Guar Crop Production

In conjunction with Texas A&M Research, West Texas Guar has conducted a number of test-plot trials to improve guar cultivation and production. Tests of planting rate, seed variety, fertility, harvest, and tillage were performed. In this section, you will find the results of this research and what we've learned from our own guar production.

The Crop Production Section is divided into the following areas:

Why Grow Guar?
Land Preparation
Planting
Growth
Diseases
Insects
Fertility
Cultivation
Harvesting
Yield
Standards

Why Grow Guar?

Guar can help some Texas and Oklahoma farmers maintain production and their quality of life. Guar can be used as an alternative in dry-land production or grown in rotation with other crops, like cotton, to replenish soil-nitrogen levels and increase future crop yields. West Texas Guar has measured an increase in cotton production greater than 12% following a guar rotation.

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Land Preparation

Guar grows in many well-drained soils; the best in sandy loam. It is tolerant of soil salinity and alkalinity.

Guar needs a firm seedbed with bed uniformity. Deep broken ground must have firm soil to prevent moisture loss during germination in loose soil. Land can be prepared by conventional till, minimum till, or conservation till. Conservation till requires a minimum bed height of 4 inches and an maximum height of 8 inches, or a somewhat peaked bed for easier harvesting. Broadcast planting is the preferred method in the upper Rolling Plains.

A pre-plant herbicide can be used. Treflan applied at 1 to 1 1/4 pint per acre is preferred. Prowl may also be used, but due to guar's oil-based composition is not recommended.

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Planting

Guar should be planted in moist to wet gound with a soil temperature above 70 F. Planting should be on a peaked bed in ridge-till operation. The planting depth, like that of milo or cotton should range from 1 to 2 inches. A thick stand will produce an increased node-setting length from the ground, thus producing a more harvestable bean.

We recommend a seeding rate of 5 to 10 lb. (65,000 to 130,000 seeds) per acre with an optimum seeding rate of 8 lbs. (100,000 seeds) per acre. Research by the Texas Agricultural Extension Service (TAEX) indicated no yield difference between 2 anf 10 lb. seeding rate. We do not have enough experience to confirm this report.

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Growth

When the soil is moist and the soil temperature id above 70 F, seedlings should emerge within 10 days of planting. Guar growth is slow for the first three weeks. During the first growth period, the visible part of the plant seems dormant. This is normal. At this time, the taproot is developing a strong root system or may have poor inoculation, like most legumes.

The guar growing season is typically 120 days, but can be 90 to 120 days with timely rains or irrigation. Guar prefers a hot, dry climate and thrives in areas receiving less than 30 inches annual rainfall. It is an indeterminate plant, therefore, when there is a lack of moisture, guar will stop growing but it will not die.

Guar, a summer annual, has smooth leaves, pods and stems with single stem fine or basal branching. Guar will range in height from 6 to 46 inches. In west Texas, pods are generally 1 to 3 inches in length with an average of 7 to 9 beans per pod. Beans vary in color from light tan to dark black. One pound of harvested guar will contain 10,000 to 20,000 beans.

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Diseases

There are only two major diseases that effect guar.

1. Alternaria Leaf Blight or Target Spot. This fungus will appear on the plant with repeated days of cool, wet weather. It will cost $4 to $6 per acre to kill. There has not been a documented case of alternaria leaf in the High Plains of Texas in the last 20 years.

2. Bacterial Leaf Blight. This is a seed disease which will cause the plant to begin premature defoliation. It is caused mainly by contaminated seed. At West Texas Guar, we try our best to not have contaminated seed, but we did see two mild cases in 1999. The plants were located in low-lying areas, and the bacterial blight was believed to be caused by a lack of rotation. The disease appeared in less than 1% of the plant population in the infected area.

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Insects

Guar midge is the primary insect pest. It can cause up to a 30% loss in production. Guar midge is usually concentrated in sandier soils and infestation will take place between 45 and 90 days of emergence. Chance of infestation may be significantly reduced by rainfall or sprinkler irrigation. Other potential insect threats are gall midge, threecornered alfalfa hoppers, white flies, white grubs, thrips and aphids.

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Fertility

Guar needs approximately the same fertility as cotton. We recommend 50 to 150 lbs. of an 8–18–7–3 for dry land and 80 to 150 lb. of the same 8–18–7–3 for irrigated land.

In 1999, Dr. Calvin Trosle of TAEX conducted irrigated and dry land nitrogen fertility trials that concluded that Nitrogen had little effect on guar production. West Texas Guar has observed a higher yield where phosphate and potash were applied or built up in the soil. We also observed an improved guar yield (approximately an additlional 400 lbs. per acre) with one foliar feed application.

West Texas Guar has not yet conducted a foliar application trials, but after observing all fertility methods, we believe 2 to 3 foliar feed applications will achieve maximum guar production with minimum investment.

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Cultivation

Normal cultivation practices for row-crop operations should be used. Guar should not be cultivated, knifed, or plowed more than twice. Since guar growth is somewhat slow in the first four weeks, it is susceptible to sand damage. Therefore, sand fighting is at the grower's discretion.

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Harvesting

For the past 30 years, guar grown the U.S. has been harvested primarily with a conventional grain header, regardless of condition of planting condition or cultivation. In 1998, West Texas Guar conducted an independent harvest trial, with a conventional platform header and a flex header. The results were inconclusive because we had no proven method of determining bean loss per acre.

In 1999, working with TAEX's Dr. John Sie and Dr. Calvin Trostle, we developed a method for determining harvest yield and bean loss and conducted another trial. This harvest trial compared a pickup attachment, a row-crop header, and a flex header. The row-crop header gathered the highest quantity per acre — 20% more than the other methods tested. Read the harvest efficiency report.

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Yield

In 1999, guar yields ranged from 350 to 1725 lbs. per acre on dry land. Irrigated land yielded from 500 to 2250 lbs. per acre. The average production for 1999 was 774 lb. per acre. Under ideal conditions, guar yields can be as much as 4500 lbs. per acre.

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Standards

Guar beans are graded by moisture and minimum test weight in pounds per bushel. The price paid is dependent on this grade with Number 1 having the highest value. The grading system is as follows:

GRADE MOISTURE MAXIMUM MINIMUM TEST WEIGHT LB./BUSHEL
Number 1 13.5 60
Number 2 14.0 59
Number 3 14.5 58
Number 4 15.0 57
SAMPLE GRADE above 15.1 below 56.9

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