Introduction to Cotton Growth and Development

Cotton plant growth and development is a unique and complex process. Cotton is actually a perennial shrub with tropical origins that is produced in an annual row crop environment in the US. Successful cotton production depends on an integrated management strategy that recognizes and adapts to the unique characteristics of the crop.

Perennial Growth Habit

A defining characteristic of cotton growth and development is that it is a perennial plant. Being a perennial plant means that it flowers and sets fruit over a long period of time. In its native habitat, or with adequate warmth, cotton would not die in the fall. Perennial plants also flower and produce seed as a secondary mechanism, as opposed to vegetative growth. Because cotton lint is produced from the seed coat, it is the essential challenge of cotton production to overcome the perennial nature of the plant. Nearly everything we do to manage a cotton crop is in response to its perennial nature in an attempt to produce seed and lint in an annual row crop environment.

Tropical Origins

Another distinguishing characteristic of cotton results from its tropical origins. Cotton is adapted to regions where temperatures range from warm to hot. Grown as an annual crop in the United States, it is often necessary to plant cotton before the onset of consistently favorable temperatures. While cotton struggles to emerge from the soil and grow, diseases, weeds, and insects adapted to our environment can damage the crop. When several pests are present simultaneously, especially when accompanied by chemical stress, crop development may be severely retarded. Earliness, often our best indicator of high yields, strongly depends on favorable environmental conditions during the early season. Cool and wet conditions during the early part of the growing season adversely affect cotton development.

Cotton Plant Growth Regulators

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Growing Degree Days

The development of vegetative growth and fruiting forms is highly related to temperature if adequate moisture is available. The relationship between cotton development and temperature is best described by DD-60s. The equation for determining DD-60s is:

(°F Max + °F Min Temp)/2 - 60 = DD-60s

For example, if today’s high and low temperatures were 80° F and 60° F, then the formula would give this answer: (80° F + 60° F)/2-60 = 10 DD-60s.