cotton stripper

A cotton stripper is a large self-propelled or tractor-mounted harvester that removes cotton bolls from the plant by mechanical action, collecting both mature and immature bolls together. Unlike a picker, which selectively removes only open bolls using spindle rotation, a stripper uses rotating drums or belts with rasp surfaces to comb or brush bolls from stems and leaves, catching ripe and unripe material in a common stream.

Strippers work fastest on plants that have been desiccated or defoliated, either naturally after frost or chemically by herbicide application days before harvest. The machine operates at ground level, stripping bolls from the top 18 to 36 inches of the plant depending on design and adjustment. Feed systems move plants into the working heads, where rasp drums rotating at 400 to 600 rpm grab and pull bolls loose. Collected material falls onto a conveyor that feeds an onboard stripper module or module builder, compressing the cotton into round or rectangular bales as the machine moves across the field.

A key trade-off exists between speed and quality. Strippers harvest 4 to 6 rows at once and move at 2 to 4 miles per hour, making them faster than pickers on large acreage. However, the indiscriminate collection of bolls at all stages of maturity, together with leaves, stems, and soil, produces a harvest stream with higher trash content and lower staple length. The cotton must then undergo additional cleaning at the gin, which adds cost but is often justified by the labor savings and speed of mechanical stripping.

Variants and field application

Modern strippers come in two main configurations: mounted units attached to a tractor, or self-propelled combines that integrate harvesting, module building, and even some cleaning into one machine. Self-propelled strippers weigh 25,000 to 35,000 pounds and require substantial fuel consumption and maintenance. Mounted strippers are lighter and more flexible for smaller operations or mixed cropping.

Stripper performance depends heavily on plant condition and weather. Wind and rain before or during harvest increase trash content and reduce efficiency. Plants must be sufficiently defoliated or desiccated for optimal stripping; green plants with leaves intact tangle in the machinery and cause blockages. Field preparation, herbicide timing, and seasonal conditions therefore determine whether a stripper delivers its economic advantage or becomes a bottleneck.