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May 2010 Archives

EARLY SEASON TAN SPOT

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Early season tan spot can be readily found across the Red River Valley. Especially in wheat on wheat situations the disease can readily be found. One of the characteristic symptoms of these infections at the 2 to 3 leaf stage is a yellowing discoloring of whole leaves. This is a more extreme expression of the same the yellow halo that surrounds the tan spot lesions in more mature plants. Be careful not to mistake this yellowing for a nitrogen deficiency.

There are a number of fungicides registered for control of early season leaf spot diseases in wheat. The table below lists the products that are available and the recommended use rates.
10 Fungicide Table Early Season Wheat.jpg

Research at both NDSU and the University of Minnesota has shown that once early season tan spot is left uncontrolled, yield reductions of 4 to 5 bushels will result if conditions continue to favor the development The greatest economic response from early season fungicide use occurs when susceptible cultivar are planted into wheat stubble. Even fields that were in wheat two years ago may have enough remaining wheat residue at the surface to see low levels of tan spot infection.

Most of the fungicides can successfully be tank mixed with the commonplace herbicides. Always check the label of both the herbicides and fungicides for tank mix restrictions. Research at the Northwest Research and Outreach Center has shown that the combination of any of the EC formulations of fungicides in combination with the common wild oat herbicides (Puma, Discover, Axial, Silverado) and Bronate Advanced can result in some bromoxynil injury on the both wheat and wild oats. This injury generally didn't affect grain yield of the wheat or the control of the wild oat, except in the combinations that included Silverado in which case wild oat control was diminished.

High Temperatures, Spikelet Counts, and Yield Potential

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Much of the earliest planted wheat in the Red River Valley is approaching the 5 leaf stage. At this time the initiation of the head has begun. After the number of tillers that were initiated over the past three weeks, the number of spikelets is the second the three yield components that ultimately will determine yield. Like tillering, the number of spikelets is also greatly influenced by temperature. The figure below show what happens as the average maximum temperature increases from 65 to 85; the average spikelet counts declines almost by a third from 17 to 13.
10 Spikelet Count.jpg

Although cooler daytime temperatures would be desirable to maximize the yield potential, you shouldn't be completely discouraged or disillusioned. The beauty of wheat is its great ability to compensate between yield components. If the conditions during anthesis and grain fill are favorable for wheat the crop will put its energy in additional kernels per spikelet (3 to 4 rather than 2 to 3) and larger kernels.

By Dan Martens, Extension Educator, Stearns-Benton-Morrison Counties
Posted Originally Thursday Evening May 27, 2010
Alfalfa Harvest Alert Data May 27, 2010.pdf

By Dan Martens, Extension Educator, Stearns-Benton-Morrison Counties
Updated on Wednesday Evening May 26
This is a report of information from fields sampled on Monday May 24 with a couple of updates from May 20. We have a lab report from Motley sample fields now.
Alfalfa Harvest Alert Data May 24, 2010.pdf

For more information about doing scissors cut sampling or using PEAQ sticks or charts, look in the center of the U of M Extension Forages web page at:
http://extension.umn.edu/forages





By  Dan Martens, Extension Educator, Stearns-Benton-Morrison Counties
UPDATED Friday Evening May 21, 2010
We have more information back from May 20 sampling. Information is posted in this pdf document and will be updated here with a few more lab results on Monday if all goes well.
Alfalfa Harvest Alert Data May 20, 2010.pdf

For more information about doing scissors cut sampling or using PEAQ sticks or charts, look in the center of the U of M Extension Forages web page at:
http://extension.umn.edu/forages




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

I am posting here the grouped and averaged summary for the auction held at Sauk Centre on May 6 and May 20, 2010 ... and end of auction season summaries.

SC Hay Auction 05 06 10.pdf A list of all tested hay lots and bedding materials sold ... grouped by kind of hay and type of bale ... cost per pound of dry matter and cost per RFV point are calculated.

SC Hay Auction 05 20 10.pdf Hay by groups as described for May 6

Summary Selected Lots 2009-2010.pdf This is a summary of selected lots through the year including an average and ranges for these groups through the year.

Graph SC Hay Auction 2001-2010.pdf This is a line graph of the averages for medium square bales in 4 RFV groups completer through May 2010.
By Dan Martens, Extension Educator, Stearns-Benton-Morrison Counties
Updated May 19, 2010 ~ 5:30 p.m.
Some Harvest has started.
Report for field samples on Monday May 17:
Alfalfa Harvest Alert Data May 17, 2010.pdf

For more information about doing scissors cut sampling or using PEAQ sticks or charts, look in the center of the U of M Forages web page at:
http://www.extension.umn.edu/forages/



Corn Stand Evaluations

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Dr. Jeff Coulter, Extension Corn Agronomist, and Bruce Potter, SW Minnesota IPM Specialist


An unfortunate weather event. The frost on the morning of May 9, 2010 has some corn growers and those who advise them a bit nervous. The frost damaged corn plants I looked at on Monday all had firm green tissue from the soil surface and below and should come through the frost well. The injury stopped at the soil line and after the recent rainfall the green tissue is now above the soil surface. The cold, wet weather since the frost has added another level of stress which, by itself, might reduce stands slightly. There is some potential for these two situations may create a situation favorable for stand reducing pathogens. Warmer weather is in the forecast and frost injured corn plants will begin shooting new leaves soon. In fact, many fields have recently begun to improve in appearance. An idea of the extent of stand loss, if any, should be visible by May 18. To avoid unnecessary wear and tear on your psyche, the remainder of the week and weekend should be spent on something relaxing. The fishing opener is one viable option.


By Dean Malvick,  Department of Plant Pathology

 

Early planting and warm weather in April, followed by an extended period of cool, wet weather and frost in May has created stress for corn seedlings throughout much of Minnesota.  As of May 9, 94% of the corn in Minnesota was planted and 32% had emerged (compared to the 5 year averages of 64% planted and 9% emerged).   While the stress of the cool conditions and frost may only set back the corn slightly, it could also set up a situation for seedling disease in some areas.  Keep in mind that many factors other than disease result in poor stands, reduced growth, and low vigor.  In most years and in most fields, seedling diseases are a minor problem, but this year they may be more common than usual.  

By Dan Martens, Extension Educator, Stearns-Benton-Morrison Counties
UPDATED Monday Evening May 17
ALL test and field information for May 13 IS POSTED NOW in the document here:

Alfalfa Harvest Alert Data May 13, 2010.pdf

For more information about doing scissors cut sampling or using PEAQ sticks or charts look in the center of the U of M Extension forages web page at:
http://extension.umn.edu/forages

by Mark Seeley, Extension Climatologist

Frost / freeze analyzed maps available

Last weekend (May 8-9) brought widespread overnight frosts and freezes to many parts of Minnesota. Reports indicate that some fruits and crops were damaged, especially in low-lying areas, but many may recover. Further, it appears this may be the last frost occurrence for the season over most of the state, as a significant warming trend is expected to start this weekend.

As is often the case many growers and crop advisors are concerned about assessing any damage due to these low temperatures (primarily 27-32 degrees F), but patience is required. It always takes a few days to sort out which areas might be permanently killed, as many plants, depending on stage of development are resilient and begin regrowth within a week.

The Minnesota Climatology Working Group offers daily analyzed maps to examine the spatial extent of frosts and freezes.

For those interested in storm spotter training

For Minnesota citizens who are interested in becoming storm spotters for the National Weather Service, SKYWARN spotter training classes will be offered free of charge during the month of May on eight different occasions. National Weather Service also encourages citizens to become involved in the eSpotter System which supplements information about storm location, intensity, and aftermath damage assessment. If you are interested in these programs or the free training sessions you can visit the web site.

By Dan Martens, Extension Educator, Stearns-Benton-Morrison Counties
UPDATED May 13 Evening
THINGS HAVE NOT CHANGED MUCH SINCE LAST THURSDAY. This report shows information we have gotten so far from May 10 sampling and field observations. We expect lab reports from two sites yet. 
For more information about doing scissors cut sampling or using PEAQ sticks or charts look in the center of the U of M Extension forages web page at: 

http://www.extension.umn.edu/forages

Click the link below to look at the data from May 10, 2010. See when some fields were at today's height in 2009. New May 10 information will be updated by edits to this entry.

Alfalfa Harvest Alert Data May 10, 2010.pdf


By Dan Martens, Extension Educator, Stearns-Benton-Morrison Counties
UPDATED MAY 7 - 4:15 p.m.

This report shows Alfalfa Harvest Alert information from field observations and forage tests in Caver/Scott, McLeod/Meeker, Stearns/Benton/Morrison, and Wright Counties. It includes RFV & RFQ numbers on some samples and some notes related to samples.

For more information about doing scissors cut sampling or using PEAQ sticks or charts look in the center of the U of M Extension forages web page at:
http://www.extension.umn.edu/forages

Click the link below to look at the data from May 6, 2010. This information will be updated by edits to this entry. Most of these fields will be sampled on Monday and Thursday mornings until they are harvested. Crop height appears to be 1 to 2 weeks ahead of last year.

Alfalfa Harvest Alert Data May 6, 2010.pdf

ALFALFA FROST Concern? See continued reading noted below.

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

Updated May 5.

This report shows information from field observations and forage tests in Caver/Scott, Mcleod/Meeker, Stearns/Benton/Morrison, and Wright Counties. The Alfalfa Harvest Alert Project includes using forage lab tests and the PEAQ process for estimating forage quality as a gauge for making harvest decisions. PEAQ stands for Predictive Equation for Alfalfa Quality. It estimates what the forage test of a fresh cut sample might be based on the height of the tallest steam and the maturity of the most mature stem.

We generally expect "feed in the bunk" to be 15 to 25 RFV points lower than what a fresh cut lab test would indicate or what the PEAQ stick or chart would read. For more information about doing scissors cut sampling or using PEAQ sticks or charts look in the center of the U of M Extension Forages web page at:

http://www.extension.umn.edu

Click the link below to look at the data from May 3, 2010. The information for May 3 will be updated by edits to this entry. Once started, most fields are sampled on Monday and Thursday mornings until they are harvested.

Alfalfa Harvest Alert Data May 3, 2010.pdf

Spring Frost Damage to Early-Planted Corn

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