1997 Low Desert Upland Cotton Advanced Strains Testing Program

S.H. Husman, Pinal County Cooperative Extension
J.C. Silvertooth, Plant Sciences Department
L. Clark, Safford Agricultural Center
J. Nelson, Maricopa Agricultural Center
T. Knowles, La Paz County Cooperative Extension
R. Wegener, Pima County Cooperative Extension
K. Johnson, Pinal County Cooperative Extension

Abstract

Upland cotton advanced strains and commercial check comparison varieties were evaluated in replicated field studies at five locations in 1997. The test sites include Parker, Az., Gila Bend, Az., Buckeye, Az., Maricopa, Az., and Safford, AZ. Ten seed companies submitted a maximum of five advanced strains entries. Three commercial check varieties were used at each site for comparison purposes and included DPL 5415, SG 125, and STV 474.

Introduction

Profitable cotton production in the low deserts of Arizona is becoming increasingly challenging due to rapidly rising input costs and cotton prices which are not tracking the increasing costs. As a result, Arizona producer's only remaining production advantage is the environmental conditions conducive to high lint yields. Variety selection to maximize yield potential is the first and most important decision a producer makes at season initiation. A major objective of these advanced strains evaluations is to provide additional data to participating seed companies relative to their strains performance under commercial production conditions at different locations. Information from these studies contribute to the database for breeder selection of varieties for possible commercialization based on performance under the low desert environmental conditions.

Materials and Methods

A range of 30 to 42 Upland cotton advanced strains representing ten seed companies were tested in 1997 on the five commercial cooperator sites in Buckeye, Az., Maricopa, Az., Paloma, Az., Parker, Az., and Safford, Az. Participating seed companies submitted entries of their choice at each respective test site (Table 1).

Plots ranged from four to six rows in width by location dependent on equipment configuration and were 38 feet long. Plots were dry planted using cone planters and irrigated up on March 31, April 10, March 27, April 1, and April 28, 1997 at Buckeye, Maricopa, Gila Bend, Parker, and Safford respectively. In order to assure an adequate stand, a seeding rate of fifteen pounds per acre was used. After stand establishment was complete, all plots were hand thinned to a targeted uniform population of 40,000 plants per acre in May, 1997.

Detailed plant mapping measurements were made throughout the season at three times targeted towards early bloom, cutout, and prior to harvest after defoliation. The plant growth and development measurements were made in order to evaluate differences in vigor, fruit retention, maturity, and yield. Measurements included plant height, number of mainstem nodes, height:node ratios, and fruit retention.

The experiments were harvested on November 20, October 29, December 17, October 9, and October 14, 1997 in Buckeye, Maricopa, Paloma, Parker, and Safford respectively. Seed cotton yields were measured by mechanically harvesting the center two rows of each plot with a modified cotton picker and bagging attachment. Weights were measured using a tri-pod and a hanging electronic scale to weigh the seed cotton from each plot. Prior to mechanical harvest, all bolls on five plants in non yield rows were hand harvested. These sub-samples were ginned to determine percent lint. Final lint yields were then calculated on a per acre basis. Each fiber sample from the ginning process was submitted to the USDA Cotton Classing Office in Phoenix, Az. for grades and HVI fiber quality analysis.

Results

Final lint yields at the Buckeye site ranged from a high of 2191 lb./acre (DPXZ 1075) to a low of 1213 lbs/A (MX Jajo 9556). Final lint yields at the Maricopa site ranged from a high of 1820 lb./acre (DPX 9229) to a low of 988 lb./acre (GCX 9641). Final lint yields at the Paloma site ranged from a high of 2117 (OA 36)to a low of 1408 (MX 0952). Final lint yields at the Parker site ranged from a high of 1552 (AP 9204 3044) to a low of 1131 (AP 9264 3003). Final lint yields at the Safford site ranged from a high of 1180 (MX Jajo 9569) to a low of 858.50 (DPX 1075). Tables 2, 3, 4, 5, and 6 represent the lint yield, seed cotton yield, and HVI and grade data for each of the five test sites.

Acknowledgments

Sincere appreciation is extended to the commercial cooperators including Wilford and Paul Hayden (Buckeye), Leon Hardison (Gila Bend), and Jose Diaz (Parker) for their cooperation and sacrifice to bring these experiments to completion. In addition, thank you Agripro Seeds, DeltaPine., Germains Seed Co., J and S Research, Mycogen (Phytogen), O and A Research, Paymaster Seed Co., Stoneville Pedigreed Seed, Sure-Grow, and Cotton Seed International for your participation and support. Finally, thanks are extended to the Arizona Cotton Growers Association for the foresight and support of this research effort.


This is a part of publication AZ1006: "Cotton: A College of Agriculture Report," 1998, College of Agriculture, The University of Arizona, Tucson, Arizona, 85721. Any products, services, or organizations that are mentioned, shown, or indirectly implied in this publication do not imply endorsement by The University of Arizona. The University is an Equal Opportunity/Affirmative Action Employer.
This document located at http://ag.arizona.edu/pubs/crops/az1006/az10063i.html
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