University of Arizona a dot Cooperative Extension

Yuma County Farm Notes

Upland Cotton Variety Testing

Mohammed Zerkoune, Extension Agent, Yuma County


A variety trial was conducted in Wellton AZ, as part of the statewide upland variety testing program. It was designed to evaluate yield and yield quality parameters of several varieties provided by seed industry. The trial was made of conventional and transgenic varieties tested under growers' cultural practices. Preliminary results are subject to change when ginning and laboratory analysis is completed. The lint yield reported in this Farm Notes is based on the assumption that the turnout will be 35%. The lint results reported show three group of varieties, those that yielded 1800 lb or higher, those between 1600 and 1800 lb and the remaining group with yield below 1600 lb per acre.

While cotton acreage tends to stabilize in Yuma County between 22000 to 25000 acres, in recent years, yield is changing. Cotton growers are no longer rewarded for the total yield they harvest from their fields. They are also compensated for the high quality lint they produce or penalized for poor quality. One of the determinant factors among the environmental variables and agronomic practices affecting yield and lint quality includes the choice of variety adapted to the cotton growing area. The objective of this experiment was to evaluate the performance of several varieties developed by cotton seed industry.

An experimental field was selected on silt loam soil in Wellton, AZ, to conduct upland cotton variety trial. Twelve varieties provided by six companies were planted on grower's field on March 20, 2003 in a six-row plot, 40" bed spacing replicated three times. Cotton was planted on wet field. All agronomic practices were similar to all varieties based on grower's management practices. Cotton field received a total of 7 irrigations during the growing season on 5-15, 5-31, 6-14, 6-23, 7-5, 7-14, and 7-24-03. Urea was side dressed at 165 lb per acre on 5-14-03. Additional application was made on 6-03-03; water run at 10 gal per acre (lb/A). On 5-26-03 Mepiclor pill was banded at ½ pint per acre, and Mepex was applied on 6-12-03 at 1 pint per acre. Insect control was made with Knack applied 10 oz per acre on 7-11-03, followed by Warrior applied at 5 oz per acre and Orthene applied at 1 lb per acre on 7-19-03. Cotton was defoliated with Ginstar applied at 8 oz per acre and 6 oz per acre on 8-27-03.

Two rows of cotton were harvested and weighed using boll buggy equipped with electronic scale to determine seed and lint weight. The remaining rows were left for the field day on 9-9-03. Fifteen pound sub-samples were collected from each plot for the ginning and fiber quality analysis. In this Farm Note, we report total seed and lint yield for each variety and lint yield calculated on the assumption that the turnout is 35% that is subject to change.

Preliminary results are reported in Table 1. Lint yield is subject to change after the ginning and laboratory analysis are made. The lint yield is calculated based on the assumption that the turn out is expected to be 35%. The results are therefore only preliminary until the actual turnout is determined from the gin. In addition, the fiber, strength, length and micronaire are needed from the laboratory to include in the final ranking.

Table 1. Seed and lint, lint preliminary upland cotton variety trial results--Wellton AZ site, 2003. Yield lint is calculated assuming 35% turnout

Total Lint & seed Lint lb/A Variety Seed companies Significant at 5%*
5673 1986 ST5599br Stoneville a
5318 1862 DP449br Delta Pine ab
5216 1826 BR303 Button Willow Research abc
5174 1811 ST4892 Stoneville abc
5144 1801 DP555br Delta Pine abcd
4820 1687 AP7126 Stoneville bcd
4754 1664 DP444br Delta Pine bcd
4670 1635 FM989br Fiber Max cd
4646 1626 ACG3601 Arizona cotton growers cd
4538 1589 ST5303r Stoneville d
4532 1587 FM960br Fiber Max d
*Means followed the same letters are not significantly different at 5% probability level

All varieties tested appeared to have reasonable yield, the lowest variety had 1587 lb per acre and the highest was 1986 lb per acre. Based on these preliminary results, varieties are grouped into 3 categories, the first group of varieties includes those with yield 1800 lb or higher, those with yield between 1600 and 1800 lb per acre and those below 1600 lb per acre.

Full Disclaimers

Issued in furtherance of Cooperative Extension work, acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture, James A. Christenson, Director Cooperative Extension, College of Agriculture and Life Sciences, The University of Arizona.

The University of Arizona is an equal opportunity, affirmative action institution. The University does not discriminate on the basis of race, color, religion, sex, national origin, age, disability, veteran status, or sexual orientation in its programs and activities.

Any products, services, or organizations that are mentioned, shown, or indirectly implied in this web document do not imply endorsement by The University of Arizona.

Information provided by:
Barry Bequette, Extension Agent, Urban Horticulture
Barry Tickes, Extension Agent, Yuma County
Mohammed Zerkoune, Extension Agent, Agriculture
University of Arizona, Tucson, Arizona.
Material written September 2003.

Yuma County: Field Crops | Farm Notes | Alfalfa Reports | Vegetables

For more Arizona Production Ag Information:
Home | Cotton | Veggies| Forages | Grains | Citrus | Crop x Crop | Insects | Diseases| Weeds | Pesticides | News | Weather | Research | Photos | Contacts | General Info. | Site Map

document located at:

Copyright © 2001 University of Arizona,
College of Agriculture and Life Sciences
Webmaster: Al Fournier (