Chapin, John S.

Cole, Joe E.

Texas A&amp;M Repository

DEC 5 1975L-900KEYS TO PROFITABLE GRAIN SORGHUMPRODUCTION IN THE BlACKlAND PRAIRIEAND THE GRAND PRAIRIEJoe E. Cole and John S. Chapin*and (4) control winter weeds with chemicals, rowdisking or rotary hoeing to avoid disturbing theseedbed.FertilizationA balanced fertilizer program is essential foroptimum yields, efficient use of water and cropgrowth to maturity within a normal period of time.The wide range of soils, rainfall and managementpractices requires tailoring fertilizer applications toeach field. The best guide is a soil test recommen-dation from a reliable laboratory that has correlatedthe level of available soil nutrients and other factorsinfluencing yield response. Send the laboratory arepresentative soil sample. In addition, a descrip-tion of soil conditions, past fertilization and futurecropping, and an estimate of expected yield shouldbe sent.If a soil test is not available, a general estimateof needs at 3,000- to 5,500-pound yield levels in-cludes:Nitrogen (N) 40 to 100Phosphorus (P,Os) 40 to 60Potassium (KrO) 0 to 40If much undecayed crop residue remains atplanting time, increase the nitrogen by 15 poundsfor each estimated ton of dry residue per acre.Fertilizer nutrients generally are used most ef-ficiently when applied near planting time. How-ever, it may be easier and cheaper to fertilize inthe late fall before rebedding, or in early winter inthe sides of beds with chisel or sweep applicators.Allow ample time for the seedbed to settle beforeplanting. Use placement methods that avoid dis-turbing the seedbed. Phosphorus and potassiummay be applied at any time prior to or at planting;however, some loss of nitrogen may occur if it isapplied too early. To reduce application costs,these nutrients are usually applied at the same timeand should be added just prior to or after rebed-ding. If soils are extremely dry or are likely to becovered with water for extended periods, nitrogenshould be applied as near planting as possible, orGrain sorghum is the major annual cash crop inthe Blackland and Grand Prairies of Texas. Averagerainfall in these areas ranges from 30 to 45 inches,but its erratic distribution often makes grain sor-ghum production more reliable than corn produc-tion. This, along with easier stand establishmentand easier harvesting, results in most growers pre-ferring grain sorghum to corn when market price isnot a significant influence.Cropping SequenceCrop rotation, to avoid growing the same cropon a field in succeeding years, will help reducediseases, insects and weeds. Suitable systems, how-ever, may vary among individual farms. Grain sor-ghum residue helps maintain proper soil physicalcondition. Rotation based on 1 or 2 years of grainsorghum and 1 year of cotton is favored in much ofthe area. Three-year rotation of grain sorghum-cotton-small grain permits soil moisture storage andjohnsongrass eradication during the fallow periodfollowing small grain harvest, and also is advan-tageous for livestock. Rotations of other crops canalso be used.Keep records of crop locations, because chemicalresidues may necessitate changes in the rotationsystem if certain chemicals are used.Seedbed PreparationSeedbed preparation should begin after harvest-ing the previous crop to allow more time for weedcontrol, soil moisture storage, crop residue decay,fertilizer application and soil firming.To prepare the seedbed: (1) shred stalks of theprevious row crop promptly; (2) chisel, disk, plowor bed to stop crop and weed growth and to mixthe plant residue into the soil; (3) bed land by fallor winter; if land is to be rebedded, complete thisoperation 6 to 8 weeks before normal planting date;*Area Extension agronomist and area Extension agronomistldeceased), The Texas A&M University System; acknowledge-ment is made to certain county Extension agents-agriculture.Extension specialists in agriculture and to certain staff membersof the Texas Agricultural Experiment Station for contributionsto the development of this publication.13.14Nutrient Pounds per acreTexas Agricultural Extension Service. The Texas A&M University System. John E. Hutchison, Director. College Stationless if weed control and other cultural practices areperformed properly. Use I pound of average-sizeseed for each 700 pounds of expected yield per acre,not to exceed 6 plants per foot on 40-inch rows(80,000 plants per acre). Seeding rates should notbe increased when planting on rows less than 40inches apart 01: broadcast. Because seed size varies,adjust planters to obtain a seeding rate similar tothe amount suggested.Example: For rows 38 to 40 inches wide andseeding rates equal to 4, 6 or 8 pounds per acre,plant 4, 6 or 8 seeds per foot of drill, respectively.For two rows per bed and rows 18 inches wide, plantone half as many seeds per foot of drill.IrrigationAdequate moisture is necessary during the cri-tical growth stages of boot, bloom and soft dough.High-yield grain sorghum uses 20 to 22 inches ofwater during the growing season. This may besupplied from moisture stored in the root zone be-fore planting and from seasonal rainfall. Producerswith bottomlands can use irrigation to maintainample moisture. Roots of mature sorghum plantscan penetrate 4 to 6 feet deep in permeable soils.They may be somewhat shallower in less favorablesoil conditions.Preplanting irrigation can be used if rainfall hasnot filled the root zone. When enough surfacemoisture is present for good germination, waterfor early growth can be applied after plant emer-gence. During the growing season, apply waterwhen 50 to 60 percent of the available moisture inthe root zone has been used. When water suppliesare limited, irrigate for ample moisture during theearly boo't to soft dough stages. Additional waterfor leaching may be needed with each irrigationwhen poor quality water is used. Rainfall, soiltexture, depth of roots, weather and water qualitywill determine the number of irrigations, the in-terval between them and the amount per irrigation.Lighter, more frequent irrigations are required onsandy, shallow soils.Figure I shows the daily use of water by grainsorghum. Daily use begins to increase at the 7-leafstage, and may be 0.30 inch per day during the bootto grain formation stages.Fig. 1. Daily water use from planting to maturity.sidedressed after planting. If anhydrous ammoniais used, apply it 2 or more weeks before planting oras a sidedressing. Sidedressing should be midwaybetween the rows, and should be completed wi thin30 days after planting.Band application usually gives the most efficientuse of phosphorus. This can be done by chisel ap-plication in the middle of rows before rebedding,or into the sides of beds after rebedding. Laborsavings with bulk broadcasting may offset bandingefficiency. The amount of phosphorus should be in-creased 40 to 50 percent if broadcast application isused. Twenty to 40 pounds of phosphorus (P~O&)per acre applied with the seed may improve earlygrowth of seedlings and help get the crop off to agood start during a cool season. This is true espe-cially on soils very low in phosphorus. Do notapply nitrogen or potassium with the seed.Zinc and iron deficiencies occur on a few soils.Iron-deficient areas may need two or three foliagesprays of iron sulfate solution at 10- to 14-day inter-vals. Zinc deficiencies can be corrected by the ad-dition of 10 to 20 pounds of zinc sulfate per acre,or lesser amounts of chelate materials.For additional information on micronutrients,obtain L-891, Iron and Zinc Deficiencies in FieldCrops} (Texas Agricultural Extension Service),from your local county Extension office.SeedBecause high quality seed are important formaximum yields, purchase seed produced by re-liable seedsmen. Select seed with high germinationand vigorous seedling growth. To insure an ade-quate stand, seed should be properly treated witha fungicide and an insecticide, and be free of nox-ious weeds and other foreign material.Select a hybrid based on previous performanceunder local or similar conditions. Ask your countyagent about hybrids grown in local demonstrationtrials and/or in Texas Agricultural ExperimentStation tests. Yields, standability, tolerance to im-portant diseases in the area and maturity require-ments should be considered. Although later-ma-turing hybrids have the potential for higher yields,under good moisture conditions and normal plant-ing dates medium- to medium-late-maturing hybridsgive the best yields most consistently over a periodof years. Medium- or early-maturing hybrids maybe more productive when planting is delayed orwhen moisture is short.PlantingPlant near the average frost-free date when awarming trend is forecast, after the soil temperatureat about 7 a.m. is at least 55 degrees F. This rangesfrom February 15 to March 20 in the central andsouthern counties, and March 10 to April I in thenorthern counties.Plant about I Y2 inches deep in moist soil. Onmedium- to fine-textured soils firm the drill rowwhen possible by rolling lightly to conserve mois-ture and insure germination. Higher yields will beproduced with row widths averaging 30 inches or0.4VI~ 0.3~ 0.2'"...~:a~~ 0.130 60DAYS90Weed ControlWeeds and grasses reduce yields and may inter-fere with harvesting. Satisfactory control can beobtained by combining timely cultivation, crop ro-tation and herbicide applications. Herbicide selec-tion should be based on specific weed and grassproblems encountered in each field.If possible, fields heavily infested with johnson-grass should not be planted to sorghum. Large-seeded grasses such as Texas panicum (Colorado-grass) are not consistently controlled with presentlyavailable herbicides.Milogard or combinations of Milogard wi thRamrod or Lorox can be used preemergence to con-trol pigweed (carelessweed), other broadleavedweeds and many annual grasses. Grass control isgenerally improved when combinations are used.Sorghum, corn, cotton or soybeans can be planted12 months after application of these herbicides.Other crops should not be planted for 18 months.If winter wheat is to follow sorghum, Igran canbe used preemergence. Wheat can be planted safely4 months after application.The preemergence herbicides mentionedshould not be used on sand and loamy sand soils.Band applications reduce costs and result in lessresidue than broadcast spraying.Postemergence herbicides include Aatrex, Ban-vel, 2,4-D and Karmex or Dynex.Aatrex plus a surfactant or ncntoxic oil can beapplied after sorghum is 6 inches tall. If oil is used,application should be made prior to the boot stage.Small (4-inch), broadleaved weeds and some small-seeded grasses can be controlled. Do not use on sandor loamy sand soils. Residue limits next crop tosorghum or corn.After sorghum is 6 inches tall, but prior toflowering, 2,4-D can be used to control broadleavedweeds. Use salt formulations with a low vaporhazard, take precautions to avoid spray drift, andcomply with restrictions in regulated counties. Ban-vel can be used from 10 to 25 days after sorghumemergence. At recommended rates it is less injur-ious than 2,4-D to nearby crops.Karmex or Dynex plus a surfactant can be ap-plied as a directed spray when sorghum is 15 inchestall and when weeds and small-seeded grasses areless than 2 inches tall.Additional information on herbicides is avail-able in MP-I059, Suggestions for Weed Control withChemicals - Agronomic Crops~ Perennial lVeeds~Fence Rows and Non-Cropped Areas (Texas Agri-cultural Extension Service). Product labels shouldbe consulted before applying any herbicide. Followall directions carefully.InsedsSeveral common insects attack grain sorghumin the Blackland and Grand Prairies:Southwestern corn borer larvae feed withincrown and stalk, causing stunting, lodging and fieldloss. Plant early to avoid late-season buildups. Ap-ply insecticides when 25 percent of plants show in-jury. Shred and plow under stalks promptly afterharvest.Corn earworms and sorghum webworms feed ondeveloping and maturing grain. Because the cornearworm is cannibalistic, insecticides often are notneeded. Plant early to avoid late-season buildups.Check plants frequently after heading. Apply insec-ticides when necessary.Fall armyworm larvae feed on seedlings and inthe whorl during the preboot stage, causing leaf rag-ging and "buck shotting." Apply insecticides whenstand or bud damage is threatened.Aphids suck plant juices. Severity of damagedepends upon plant size, kind and number ofaphids, parasites and predators. The yellow sugar-cane aphid and greenbug may cause losses fromthe seedling through grain formation stages. Thecorn leaf aphid sometimes causes seedling loss. Ex-tension publications give detection and control in-formation.So'rghum midge adults deposit eggs in floretsduring the blooming stage. Larvae consume de-veloping seeds and cause "blasted" heads. Plantearly to avoid late-season buildups. If midge arepres~nt and damage is expected, begin insecticideapplications when about 50 percent of heads firstbegin blooming.Soil insects (seed-corn maggot, corn Tootworms,wireworms~ cutworms) in larval stages feed on seeds.seedlings, roots and stems of sorghum. Preplant in-secticide application is the most effective control,but seed furrow treatment often is satisfactory.Treatments on seedlings may control cutworms.Other insects (chinch bug~ false chinch bug,stinkbug~ flea beetle) occur in local areas. Chinchbugs suck juices from young plants. Flea beetleschew holes in leaves. Stinkbugs and false chinchbugs suck juices from developing grains. Apply in-secticides when populations reach damaging levels.DiseasesFor best results in controlling the common sor-ghum diseases, use a combination of suggested con-trol practices.Seed rots and seedling diseases are caused byseveral fungi and bacteria. Seed treatment fungi-cides used by seedsmen usually give protection, butthe grower should keep crop residue out of theseedling zone and use crop rotation.Downy mildew ~ caused by a fungus, has twodistinct phases. The foliar phase is characterizedby distinctive chlorotic spots and downy-like ap-pearance on under leaf surfaces. The systemicphase is characterized by a striking chlorotic leafstripping and sterility. Rotate sorghum with non-related crops and use tolerant hybrids.Maize dwarf mosaic produces a typical chloroticmottle on upper leaves, and a red-leaf symptom onhighly susceptible sorghums. Infected plants arestunted and yield less if infected within 45 daysafter emergence. The virus overwinters in rhizomesof johnsongrass and is transmi tted by insects. Con-trol johnsongrass in and around fields. Use hybridsresistant to maize dwarf mosaic.Head smut) caused by a fungus, produces smutgalls on the stalk and causes sterile heads. Use re-sistant hybrids and rotate sorghum with an unre-lated crop.Charcoal rot causes shredded stalk interior nearground level, poor seed development and stalklodging. Infection by this fungus is likely whendrouth stress occurs near heading. Conserve mois-ture and mature the crop before usual droughtperiods.Anthracnose) caused by a fungus, forms circularto oval spots on leaves. Neck and stalk rots occurif the fungus penetrates the stalk. Use tolerant hy-brids and crop rotation where the problem exists.Leaf spots and rust, caused by several fungi andbacteria species, produce spots, strips, pustules orstreaks on leaves, depending on the organism. Usecrop rotation.Nematodes stunt the root system, resulting inpoor uptake of water and nutrients. Rotate sor-ghum with crops which do not host the nematodeinvolved.Harvest AidsIn some situations, using a desiccant to killleaves on sorghum or grass and certain broad-leaved weeds may help dry the grain faster or reduceharvesting problems. Desiccants available for grainsorghum used as feed or food usually do not killthe stalks.Sodium chlorate used with urea as a fire re-tardant may be applied in quantities of up to 6pounds per acre of active ingredient when the sor-ghum is fully mature, and 7 to 10 days before har-vest. Four pounds usually are sufficient for .desicca-tion of sorghum and grass. Follow label instructionsfor gallons of solution per acre for aerial andground application.HarvestingSorghum should be harvested when moisturein the grain has reached a proper level for availablehandling facilities. Delay means losses. Ac-ceptablemoisture for storage is 13 percent. Grain with upto 18 percent moisture may be harvested if dryingfacilities are available.Trash and cracked grain favor insects, moistureaccumulation and mold damage in stored grain.Practice good sanitation during all harvesting andstoring operations. Protect grain from rodents andinsects.To avoid waste, the combine operator shouldfollow the manufacturer's manual in regard toproper adjustment.. One way of estimating the lossis to measure off 10 square feet of row area (40inches wide X 36 inches), and count the numberof grains on the ground and in the thrashed heads.Each 40 grains is equivalent to 100 pounds of grainlost per acre.MarketingGrain sorghum producers should coordinatemarketing and production activities to improve thelikelihood of a profi t on their crops. Growers canbase their marketing decisions on a wide range ofavailable sources of information.Producers, acting individually or as a group,may select one or a combination of the followingmarketing alternatives: (I) deliver and sell the cropat harvest to a local buyer; (2) contract the crop ata pre-arranged price before harvest, then fulfill thecontract by delivering the grain at harvest for cash;(3) "hedge" the crop before harvest on the futuresmarket, then liquidate the "hedge" at harvest anddeliver the grain to a local buyer for cash; or (4)store the harvested crop on-farm or in a commercialelevator for later cash sale. The producer can selllater in one lot or he can try to achieve an averageprice by marketing in several smaller lots through-out the year.A thorough understanding of how to use thesemarketing techniques, as well as their advantagesand disadvantages, is essential to making a soundmarketing decision. This is true whether the pro-ducer is marketing individually or cooperating in agroup effort. Producers also should compare ex-pected prices from all alternatives prior to choos-ing one, as prices may vary sharply at various timesin the year. Up-to-date market information fromreliable sources should help in this analysis. Loca-tion in relation to feedlots, poultry and dairy pro-ducing units, in addition to export demand alsowill help determine which marketing decision ismost advantageous during anyone year.EconomicsSee current budgets, or obtain information fromlocal county Extension office. Also refer to L-900A,Economics of Grain Sorghum Production in theBlackland Prairie and Gmnd Pmirie (Texas Agri-cultural Extension Service).The illformation gillen herein is for educational purposes ollly. Reference to commercial products or trade lIames is made l('iththe understanding that 710 discrimillation is intended and no endorsement by the Cooperative Extension Service is implied.Educational programs conducted by the Texas Agricultural Extension Service serve people of all ages regardless of socio-economiclevels, race, color, sex, religion or national origin.Cooperative Extension Work in Agriculture and Home Economics, The Texas A&M University System and the United StatesDepartment of Agriculture cooperating. Distributed in furtherance of the Acts of Congress of May 8, 1914, as amended, andJune SO, 1914.30M-8-?5 AGR 12-2

Keys to Profitable Grain Sorghum Production in the Blackland Prairie and the Grand Prairie.

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Keys to Profitable Grain Sorghum Production in the Blackland Prairie and the Grand Prairie.

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Texas A&M Repository

Keys to Profitable Grain Sorghum Production in the Blackland Prairie and the Grand Prairie.

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Texas A&amp;M Repository

Texas A&M Repository