Estimating Cotton Lint Yield from Boll Counts

It has certainly been an interesting year for the 90,000 acres of cotton planted in Kansas in 2026. In the most recent USDA-NASS Kansas Crop Progress and Condition report on Sept. 6, cotton in Kansas was 97% setting bolls (near normal) and 46% bolls opening (well ahead of last year and the 5-year average). As we reach the end of the season, many look to estimate the potential yield of their crops, including cotton (Figure 1). Cotton yield estimation is similar to that for corn and sorghum, but with a few significant differences. Cotton lint yield is a product of three primary factors: 1) bolls/acre, 2) boll weight, and 3) turnout (or lint percent). These vary by year, variety, node, and fruiting position. Two approaches can be used to estimate cotton yield: the quick estimate and the detailed estimate.

Figure 1. Bolls are opening in a cotton field in Seward County, Kansas, in early October, with harvest aid application and harvest approaching. Photo courtesy of Logan Simon, K-State Research and Extension.

The Quick Estimate

For many crop consultants and producers, the quick procedure for cotton yield estimation will give us an adequate idea of the crop’s yield potential.

Step 1: Count Bolls

Identify five to ten representative areas in the field. Mark a 3-foot section of row and count each harvestable boll or those from blooms that developed before the last effective bloom date, generally between August 20 and 25 in Kansas (Figure 2). Do not count bolls smaller than the diameter of a quarter. Divide this number by 3 to get bolls/row foot.

Figure 2. Cotton fruiting branch with four unopened bolls from positions that developed before and one (far right) that developed after the last effective bloom date. Photo courtesy of Logan Simon, K-State Research and Extension.

Step 2: Convert to pounds/acre

A general assumption can be made that every 10 bolls/row foot equates to one 480 lb bale. To convert from bolls/row-foot, multiply by a factor of 48.

Example of the quick estimate:

The factors that go into this calculation include:

1. Number of bolls/row-foot (example: 18 bolls/row-foot)
2. Conversion factor of 48

An optional step (shown below) is to convert lint yield (lbs/ac) to (bale/ac) using the conversion factor of 1 bale=480 lbs lint.

Example calculation:

The Detailed Estimate

This more precise procedure may be favored by crop insurance adjustors. This approach requires more time and attention to detail to refine estimates beyond the assumptions made in the quick estimate.

Step 1: Determine Row Spacing

The row spacing is as simple as measuring the distance between rows, in inches.

Step 2: Count Bolls

Follow a similar approach to that outlined above, but use a 10-foot section of the row (Table 1). Divide this number by 10 and multiply by 17,424 to get bolls/acre for cotton planted on 30-inch spaced rows.

Table 1. Conversion of the number of cotton bolls in 10 feet of row to the number of bolls/acre at various row spacings.

Row spacing	Number of bolls in 10 feet of row
	100	150	200	250	300	350	400
(in)	Number of bolls/acre
40	130,680	196,020	261,360	326,700	392,040	457,380	522,720
38	137,558	206,337	275,116	343,895	412,674	481,453	550,232
30	174,240	261,360	348,480	435,600	522,720	609,840	696,960
15	348,480	522,720	696,960	871,200	1,045,440	1,219,680	1,393,920

Step 3: Estimate Boll Weight

Boll weight can be estimated by hand-picking a representative number of harvestable bolls in various parts of the field, counting them, weighing them, and then dividing the weight by the number of bolls (Figure 3). This will give a relatively accurate average boll weight for the yield estimate (Table 2).

Figure 3. Hand-pick a representative number of harvestable bolls in various parts of the field, count them, weigh them, and then divide the weight by the number of bolls. Photo courtesy of Logan Simon, K-State Research and Extension.

Table 2. Lint yields across a range of boll weights and number of bolls in 10 feet of row, assuming a harvest efficiency of 99% and 32% turnout.

Bolls in 10 feet of row	Boll weight (pounds/boll)
	0.006	0.007	0.008	0.009	0.010	0.011	0.012
	Lint yield (pounds/acre)
100	331	386	442	497	552	607	662
200	662	773	883	994	1,104	1,214	1,325
300	994	1,159	1,325	1,490	1,656	1,822	1,987
400	1,325	1,546	1,766	1,987	2,208	2,429	2,650

 

Step 4: *Estimate Harvest Efficiency*

Most Kansas cotton will be harvested with a brush-roll cotton stripper with a 99% harvest efficiency. This allows producers to maximize lint yield. This is highly affected by weather conditions and the presence of disease, which can result in lodging or excessive growth.

Step 5: Estimate Turnout

Turnout is determined at the gin as the proportion of lint in seed cotton (Figure 4) and is generally around 32% for stripper harvested cotton. Turnout can be affected by various factors, including weather conditions, variety, and overall crop health. An average value of 32% turnout can be used for stripper-harvested cotton in Kansas until data from previous harvests of the same cultivar at the same gin are available.

Figure 4. Turnout is determined at the gin as the proportion of lint in seed cotton. Photo courtesy of Logan Simon, K-State Research and Extension.

Example of the detailed estimate:

The factors that go into this calculation include:

1. Number of bolls/acre (ex, 313,632)
2. Weight per boll (ex, 0.009)
3. Harvest efficiency (percentage; as a decimal for calculation) (ex, 0.99)
4. Lint turnout (percentage; as a decimal for calculation) (ex, 0.32)

Example calculation:

Key Considerations

• Accurate yield estimates, whether by the quick or detailed approach, start with identifying five to ten representative areas in the field.
• Quality estimates of harvestable bolls are essential for accurate yield estimation. Do not count bolls smaller than the diameter of a quarter.
• Harvest efficiency and turnout can be affected by various factors, including year (weather), variety, and overall crop health.

 

Logan Simon, Southwest Area Agronomist
lsimon@ksu.edu