PROPER SUMMER ANNUAL SELECTION

dante@sirisaac.com Agronomy

As can happen thanks to mother natures ways, 2018 has started as a challenge in a few areas and now in season plantings are being delayed. Coupling that with lower than normal temperatures in those same areas, some crops are looking weak. There is talk of a higher than normal replant on corn and beans in the mid-west and expecting the same for our Pennsylvania neck of the woods. Many growers will be faced with tough decisions and looking for alternative crops to cover the forage needs. Once we break out of this cool wet period and as the temperatures warm-up and days start to get longer, an excellent alternative is planting summer annual forages as part of the summer grazing or hay production system. Summer annual forage crops such as hybrid sudangrass, millets, forage sorghums, and sorghum-sudan hybrids are crops that grow well in our region. Some of the advantages with summer annuals include rapid germination and emergence, rapid growth under warmer and drier conditions, high productivity and flexibility in utilization (grazing, hay or silage/baleage).

Planting should not occur until the soil temperature remains above 65 to 70 degrees. This will be late May to the mid-June “in most years”. Exposing young seedlings to cool air (<50 degrees) or soil temperatures (<60 degrees) can permanently slow growth, greatly reducing seasonal forage production. Compared to corn, these summer annual forages require 40% less water which makes them more drought tolerant. Brown midrib varieties of forage sorghum and sorghum-sudan hybrids are available that have improved NDF digestibility and energy content.

BMR indicates lower lignin content in the plants’ cell walls. Lignin is a fibrous component of plants that animals cannot easily digest. Lodging can be a problem with BMR varieties, especially with forage sorghum so adhere to the suggested seeding rate. With the incorporation of Dry Stalk genetics, crop will generally dry down 8-10 hours quicker to help get it made.

Forage Sorghums can grow up to 6 to 15 feet tall, are drought tolerant and are preferred for forage production because of their higher yield potential. They can be grazed, hayed or harvested for green chop or silage. Forage sorghums tend to be adapted to well-drained soils with a pH of 5.5 or above while the production is optimized if pH is maintained above 6.0. They

should be planted at a rate of 7-10 lbs/ac and a seeding depth of 1 to 1.5 inches. In general, apply 50 pounds of nitrogen per acre after emergence followed by an extra 50 pounds of nitrogen per acre after harvest or intensive grazing. Phosphorus and potassium should be applied based on soil test recommendations. To reduce any changes of prussic acid, forage sorghums should be grazed when they reach 30 to 36 inches in height and do not graze closer than 8 inches. If hay or silage is to be produced, harvest the forage sorghum at the late boot to early head stage.

SEEDWAY offers the following in forage sorghums:

FSG 114 BMR6 Forage Sorghum is a brown midrib, male sterile hybrid forage sorghum. Due to the lignin content of the stalk being dramatically reduced, digestibility improves by 35% over conventional forage sorghums. FSG 114 BMR6 forage sorghum, with this improvement in digestibility and palatability, can equal the milk production of corn. Plant at the recommended rates for your area and harvest timely for optimum yield and quality. The water requirement for FSG 114 BMR6 is 1/3 less than would be required to produce an equivalent amount of corn. Because FSG 114 BMR6 is a male sterile hybrid, volunteer growth is not an issue provided there is adequate isolation from pollen fertile sorghums. FSG 115 BMR6 Forage Sorghum is a brachytic dwarf, brown midrib, grain-producing hybrid forage sorghum. Because the lignin content of the stalk has been dramatically reduced, IVDMD is 40% greater than conventional forage sorghums. FSG 115 with this improvement in digestibility and palatability can equal the milk production of corn with a water requirement 1/3 less than required to produce an equivalent amount of corn. Because FSG 115 is a grain producing hybrid, energy will increase as carbohydrates form in the grain head. Plant at the recommended rates for your area and harvest timely for optimum yield and quality. FSG 118 BMR6 Forage Sorghum is a brown midrib, male sterile hybrid forage sorghum that reaches harvest maturity approximately 75 days from planting. Because the lignin content of the stalk has been dramatically reduced, digestibility improves by 35% over conventional forage sorghums. FSG 118 BMR6 forage sorghum, with this improvement in digestibility and palatability, can equal the milk production of rations with corn. Plant at the recommended rates for your area and harvest timely for optimum yield and quality. The water requirement for FSG 118 BMR6 is 1/3 less than required to produce an equivalent amount of corn. Because FSG 118 BMR6 is a male sterile hybrid, volunteer growth is not an issue provided there is adequate isolation from pollen fertile sorghums.

Sorghum-sudangrass Hybrids are generally a multi-cut forage or graze system. Yields are generally less than forage sorghums on a single cut but multiple cuts will have an advantage in yield. Forage sorghum sudangrass tend to be adapted to well-drained soils with a pH of 5.5 or above while production is optimized if pH is maintained above 6.0. They should be planted at a rate of 40-45 lbs/ac and a seeding depth of 1 to 1.5 inches. In general, apply 50 pounds of nitrogen per acre after emergence followed by an extra 50 pounds of nitrogen per acre after harvest or intensive grazing. Phosphorus and potassium should be applied based on soil test recommendations. To reduce any changes of prussic acid, forage sorghums should be grazed when they reach 30 to 36 inches in height and do not graze closer than 8 inches. If hay or silage is to be produced, harvest the forage sorghum at the late boot to early head stage. Sorghum sudangrass hybrids should not be grazed until they reach a height of at least 24 to 30 inches. The first grazing can occur 45-50 days after emergence for Sorghum Sudan grasses. Do not graze closer than 8 inches. Hay or silage should be cut at the late boot to early head stage.

SEEDWAY offers the following:

FSG 214 BMR6 Sorghum Sudangrass hybrid produces a high tillering high-quality forage that has excellent early vigor. The high leaf to stem ratio means that you can count on high protein. The digestibility of this hybrid has been increased by 20% due to the BMR 6 trait. The dry stalk gene allows a more timely harvest due to reduced drying time. FSG 215 BMR6 Sorghum Sudangrass produces some of the highest dry matter yields of any BMR and non-BMR hybrid sorghum-sudangrass commercially available with excellent nutritional quality and early vigor. FSG 215 BMR6 is highly digestible with increased efficiency and improved animal utilization due to reduced lignin, the limiting factor in forage digestibility. This hybrid has excellent drought tolerance and is quick growing, allowing the maximum tonnage in the shortest amount of time. Fine sweet stems makes FSG 215 BMR6 an excellent choice for grazing, hay, green chop and silage.

Hybrid Sudangrass can be planted at a rate of 25 to 30 lb/ac at a depth of 0.5 to 1.0 inch. These grasses do not tolerate low pH and a minimum pH of 6.0 is required for optimum production. Both species can be adapted from well to poorly drained soils. Apply 50 pounds of nitrogen per acre after emergence followed by an extra 50 pounds of nitrogen per acre after harvest or intensive grazing. Phosphorus and potassium should be applied based on soil test recommendations. Hybrid Sudangrass and sorghum sudangrass hybrids should not be grazed until they reach a height of at least 24 to 30 inches. The first grazing can occur 30-35 days after emergence for Hybrid Sudan grasses. Do not graze closer than 8 inches.

SSG 886BMR6 is a BMR 6 Hybrid Sudangrass. The BMR 6 gene added to a sudangrass hybrid adds the high quality to a plant that has fine stems and quick regrowth. This hybrid will have fast dry down so it can be used in areas that have trouble putting sorghum sudan up as dry hay.

Pearl Millet – Pearl millet is a unique summer annual because it does not accumulate prussic acid. It is also better adapted to more acid soils with optimum production above a soil pH of 6.0. Apply 50 pounds of nitrogen per acre after emergence followed by an extra 50 lb N/ac after harvest or intensive grazing. Phosphorus and potassium should be applied according to soil test recommendations. Pearl millet should be planted at a rate of 25 to 30 pounds per acre in a firm bed and a seeding depth of 0.5 to 1.0 inch. Grazing should begin when pearl millet has reached a height of 18 to 24 inches in height. To allow regrowth, do not graze closer than 12 inches. Hay harvest should occur at the late boot to early head stage and a mower conditioner is recommended to crush the stems.

SEEDWAY offers the following:

FSG 300 Leafy Pearl Millet is a bushy type hybrid pearl millet with high yield potential which is achieved very quickly being only 63 days to the boot stage. FSG 300 has a high level of tolerance to many pathogens and high humidity, but cannot tolerate standing surface water. FSG 300 can be grown on as little as 16 inches of water, however, greater tonnage will be produced with greater water availability. FSG 300’s bushy type plant stature means that the forage produced is virtually all leaves. This greater leaf mass gives FSG 300 high crude protein concentrations and high TDN values. Summer annual forage species tend to be aggressive nitrate accumulators, especially in dry soil conditions. To avoid nitrate poisoning, do not apply excessive amounts of nitrogen fertilizer. Do not graze drought stressed or slow growing plants. A good forage producer should always have summer annual forages tested for nitrate levels before grazing or haying. Grazing annual forages with high nitrate levels is not generally a good idea, however, if a producer chooses to graze these summer annuals under stressed environmental conditions, using strip grazing and moving the animals frequently enough that they do not consume the lower one-third of the stalk where the highest nitrate concentrations typically occur is a recommended strategy. If nitrate levels are a problem, haying is likely the better alternative. Although the hay is still toxic in terms of nitrate levels, it can be ground and diluted into other forage stocks to minimize nitrate concentrations in livestock diets. Nitrates are stable in hay and can cause poisoning months later. When high nitrate forage is harvested as silage, nitrates can be reduced by 40-60% during the ensiling process, but there is still need to test for nitrate concentrations. Horses should not graze sorghum, sudangrass, and sorghum-sudangrass hybrids. These species can cause cystitis (an inflammation of the bladder), which can lead to urinary disorders, lack of coordination, and paralysis in severe cases.

– BY SCOTT RUSHE,
FORAGE MARKET DEVELOPMENT MANAGER