TITLE:

             Dryland Commercial Sorghum Variety Trial at AG-CARES, Lamesa, TX, 2001

AUTHORS:

Jim Barber & Calvin Trostle, Sorghum PROFIT, Texas Cooperative Extension-Lubbock; John Farris, CEA-Dawson Co.; Danny Carmichael, TAES-Lubbock, j-barber@tamu.edu,

(806) 746-6101

METHODS AND PROCEDURES:

Soil Type:              Amarillo fine sandy loam

Planting:                June 28, 2001 on 40” rows

Previous Crop:     Sorghum

Seeding Rate:       ~26,000 seeds/acre with vacuum planter (about 1.6 lbs./acre, a seeding rate appropriate for the low moisture conditions at the time of planting)

Plot Set-up:           Two strips per variety, approximately 800’ long

Harvest Area:        Drought loss on all hybrids

Fertilizer:               None

Herbicide:             Atrazine

Insecticide:            None

Rainfall:                See Lamesa area summary elsewhere in the AG-CARES report, 2.32” for June 28-Oct. 31

Date Harvested:   None

Number of Entries:29

RESULTS AND DISCUSSION:

For 2001, we made our best guess at 32 modern grain sorghum hybrids (see table) for testing, mostly medium maturity. We expect yield trials to help producers improve hybrid selection for the lower Texas South Plains by identifying top-yielding hybrids over time. We believe that good hybrid selection more than justifies the sometimes higher cost of modern hybrid seed, and can add 200 to 400 lbs./A in yields compared to older though familiar hybrids that a typical farmer in Dawson Co. might choose.

Due to heat and dry conditions at AG-CARES, Lamesa, planting moisture and subsequent stand establishment and growth were severely affected, even though seed drop was reduced to 26,000 seeds/acre. Because of the delay in planting 5 days after the rain of June 23, seedling roots did not penetrate the dry soil around the disk opener furrow. In fact, a “ribbon of roots” formed in the seed furrow, a phenomena that locals have observed on rare occasion before. No harvestable yields were achieved. Most stands were less than 10,000 plants/A. Rainfall amounts after planting were July, 0.00”, August 0.67”, September 1.35”, and October 0.30” for a total of 2.32”. We estimated that about 2” of available soil moisture existed at planting below the 10” depth. Sorghum typically requires 5-7” of total moisture to reach the point of seed production.

The five-year history of grain sorghum production in the June-planted commercial dryland hybrid trial at AG-CARES-Lamesa is 1997, 3529 lbs./A; 1998, 3508 lbs./A; 1999, 1590 lbs./A; 2000 & 2001, no harvestable yield. Constraints to adoption of top sorghum hybrids are mainly twofold: 1) Producers view sorghum as absolutely a minimal input crop, and they will plant cheap seed because the seed costs $0.50-1.00/A less, that is, they are not confident that a better hybrid will make any difference due to weather, drought, etc. 2) Many growers continue to use too high seeding rates thus in a dry year it doesn’t matter which hybrid you use, you grow a lot of vegetation without getting grain yield (not enough moisture per plant for grain).

For the most recent three-year grain yield history of many of these sorghum hybrids at AG-CARES, see the 1999 Dawson County/AG-CARES report. The trial will be repeated in 2002.

Table 1. 2001 AG-CARES Commercial Sorghum Variety Trial entries.

*Grain color: BZ=Bronze, C=Cream, R=Red, Rt=Red translucent, W=White, Y=Yellow.

**Plant color: P=Purple, R=Red, T=Tan.

#Formerly Asgrow.

##Formerly Dekalb.

^Formerly Mycogen.

^^Formerly Novartis.