There have been some surprises this spring with rye showing
up in fields when there was no rye planted previously, at least not
intentionally. I figured it would be worthwhile to briefly discuss seed purity
standards and control options.
First we have to make a distinction between PVP protected
varieties and varieties that are, or are no longer, protected under PVP. If a
variety is protected under Title V of the Plant Variety Protection Act,
certification of the seed is required. Certification standards for the maximum
number of seed of the other crops are 5, 10, and 30 seeds per 10 lbs. of seed for
foundation, registered and certified classes of seed, respectively. That is
roughly equivalent to 0.004%, 0.008% and 0.024% seed of other crop species in a
seed lot of wheat, barley, or oats. The
same standards apply to all varieties sold as certified seed - whether PVP
protected or not.
If the grain you buy is not certified but still is intended
to be used as seed, Minnesota’s seed law requires that such seed is properly and
truthfully labeled. The statute
considers a seed lot with less than 5% of another species a single species rather
than a mixture as long as the percentage of other crop species is accurately
stated on the label. These requirements
are consistent with those of neighboring states and the Federal Seed Act.
A common misconception is that seed used for cover crop does
not need to be certified and or labeled as such (i.e. is exempt from the rules and regulations of
the applicable statutes) as there is no intention to harvest the crop for grain.
If the variety in question is protected under PVP, certification is a
requirement. If the variety is not protected under PVP, then proper labeling,
including the % of other crop species, is still required.
Thus buying seed with up to 5.0% rye seed can be perfectly
legal if the variety is not PVP protected and the label stated that the seed
lot contained 4.99% other crop seed. Unfortunately that may now have created
some management issues as rye survives even Minnesota’s harshest winters.
Removing rye from the small grains using a selective herbicide
is not an option. This means that you’ll
likely have rye, and possibly some ergot in your harvested wheat, barley or
oats. A Kwik Kleen grain cleaner and/or
gravity table are really your only options to remove rye and ergot from
harvested grain. This should work well for barley and oats, but will only be
partially effective in wheat.
In the future ask your seed supplier for
purity and germination information about the seed you are buying. Cutting
corners and planting the cheapest seed available may be more expensive in the
long run. The Minnesota Crop Improvement Association has two PDF fact
sheets available that also discuss the options and pointers on cover crops. You
can find those recources here and here.
By Dan Martens, Extension Educator, Stearns-Benton-Morrison Counties, email@example.com, 320-968-5077 if a local call to Foley or 1-800-964-4929
UPDATED DOCUMENT Friday May 22 at 5 p.m. (All but 2 Thursday/Friday Data)
Here is a link to all the Alfalfa Harvest Alert Scissors-Cut information we have received so far from sampling done on Thursday May 21: May 21 Alfalfa Harvest Alert Scissors Cut Data
Please let me know if something looks to be in error.
Please note cooperators and sponsors listed in this report, and tell them and cooperating farmers, “Thanks for your efforts with this.”
Please plan and works for a SAFE hay harvest.
Hope you have a meaningful and enjoyable Memorial Day.
On behalf of U of M Extension Colleagues Nathan Winter and Abby Neu,
As people begin to assess soybean stands following the low temperature conditions of May 19th, questions are coming my way regarding the possible interaction of frost with soil-applied PPO herbicides. Is it possible? My answer is yes. Is it widely prevalent? As I receive more reports from around the state my current answer is, not likely.
An interaction of frost with soil-applied PPO herbicides is possible because cold temperatures slow the rate of emergence of the soybean through the herbicide-treated soil and the soybean is limited in its ability to metabolize the herbicide. However, the crook stage of the soybean plant that is expressing injury symptoms appears to be targeted to soybeans planted in early May (May 2 to 4 are frequently mentioned). Soybeans planted in early May were just cracking from the soil at the time of the low temperature conditions and were vulnerable to freeze damage.
Bruce Potter, IPM Specialist, Phyllis Bongard, Extension Educational Content Development and Communications Specialist, and Seth Naeve, Extension Soybean Agronomist
Figure 1. Projected low temperatures ending Tuesday, May 19.
Spring frost damage to soybean is relatively rare in Minnesota, as the last average frost dates usually occur before soybeans are normally planted. However, soybean planting and emergence is well ahead of the 5-year average, leaving the crop more vulnerable to early season frost events. Temperatures dropped into the low 30s and upper 20s (F) overnight in the west-central and northwestern parts of the state, likely resulting in some degree of frost injury to emerged soybeans in select areas.
This year’s early and dry spring has facilitated some of the earliest corn planting dates of all time in Minnesota. This early start to the growing season should allow the corn crop to pollinate earlier than normal. Early corn planting also allow kernels to fill when days are longer, reduces the risk of injury due to an autumn freeze before crop maturity, and allows increased time for grain dry-down prior to harvest.
Assessing frost injury
Patchy frost is expected across Minnesota tonight and tomorrow morning. Frost damage can occur when air temperatures are in the mid-30s on calm nights, as the lack of wind allows the transfer of heat from air near the ground to the air above, resulting in colder temperatures near the soil surface. In general, frost damage tends to be worse in low areas where cold dense air settles, near field edges where vegetation reduces the potential for heat transfer from the soil to the air above, and in fields where high levels of surface residue coverage limit heat transfer from soil. In addition, fields that were recently row-cultivated prior to cold temperatures are more susceptible to frost injury, as tillage dries the surface soil, thereby reducing the amount of heat and moisture that can be transferred between the soil and air.