Determining Cotton Plant Populations

Plant Population

One of the first things to do early-season is to determine plant population so management can be tailored appropriately. There are a number of different methods for estimating plant population or density, all of which involve counting the number of cotton plants in a certain distance of row. One method, which closely corresponds to our seeding guideline, is determining the average number of plants per foot, and then using the table below to convert those values to plants per acre. This method is beneficial because it does not require the measurement of a certain distance which varies with row spacing, but it does require the use of this table.

Row Width Average Number of Plants Per Foot
2 2.5 3 3.5 4 4.5 5 5.5 6
Plants Per Acre in Thousands
30" 35 44 52 61 70 78 87 96 105
32" 33 41 49 57 65 74 82 90 98
36" 29 36 44 51 58 65 73 80 87
38" 28 34 41 48 55 62 69 76 83
40" 26 33 39 46 52 59 65 72 78

Once you determine final population, you need to begin tailoring your management practices in each field to the population present. The accompanying chart provides some general guidelines on growth and development as related to population as well as some of the management practices which may be considered.

Effects of Low Densities Effects of High Densities
Bushier plants with more vegetative branches Taller, more compact (narrower) plants
Earlier fruiting, but delayed maturity Delayed fruiting on the plant
Greater verticilium wilt susceptibility Lower verticilium wilt susceptibility
Increased drought tolerance Decreased drought tolerance
Delayed cutout Earlier cutout
Decreased picker efficiency Increased picker efficiency

This article is from the Cotton Management Guide, a publication with year-round advice on managing high-yielding cotton. Download the Deltapine Cotton Management Guide now or sign up for new content to be delivered to your email each month.​​​

Click here to learn about monitoring cotton growth.