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Extension > Minnesota Crop News > May 2012

Thursday, May 31, 2012

Freeze injury in small grains

Jochum Wiersma, Small grains specialist

The last two mornings thermometers have dipped below 32°F in many places across Northwest Minnesota. Unlike the freezing temperatures we endured in April, these lows may have actually caused some damage as most fields are now at or past the jointing stage. Kansas State University has published an excellent bulletin about freeze injury in wheat that describes in detail what the damage looks like and what the yield impact can be. Simply follow this link: Spring Freeze Injury to Kansas Wheat

Understand that any freeze injury is probably localized to sheltered and low lying areas. You should also now that damage to the growing point may not be evident immediately. Leaf tissue that is damaged should show symptoms after a day or two.

Small Grains Disease Update

05/31/2012

Winter and the earliest spring wheat fields are heading across the State. While producers in the southern half of the State comment that their winter and spring wheat has never looked this good, the northwest part of the State suffered enough drought stress to impact the yield potential of the spring and winter wheat crops. The drought and last week's heat caused tillers to be aborted and crop phenology to advance rapidly, with some field moving from jointing to having the flag leaf fully emerged in just over a week. A few initial counts of the number spikelets per spike were disappointing.

There are confirmed reports of stripe rust across the state but there are no confirmed cases of leaf rust to date. More details scouting reports will be available as of next Monday morning.

Now is the time to scout the fields to assess yield potential and the presence of any foliar diseases such as tan spot and leaf or stripe rust. Keep an eye on the weather forecast and the disease forecasting models to determine the risk for Fusarium head blight to decide whether an application at anthesis is warranted.

Wednesday, May 30, 2012

Scouting Alfalfa Fields for Nutrient Deficiencies

By Daniel Kaiser, Extension Nutrient Management Specialist

The dry conditions in March and April have given way to extremely wet areas in some parts of Minnesota.  Since alfalfa stands got an early start this year there were a few concerns popping up early in the southeastern part of the state on areas of fields yellowing.  While there may have been some effects due to the cool weather in April a couple of nutrient could be of concern.

Potassium and Dry Soils

Daniel Kaiser and Jochum Wiersma, University of Minnesota Extension

Weather conditions have been extremely variable around the state of Minnesota this year. While some areas have experienced near record rainfalls others have still been in the midst of a drought. These differences have brought some interesting questions regarding management of potassium and soil testing in the midst of dry soil conditions.

Dry soil conditions can be challenging for crops to take up nutrients.  Elements such as phosphorus and potassium move to the plant roots via diffusion.  Diffusion is a process by which things move from areas of high concentration to areas of low concentration.  If you can think back to high school science if you open a bottle of ammonia at one end of the room over time you will smell the ammonia as it diffuses through the air.  That is a simplistic explanation of a more complex process in the soil.

Tuesday, May 29, 2012

When it rains, it pours! What is happening to my nitrogen?

John A. Lamb and Daniel E. Kaiser, Soil Fertility Specialists

Nitrogen is important for corn growth. This has been a concern on growers' minds since March. First concern was with the poor tillage conditions last fall. Did the nitrogen applied stay in the soil. We attempted to answer that question in a March 18 Crop News. At the time of that E-news, drought was the weather condition on everyone's mind. Now with the record rainfalls, there are concerns if nitrogen has been lost to leaching or denitrification.

Friday, May 25, 2012

Central MN Alfalfa Harvest Alert Data - May 25, 2012

by Dan Martens, Extension Educator, Stearns-Benton-Morrison Counties


The link listed here provides Central MN Alfalfa Harvest Alert Scissors-Cut data through May 25. If we get additional information for May 25, it will be updated in the link posted here.

Alfalfa Harvest Alert Data 2012 May 25.pdf
Read more for some observations about insects, fertilizer, and a Forage Field Day and Dairy tour planned for June 15 near St. Anthony north of Albany in Stearns County.
 

Wednesday, May 23, 2012

Volunteer Corn - An Issue in Corn and Soybean

By Liz Stahl and Jeff Coulter

Growers are finding high populations of volunteer corn in their fields this spring. Factors likely contributing to this include lodging in many fields last fall due to poor stalk quality and drought conditions, and higher harvest losses due to low grain moisture at harvest. Other factors that can lead to high populations of volunteer corn the following year include storm damage and ear droppage. The question arises: When are populations of volunteer corn high enough to warrant control?

vol corn in corn.jpg
Figure 1. Volunteer corn in corn

Monday, May 21, 2012

Central MN Alfalfa Harvest Alert Data - May 21, 2012

by Dan Martens, Extension Educator, Stearns-Benton-Morrison Counties
UPDATED May 22 5:30 p.m.
The link listed here provided Central MN Alfalfa Harvest Alert Scissors-Cut data obtained through May 21. Additional Information might be added to this report on May 23 later in the afternoon or evening. If so it will be edited here at this link. We will sample again on Thursday Morning, weather permitting.

It looks like finding a WEATHER opportunity may be the primary decision factor for a lot of the hay crop in this area now milk cow quality hay. There are some fields yet that are just starting to show some bud development and might have a little time to grow yet.

PAST HAIL. Good news for hailed off field on May 1 north of Albany. It is a very nice looking stand of 12 inch alfalfa now. Nearly every stem was broken at 3 to 7 inches by the hail.

Remember, for scissors-cut sampling, we like to have 3-4 samples that are 3 or 4 days apart to establish a trend line to gain more confidence in the numbers.

Alfalfa Harvest Alert Data 2012 May 21.pdf

ALFALFA WEEVIL RESOURCE. There a couple notes at the end of the posted report finding some alfalfa weevil larva in a field today... and a resource listing some threshold guidelines. Here's another:
AW trtmnt thresholds.pdf




Friday, May 18, 2012

Not all Yellows are Created Equal (or, more correctly, not all yellows have an equal creation...)

Ian MacRae (UMN), Jochum Wiersma (UMN), Janet Knodel (NDSU), and Bruce Potter (UMN)

Leafhopper populations are increasing in the northern RRV. Fields which held low numbers on Friday have significantly increased populations this week. These are all winged adults and so are likely the populations from the southern part of the state that are migrating north. We don't have any data on what impact on yield these higher populations of leafhoppers may have on small grains but sap-feeding leafhoppers generally don't impact yield. Having said that, leafhopper populations in typical years are much lower; in dry conditions, sap feeders have been known to exacerbate drought stress. Generally, leafhoppers are more important as vectors of the disease, Aster Yellows (AY). Caused by a phytoplasm, AY can infect wheat, and under the right conditions cause yield loss. Symptoms show up a couple of weeks after infection by the leafhopper and include yellowing of leaves, often accompanied with reddish or purple coloration (similar to BYDV).

Thursday, May 17, 2012

May 17 2012 Alfalfa Harvest Alert Data - Central MN

by Dan Martens, Extension Educator, Stearns-Benton-Morrison Counties
UPDATED MAY 18 9 PM
The link listed here provides Central MN Alfalfa Harvest Alert Scissors-Cut and PEAQ data obtained as of May 17. I expect to get a few more lab reports back on Friday and will aim to update the document posted at the link listed here sometime later Friday afternoon.

More buds - and more harvest decisions. As fields appear to meet harvest goals, farmers are making harvest decisions.

Remember, for scissors-cut sampling, we'd like to have 3-4 samples that are 3-4 days apart to establish a trend line to gain more confidence in the numbers. Thinking about a trend line takes out some of the "bounce" we see sometimes from one sample to the next.

Alfalfa Harvest Alert Data 2012 05 17.pdf

Check the notes at the end of the report for some discussion about why we might see better RFV in some fields this year. We'll find out in the feed bunk and for dairy herds in what cows are able to do with it.

CORN EMERGENCE - On another topic, we've had some calls in central MN this week about problems with corn emergence, mainly due to heavy rains around May 1 and 6. One key point to remember is that for corn that starts to leaf out underground, those plants will likely NOT make it to the surface. For some discussion about evaluating stands do a website search for "Minnesota Extension Corn Emergence" or go direct to:
Evaluating corn stands (2002)

Please continue to have a safe spring work season, hay harvest, and other things you enjoy in the spring.

Monday, May 14, 2012

May 14 2012 Alfalfa Harvest Alert Data - Central MN

by Dan Martens, Extension Educator, Stearns-Benton-Morrison Counties
UPDATED MAY 15 5 pm

The link listed here provides Central MN PEAQ and Scissors-Cut sample information from Monday May 14... and a list from past sampling days for each cooperating farm.

We will have more lab reports for Monday sampling on Tuesday and I will update the link listed HERE with new data as we get it. Remember, for scissors-cut sampling, we like to have 3-4 samples taken 3-4 days apart to consider a trend line to provide more confidence in the numbers. The can bounce up and down some based on the chance of what is clipped each day.

Alfalfa Harvest Alert Data 2012 05 14.pdf

Read more for some other observations and resources

Thursday, May 10, 2012

Central MN Alfalfa Harvest Alert Data - May 10, 2012

by Dan Martens, Extension Educator, Stearns-Benton-Morrison Counties
UDATED MAY 11 about 10 PM

This is the information from PEAQ field notes and Scissors-Cut sample lab tests on May 10 for the Central MN Alfalfa Harvest Alert Project. We expect to get more sample information from today on Friday and we'll aim to update this posting here sometime on Friday night.

Alfalfa Harvest Alert Data 2012 05 10.pdf

The data for entries in the "height" column marked with an asterisk are still from a previous sample date.

Tuesday, May 8, 2012

Update on Aster Leafhoppers in Wheat

by Ian MacRae, Jan Knodel, Bruce Potter, Jochum Wiersma

High populations of Aster Leafhopper (also called 6-spotted Leafhopper) have been reported in small grains over the past couple of weeks. Starting in the south but now spreading to northern MN and ND. Aster Leafhoppers are greyish leafhoppers; the adults have clear wings and 6 spots between the compound eyes (Figure 1). Other than their coloration, the adults and nymphs both very much resemble potato leafhopper. The leafhopper uses it's piercing sucking mouthparts to feed on the plant's sap. The damage caused by Aster Leafhopper feeding is more localized than that produced by potato leafhopper. Feeding may produce localized necrosis or stippling (Figure 2), however, damage is much less than that caused by the Potato Leafhopper.

Monday, May 7, 2012

Central MN Alfalfa Harvest Alert Data - May 7, 2012

by Dan Martens, Extension Educator, Stearns-Benton-Morrison Counties

UPDATED MAY 9 about 9 PM - Added report from Maus farm near Freeport
The link listed here provides Central "MN Alfalfa Harvest Alert" scissors-cut data and PEAQ readings for May 7 and previous dates.
Alfalfa Harvest Alert Data 2012 05 07.pdf

Some fields are looking about ready, depending on goals, weather and soil conditions. Some fields may be 10 days to 2 weeks later. Read more for other resources.

Friday, May 4, 2012

Alfalfa Hail Damage and Management Decisions

by Dan Martens, Extension Educator, Stearns-Benton-Morrison Counties

Hail did some damage to alfalfa fields as well as automobiles and homes on Tuesday afternoon and evening on May 1 at places  from out toward Padua in western Stearns County to Albany. In some fields nearly all stems in established alfalfa were broken as stripped of leaves. These will need to start again with new shoots from the crown. In new emerged alfalfa seedlings, stems broken below the leaves are done. I'll attach an article here written previously by Wisconsin Extension Specialist Dan Undersander that offers some discussions about decisions that might be made.
 Hail Alfalfa Undersander.pdf

You can also check this article by Undersander and Krishona Martinson at U of M, also from a previous hail experience: Alfalfa hail damage and management decisions


May 3 2012 Alfalfa Harvest Alert Scissors-Cut Data

by Dan Martens, Extension Educator, Stearns-Benton-Morrison Counties
The link listed here provides Central MN Alfalfa Harvest Alert Scissors-Cut data obtained as of May 5. Addition information might be added to this report on May 7. If so it will be edited here. Remember, for scissors-cut sampling, we like to have 3 or 4 samples that are 3 or 4 days apart to establish a trend line to gain more confidence in the numbers.
Alfalfa Harvest Alert Data 2012 05 03.pdf

For more information about scissors-cut sampling or PEAQ go to  http://www.extension.umn.edu/forages
Or search for Midwest Forage Association


Thursday, May 3, 2012

On Farm IDC Management Strip Trials

Daniel Kaiser, University of Minnesota Soil Fertility Specialist

Research on Iron Deficiency Chlorosis (IDC) has been identifying methods to manage the problem for soybeans. Since 2010 research has been conducted using strip trials within farmers' fields. Currently we are looking for a 5 acre area to conduct a field study looking at the effect of Soygreen and oat cover crops on areas of the field that range from no-IDC to severe IDC. Our goal is to determine the economic benefits of the treatments on varying IDC severity within fields planted with two soybean varieties with varying tolerances to IDC.

Wednesday, May 2, 2012

Alfalfa Scissors Cut Project Starts for 2012

by Dan Martens, Extension Educator, Stearns-Benton-Morrison Counties    

The Central MN Alfalfa Harvest Alert Scissors-Cut and PEAQ Sampling project has started for 2012 with data collected in Carver, Scott, McLeod, Meeker, Wright, Stearns, Benton and Morrison Counties.

Data from fields measured and sampled on April 30, 2012 are posted at
 Alfalfa Harvest Alert Data 2012 April 30.pdf

Sauk Centre Hay Auction April 19, 2012

By Dan Martens, Extension Educator, Stearns-Benton-Morrison Counties

This information is from the Sauk Centre Hay Auction held on April 19, 2012. I am posting three reports:

Apr 19, 2012 SC Hay Auction.pdf ... A list of all tested hay lots and bedding materials sold ... grouped by kind of hay, RFV and type of bale ... cost per pound of dry matter and cost per RFV point are calculated.

History of Selected Lots 2011 2012.pdf ... A summary of auctions held this year: Medium Square Alfalfa 101 to 200 RFV divided in 25 point groups, and bedding material.

Graph SC Hay Auction 2001-2012.pdf ... A line graph of auction seasons from 2001 to 2012

Tuesday, May 1, 2012

Small Grain Disease Forecast System and Disease Commentary Online

The 2012 growing season is well under way. The spring planting progress has been at a record pace, a consequence of a very dry fall and winter and a very warm March. Winter wheat has very little winter injury and stands are generally very good.

The winter wheat crop is at or near jointing and some of the earliest spring wheat fields are not far behind. This means that it is time to start scouting for early season tan spot.

To aid in your decision whether a fungicide is needed to control early season tan spot you can go to http://mawg.cropdisease.com to evaluate the risk that conditions are favorable for tan spot to develop. Make sure to select the model for tan spot in the left hand model.

An overview article of control of early season tan spot can be found here:
http://www.extension.umn.edu/b-assets/efans/cropnews/2010/05/early-season-tan-spot.html.

Be aware that tank mixing fungicide with certain herbicides can result in temporary crop injury. See here for details here http://www.plantmanagementnetwork.org/sub/cm/research/2011/mixing/ and http://www.extension.umn.edu/b-assets/efans/cropnews/2011/06/early-season-tan-spot-and-risk.html



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