Yield is essentially controlled by the genetic potential of the plant and the environment in which it is grown. This in turn is further modified by cultural practices. At an agronomic level, yield can be considered in terms of its major components, boll number per hectare times the average boll weight.
The growth habit of a cotton plant is indeterminate, which means it flowers over an extended period of time. There are two phases of the growth of a cotton plant - vegetative and reproductive growth. The vegetative phase is when the plant develops its framework, producing leaves, stems and a root systems to support potential boll load. Due to the indeterminate nature of the cotton plant, the reproductive phases is a balance between vegetative and reproductive growth, with strong competition for resources such as water, nutrients and carbohydrates.
Balancing the reproductive and vegetative growth enables the plant to retain and develop fruit while continuing to grow nodes (stems) and leaves for photosynthesis. Matching the overall carbohydrate supply to bolls with climatic and agronomic resources will ultimately lead to a greater profitability.
High yielding cotton production requires sound agronomic practices that protect the crop from losses caused by weeds, diseases and insects and provide adequate nutritional and water resources that are matched to the climatic conditions. Final yield is a dynamic relationship between boll number and boll weight.