Response of Cotton Individual Plant Yield to Plant Population

Cotton is well-known for its yield stability to a wide range of plant populations. Growth and yield of two cotton varieties with different plant architectures (columar type DP0949B2RF and bush type ST4498B2F)  and nine planting densities from 5,000 to 70,000 plants/acre were used to study the response of cotton growth and yield to plant population and architecture in 2011 and 2012 at Maricopa Agricultural Center. Boll numbers and weights from vegetative branches and main stems of each plant in 2-3 meter-row in each plot were taken before harvest to study response of indivudual production to plant population. The results indicates that the bush type variety ST4498B2F had a higher ability to compensate for yield loss under low plant population than the columnar type DP0949B2RF. The differences between the varieties were not significant when plant population was over 25,000 plants/acre. This study suggests that a final plant population of 25,000 to 35,000 plants/acre should be recommended to growers in Central Arizona. Bush type varieties have more yield stability, especially at low plant population. Columnar type varieties may be more suitable for narrower row spacing due to their more compact architecture. Indivudual plant yields compensated a wide range of plant populations. Variations in indivudual plant yields were affected significantly by plant populations.