TITLE:

Guar Varieties and Dryland Guar-Cotton Rotation Trial at AG-CARES, Lamesa, TX, 2000

AUTHOR:

Calvin Trostle, TAEX-Lubbock; Danny Carmichael, TAES-Lubbock.

c-trostle@tamu.edu, (806) 746-6101

METHODS AND PROCEDURES (for guar planting):

Soil Type:                Amarillo fine sandy loam

Planting:                  June 14, 2000 on 40” rows; reseeded July 7, 2000.

Previous Crop:        Cotton

Seeding Rate:          ~55,000 seeds/acre with vacuum planter (~4 lbs./acre) and ~110,000 seeds/acre (~8 lbs./acre)

Plot Set-up:             Four replicated strips, test area per variety 4 rows X 105’

Harvest Area:          Drought loss on all treatments

Fertilizer:                 None

Herbicide:               1.0 pt Treflan

Insecticide:              None

Rainfall:                  See Lamesa area summary elsewhere in the AG-CARES report

Date Harvested:       None

RESULTS AND DISCUSSION:

No harvestable yield was obtained for guar or cotton in 2000 due to drought.

Interest in guar has increased since 1998 in the Texas South Plains with about 25,000 acres planted as either a primary crop or catch crop after hailed-out cotton. Guar is an indeterminant, drought tolerant legume, that is harvested for its gum in the seed endosperm. Little production information in Texas has been generated since the early 1980s.

A long-term 2:1 cotton-guar dryland rotation was established at AGCARES as well as continuous cotton strips to gauge guar production among four varieties (Esser, Kinman, Lewis, and Santa Cruz), nitrogen and phosphorus applications, and two seeding rates. No treatments were applied to the cotton. Continuous cotton will be maintained to evaluate the potential rotational benefit of guar to cotton. Old TAES information from Vernon, TX, suggests that rotational yield benefits to cotton were 15% the year after guar.

Guar was seeded on June 14 into good moisture at 1.5” deep. A subsequent rain appeared to sink the seed, and with a light crust which developed, poor emergence was obtained. We reseeded the stand in early July, but conditions were too dry to improve the stand. The guar stand, however, is sufficient to examine cotton yields on the rotated ground in 2001.

For more information about guar check with your local ag. agent or Calvin Trostle for ‘Guar Production Factsheet for West Texas’ (updated January, 2001) or the old TAES-Vernon document ‘Keys to Profitable Guar Production.’