Short Staple Cotton Advanced Strains Trial, Safford Agricultural Center, 1997

L.J. Clark, Safford Agricultural Center
E.W. Carpenter, Safford Agricultural Center
G.L. Hart, Maricopa Agricultural Center
J.M. Nelson, Maricopa Agricultural Center

Abstract

Twenty five short staple advanced strains/varieties were grown in a replicated field on the Safford Agricultural Center in 1997. These included thirteen lines from Australia (including transgenic Bt lines), four lines from Georgia, five lines from NMSU, and two lines from Terra. The transgenic Australian lines dominated the trial with three of them yielding over 3 bales. The next nine varieties yielded over 2.5 bales per acre, they included six Australian variety, DP 90 (the standard variety) and an experimental from New Mexico. IF 1003 was the highest yielding non-transgenic variety in the trial. Much agronomic information is included in the paper as well as HVI values for each variety.

Introduction

Over the years, the short staple variety trial on the Safford Agricultural Center has grown from a dozen varieties to more than fifty. In 1995 the advanced strain portion of the trial was separated from the registered varieties. That trial contained 15 advanced strains and DP 90 as a standard. In 1996 the trial grew to 34 advanced strains and in 1997 the trial made another quantum leap, two advanced strains trials were grown, one under the direction of Steve Husman, grown in 5 locations around the state, which contained over 30 varieties and the trial reported in this paper containing 25 varieties. The main objective of this trial is to screen advanced strains so the strongest can be selected and developed as registered varieties. By cooperating with and encouraging breeders to work at this elevation, we hope to strengthen the varieties available for the southeastern part of Arizona, and parts of New Mexico and Texas with similar climates.

Materials and Methods

This trial was designed as a replicated small plot trial with four replications. The plots were planted with a cone- type planter which distributes a given weight of seed uniformly over the length of the plot. The following crop history provides the information on how the crop was managed:

Crop History

Previous crop: Cotton
Soil type: Pima clay loam variant
Planting date: 23 April 1997         Rate: 25 pounds per acre
Herbicide: 1.5 pts/ac Triflurilin pre-plant, Cotton Pro at lay-by
Fertilizer: 100 lbs of urea under a green manure crop 2/10/97, 100 lbs/ac of urea sidedressed on 6/3/97 and 7/14/97
Insecticide: five applications for pinkie, aphid and whitefly
Pix/Prep: None
Defoliation: Ginstar
Irrigation: Furrow, watered up +7 irrigations (ca. 30 inches + 6.0 inches of rain)
Harvest dates: 1st pick: 17 October         2nd pick: 4 November
Heat units per growing season: 3730 (86/55)

In early October 25 boll samples were taken to determine boll weights. These hand picked samples were also used to determine percent lint turnout. This produced values that are 8 to 10 percent higher than lint turnout values taken from grab samples. Plots were picked with an IH 782 picker modified for small plot use. Plots were picked individually, weighed and grab samples taken for fiber analysis.

Results and Discussion

The spring of 1997 was cool and stand establishment was difficult, but after the middle of May, the weather warmed up and pushed crop development along. The first frost came on October 25th, about a week ahead of normal, but the extraordinary heat of the summer had finished the crop before frost.

Yield and agronomic data for the study are included in Tables 1 and 2. The varieties in all the tables are placed in order of lint yield shown in the fourth column of Table 1. Comparing the values in Table 1 with those of the previous year (1), the 1997 lint yields were about 200 pounds lower,but the percent first pick and the plant populations were about the same. The highest yielding variety, IG 1011Bt, an Australian transgenic line, yielded 8.6% above the DP 90 standard which compares with the highest yielding variety in 1996 yielding 1.7% higher than the standard. Some differences are seen between maturities of varieties as shown by the percent first pick. Not much more can be said about yield comparisons without getting into too much detail for this report. The values are there for the reader to use as they see fit.

In Table 2 it is interesting to note several items. Plant heights are short, the average is 4 inches shorter that the previous year and because of this the height to node ration (HNR) is low. It was generally noted in the Safford Valley that plant heights were shorter than normal, perhaps tied to the slow start in April and May. The first fruiting node was about the same as the previous year and in an area that was considered acceptable. Boll weights were heavier than last year.

Of equal interest to the yields are the fiber values of the advances strains. The HVI values are reported in Table 3. The average HVI values were considerably lower than 1996. The average length was 0.08 inches shorter and the uniformity and strength were off a couple of points. The best fiber in the trial was found in the New Mexico lines but a couple of the Australian lines and Georgia lines were also good.

References

  1. Clark, L.J., E.W. Carpenter, G.L. Hart and J.M. Nelson. 1997. Short staple cotton advanced strains trial, Safford Agricultural Center, 1995. Cotton, A College of Agriculture Report, The University of Arizona, Tucson, AZ. Series P-108, pp. 134-138.
  2. Husman, Stephen H. 1998. University of Arizona upland cotton advances strains 1997 testing program. Handout prepared in Pima County Extension Office

Acknowledgments

Appreciation is expressed to the many seed companies that contributed seed and financial assistance to make this trial a success.


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/az10063h.html
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