As crop growers approach the beginning of August, especially across the northern U.S. and southern Canada, they become very aware of night temperatures starting to drop. This occurrence starts slowing the production of the warm season crops – soybean, corn, sorghum, sudangrass, their hybrids and millets.
As warm season crops start fading, cool season crops can thrive under these conditions. These don’t seem to keep such close track of growing degree days. Stands of straight cool season grasses, if fed nitrogen and sulfur, plus adequate autumn rains, can give good yields in early October.
Note: Cool season crops will not dry down fast in autumn; thus, wide swath same-day haylage (and the proper inoculant) will make high quality forage. For those planting in early August, fall-planted forage oats offer the biggest yield potential. Planted at three bushels/acre of grain-type oats in early August, one can expect to harvest two to four tons of whole plant dry matter per acre by September’s end (for the Albany, NY, area). Replicated research at Cornell’s Valatie, NY, experimental farm showed no increase for higher seeding rates.
With delayed planting, yields fall dramatically. September’s normally cool nights conserve sugars, producing highly digestible forage fiber. With sufficient N plus S (or manure), forage oats should easily reach 18% crude protein.
Growing fall oats isn’t foolproof. There are critical steps for success. Planting at July’s end or Aug. 1, especially in more southern areas, brings the risk that aphids introduce barley yellow dwarf virus, which can kill oat plants. Cool nights with heavy dew apparently knock down aphids, reducing loss potential.
Dr. Elson Shields of Cornell reported, “Since barley yellow dwarf virus is circulative, a neonic insecticide seed treatment will kill many aphids before they transmit the virus – most of your problems would be in the disease area like rust.”
Other Cornell agronomy researchers reported that rust populations in New York mutated to overcome certain oat resistance genes, enabling them to infect older, previously resistant varieties. Scouts report having exited fields of susceptible oat varieties covered in rust spores, resembling orange highway cones.
There are two resistant oat varieties available: Steuben and Hayden. Developed by Cornell plant breeder Dr. Mark Sorrells, these varieties seem, at present, to solve rust issues. The other alternative is scouting to apply properly timed fungicide to control rust.
Growers are generally cautioned against planting late summer oats without fungicide. There have been cases where untreated oats were planted at July’s end, but by the last of August such stands perished from rust infestations. Both Shields and Sorrells advise against indiscriminate use of neonics – these pesticides can be toxic to honeybees.
Let’s mentally leave late summer-planted oats in favor of winter forages (still often called “cover crops”). Triticale is a hybrid of wheat (Triticum) and rye (Secale), developed in 1888 by German plant breeder Wilhelm Rimpau. He successfully crossed wheat and rye, yielding partially sterile hybrids. The University of Nebraska at Lincoln (UNL) manages a winter triticale breeding program to complement winter wheat and winter barley breeding efforts.
Winter triticale’s main purpose is to provide western Nebraska locally adapted feed grains. There, historically not enough grain is produced for local livestock. Of the fall-planted winter crops, triticale is less hardy than wheat. Rye is the hardiest winter cereal. Winter triticale functions well as a forage or hay crop, producing more biomass per acre than winter wheat or barley. UNL agronomists seldom compare winter triticale to winter rye; rye has a much greater tendency to produce volunteer plants the next year.
In the Northeast, winter forages hit their optimum level of maturity (barely forming seed heads) from May 10 – 20. This is usually 10 days before perennial forages on neighboring fields yield the most digestible dry matter per acre. Autumn-planted winter forages start waking up as the last snow finishes melting, while soil temperatures are still in the low 40s. Thus, triticale is harvestable, usually at 24 – 30 inches in height, as soil temperature commonly hits the 50º milestone – the point at which corn can be safely planted.
Let’s examine winter forages again: rye, triticale, wheat, barley and speltz. These cold-footed crops benefit well from manure applications during late autumn and winter. Most small grain experts believe triticale can metabolize up to 70 lbs. of N from November through March. Semi-solid manure averages about 1% actual N. An acre of triticale can be expected to process and store the nutrients from about 7,000 lbs. of manure over the five-month period (70 lbs./1%).
Math gets shaky when it comes to rye; with rye taller than triticale, most agronomists recommend that growers limit N applications for Secale to 50 lbs. from November to March. Because of rye’s height – one to two more feet than triticale – much extra N commonly causes lodging. Thus, presuming typical 1% actual N in semi-solid manure, let’s limit fall/winter lbs./acre of that soil amendment to 5,000 lbs.
Moving toward Labor Day, I recommend growers plant the cheaper (compared to triticale) bin-run winter rye seed before planting the “grass seed” mixture next spring, because these cold-footed crop seeds can be planted into the disked-up winter rye sod. It’s a good idea to allow seven to 10 days to “mellow out” rye’s allelopathic (natural weed-killing) properties. This will help the good guy seedlings avoid falling prey to botanical “friendly fire.”
Five years ago, I recommended that a Butternut Valley (Otsego County) dairyman plant a winter forage blend on run-out alfalfa stands right after Labor Day. He planted 50 lbs./acre each of oats and winter rye, hoping to get a cutting before snow flew. He didn’t need roughage, so he let the stand ride out winter. The oats froze to death, and the rye went dormant. I worried about the survivability of rye. The farmer and I were pleasantly surprised, late the following March, to see the rye waking up, successfully pushing through the thatched oats.
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