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L-907

KEYS TO PROFITABLE GUAR PRODUCTION R. J. Hodges, Murray L. Kinman, Norman W. Brints, Emory P. Boring "' and James R. Mulkey, Jr.*

Guar, Cyamopsis tetragonoloba, is a drouth­ textured and sandy loam soils, with good structure tolerant summer annual legume. It was introduced and well-drained subsoils. Guar has been grown into the United States in 1903 from India, where successfully following flax when moisture is avail­ it is grown for exports, as a vegetable for human able on the heavier soils of South Texas. consumption, as cattle feed and as a green manure crop. MOISTURE REQUIREMENTS The guar seed (called a bean) has a rather large The guar plant is drouth resistant; when endosperm which sets it apart from most other moisture is short, growth stops until moisture be­ legumes, 'which have little or no endosperm. The comes available. Such intermittent growth length­ guar endo perm contains galactomannan gum ens the growing season. Peak water use periods which forms a viscous gel in cold water. Perhaps of guar are not as critical as for grain sorghum. the best-known use of guar gum is as a stiffener Guar responds to irrigation since adequate available in soft ice cream, Whip and chill puddings and soil moisture insures maximum production of forage whipped cream substitutes. Such products use the and beans. It is best adapted to areas of 20 to most highly refined food grade guar gum, and 30 inches of annual rainfall. Excessive rain after account for only a small portion of total production. maturity causes the seed to turn black and shrivel Larger volume uses of guar gum are in cloth and which lowers the quality of the beans. Dry fall paper sizing, oil well drilling muds and ore flota­ weather for harvesting is preferred. Profitable seed tion. Heavy imports of guar gum have been from production in areas of high rainfall and humidity India and Pakistan as partially processed endosperm is questionable; however, in such areas it might material. be used as a green manure crop. The meal remaining after the extraction of gum ROTATIONS contains about 35 percent protein, of which about 95 percent is digestible, making it an excellent Guar fits well into a crop-rotating program. It protein supplement for ruminants. It is equal or is a deep tap-rooted summer legume and is an superior to cotton seed meal in amino acids. Enough excellent soil-improving crop. It works well in gum remains in the meal to make it an excellent rotation with cotton, grain sorghum, small grains, feed pelleting material. Toasting improves its vegetables and flax. Increased yields can be ex­ palatability when fed to livestock. pected from crops following guar because of Commercial production of guar began in the increased soil fertility. When used in rotation with early 1950's in South Texas, but the center of pro­ cotton, yield increases of that crop of 15 percent duction quickly moved to the sandy soils of the have been measured. Rolling Plains area of Texas and Oklahoma. Offi­ When harvested for seed, guar still returns cial statistics are unavailable, but Texas farmers considerable dry organic matter to the soil surface plant around 100 thousand acres annually. About as a mulch. half of the planted acreage is harvested. The In a 3-year test at the Chillicothe Experiment remainder is plowed under as green manure for its Station, cotton planted in two-in·four-out systems soil-building properties. produced 250 pounds lint cotton per acre. The SOIL REQUIREMENTS same system, with the two center rows interplanted Guar grows well under a wide range of soil with guar, produced 220 pounds of lint cotton and conditions. It performs best on fertile medium- 500 pounds of guar for a cash advantage exceeding $15 per acre. ·Respectively, Extension agronomist, Texas A&M University; research agronomist, Crops Research Division, Agricultural SEEDBED PREPARATION Research Service, USDA; Extension area farm management Prepare the seedbed for guar the same as for specialist and Extension area entomologist, Vernon, Texas and assistant professor in charge, Texas A&M University cotton, com or grain sorghum. It should be firm, Agricultural Research Station at Chillicothe. free of weeds and the row surface should be slightly

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Texas A&M University • Agricultural Extension Service • John E. Hutchison, Director • College Station to well above general ground level to facilitate Seeding rates, based on percent germination to harvest. Plants on slightly raised beds after the assure a maximum of five plants per linear foot final cultivation insure maximum recovery of low­ of row, are suggested. Broadcast plantings are not set beans at harvest. Guar usually is planted in recommended where moisture is insufficient to 36 to 40-inch rows; however, row spacings of 10 to support the greater plant population. 20 inches might increase yields if moisture is Guar should be planted I to I Y2 inches deep. adequate. PLANTING EQUIPMENT QUALITY SEED Guar usually is planted with equipment em­ Use good-quality, preferably certified seed of ployed in planting grain sorghum. Beveled or recommended varieties. Planting seed should be tapered holes on the bottom side of plates crush of high germination, plump, true to variety and guar seed and cause gumming or clogging. Straight free from other crop and weed seed. holes give less problems. Addition of graphite or a dry detergent in the seed box helps avoid the Since the inoculum of the bacterial blight gumming problem. Reduce seed weight on the disease can be seed-borne, the use of certified seed plates by filling the planter box only about one­ to eliminate admixtures of old varieties, Texsel and third of capacity. Groehler, with improved varieties is important. Diseased Texsel or Groehler plants scattered Equipment designed for seeding vegetable or oil through a field can provide inoculum for spread seed crops has advantages for seeding guar. Special of the disease. New guar varieties are resistant, adapters designed for conventional planter boxes in but not immune, to the disease. -seeding oil crops such as soybeans may be suitable also. INOCULATION OF PLANTING SEED RECOMMENDED VARIETIES Inoculate planting seed just before planting with The development of disease resistant vanetIes a special guar inoculant or the cowpea (Group "E") has stabilized and increased sufficiently to allow inoculant. Sunlight, heat and excessive drying will guar to become a crop of economic importance impair or destroy effectiveness of the bacteria. when adapted. During seasons of normal rainfall, Properly inoculated guar will fix atmospheric these improved varieties permit production of nitrogen in amounts similar to cowpeas or other maximum yields partially resulting from improved legumes. For this reason, crops following guar in harvest efficiency because the pods are set higher rotation generally benefit from the residual nitro­ above the ground level. gen. Brooks, released in 1964, was the first improved variety. It replaced Texsel and Groehler and has PLANTING DATES occupied about 95 percent of the acreage since 1966. Plant guar when continuous warm weather is It is a high-yielding variety of known resistance to assured. It has higher temperature requirements the major guar diseases, Alternaria leaf spot and than cotton for stand establishment. For rapid bacterial blight. It is medium late in maturity establishment, soil temperatures at planting time and of the fine-branching growth habit. Small should be above 70 degrees F. A warm seedbed, racemes of medium-sized pods are well distributed adequate soil moisture and warm growing weather on the main stem and branches. Leaves and stems are essential. Seeding dates can range from March are glabrous (free of hair). The seed are of medium to August in the region of adaptation. Optimum size averaging 3 grams per 100. First pods are set seeding dates in South Texas are April IS to May higher above the ground level than those of old 31; in Central West Texas, May IS to July 1. varieties Texsel and Groehler. Although late plantings usually give satisfactory stands, seed frequently mature during lengthy Hall is a moderately late-maturing variety, periods of rainfall, which may cause staining and slightly later than Brooks. It is resistant to bacterial reduction of bean quality. Late plantings may be blight and Alternaria leaf spot. It is considered satisfactory for summer cover or SOil-improving a full season variety. Plants are relatively tall, crops. coarse and possess the fine-branching growth habit. Small racemes of medium-sized pods are well dis­ SEEDING RATE AND DEPTH tributed over the main stem and branches. Leaves and stems are glabrous. Seed are average size The following seeding rates (based on 85 percent averaging slightly less than 3.0 grams per 100. This germination) are suggested: variety appears best adapted to heavier soil types Single rows 4 to 6 lb. per A. and higher elevations. Double rows 6 to 8 lb. per A. Mills is an early maturing variety which is Broadcast 10 to IS lb. per A. resistant to bacterial blight and Alternaria leaf spot. Plants are short in stature and possess the fine­ Cultural Practices, Usual Dates, Times Over and Hours' Per Acre branching growth habit. Small racemes of above For Production and Harvesting of Guar average-sized pods are well distributed on the main Cultural Usual Times Hr. per stem and branches. Leaves and stems are pubescent practices dates over A. (hairy). Seed are above average in size, averaging about 3.4 grams per.lOO. In dry seasons; Mills does Chisel or hoeme March - May 1 0.4 Harrow April· May 1 0.2 not grow tall enough for efficient harvest. Yields Bed land April - May 1 0.3 generally are lower than those of Brooks and Hall Knife or sweep beds May 1 0.3 Plant & fertilize . May - June 1 0.3 and the variety has not g';lined much grower accept­ Cultivate June - July 3 0.9 ance. When diseases cause defoliation and prema­ Combine Nov. - Dec. Custom Hauling Custom ture death, susceptible varieties may be ready for -- harvest considerably earlier than Mills. Tota/ ·2.4 FERTILIZATION Fertilize according to results of a soil test. Apply pressed by a brown zonate or target-like lesion on fertiliz.er to the side and below the seed at planting the leaf. Lesions enlarge, join and cause the leaf or below the seed before planting. On fertile land to drop off. or where preceding crops have been fertilized Bacterial blight. This seed-borne disease causes heavily, fertilizer requirements for guar can be loss of plants from the seedling stage until maturity reduced or omitted. Guar, like most legumes, if environmental conditions are favorable. Symp­ requires high levels of phosphorus. In lieu of a toms include large angular lesions at the tops of soil test, consider using 20 to 30 pounds of phos­ leaves which cause defoliation and black streaking phorus (P 0 ). Fertilizer applied to guar should 2 5 of the stems. This causes the affected branches or increase yields of following crops. entire plant to die. This is potentially the greatest WEED CONTROL disease hazard to guar. Guar seed yields can be reduced greatly by weed Southern blight. Symptoms of this fungus dis­ competition. Also, weedy fields create harvesting ease are whitish fungus growth at the base of the problems. Do not seed guar in fields heavily infected plant. Small seed-like structures (sclerotia) infested with Johnsongrass. Early preparation of which tum dark with age and resemble radish seed land and mechanical cultivations during the grow­ are found in these fungus growths. The disease ing season will be helpful. Avoid covering the usually causes rapid death of the plant and is sug­ lower branches during cultivations to prevent de­ gestive of a wilt disease. Sanitation is important velopment of southern blight. Usually in the in controlling southern blight. Planting essentially Rolling Plains, guar planted in late June has less flat or in shallow furrows and avoiding covering weed competition. parts of the lower branches during cultivation will Trifluralin (Treflan) has been registered for use help control this disease. Practice rotation with on guar by USDA. Instructions on the label should disease-resistant crops such as grain sorghum and be followed closely. pasture grasses over a 3 to 4-year period. No resist­ ant varieties are known. INSECTS Cotton root rot. Guar is resistant but not im­ Field or storage insects have not been a major mune to cotton root rot. The cotton root rot problem in guar production. Farmers should watch fungus attacks guar, but seldom is lethal. their fields closely and contact the local county Top necrosis virus. Leaves drop off and terminal agent for assistance if infestations occur. ends of the stalk die and tum brown. The Lower Up to six larvae belonging to the genus Conta­ Rio Grande Valley is the only area where the disease rinia} a close relative of the sorghum midge, were has caused serious commercial losses. No control observed in unopened flower buds of guar in is known. Other viruses attack guar but have not September, 1969. On heavily infested plants, bean caused serious losses. set was poor. This insect possibly reduced yields in Knox and Haskell counties and occurred in GUAR AND GOVERNMENT PROGRAMS several other Rolling Plains counties. Currently, Guar is approved as a cover crop on conserving effective control measures for the pest are unknown. base acreage. Guar also is classified as an alternate crop and may offer opportunities for planting on DISEASES diverted acres. Since the harvest of guar planted Alternaria leaf spot. This fungus may become on diverted acres is treated differently each year, severe during periods of heavy dew and high plans to do so should be cleared with the county humidity or similar conditions. Symptoms are ex- ASC office annually. HARVESTING efforts by both companies to obtain a larger per­ Even when guar is planted as a full-season crop, centage of their total guar supply from domestic harvest usually is delayed until after frost. In dry production. seasons it may be possible to harvest early planted The market price of guar beans is based on guar before frost. Guar usually does not shatter equivalent price of splits (endosperm portion of and will stand quite well in the field; but for best seed with hull and germ removed) imported from quality, it should be harvested as soon after matur~ Pakistan and India. ity as possible. Harvest when the seed POds are Official grain standards for guar beans have brown and dry and when a moisture content is not not been established by the U. S. Department of more than 14 percent. Agriculture. However, commercial companies have For harvesting, an ordinary grain combine with standards establishing prices paid for beans. Grade few adjustments may be used. The cylinder should factors considered by the purchaser are the moisture, be slowed and the combine speed reduced to a rate foreign material and weight per bushel. that will permit proper threshing of the beans. Since guar beans are heavy (60 pounds per bushel), ECONOMICS OF PRODUCTION a high fan speed can be used to clean out foreign Income and expense for guar vary from year to material. The heavier the yield, the slower the year and according to soil types. Production costs machine must move. Reel speed should be slightly often vary widely between farms because of fertilizer greater than the combine ground speed. Excessive usage and chemical weed control practices. Produc­ or inadequate reel speed can cause shattering of tion practices and rainfall received during the seed pods. Reels should run just deep enough in growing season cause harvested yields to vary from the guar to control the stalks, and should be about about 300 pounds to more than a ton per acre. 6 to 12 inches ahead of the cutterbar. Some opera­ Increased production efficiency is possible by tors replace the wooden reel bats with Y2-inch steel adopting practices proved profitable through re­ rods to reduce shattering. search and result demonstrations. Decisions to When harvested for hay, leaves of guar shatter adopt improved production practices are made by readily unless extreme care is taken during the considering added cost and added returns due to curing process. For hay, the crop should be cut change in practices. Adequate records and accounts when the first lower pods turn brown. Other crops are necessary for measuring progress and making are available which are better suited for hay pr

Market demand for guar is expected to increase Total harvest cost $ 4.80 for the next several years. Reasons are (1) the wide Total specified cost $14.77 use of the galactomannan gum of the guar bean in Income over specified cost $22.03 a growing number of different products, and (2) 1Fertilizer usage should be determined by soil test.

The authors gratefully acknowledge suggestions and critique of manuscript by Orbie C. Cannedy, plant manager, Stein, Hall ;,. Co., Inc., Vernon, Texas and H. H. Partridge, field agronomist, General Mills, Inc., Munday, Texas.

Cooperative Extension Work in Agriculture and Home Economics, Texas A&M University and the United States Department of Agriculture cooperating. Distributed in furtherance of the Acts of Congress of May 8, 1914, as amended, and June 80, 1914. 12M-3-70 AGR 5