Sorghum-sudangrass crosses are a warm season, or C4 grass. Because warm-season grasses process sunlight into sugars (photosynthesis) differently than do cool-season (C3) grasses, sorghum-sudangrass:
- Must be planted after soil temperatures reach 60 F degrees and are rising
- Grow very little at temperatures lower than 60 F degrees
- Grow best at 77 F degrees and higher
- Will produce a ton of silage with half the rain or irrigation needed by corn silage
- AS 6504 has outstanding regrowth makes this hybrid excellent for rotational grazing.
- The photo-period sensitive characteristic provides an extended window of harvest and consistent quality in the growing season.
After germination, sorghum-sudangrasses thrive in hot, dry weather. They die soon after a freeze. These forages produce quick tons of highly digestible (high-energy) silage or p[pasture: they are an excellent source of pasture for the hottest months.
BMR (brown mid-rib) is a natural trait (not GMO) that produces lower levels of lignin in these plants. BMR Gene 6 is the highest BMR level, meaning that it contains the lowest level of lignin of any sorghum or sudan. AS 6504 if a BMR 6 variety.
Sorghum-sudangrass will be harvested for baleage or haylage about 45 days after planting. Grazing is usually initiated a week to 10 days earlier. Fertilizer needs are 1 to 1 1/4 units of nitrogen per growing day, i.e., 45 to 50 units for the first cut and 30 to 35 units for each subsequent cut. Potassium, phosphorous and sulfur are also needed on most farms. All fertilizer needs are equivalent of the needs for 100-bushel corn.
Manure can be used for the original application of fertilizer; however, commercial nitrogen is best source after a cutting. Nitrogen needs for grazed sorghum-sudangrass must be reduced proportionally so that cows can be brought in to graze earlier with danger of nitrate poisoning. Sorghum-sudangrass should not be grazed for 7-10 days after a killing frost as it takes about seven days for the prussic acid produced by the frost to dissipate.
Sorghum-sudangrass usually emerges in about 10 days and then can grow 3 to 6 inches per day. A conventional or no-till drill is used for the seeding, and planting depth should be 1 to 1 1/2 inches.
Planting after a small grain crop (rye or triticale, for example) requires dealing with the allelopathic effects from the dying grain plants. This can be accomplished with either minimum tillage or heavy application of liquid manure.
Because no herbicides are available for sorghum-sudangrass, weed-management activities must precede planting.
Tags: AS 6504, Sorghum Sudan