Short Staple Variety Trial, Greenlee County, 1997

Abstract

Six short staple cotton varieties including two New Mexico acalas varieties and one advanced strain, two Australian varieties and a SureGrow variety with higher yield potential were tested in this study. The SureGrow variety, SG 125 had the highest lint yield with a yield of 875 pounds of lint per acre, out producing the following varieties by 80 pounds per acre. The average yield was about 100 pounds per acre lower than the previous year, and 50 pounds less than the 5 year average due to a cold spring and an early frost. In addition to lint yields; percent lint, plant heights, height to node ratios, plant populations and lint hvi values are shown. A lint yield comparison for 1993 through 1997 is included in this paper.

Introduction

This experiment and a sister experiment in Cochise county are a continuation of varietal evaluations on the acala varieties that grow in the high deserts of Arizona and New Mexico. The current New Mexico 1517 acalas and the advanced strains that are near approval are the backbone of the trial with newly developed acalas from California also being included. This year two Australian varieties and one SureGrow variety, with high yield potential, were also included in this trial to see if they would be beneficial to local growers.

Materials and Methods

The varieties were planted in two row plots in four replications on the Stan Jones farm in Virden, NM, using their equipment and normal cultural practices. The crop history listed below outlines the important things that took place during the growing season.

Crop History - Jones farm

Previous crop: Grain sorghum

Soil type: Pima sandy loam

Planting date: 30 April 1997         Rate: 17 pounds per acre

Fertilizer: 200 lbs/ac anhydrous ammonia

Herbicide: Treflan and caparol

Insecticide: None

Pix/Prep: None

Defoliation: None

Irrigation: Furrow

Harvest date: 11 November

Heat units (86/55) to harvest: 3734 at the Safford Agricultural Center adjusted to 3260 for Duncan. Adjustment factor of 0.873 calculated from Brown (1) HU data for Safford and Duncan.

Plots were mechanically picked using the cooperator's machines, with plots being weighed using a basket scale and then dumped into a module builder. Sub-samples were taken to determine lint turnout and fiber quality.

Results and Discussion

The spring of 1997 was cold and stand establishment was slow. Then after the middle of May the weather warmed up more than normal, aiding greatly in the crop development.

The yields are shown in Table 1. The SureGrow variety produced approximately 80 more pounds of lint than 1517-95 principally due to the higher lint turnout. With a 7 cent premium, the values of those two varieties would be about the same. Planting densities were very uniform between all varieties and in the optimal range. Table 2 shows more agronomic values from the varieties. It is interesting to note that the 1517 cultivars have larger bolls than the other varieties, including B 5008 from the same breeding program. It appears that 1517-91 may have lost some of it's yield potential early in the season, its first fruiting branch is higher than the other selections. The height to node ratio (HNR) is very uniform across varieties and in an area that would indicate good growth during the season.

Table 3 contains the HVI (High Volume Instrument) values for the lint. The three cultivars from the New Mexico breeding program had superior length, strength and uniformity compared to the other varieties even though the Australian varieties graded better.

Table 4 contains a five year yield summary of varieties. IF 1001 has the highest lint yield average followed by the three New Mexico lines. The actual values of the varieties would depend on cotton prices and the premium offered for the New Mexico acalas. With prices as they were in 1997, the top four varieties would be very close in value. The number of heat units (HU) was the lowest within the past 4 years as was the yield. The correlation between HU and yield is not significant at the 95% level of probability (p=15.3)

References

1. Brown, Paul W. 1991. Normal values of heat unit accumulation for southern Arizona. Extension Report 190041, May 1991.
2. Clark, Lee J. 1997. Short staple variety trial, Greenlee county, 1996. Cotton, A College of Agriculture Report, The University of Arizona, Tucson, AZ. Series P-108, pp. 155-158.
3. Clark, L.J. 1998. Short staple variety trials in Cochise County, 1997. In this publication.

Acknowledgments

Appreciation is expressed to Stan Jones and John Swapp for their interest and cooperation in this study. Seed was provided by New Mexico Crop Improvement, Australian Cotton Seed Distributors and SureGrow. A special thanks is due Stoneville Pedigree Seed Co. for their help in ginning the grab samples to provide the percent lint turnout for this field trial and the sub-samples from which HVI analyses were run.