TITLE:

Conventional and Transgenic Cotton Variety Performance Under LEPA Irrigation, AG-CARES, Lamesa, TX, 2001.

AUTHORS:

Randy Boman, John Farris, Mark Stelter, Mark Kelley, Alan Helm, Tommy Doederlein; Extension Agronomist-Cotton, CEA-Agriculture Dawson County, Extension Assistant-Cotton, Extension Assistant-Cotton, Extension Assistant-Cotton, and EA-IPM Dawson/Lynn Counties.

MATERIALS AND METHODS:

            Varieties:                   AFD 2050, All-Tex Excess Plus, FiberMax 958, FiberMax 989

                                                FiberMax 989RR, FiberMax 989BG/RR, Paymaster 2200RR,

                                                Paymaster 2280BG/RR, Paymaster 2266RR, Paymaster 2326RR,

                                                Paymaster 2379RR, Stoneville 4793R

            Experimental design: Randomized complete block with 4 replications

            Seeding rate:             15 lb seed/acre in 40-inch row spacing ( John Deere Max Emerge vacuum planter)

            Plot size:                    4 rows by variable length due to pivot pie (340-810 ft long).

            Planting date:           May 30 (May 10 planting was destroyed by hail)

            Weed management:Treflan was applied preplant incorporated at 1 pt/acre across all varieties on April 10. No Roundup herbicide was applied on Roundup Ready varieties due to insufficient weed pressure.

            Irrigation and rainfall:LEPA irrigation

                                                April:             1.50"

                                                May:               2.10"

                                                June:               2.00"

                                                July:               4.50"

                                                August:4.40"

                                                September:    2.00"

Rainfall

                                                April:             0.09"               July:               0.00"

                                                May:               1.60"               August:0.67"

                                                June:               1.43"               September:    0.00"

Total moisture: 21.46"

            Insecticides:              Temik, 3 lb/acre in-furrow at planting. No additional insecticides were required (lepidopterous larvae populations did not exceed thresholds) except active boll weevil eradication.

            Fertilizer management:Nitrogen fertilizer (30 lb N/acre using 32-0-0) was applied preplant through the pivot system. An additional 90 lb N/acre (32-0-0) was fertigated in 30 lb N/acre increments during the season.

            Harvest aids:            Harvest aids included Super Boll (ethephon) at 1 pt/acre plus Ginstar at 6 oz/acre applied at 60 percent open bolls with a follow-up application of Cylcone at 16 oz/acre.

            Harvest:                     Plots were harvested on October 23 using a commercial John Deere 7445 with field cleaner. Harvested material was dumped into a weigh wagon with integral digital scales to determine individual plot weights. Plot yields were adjusted to lb/acre.

            Gin turnout:              Grab samples were taken by plot and ginned at the Texas A&M Center at Lubbock to determine gin turnouts.

            Fiber analysis:         Lint samples were submitted to the International Textile Center (ITC) at Texas Tech University for HVI analysis, and USDA Loan values were determined for each variety by plot.

            Ginning costs           Ginning costs were based on $1.55 per cwt. of bur cotton and $100 per

            and seed values:       ton for seed value. Ginning costs do not include bagging, ties and checkoff.

            Systems costs:           Systems costs were determined by variety per acre using manufacturer’s suggested retail prices for seed, and appropriate technology fees for Bollgard and/or Roundup Ready based on the 15 lb/acre seeding rate.

RESULTS AND DISCUSSION:

Significant differences were noted for most parameters measured (Tables 1 and 2). Lint turnout ranged from 26.5% to a high of 33.9%. Lint yields varied from a low of 769 lb/acre to a high of 1089 lb/acre. Lint Loan values were generally very high, with the exception of discounts for high micronaire in some replications of Paymaster 2326RR (average 4.9). This resulted in a $0.5075 loan value for Paymaster 2326RR. After including lint and seed value, total value for varieties ranged from a low of $501.94 to a high of $678.51. When subtracting ginning and systems costs, the net value among varieties ranged from $611.95 to $448.05, a difference of $163.90/acre. These data indicate that substantial differences can be obtained in terms of net value/acre due to variety selection. It should be noted that no inclement weather was encountered in this trial prior to harvest. High intensity rainfall and/or high wind events were not experienced to potentially cause pre-harvest losses with the open boll picker-type varieties (FiberMax 958, FiberMax 989, FiberMax 989BG/RR, FiberMax 989RR, and Stoneville 4793R). Producers should take note that the harvest period optimum encountered in 2001 is not considered “normal” for the Texas High Plains. Additional multi-site and multi-year applied research is needed to evaluate varieties across a series of environments.

ACKNOWLEDGMENT:

Appreciation is expressed to Danny Carmichael, Research Associate - AG-CARES, for his assistance on this project.