1. New K-State Extension crop production/cropping systems specialist

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1 Number 37 June 16, New K-State Extension crop production/cropping systems specialist 1 2. Doublecropping soybeans and sorghum into wheat 2 3. Small grain cereals as forage crops 3 4. Sunflower germination and early-season growth troubleshooting guide 6 1. New K-State Extension crop production/cropping systems specialist Kraig Roozeboom begins his new position as K-State Extension crop production/cropping systems specialist on Monday, June 19. Roozeboom was formerly in charge of the crop performance testing program at K-State. The process to hire a new coordinator of the performance tests has begun, but that position will probably not be filled until later this summer or fall. In the meantime, Roozeboom will continue to coordinate the performance tests in addition to his new duties. He will make sure the wheat performance test data is compiled and reported, and that the various other crop performance tests are maintained at their current level until a new person is hired. In his new position, Roozeboom will be moving into the main Extension Agronomy office, on the second floor of Throckmorton Hall. He will have a new phone number, although that number is not yet finalized. For now, you can reach him at the main Extension Agronomy number of , or by at kraig@ksu.edu. Roozeboom will be assuming the position formerly held by Dale Fjell. There will be a slight shift in emphasis, however. Fjell s position focused primarily on crop production practices of grain sorghum, corn, soybeans, sunflowers, and other row crops. Roozeboom will also focus on row crop production, but his emphasis will also include cropping systems crop rotations and management systems. Roozeboom s appointment is 80 percent Extension and 20 percent research. -- Steve Watson, Agronomy e-update Editor swatson@ksu.edu 1

2 2. Doublecropping soybeans and sorghum into wheat In some areas of Kansas, there will be enough moisture to doublecrop soybeans or sorghum, or some other summer crop, after wheat this year. Most of the wheat fields have weeds in them that will have to be controlled. Doublecropping offers a chance to manage what grows in those stubble fields, instead of letting them grow up in weeds. What s the best timing for weed control, planting, and fertilizing when doublecropping? As you harvest the wheat, note the weed situation. If there are tall weeds, i.e. winter annuals like prickly lettuce and marestail, or summer annuals such as sunflower and kochia that have gotten an early start in thin wheat, they will be topped by the combine sickle. These weeds will have to grow new tops and top leaves before they can be controlled with herbicides. This could delay application by two weeks or more. In thicker wheat that had a fall or spring herbicide treatment, there should be no winter annuals, and summer annual weeds should still be below cutter bar height. After a few days of post-harvest winds to settle the straw, these weeds should be readily controlled with glyphosate. Do not add 2,4-D to the glyphosate unless you are prepared to delay planting by 7 days per pint of 2,4-D (4 lb ae/gal). Soybeans. If planting Roundup Ready soybeans for grain, then producers should plant the beans as soon after wheat harvest as possible, even right behind the combine. This is important to give soybeans enough growing time. Soybeans to be used as forage or cover crop can be planted later. To keep costs down, producers should consider using reduced seeding rates (60,000 to 90,000 seeds per acre). Also, some seed companies offer discounted seed for double cropping. And, don t neglect the seed inoculant. Most stubble fields will have enough weed pressure to warrant a glyphosate application within a week after planting. Where few weeds are present, and where topped weeds need more time for make new leaves, a 2- to 3-week delay may be warranted. As they grow, soybeans in wheat stubble use up much of the soil moisture from summer rains. This and the shade they produce will help reduce development of weeds and volunteer wheat. Sorghum. When doublecropping grain sorghum or a forage sorghum, producers will have to be sure to burn down any weeds and grasses that may be present after wheat harvest before the sorghum emerges. If soil moisture is good after wheat harvest, producers may want to plant as soon as possible, then apply the burndown herbicide at some point between the time of planting and before the sorghum emerges. The timing will depend on whether rain is in the forecast (which could delay the spray application and speed up the date of emergence) and whether there s enough time to get back into the field and make the spray application before the sorghum emerges. If the weeds have been topped, producers will have to wait until regrowth begins before spraying, even if it means a delay in planting the sorghum. There are no herbicides that can be used postemerge in sorghum to control grasses, and very limited postemerge broadleaf weed control options. After the sorghum emerges, atrazine and crop oil can be used postemerge for very small grasses, volunteer wheat, and broadleaf weed control. In doublecropped sorghum, producers should avoid using any postemerge herbicide that could delay 2

3 heading, such as 2,4-D. When doublecropping grain sorghum after July 1, producers should use shorter-season hybrids. If wheat harvest is running late, producers should not cut corners and rush the harvest just to get sorghum planted a little earlier. It s better to take time and do the best possible job with wheat harvest. If it gets too late to plant grain sorghum, producers can always plant a forage sorghum, sudangrass, or millet for forage production. In most cases, the first thing producers should do is get the soybeans or sorghum planted, then worry about weed control later. The grain yield potential of doublecropped beans or sorghum usually starts declining rapidly the later it s planted. -- Dave Regehr, Weed Management Specialist dregehr@ksu.edu 3. Small grain cereals as forage crops Producers needing forage this year may want to consider planting a small grain cereal crop for forage this fall. There are five main small grain cereals that can be used as forage crops in Kansas: winter or spring wheat, winter or spring barley, spring oats, rye, and winter or spring triticale. Of these, winter wheat is the best all-purpose winter forage, but each of the other options has advantages and disadvantages. Additionally, public and private efforts are providing improved dual-purpose varieties of these cereals that are not only forage, but potential grain crops. At the South Central Experiment Field, Hutchinson, we are examining these crops for their forage and grain potential and beginning to examine how production is affected by cultural practices. If the producer needs a particular type of forage (hay, silage, or pasture), the following information may simplify the choice a bit. Hay: Small grain cereals can be used as a hay crop, either as an emergency feed or as part of a planned program. Yields often average about 3-5 tons (air dry) per acre, with protein typically 9-11 percent. The moisture content at baling should be about percent for small, rectangular bales. The quality of hay made from wheat, barley, and oats at the late-boot stage is similar. Of the small grain cereals, triticale hay is the most variable in quality. Rye is often of slightly lower quality since it is composed of more hollow stem material than the other cereals. Hay quality is more dependent on stage of maturity at harvest than is silage quality. Small grain hay will have the highest quality when harvested at the late-boot stage. A popular time to harvest small grain cereals for hay is at the early milk stage, as this is the best compromise between highest dry matter (DM) yield and maximum hay quality. If protein 3

4 content is an overriding factor, the crop should be harvested at the late-boot stage. DM yields are about percent lower at this stage compared with the dough stage. Although the feeding value of small grain hay is less than that of small grain silage, these hays are an excellent forage for young calves, replacement heifers, beef cows, and dry dairy cows. Rough awns in small grain hay can cause cattle considerable soreness and irritation to eyes, mouth, lips, gums, and lower surface of the tongue. A crop with rough awns should be ensiled rather than baled to minimize this occurrence. Also, harvesting at the late-boot stage rather than the milk or dough stage reduces palatability problems caused by rough awns. Producers wanting small grain cereal hay may want to consider planting awnless varieties of wheat or barley. Occasionally, nitrates accumulate in small grain cereals. This tends to occur as a result of drought, hailstorms or late frosts. Nitrate accumulation in small grains is more of a concern with hay than with silage. Oat hay is more likely to have a high nitrate level than other small grain cereal hays. Silage: Small grain cereals can produce average to high-quality silage. Mid- to latedough stage barley silage generally has the highest quality among the cereals. At the latemilk to late-dough stages, barley has the greatest grain-to-forage ratio, followed by wheat, triticale, and oats. Wheat, barley, triticale, and spring oat silage yields are similar about 5-7 tons of 35 percent DM forage per acre in the late-boot stage and 8-10 tons in the late-dough stage depending on growing conditions. Wheat and triticale silage yields are generally more consistent than barley or oat silage yields. Total production of digestible energy and crude protein per acre in wheat, barley, and oat silages is highest when they are harvested at the mid- to late-dough stages. Although the percentage of crude protein decreases as cereals mature from the boot to late-dough stages, the tonnage of silage dry matter (DM) nearly doubles during this period, so that the total protein production per acre is higher. Late milk to late dough stage wheat, barley, and oat silages are usually about 2 to 4 percentage points higher in crude protein than corn and forage sorghum silages. The feed value of small grain silage for growing/backgrounding cattle can be compared with that of whole-plant corn silage as follows: Barley 90 to 100 percent of corn. Wheat 70 to 90 percent of corn. Oats 60 to 80 percent of corn. Triticale 50 to 70 percent of corn. Rye 50 to 65 percent of corn. When fed to finishing cattle in high-grain rations, wheat, barley, and corn silages support similar feedlot performance. Growing beef cattle should gain pounds per day 4

5 when fed rations containing percent good-quality wheat or barley silages. Feeding cereal silages can produce up to 50 percent more beef per acre than feeding the grain alone. Ideally, small grain should be ensiled at percent moisture. Higher or lower moisture levels result in poor quality silage and, in some cases (higher moisture levels), butyric acid production. The mid- to late-dough stages of wheat normally last only a few days. The crop becomes too mature to ensile successfully at later growth stages. If large acreages are to be harvested, it is a good idea to start cutting at the late milk stage so that all the crop can be in the silo before the end of the late dough stage. If silage harvest is delayed, the cutter bar can be raised and the upper half of the plant direct-cut as head chop silage. This will reduce harvesting time, increase the density of the ensiled material and increase the energy and protein value of the silage. Barley usually matures a week earlier than wheat; and wheat matures 1-3 weeks before spring oats, depending on the late spring and early summer weather conditions. Typically, winter triticale matures days later than winter wheat. Pasture: Generally, rye has the highest total season-long production, followed by triticale, wheat, and barley. However, rye becomes stemmy and unpalatable earlier in the spring than other cereals. Since rye is less palatable and higher in fiber than wheat or barley, cattle gains during grazing are normally greater on wheat, triticale, and barley pasture than on rye pasture. Barley produces palatable growth rapidly in the fall under favorable conditions. It is considered superior to other cereals for fall and early winter pasture, but wheat, triticale, and rye provide better late winter and spring grazing. Wheat usually produces most of its forage in late fall and early winter, and again in the spring. Triticale falls in between rye and wheat in its period of peak production. If a producer wishes to extend the grazing season as long as possible in the spring, triticale is the best option. In terms of overall forage quality of pasture, barley is highest, followed by wheat, triticale, and rye. During the fall and early spring periods of peak production, the crude protein content of small grain pasture is normally about percent. Growing cattle require about 12 percent crude protein, thus no protein supplements are necessary. Spring oats can be pastured, but the total length of grazing is limited. Spring oats for grazing should be planted as early as possible in the late winter/spring. The quality of oat pasture is very high. Stocking rates must be adjusted to match the crop s production potential. For example, if the pasture is heavily stocked during the fall, provisions for additional feed must be made to maintain good cattle gains during winter months when pasture production declines. Plan stocking rates to match the seasonal production potential of each crop. When vigorous growth resumes after winter dormancy, make sure the stocking rate is adequate or forage growth will outpace demand and become rank. 5

6 Under good growing conditions, a well-fertilized small grain dryland pasture can carry about 500 pounds of cattle per acre. Under poor growing conditions, stocking rates should be reduced considerably. Cattle gains of 1.5 to 2.5 or more pounds per acre per day are possible during periods of good pasture production. Under irrigation, with intensive management, much higher stocking rates are attained. Fall grazing management is critical to the success of small grain pastures. Begin grazing when the plants are well rooted and tillered, usually about 6 to 8 weeks after planting. If the foliage is too tall when the animals are introduced, or if the crop is overgrazed, the plants will be more susceptible to winterkill. Make sure some green leaves remain below the grazing level. The minimum stubble height should be about 3-4 inches. Rye has a more upright growth pattern than most wheat varieties, so it should not be grazed as low. Barley and triticale are more susceptible to winterkill than rye or wheat. However, newer varieties are exhibiting increased winter hardiness. Small grain pastures can cause bloat. Daily supplementation with poloxalene (Bloat Guard) is highly effective in reducing bloat. Feeding high-quality grass hay, silage, and/or an ionophore such as Rumensin or Bovatec can also provide some protection against bloat. Rumensin and Bovatec have also been shown to increase stocker cattle weight gains on wheat pasture. Mineral supplements containing magnesium are necessary when grazing cattle on small grain pasture to minimize the occurrence of grass tetany. If cereals are planted for both pasture and grain production, cattle must be removed prior to jointing. Split nitrogen applications are also very important to allow for normal plant and grain development after cattle removal. Until recently, wheat was the only fall cereal typically grown as a dual-purpose crop. New triticale varieties are now available that not only provide high quality forage, but also possess high potential grain yield. Producers may want to consider triticale as a dual-purpose cereal as there is a growing interest in triticale grain in hog rations and as an organic flour alternative for wheat. Many producers are hesitant to plant rye and triticale due to contamination risks for succeeding wheat crops. However, if proper sanitation measures are followed, contamination risks are nonexistent. -- Vic Martin, Grazing Systems and Alternative Crops, Southcentral Experiment Field vmartin@ksu.edu 4. Sunflower germination and early-season growth troubleshooting guide Sunflowers are a tough crop once they get established, and can withstand hot dry weather relatively well. But getting a good uniform stand, and good early season growth is crucial. There are several problems that may occur. The following are some of the more common causes of problems that occur on sunflowers in Kansas. 6

7 Causes of poor germination. * Dry soils. Sunflowers require considerable soil moisture to germinate. Wherever the soil is very dry, the seed may not germinate. * Seeding depth. For semi-dwarf sunflowers the recommended seeding depth is 1.5 inches, and 1.5 to 2.0 inches for non-semi-dwarf sunflowers. The deeper the sunflower seed is planted past those recommended guidelines, the more problems the seed may have in reaching the surface and becoming established, especially if the seeding depth is deeper than 3.0 inches. *Crusting. Hard rains prior to emergence, along with hot days, can bake the soil surface in conventionally-tilled sunflowers, which can severely impede sunflowers from emerging. Sunflowers planted no-till typically do not have a problem with crusting if sufficient residue is on the soil surface. * Wireworms. Wireworms can be in high numbers in fields especially in those fields where sunflowers are planted no-till into wheat stubble. Wireworms will feed on the seed and seedlings as the plants try to become established, and stands can be significantly reduced. If replanting is necessary, farmers should use seed treated with an insecticide that will suppress wireworm damage. * Herbicide carryover. High ph soils, above 7.0, are common in western Kansas, which causes herbicides such as atrazine and sulfonylureas (Glean, Finesse, etc.) to persist in the soil longer. Herbicide carryover symptoms occur across the field, but more than likely the carryover will be prevalent at the ends of the fields where the spray operator turned. In these areas, a 2X application of the herbicide may be applied. In addition, there may be spots in the fields where the soil ph is closer to 8.0 which allows for longer persistence of the herbicide. Causes of poor early season growth. * Nitrogen deficiency. If soils are deficient in nitrogen, sunflower seedlings may grow slowly and have a pale green color. * Herbicide injury. Spartan is a commonly applied herbicide for weed control in sunflower. However, this herbicide can cause early season injury. Chlorosis and leaf crinkling on sunflower seedings can occur with poor seed furrow closure where the herbicide has direct contact with the seed, or with higher application rates than what is recommended for the soil type. Plants will grow out of this over time unless excessively high rates have been used. * Cutworms. Cutworms can clip off sunflower seedlings below the cotyledon, thus killing the plant. Rescue applications of an insecticide will stop the damage from spreading. 7

8 * Soil compaction. Sunflowers can develop a deep tap root in soils with good tilth. But if there is a layer of compaction in the soil, sunflower roots will not be able to penetrate it and this can stunt growth. If compaction is thought to be a problem, try pulling the sunflower out the ground at flowering. If there is little to no compaction, you will not be able to pull the sunflower out. *Predation. Animals such as jack rabbits and pocket gophers can substantially reduce sunflower seedling numbers especially on small fields. Feeding from rabbits may not be apparent during the day, but check the field at night. You might be surprised at the number of rabbits in the field. -- Brian Olson, Northwest Area Extension Crops and Soils Specialist bolson@ksu.edu These e-updates are a regular weekly item from K-State Extension Agronomy. All of the Research and Extension faculty in Agronomy will be involved as sources from time to time. If you have any questions or suggestions for topics you'd like to have us address in this weekly update, contact Jim Shroyer, Research and Extension Crop Production Specialist and State Extension Agronomy Leader at or jshroyer@ksu.edu. 8

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