Ohio Agronomy Guide, 14th Edition

Bulletin 472-05

Chapter 6: Small Grain Production

Dr. Jim Beuerlein, Dr. Pat Lipps, and Dr. Ed Lentz

NOTE: Material in this chapter related to pesticides may not be valid after 2005. Please contact the county office of Ohio State University Extension or the Agronomy Team web site at www.agcrops.osu.edu for current information.

The major objective of a small grain production system is the interception, fixation, and storage of sunlight energy. The most important components of such a system are variety selection, timely planting, disease control, and adequate fertilization. The effects, interactions, and relationships of various inputs to small grain production systems are discussed here.

Wheat Production

Ohio is a leading state in the production of soft red winter wheat and enjoys an outstanding reputation for the quality of its crop. Flour made from soft red winter wheat is superior for making cakes, crackers, cookies, and all sorts of pastries. Any contamination from hard red wheat or soft white wheat in marketing channels reduces its market value and the quality of flour made from it.

Attempting to produce ultra-high yields by using extra inputs is not profitable for most Ohio wheat producers. That is because the climate of Ohio limits maximum wheat productivity. Most years, Ohio’s weather is too wet in May and June, resulting in serious disease and loss of yield. June and July is usually too hot and kills our crop well before it has time to reach its maximum yield potential. When we have one of those rare dry springs with low disease levels followed by a cool June, the yields of some fields have reached 120 bushels per acre or more. Because those good growing seasons are rare, we should manage for the more normal weather. It is the weather that usually prevents us from taking advantage of high management inputs such as high seeding rates and extra nitrogen.

The most prudent production system is one of defensive management—planting after the fly-safe date to dodge diseases; holding seeding and nitrogen rates down to reduce disease and lower the cost of production; using resistant varieties instead of applying fungicides, etc. This management system will not produce the maximum possible yield in those really good years, but it will be the most profitable system for all those other years (the norm) when the weather is not ideal for maximum yields.

A research study conducted at three locations in 1999 and 2000 compared high and low levels of inputs to determine their effect on winter survival, tiller production, heads per acre, and yield. The high-management system included a seeding rate of 30 seeds per foot of row, 50 pounds of fall-applied nitrogen followed by 100 pounds in April, and the application of fungicide at various times. The low-management system used a seeding rate of 20 seeds per foot, 25 pounds of nitrogen in the fall, 75 pounds in the spring, and a disease-resistant variety that required no fungicide. The high-management system cost $31 per acre more than the low-cost system but produced only 2.7 (89.2 vs. 91.9) more bushels of grain per acre. The extra seed and nitrogen alone raised cost by $16 per acre. These studies and many other similar studies indicate that in Ohio, the key to wheat profits is good management and low production costs.

High yields and low cost of production are necessary for wheat to be a viable economic partner in the crop-rotation sequence. Increased profitability will only come from improved management. The guidelines presented here will help minimize the factors limiting wheat yields and also lower production costs. Additional specific information on wheat can be obtained at county offices of Ohio State University Extension or on the Internet at: www.agcrops.osu.edu/wheat.

Variety Selection

A wheat variety performance trial is conducted annually by Ohio State University’s Ohio Agricultural Research and Development Center to measure yield and other agronomic characteristics important to producers of the crop. Information on wheat variety performance can be obtained in the annual Ohio Wheat Performance Test, Horticulture and Crop Science Department Series 228, available at county Extension offices or on the Internet at: www.agcrops.osu.edu/wheat .

The yield potential of currently available varieties is generally in excess of 150 bushels per acre. This yield is not approached, however, primarily because of a short grain-fill period caused by high air temperatures in late June and early July which kill the crop. Accordingly, growers need to select wheat varieties with high yield potential, high test weight, good winter hardiness, and good straw strength. Always select varieties with adequate resistance to the diseases prevalent in your area of the state. Information on variety performance should be obtained from multiple sources, such as seed companies and university performance trials, where multiple sites and years of testing are presented.

Always plant more than one variety each year to reduce the risk of disease losses and to spread out harvest dates. Select varieties with resistance to wheat spindle streak mosaic, powdery mildew, and leaf rust. Varieties with moderate resistance to Stagonospora blotch and Fusarium head scab are also available. Avoid varieties highly susceptible to Fusarium head scab. Information on the reaction of varieties to various diseases can be obtained from seed company dealers and on the Ohio Field Crop Disease web site at: www.oardc.ohio-state.edu/ohiofieldcropdisease/ .

High-Quality Seed and Seed Treatment

Purchase only high-quality seed that has been thoroughly cleaned to remove shriveled kernels and that has a germination of 90% or better. All seed should be treated with a seed-treatment fungicide to control seed-borne diseases like loose smut, common bunt, Fusarium scab, and Stagonospora glume blotch. Treatments containing the fungicides difenconazole or tebuconazole (TBZ) have been very effective in controlling most seed-borne diseases. TBZ can be added to improve efficacy against seed-borne Fusarium found on scab-affected seed.

Basic information on seed treatments can be found in Table 6-1, but more information is available in Ohio State University Extension Bulletin 639, Seed Treatment for Agronomic Crops, and OSU Extension Bulletin 639A, Efficacy of Seed Treatment Fungicides for Agronomic Crops in Ohio. Both bulletins can be found on Ohio State’s web site at: ohioline.osu.edu/b639/b639_17.html.

Crop Rotation

Plant wheat following soybeans. A three-year rotation of corn-soybean-wheat appears to be optimum for sustained yield of all three crops. Crop rotation is the most effective method to reduce pathogen populations that affect the three crops in the sequence. The purpose is to provide enough time away from the host plant for pathogens to die out before that crop is planted again. Wheat should never follow wheat or spelt in the rotation sequence.

Soil-borne diseases, like Take-all and Cephalosporium stripe, can cause complete crop failure in non-rotated fields. Foliar diseases, like powdery mildew and Stagonospora glume blotch, may also become more of a problem. Wheat should not follow corn in the rotation because the same fungus that causes Gibberella stalk rot in corn also causes Fusarium head scab in the wheat. Planting wheat into corn residues greatly increases the risk of a severe outbreak of scab in the wheat crop. Wheat also serves as an excellent rotation crop for corn and soybeans, allowing populations of pathogens (like soybean cyst nematode and Sclerotinia) to decline before host crops are again planted in the field.

Land Selection and Preparation

Wheat grows well in a range of soil types; however, well-drained soils with medium to fine texture produce the highest yields in Ohio. Adequate drainage is essential; thus, tiling poorly drained fields is important. Plan the crop-rotation sequence far enough in advance to plant early-maturing soybean varieties in fields to be planted to wheat in the fall. This will permit planting of wheat at the optimum time for maximum winter survival and yield potential. Drilled, medium-season soybean varieties, planted early yield as well as full-season varieties.

Planting no-till wheat into soybean stubble has been very successful in reducing erosion and almost totally eliminates spring heaving, which also reduces production costs. Soybean residues should be evenly spread across the field during harvest to ensure uniform seeding depth (1.5 inches). Do not plant into soils that are too wet and monitor planting depth when the soil is hard and dry.

Planting Date

Wheat should never be seeded prior to the fly-safe date because of the possibility of severe damage by diseases and Hessian fly (Figure 6-1). The best time for seeding is a 10-day period starting the day after the fly-safe date. Long-term average yields are highest from seedings made during that time (Figure 6-2). Seeding during that time usually produces ample growth for winter survival and reduces the likelihood of fall disease infections and attack by potentially damaging insects. Occasionally, when freezing weather is delayed until late November or early December, wheat seeded more than three weeks after the fly-safe date is equal in yield to that seeded during normal planting time. Because of reduced fall growth, late seeded wheat is less winter hardy and more susceptible to spring heaving.

Figure 6-1. Hessian fly-safe dates for planting wheat for Ohio counties.		Figure 6-2. Effect of planting date on wheat yield.

Seeding Practices

When planting at the proper time and into soil that is not too wet, seed should be planted 1.5-inches deep. Row width should be six to eight inches. Planting by bushels per acre is very inaccurate due to variability in seed size from year to year and from one variety to another. Low seeding rates result in inadequate stands and winter injury, while excessively high rates increase lodging and disease pressure.

Do not plant weak-strawed varieties prone to lodging. Calibrate the drill each year for each variety and seed lot planted. The optimum seeding rate is 1.2 to 1.6 million seeds per acre (18 to 24 seeds per foot of 7.5-inch row when planting during the two weeks following the fly-safe date). During the third and fourth week after the fly-safe date, plant 1.6 to 2.0 million seeds per acre (24 to 30 seeds per foot of row). Do not plant faster than the speed at which the drill was calibrated. The number of seeds per pound and germination rates are critical factors that need to be known before a proper seeding rate can be determined and the drill calibrated. This information should be listed on the bag of seed. The information in Tables 6-2 and 6-3 can be used to accurately calibrate grain drills.

Row Width

Wheat row spacing work conducted in the mid-1980s indicated that wheat grown in 14-inch rows produced yields that were 94% of yields from rows spaced seven inches apart (61 bushels compared to 57.3 bushels). Because the seeding rate per foot of row for wheat is the same for all row widths, the seed cost for 15-inch rows is half that for 7.5-inch rows. When wheat seed costs $12 per unit and wheat grain is worth $3 per unit, the lower yield from wide rows is almost offset by the reduced seed cost. The additional savings from drills with fewer seed meters and planting units made the two row spacings equally profitable based on the 1980s data.

The results of studies conducted in 2000 and 2001 appear in Tables 6-4 and 6-5. In both years, the plots were planted within 10 days after the fly-safe date at the rate of 25 seeds per foot of row for both row spacings (120 lbs. and 60 lbs. for 7.5-inch and 15-inch rows, respectively). Nitrogen (30 lbs. per acre) was applied at planting each year to stimulate fall growth, tillering, and improve winter hardiness.

These data indicate that some wheat varieties may be more profitable to produce in wide rows than narrow rows due to savings in seed and machinery cost. Varieties that perform well in wide rows tend to be either tall by nature or grow tall due to favorable weather. They also have a non-erect growth habit that allows them to fill in the wide-row middles. High rates of tillering also favor higher yields in wide rows. Tillering is favored by planting within seven days after the fly-safe date and the application of 30 pounds of nitrogen at planting. Normally, 15-inch-row wheat yields 5% to 15% less than wheat grown in 7.5-inch rows. In 2001, excessive tillering and vegetative growth reduced that normal difference in yield.

Lodging Control

Lodging is a serious deterrent to high yields. Cultural practices that tend to increase grain yield also increase the likelihood of lodging. Using recommended seeding rates (18 to 24 seeds per foot of 7.5-inch row), applying proper rates of nitrogen, and selecting lodging-resistant varieties prevents lodging in high-yield environments where yields of 100 bushels per acre are anticipated. When lodging occurs, the severity of foliar disease increases, resulting in reduced grain yield and quality. Additional effects of lodging are reduced straw quality and slowed harvest. The prevention of lodging increases dividends through a combination of reduced input costs and improved grain and straw quality.

Fertilization

Nitrogen

Providing adequate nitrogen for the wheat crop is an important step toward high yields. However, as the nitrogen rate increases, the potential for lodging and disease also increases. The amount of fertilizer nitrogen required varies greatly, depending on the level of soil organic matter, carry-over nitrogen from previous crops, and yield goal. In general, each 1% of organic matter supplies eight to 12 pounds of nitrogen per acre through organic matter oxidation. Nitrogen available from a previous soybean crop ranges from 20 to 40 pounds per acre.

Current recommendations are to apply 20 to 30 pounds of nitrogen at planting to stimulate fall vegetative growth. Spring nitrogen should be applied between March 1 and April 30 (Table 6-6). When starter nitrogen is applied in the fall, spring applications in mid- to late April are satisfactory. When no nitrogen is applied in the fall, the spring application should be made before April 15.

Most sources of nitrogen are satisfactory for wheat. Urea and 28% solutions (urea-ammonium nitrate) are often the most common. Urea has the least potential to cause damage to the crop. Damage is generally insignificant from broadcast applications of 28% solution applied early, but the potential for damage increases as the crop matures. Dribble band applications will minimize damage from 28% solutions. Urea-ammonium nitrate solutions will have some nitrogen available immediately at application time; urea will have a short lag as it converts to ammonium and nitrate forms of nitrogen. The nitrate fraction of 28% solutions will be susceptible to loss after application until plant uptake. Urea may have volatilization losses if temperatures are exceedingly warm.

The spring application should be the total nitrogen recommendation less the amount applied in the fall. No credits are given for previous crops. For example: A 90-bushels-per-acre wheat crop would require 110 pounds of nitrogen (Table 6-6). If the grower applied 30 pounds in the fall, the remaining 80 pounds should be applied in the spring.

A split spring application program may be a benefit in poorly drained fields that are prone to nitrogen loss or in fields prone to lodging. For these programs, it is important that the first application occurs soon after initial green-up and the second application at initial jointing (Feekes Growth Stage 6). The time of application is not as critical in a single spring topdress (providing some nitrogen was applied in the fall), but applications should be made after initial green-up and before the second visible node on the stem (Feekes Growth Stage 7). Up to half the total intended amount of nitrogen can be applied in the second application.

Phosphorus

Small grains respond well to phosphorus fertilizer on soils testing up to 45 ppm. Therefore, to maximize yields, the soil P level (Bray P1) should be 45 ppm or higher. A 1:4:2 ratio provides the proper balance of starter fertilizer. Table 6-7 contains the recommended phosphorus applications. Phosphorus should be applied before planting when the soil-test level is below 45 ppm. Actual phosphorus recommendations are determined by the yield goal and soil-test level. Phosphorus and fall-applied nitrogen are often applied as diammonium phosphate (DAP) or monoammonium phosphate (MAP).

Potassium

The small-grain response to potassium application is less than that of phosphorus. When the K soil-test level is maintained at 75 ppm plus five times the CEC (Cation Exchange Capacity), a potassium application equal to the crop removal plus 20 pounds of K2O per acre produces optimum yields if no other factors are limiting. If the soil-test K level is maintained at 175 ppm plus five times the CEC, then no application of potassium is needed for optimum yields. See Table 6-8 for recommended potassium applications.

Recommendations for potash are based upon the yield goal, soil Cation Exchange Capacity (CEC), and the soil-test level. Soils with higher CEC values have a greater chance of potassium becoming unavailable to the crop and require more potash than low CEC soils. Table 6-8 recommendations only account for grain removal of potassium by the crop. Recommendations should be greater in fields where the straw may be baled and removed.

Manganese

Wheat is almost as sensitive to manganese deficiencies as is soybean, and the problem occurs in the same areas of fields. Deficiency symptoms are usually not severe enough to be seen but will reduce yield. Maintaining soil pH between 6.5 and 7.0 will usually eliminate the problem. Manganese sulfate can be applied in a band or in contact with seeds when it is recommended by a soil test. A more practical application method is to mix some manganese sulfate (four pounds per acre) with liquid nitrogen for application at or before green-up in the spring.

Disease Control

Disease is often the major factor limiting yield of wheat in Ohio and other Midwestern states. Yield losses as high as 30 to 50% are common where no disease control is practiced. Effective disease management requires knowledge of the diseases most likely to occur in a production area. Producers should fine tune their disease-control strategies for those few diseases encountered each year. Correct diagnosis is the cornerstone to effective control, and producers with little experience identifying diseases should seek help from competent sources, such as Ohio State University Extension or an agricultural consulting service.

A comprehensive wheat disease-management program consists of the following practices:

1. Select varieties with resistance to the important diseases in the area. Powdery mildew is most common throughout Ohio, except in the northwestern part of the state. Stagonospora glume blotch is most severe in central, west central, northwestern, and southern Ohio. Leaf rust has the greatest potential for damage in southern Ohio. Monitoring wheat diseases aids a producer in selecting varieties with resistance to the common diseases of his or her community.
2. Plant well-cleaned, disease-free seed, treated with a fungicide that controls seeding blights, bunt, and loose smut.
3. Plant in a well-prepared seedbed, after the fly-safe date.
4. Rotate crops; never plant wheat where the previous crop was wheat or spelt. A two- to three-year rotation from wheat prevents most pathogens from surviving in fields.
5. Plow down residues from heavily diseased fields, especially those affected by Cephalosporium stripe or Take-All. Plowing enhances decomposition of residue and death of the disease-causing fungi.
6. Use a well-balanced fertility program based on a soil test. Apply sufficient amounts of phosphorus, nitrogen, and potassium in the fall for vigorous root and seeding growth. Spring top-dress with nitrogen at the rate recommended to achieve the yield goal. Excessive nitrogen increases the severity of foliar disease and lodging.
7. Control grass weeds. Destroying volunteer wheat, quackgrass, and other grass weeds in and around potential wheat fields reduces the amount of disease inoculum available to infect the crop.
8. Apply fungicides only if warranted. Scout fields from flag leaf emergence through flowering. Foliar fungicides are able to control the following diseases—powdery mildew, leaf rust, and Stagonospora nodorum leaf and glume blotch. Stagonospora leaf blotch and powdery mildew are the most severe. Know symptoms, severity ratings, and disease thresholds before scouting fields. The earlier the fungicide is applied after reaching the threshold level, the greater the yield response.

Growers should become familiar with symptoms of the common diseases affecting wheat in Ohio. Correct diagnosis and scouting are important steps in identifying the yield-limiting diseases on your farm. Help in diagnosis can be obtained from OSU Extension or other crop consultants. OSU Extension Bulletin 785, Wheat Disease Control in Ohio, provides descriptions and pictures of the common diseases in the state. This bulletin can also be found on OSU’s web site Ohioline at: www.ohioline.osu.edu/b785/index.html. Additionally, information on wheat-disease diagnosis and control can be obtained on the web site Ohio Field Crop Diseases at: www.oardc.ohio-state.edu/ohiofieldcropdisease/ . The symptoms and appropriate control measures for several important wheat diseases are provided in Table 6-9.

Planting disease-resistant varieties is the most effective and economical means for controlling diseases. Select resistant varieties based on research conducted by universities and seed companies. Varieties are available with moderate to high levels of resistance to leaf rust, powdery mildew, and wheat spindle streak mosaic. Varieties with moderate levels of resistance to Stagonospora leaf and glume blotch and Fusarium head scab are also available. However, varieties rarely have good resistance to all diseases. When varieties have high resistance to a disease, they effectively limit losses in yield. Resistance to leaf rust and powdery mildew may fail due to the development of new races of the pathogens. Combining the use of resistant varieties with good crop rotations, planting after the Hessian fly-free date, and the use of seed-treatment fungicides will improve disease control.

Scouting fields for disease is essential when growing moderately susceptible and susceptible varieties to determine the need for fungicide applications. This involves checking the level of disease on 30 to 50 individual tillers randomly selected throughout the field. Fields should be scouted for powdery mildew at flag-leaf emergence and boot stage (Feekes Growth Stage 8 and 10, respectively; see Figure 6-3) and scout for Stagonospora leaf blotch and leaf rust at boot stage and full-head emergence.

Figure 6-3. Feekes Wheat Growth Stage Scale.

The upper two leaves on tillers and the glumes on heads contribute most to grain fill. Thus, it is important to keep these upper plant parts free of disease to avoid yield loss. Fungicides should be used only on susceptible and moderately susceptible varieties in fields that have a yield potential of 60 or more bushels per acre. Disease thresholds are 1% of leaf area affected on the leaf below the flag leaf up to boot stage (Feekes Growth Stage 8 through 10), and 1% of leaf area affected on the flag leaf between head emergence and flowering (Growth Stage 10.1 to 10.5.1, Table 6-10). When these disease levels are present, a fungicide should be applied as soon as possible to protect leaf tissue before more becomes infected. One percent leaf area affected roughly translates to five to 10 leaf-rust pustules, two to three powdery-mildew pustules, or one to two Stagonospora nodorum blotches. Table 6-11 shows the efficacy of several fungicides for wheat-disease control, while Table 6-12 shows the predicted yield loss to powdery mildew, based on variety susceptibility and disease level.

Insect Control

Several different insects can be important on wheat in Ohio. Management of insect pests affecting wheat often emphasizes nonchemical control measures. Hessian fly is controlled primarily by delaying planting until late September or early October, depending on location of the field in the state. Cereal leaf beetle and aphids are usually controlled by beneficial parasites. However, populations of some pests, especially cereal leaf beetle, armyworm, and sometimes aphids, may occur in numbers warranting rescue treatment with insecticides. The insect pests that may impact wheat are reviewed here:

The Hessian fly passes through two generations per year in which adult flies deposit eggs, maggots hatch on leaves and feed on stems, and then maggots pupate into the commonly recognized flaxseed stage. Damage by the maggots occurs in the late spring and early fall following activity by adults in early spring and late summer. Flaxseed pupae are located within the leaf sheaths of plants in the spring, resulting in the broken wheat stems and lodging associated with that damage. Under serious infestations, the problem is generally detected after the damage has been done and the fly is in the flaxseed stage. Thus, rescue treatments are not warranted. The major tactic for controlling Hessian fly is planting wheat after the Hessian fly-safe date for your county (see Figure 6-1).

English grain aphid and the cherry oat aphid may cause limited feeding injury. The greenbug, which produces a toxin that affects the wheat plant, rarely occurs in Ohio. To determine the need for treatment, first identify the aphid. English grain aphid has black cornicles or tailpipes on the tip of the abdomen, oat-bird cherry aphid has a red-orange spot between the cornicles, and the greenbug has a dark green stripe on the back and the tips of the cornicles are black. Keep in mind that natural predators usually control most aphid populations on small grains. Greenbug infestations that are great enough to cause economic damage are rare in Ohio. Aphids also are important in Ohio because they may transmit the barley yellow dwarf virus that causes stunting and yellowing of wheat and other small grains. However, it is not economically feasible to control transmission of barley yellow dwarf virus with insecticides because aphids can transmit the virus within six hours of landing on the plant.

Overwintering cereal leaf beetles appear in the spring and lay eggs, which hatch into larvae that feed on wheat and oat leaves. Larvae appear as small black slugs due to accumulated fecal matter on their backs. There is one generation per year with new adults appearing in late spring. A complex of parasitic wasps generally controls cereal leaf beetle, but treatment of fields may be warranted when mild winters adversely affect natural control. An infestation averaging one larva per stem may result in a loss of three bushels per acre.

Adult armyworms become active in late April and early May and are attracted to grass crops, including wheat. Larvae are active in late May and June and can feed on leaves and emerging heads. Most serious damage occurs when larvae feed on stems and clip heads completely off. Detection of larvae is initially along the edge of fields and low-lying areas. When six or more larvae can be seen per linear foot of row, or head clipping is evident and larvae are not fully grown (larvae are predominantly one-inch long or less), a rescue treatment may be needed.

Insecticides labeled for use on small grains are listed in Table 6-13. For more information on managing insect problems and for the chemicals labeled for wheat insects, see Extension Bulletin 545, Insect Pests of Field Crops, which is available on the Internet at: ohioline.osu.edu/b545/index.html .

Weed Control

Wheat competes well with weeds, especially when good production techniques result in an initial uniform stand establishment and when loss of stand due to winter injury is minimal. Effective weed control and prevention of weed seed production in prior crops will reduce the risk of weed problems in wheat. Some wheat fields can benefit greatly from herbicide application, and failure to scout fields and take the appropriate measures can result in yield loss and harvesting problems in these fields. The weeds that appear above the wheat canopy late in the season, such as ragweed and Canada thistle, can often be easily controlled with a spring herbicide treatment. The most common weed problems in wheat are:

1. Winter annual weeds, such as common chickweed, purple deadnettle, shepherdspurse, and field pennycress. These weeds become established in the fall along with the wheat and can interfere with early development of wheat in the spring. Dense populations of winter annual weeds should be controlled in late fall or early spring to minimize interference with wheat growth.
2. Wild garlic, which contaminates harvested grain with its bulblets. Several herbicides are effective if applied in the spring after garlic has several inches of new growth.
3. Canada thistle, which can greatly suppress wheat growth due to its tendency to occur in dense patches. Most wheat herbicides have some activity on thistle and can suppress it adequately, if not applied too early in spring.
4. Summer annual broadleaf weeds, such as common and giant ragweed, which can begin to emerge in late March. A healthy wheat crop can adequately suppress these weeds, but herbicide application is occasionally warranted.

It is very important to apply herbicides at the correct stage of growth (Figure 6-4) of the wheat plants in order to avoid herbicide injury to the wheat. When wheat has not yet reached the jointing stage, any herbicide labeled for wheat can be safely applied. As the wheat growth stage advances past jointing and then past boot stage, herbicide choices become much more limited. Most herbicides can be applied in nitrogen fertilizer solution when the wheat is top-dressed. This may increase injury somewhat, and some labels recommend adjusting surfactant rates to minimize injury.

Figure 6-4. Wheat growth stages and herbicide application.

Complete information on herbicides available for use on wheat, effectiveness of herbicides on individual weeds, and proper timing of herbicide applications can be found in the small grain section of OSU Extension Bulletin 789, Weed Control Guide for Ohio Field Crops, available from OSU Extension county offices or on the Internet at: ohioline.osu.edu/b789/index.html . Table 6-14 contains the formulations, application rates, and time of the most commonly used herbicides. Consult product labels for crop rotation restrictions and tank mix recommendations.

Table 6-15 compares the relative effectiveness of herbicides on individual weeds. Ratings are based on labeled application rate and weed size or growth stage. Performance may vary due to weather and soil conditions, or other variables.

Weed control rating: 9 = 90% to 100%; 8 = 80% to 90%; 7 = 70% to 80%; 6 = 60% to 70%; 5 = 50% to 60%; 0 = less than 50% control. N = No Information.

Production of Other Small Grain Species

Fertilizer recommendations for the other small grain species are provided in Tables 6-16 through 6-18. Weed control recommendations can be found on the Internet at: www.agcrops.osu.edu/weeds, and insect control recommendations can be found in Extension Bulletin 545, Insect Pests of Field Crops, available at: entomology.osu.edu/ag/.

Spelt

Spelt, sometimes referred to as Speltz, is a type of wheat not considered in the official grain standards. Spelt is primarily used as part of the grain ration for livestock and is usually ground or milled before feeding. It is an excellent replacement for oats in rations needing bulkiness. Spelt can be grown in areas where winter wheat safely survives the winter. Common spelt is very susceptible to leaf rust, powdery mildew, stinking smut, and loose smut. Spelt is tall, with moderately weak straw, and late maturing compared with most wheat varieties. Because spelt does not thrash completely free of its surrounding chaff, there is no official bushel weight. Usually, 20% to 30% of its total weight is the surrounding chaff. This should be considered when comparing yields with wheat. Treatment of the seed with a fungicide prior to planting helps prevent a disease problem, but the fungicide label should be consulted for clearance before use on spelt. Spelt has similar susceptibility to insects as wheat.

Currently available varieties include Champ, Comet, Oberkulmer, and Sava. Spelt should be managed like wheat except for the seeding rate (15 to 20 seeds per foot of 7.5-inch row or two to three bushels per acre) and nitrogen application rate of 50% to 70% that of wheat. Spelt should not be planted following wheat, and the fly-safe date should be adhered to. Mature grain standing in the field dries more rapidly after rain than the other small grains because of the water shedding characteristics of the grain chaff. Combine settings include a slow cylinder speed (similar to soybeans) and very little air to the screens.

Spring Oats

Several varieties of spring oats (Armor, Burton, Jay, Ogle, Ida, and Gooding) having high yield potentials, good test weight, and stiff medium-short straw are available. Some varieties are resistant to the common diseases of oats. Spring oats is the first crop to be planted in the spring. Therefore, the selection of fields with well-drained soil is essential to permit timely planting. Spring oats should be seeded as early in the spring as soil conditions permit, preferably between March 1 and April 15. Grain yields decrease rapidly as seeding is delayed past mid-April. The proper seeding rate is 15 to 20 seeds per foot of 7.5-inch row (75 to 100 pounds of high-quality seed per acre). The seed should be planted no more than one inch deep to assure rapid emergence. Although oats can be established using no-till seeding techniques, little if any crop residue should be present to allow the soil to warm rapidly and aid germination and emergence. Fall preparation of the seedbed eliminates the need for tillage in the spring and sometimes permits earlier planting than when tillage is needed. This technique also eliminates the soil compaction associated with soil preparation.

Soil pH should be above 6.0 unless a legume is also seeded, in which case the soil pH should be 6.5 to 7.0. Phosphate and potash should be applied in the fall. Nitrogen should be applied in the spring anytime before emergence.

Winter Barley

Although barley is an excellent animal feed and easily replaces corn in rations, very little winter barley is grown in Ohio because of a general lack of winter hardiness. If grown, barley should be seeded between September 15 and 30 to increase its chances of surviving the winter. Seed 15 to 20 seeds per foot of 7.5-inch row (90 to 120 pounds of high-quality seed per acre).The soil pH should be between 6.5 and 7.0, and recommended levels of phosphorous will improve winter survival. Twenty pounds of nitrogen per acre and the recommended phosphate and potash should be applied preplant.

Spring Barley

Yield performance of spring barley in Ohio has been very poor, and it is an unprofitable crop to produce.

Triticale

Triticale is a human-made species resulting from a cross of wheat (Triticum) and rye (Secale). Hybrids of wheat and rye crosses date back to 1875, but intensive work on such hybrids was started only about 30 years ago at the University of Manitoba. Both winter and spring types have been developed. The protein content of triticale is normally higher than wheat, and the amino acid composition of the protein is similar to wheat. Feeding trials have found triticale to be unsatisfactory for hogs, and triticale produced less weight gain and feed efficiency in beef cattle than barley. Forage yields have been similar to wheat and rye. The cultural practices and fertilization practices recommended for wheat are satisfactory for triticale.

Winter Rye

Winter rye is usually used as a winter cover crop because of its tolerance to adverse growing environments. Winter rye is the most winter-hardy and earliest-maturing cereal grain grown in Ohio. It is more productive than other cereals on infertile, sandy, or acidic soils, and on poorly prepared land. When used as winter cover, winter rye is usually seeded at a rate of 60 to 90 pounds per acre. When grown for grain production, winter rye should be seeded between September 20 and October 20 at a rate of 85 to 115 pounds of high-quality seed per acre. The seed should be planted one inch deep. When used as a winter cover crop or a green manure crop, it should be seeded in early September. Fertilization is similar to wheat, but nitrogen application should be limited to 50 pounds per acre. Rye competes well with weeds, and herbicides are generally not needed. Bromoxynil (Buctril), MCPA, and 2,4-D are labeled for use.

Few diseases attack rye, but Ergot can be a serious problem. Rye is attacked by most of the insects that attack other small grains.

Weed Control for Small Grains

Winter small grains usually compete quite well with most weeds, especially when sound management practices are used to produce a good stand. Most broadleaf weeds that do become a problem can be controlled with herbicides. These herbicides reduce small grain yields if applied at the incorrect stage of growth. Grasses usually do not become an economic problem in small grains, and at the present time, no herbicides are available to control grasses if a problem with grasses occurs. Small grains are very sensitive to triazine residues. To avoid an atrazine or simazine residue problem, do not use either of these products for weed control in corn when a small grain crop will be seeded that fall and no more than 0.8 pound active ingredient per acre (1 lb per acre 80WP, 0.9 lb per acre of Nine-O, or 0.8 qt per acre of 4L) when oats will be planted the following spring.

Specific chemical weed control recommendations for small grains can be found in Extension Bulletin 789, Weed Control Guide for Ohio Field Crops, available from the county Extension offices or on the Internet at: ohioline.osu.edu/b789/index.html.