Hoegemeyer - the right seed

Fall is in full swing and cold winter temperatures are not far off.  Fall planting of cover crops towards the end of October are limited with the best option being cereal rye.  Cereal rye is very winter hardy and has the best chance to establish itself before winter.  It may be a little too late in the game to try a cover crop out this fall, but late winter/early spring offers an opportunity to establish a cover crop before planting of row crops. 

Oats, spring barley, canola, and Austrian winter peas can be planted as soon as you can get a drill into the ground.  This allows these cover crops to be planted in late-February /early March and to establish into dense cover/forage before most row crops are planted (mid-April/early-May).  Planting of your row crop into the live growing residue is an option and the spraying the easily killable cover crop once corn or soybeans emerge.  This residue will out-compete winter annual weeds and create a matted surface which reduces evaporation from the soil.

Data from recent Hoegemeyer Agronomy Research provides information on cover crops and their moisture conserving characteristics.  Contrary to popular belief, a live growing cover crop planted in the spring will use less moisture than the evaporation from bare soil.  This data is significant and should suggest the planting of a spring cover crop on a small portion of your farm to see for yourself.  Drought seems to be common everywhere, even if average rainfall is over 30 inches, a crop is still likely to be stressed during the growing season and anyway to conserve moisture should help these cash crops out.

If you have questions about cover crops on your farm, be sure to ask one of our Hoegemeyer agronomists.  We are conducting Hoegemeyer Agronomy Research to understand the benefits of cover crops and will provide results once our research is compiled.
 

Several questions are circulating around this year in regards to ear molds/kernel rots and potential for alfatoxin production in drought stressed fields. Here are a few details describing the specifics pertaining to aflatoxins.

Aflatoxins are a subgroup within a larger more general group called “mycotoxins”. Several ear rots and storage molds which occur every year to some degree are capable of producing mycotoxins. The term “mycotoxins” refers to “toxic chemicals” in a broad general spectrum including aflatoxins, fumonisins, tricothecenes, and zearalenone, some of which are much more problematic than others. Just because an ear and/or kernel mold is visually present does not necessarily confirm the presence of a mycotoxin or more specifically aflatoxin. Aflatoxins are a specific group of mycotoxins that get significant attention due to their potential to be relatively toxic to livestock and humans at varied levels. The specific B1 aflatoxin is also a known potent carcinogen which especially draws attention for regulation. Aflatoxins are produced by at least two species of Aspergillus. This kernel/ear mold is recognized by its somewhat olive green color. Although the presence of the mold indicates a higher risk of aflatoxin production, aflatoxins are not automatically produced when grain becomes moldy.

Environmental conditions will dictate if and at what level aflatoxins are produced. Problems associated with Aspergillus and aflatoxins are most common in hot, dry years (I think the summer of 2012 would fit that description).  Fungi survive in plant residue from prior years. The fungi does best in corn from silking through grain fill when drought conditions are present during hot days and warm nights.  The spores are carried by the wind and can enter the ears through injury caused by insect feeding, hail, drought, early frost and high wind which help to expose kernels to the fungus.   In summary, if Aspergillus is readily evident within a field, aflatoxin production is definitely more likely considering the conditions we had this year. Those fields under high suspicion should likely be evaluated and managed separately. The following are some steps that can be taken to manage or reduce aflatoxins in grain:

1)  Control ear-attacking insects.
2)  Scout. Indentify early. If present, early harvest and drying of grain can help reduce further development.
3)  Adjust combine to minimize kernel damage.
4)  Clean grain bins and handling equipment.
5)  Dry moldy corn immediately to 15% or less moisture when storing in the short term. Long term storage is not suggested.
6)  Cool grain after drying and maintain at 35-40 degrees F through winter.
7)  Control storage bin insects.
8)  Check bins regularly.

Fig. 5.7 Yellow-green powdery growth of Aspergillus flavus on a corn rootworm-damaged corn ear can produce aflatoxins. Courtesy of Alison Robertson, Iowa State University.

The FDA has suggested recent exemptions to the long-standing action level of 20 ppb. They are as follows:

Human food and milk <0.5 ppb

Corn of unknown destination <20 ppb

Young animals <20 ppb

Dairy cattle <20 ppb

Breeding cattle, swine, and mature poultry <100 ppb

Finishing swine <200 ppb

Finishing cattle <300 ppb

Elevators will likely have their own testing protocols as well as tolerance levels depending on where the grain is being channeled to for end use.

      Sources:    Iowa State University
       Hoegemeyer Hybrids Agronomy

Hopefully aflatoxins will not be a problem in your fields but be prepared and have a plan of action if you have concerns.  If you have further questions, contact your local Hoegemeyer Agronomist of District Sales Manager. 
 

It seems just about every district within the Hoegemeyer trade area has areas suffering from the hot and dry weather we have been subject to this year. Damage varies from minor to total crop loss at this point. Many corn fields are or recently have reached reproduction stages (tassel/silk).  It’s at this time that historically most foliar fungicide application takes place. With the hot and extremely dry conditions across much of the area, foliar fungal disease development is relatively low and/or slow to develop vs. crop stage and calendar date. Most foliar fungal pathogens in corn require moisture to either infect or progress. This is generally produced by high humidity, heavy dew, irrigation, and rainfall that wets the crop canopy for extended periods of time. Gray Leaf Spot, for example, which is one of the most common and potentially damaging foliar fungal diseases, requires somewhere around 12 hours of continued leaf wetting in order to infect. This is hard to accomplish without the aid of humidity and at least average rainfall. There are three sides to the “disease triangle”. They are 1) pathogen, 2)host plant, and 3) environment. A field with high levels of both host and pathogen will not produce heavy disease unless the environment is favorable for disease development. If one side of the triangle is low then it will lessen the amount of total disease present. That being said, southern rust has recently been confirmed at low levels within several center pivot irrigated fields in southern Nebraska which warrants monitoring. If humidity levels begin to creep higher along with the nighttime temperatures, this sporadic yet potentially damaging disease could spread more rapidly.

Disease-free ear leaf of HPT 8345 Hx/LL/RR at Hooper, NE - 7/11/12

With the current relatively low levels of fungal foliar disease, other potential benefits of fungicide applications have garnered some attention. There are various instances and even some 3rd party research trials that have shown a positive yield response to fungicides even in the absence of significant disease and/or when corn is under drought stress, however yield increases in these situations have been fairly inconsistent and much less than when disease is present. The theory is that some fungicides (strobilurins) have a positive physiological effect by aiding in more efficient respiration under hot and dry conditions and can increase water use efficiency.  I feel this is valid information but applications targeted specifically for drought stress purposes alone are hit or miss and are not likely to produce consistent profitable results, especially if drought stress is at moderate to severe levels. An application will not save a severely drought-stressed crop. Fungicide applications should target disease and be timed to provide best results based off disease progression. Most current foliar fungicides have about 21 days of residual activity. Disease has been slow to develop thus far but could increase quicker if the weather pattern changes in the coming few weeks. Therefore this year, fungicide applications taking place toward the tail end of the window (brown silk) may be of more benefit in terms of disease protection than earlier applications.
 

Non-disease related benefits are real but should most often come along for the ride and not be specific targets of foliar disease fungicide applications when consistent yield increases are the main goal. If you have questions regarding fungicides contact your Hoegemeyer DSM or Agronomist. Now let’s get some RAIN!!!!!!!