint from Progressive Farmer distributed by the National Cotton Council, the next level of progress in the growth cycle is "the stand." A good stand is described as "the number of healthy, vigorous seedlings" that are evenly distributed in the field. This may be one to four plants per foot of row depending on soil type, row width, planting date, and level of moisture during the growing season. Seedlings typically emerge five to fifteen days after planting (see Growth Cycle Table).
The second stage of growth includes the development of a good plant structure both above and below the ground. There are four organs that carry out growth and reproduction. They are the roots, stem, leaves and fruits which are comprised of squares, flowers and bolls. Once again soil type and growing conditions, including weather, moisture, disease and insect pests will determine the amount and quality of the yield.
The root system of the cotton plant consists of a primary or taproot from which grow many branches or lateral roots. A mature cotton plant can have roots that run up to nine feet deep, but normally the root structure is found in the top two feet of soil.
The stem structure of the cotton plant is very distinctive, and is comprised of an erect main stem consisting of a series of nodes or branching points and internodes or open stalks. "As the plant grows, the internode above the cotyledons (the leaf like fronds that are the first growth signs from the germinated seed) extends, and a new node is formed from which the first leaf unfolds."
At the center of this growth spiral is the terminal bud. The plant's growth pattern, which keys on the terminal bud, is essential to a well shaped plant and a timely development of the cotton boll. Should the terminal bud be damaged or destroyed slower growth and lower yield will probably be evident in the plant.
The next phase of growth is the fruiting phase. If all has gone well with the planting and cultivation efforts, at about the five to eight week point of the growth cycle, the plant has now begun to produce "squares". This timing depends on the type of cotton planted and the part of the country the grower is in. Blooms should emerge about three weeks later, about sixty to eighty days from planting.
The next phase is where the fiber develops, the boll stage. All through the fruit bearing part of the growth cycle the cotton plant sheds squares, blooms and bolls. This natural thinning is sometimes supplemented by grooming and pruning by the grower. The purpose for this is to maximize the yield of fiber from the plant. "Cutout" is a term to describe when the plant stops flowering and turns its efforts to maturing and production of fibers. Once again many internal and external forces can play upon the plant to affect this process. If all goes well the bolls go through the "filling" process whereby the fibers grow in length and in thickness. When the fiber bolls are ready, at about one hundred and ten to one hundred and thirty days, they open to reveal the cotton fibers.
This short explanation of the cotton growing process can be amplified by requesting the following materials from the National Cotton Council or the National Cotton Batting Institute.
- How A Cotton Plant Grows © 1982 Progressive Farmer, Inc. Reprinted from seven articles that appeared in that publication.
- Cotton From Field To Fabric © The National Cotton Council. This publication is full of interesting facts about growing, ginning and spinning cotton.
- Cotton And Textiles - Sharing a Common Thread © The National Cotton Council.
- The Story of Cotton © The National Cotton Council. A small booklet that outlines the history, growth and production of cotton.
- All quotes are from How A Cotton Plant Grows © 1982 Progressive Farmer, Inc. By Del Deterling with Dr. Kamal El-Zik.