03 Nov Forage Sorghum: A great choice for summer grazing and haying.
Forage Sorghum is a great choice for summer grazing because sorghum responds well to the high temperatures we experience in the summer. It is also very flexible and can be fit into small windows between other crops to “make a little hay” when a grain crop will not fit. Forage sorghum can do some impressive things in 40 days with a little water, sunshine, and fertilizer and do it at without costing you a fortune.
One clarification, when we use the term “forage sorghum” in most cases we are talking about either a sorghum by sudangrass hybrid or a sudangrass hybrid. Sudangrass is a sorghum a “cousin” to sorghum and endears itself to forage growers because of it’s fine stems and fast regrowth potential. 60 years ago, someone decided that crossing sorghum by a sudangrass would give us the best of both worlds by creating a crop that has the high yields of sorghum and regrowth potential of sudangrass. Whoever thought this up was not wrong and is the reason that most “forage sorghum” is a sorghum by sudangrass cross.
There are lots of choices to make when selecting a forage sorghum. The first is do you want a hybrid that heads or is headless or photoperiod sensitive? I have found that this choice really seems to come down to past buying habits or the fact that the hybrid I like happens to be headed, or I just plant what my seed retailer has. The big difference is that a headed forage sorghum begins to decline in forage quality after pollen shed or anthesis occurs. If you delay harvesting, primarily protein levels begin to decline as the seed begins to accumulate starch. The yield also does not increase very much after this period and any yield increase you are getting is likely from starch accumulation in small seed that your animal will probably not be able to utilize anyway. Headless or photoperiod sensitive hybrids do not have this defined morphological stage and continue to grow leaves and stems until you cut it. The quality does not decline as bad either. For these reasons, I am a big fan of headless hybrid because they have a wide harvest window and let’s be honest, at most farms, harvesting the forage sorghum is not often the highest priority, so having some flexibility is nice. If you are going to graze your forage sorghum, headed versus headless is less important because if you are managing it correctly the animals will keep it grazed down and you should never see a head on a headed hybrid.
Now you have to make a decision on traits. In forage sorghum you currently can find hybrids with brachytic dwarf (BD) and brown mid-rib (BMR). Brachtyic dwarfism is a trait that reduces the internode length in several nodes in the middle of the plant. This means the plant will be shorter and have a higher leaf to stem ratio since the leaf number is the same as a taller version. So a leafier hybrid is what you end up with. Yields tend to be lower in BD hybrids. Brown mid-rib trait causes the plant to have lower lignin content and have lignin that is more digestible. This means that more of the forage the animal eats turns into more muscle or milk. BMR hybrids have come a long way in terms of yield and standability and are great choices for most summer grazing situations. SP4105 is a headless, BMR hybrid that our customer rave about. Great yields and excellent quality forage. Do not be afraid to spend the extra money on a BMR hybrid, the little bit of extra cost is worth it.
At Sorghum Partners, we have all of the choices we talked about above. Sordan 79 and Sordan Headless are conventional hybrid that yield very well and are headed and headless, depending on what you are looking for. We also offer SP4555 and SP4105 that are BMR hybrids that head (SP4555) and are headless. If you are after the whole package, SP6205 Bd is a brachytic dwarf hybrid with BMR. If you are after sudangrass hybrids Trudan 8, Trudan Headless and SP7106 BMR, which is headless.