Posts Tagged ‘16:1’

WCU Volume 16, Issue 1 – February 29, 2008

Wednesday, March 26th, 2008

PDF Version of WCU 16:1, February 29, 2008 

In this Issue:
From the Editor: Special Wheat Issue and Subscription Information for the 2008 WCU

Wheat Pests
Management of Hessian Fly in the Spring
Management of Aphids: Barley Yellow Dwarf Transmission and Direct Aphid Damage in the Spring
Winter Grain Mites
Cereal Leaf Beetle
True Armyworms and Grass Sawfly

Wheat Diseases
Powdery Mildew Questions and Answers
Septoria and Stagonospora Diseases

Wheat Water & Nutrients
Irrigating Wheat
Nitrogen Applications to Wheat in a Cover Crop Program that Restricts Fertilization until Mid-March 2008
Wheat Nutrition – Adding an Extra Touch
Wheat Nutrition – Secondary Macronutrients and Micronutrients

Even More Wheat Info
Small Grain Weed Control
Precautions for Herbicide Use with Nitrogen Applications in Small Grains
New Confusion Formulations for Small Grain Herbicides
Understanding the Falling Number Wheat Quality Test
Will Spring Wheat Work in Delaware? Not Very Well

Will Spring Wheat Work in Delaware? Not Very Well

Wednesday, March 26th, 2008

Gordon Johnson, Extension Ag Agent, Kent Co.; gcjohn@udel.edu

I have had several questions on the potential for planting spring wheat in Delaware. With the high wheat prices, the thought is to take advantage of this opportunity and then double crop with soybeans. Spring wheat varieties are not adapted this far south, would be late in coming off, and would be a large risk. I read a good article on this subject from Purdue University1. Here is some information on this topic:

1) We do not recommend growing spring wheat in Delaware. Spring wheat is not adapted for latitudes south of 43 degrees (Dover is 39 degrees).

2) Spring wheat would yield half of what our winter wheat varieties would (I would estimate that yields in DE would be between 30-40 bu/A, at best). (more…)

Understanding the Falling Number Wheat Quality Test

Wednesday, March 26th, 2008

Carl German, Extension Crops Marketing Specialist; clgerman@udel.edu

Introduction
Protein and moisture are key quality tests for both grade and marketing price of wheat. Farmers are most familiar with these tests since almost all SRW wheat is purchased on milling quality.

When it rains just before harvest, grain may start to germinate (or sprout) in the head. The germination causes an increase in alpha amylase, an enzyme that breaks down starch. There are also increases in enzymes that break down proteins. Of these, the starch degrading enzyme has a greater effect on reducing the quality of flour, and of products made from the flour. The longer the grain sprouts, the greater the amount of the alpha amylase formed. If badly sprouted grain is milled, the flour can cause product problems1.

Falling number is a test more recently introduced into country elevators and mills. It gives an indication of the amount of sprout damage that has occurred within a wheat sample. Generally, a falling number value of 350 seconds or longer indicates a low enzyme activity and very sound wheat quality. As the amount of enzyme activity increases, the falling number decreases. Values below 200 seconds indicate high levels of enzyme activity. (more…)

New Formulations/Confusion for Small Grain Herbicides

Wednesday, March 26th, 2008

Mark VanGessel, Extension Weed Specialist; mjv@udel.edu

Remember the good old days when someone said they used “Harmony” on their wheat and you knew exactly what they meant. Then came Harmony Extra, Harmony GT, followed by Harmony Extra XP and Harmony GT XP. Now there is Harmony Extra SG with TotalSol and Harmony SG with TotalSol. These are new soluble granule (SG) formulations with 50% active ingredient. Granules are supposed to fully dissolve and solution will appear relatively clear. It appears to take longer to go into solution than the previous formulations, so if mixing in a 5-gallon bucket before adding to nitrogen carrier, it may take up to 10 minutes of constant stirring if the water is cold. Use patterns have not changed with the new formulation, but the concentration of the product has.

Harmony Extra 50SG with TotalSol is DuPont’s new formulation for the combination of thifensulfuron and tribenuron. The “old” Harmony Extra XP formulation was 75% active ingredient and the new Harmony Extra SG is a 50% active ingredient, so the SG formulation requires more product to get the same active ingredient. (0.6 oz/A Harmony Extra SG TotalSol = 0.4 oz/A Harmony Extra XP). The use pattern has not changed with the SG formulation. (more…)

Precautions for Herbicide Use with Nitrogen Applications for Small Grains

Wednesday, March 26th, 2008

Mark VanGessel, Extension Weed Specialist; mjv@udel.edu

It is common to add herbicides when “top-dressing” nitrogen to small grains. These precautions are from manufacturers’ labels:

Harmony Extra or Harmony should be dissolved in a small amount of water first. If liquid nitrogen is less than 50% of the spray mix, then include a surfactant. For 2,4-D it varies with the formulation. The ester formulation (2,4-D ester) can be mixed directly with nitrogen, but labels recommend good agitation. Amine formulation of 2,4-D (2,4-D amine) should be mixed with 3 to 5 parts of water before adding it to the nitrogen solution. Buctril label cautions about potential leaf burn when mixed with liquid fertilizer, but leaves emerging after application are not affected. For MCPA, it varies some with the manufacturer. The ester formulation should not be applied with liquid nitrogen. The amine formulation varies, ranging from no mention of liquid nitrogen to application is allowed. Osprey restricts applications to within no less than 2 weeks of a nitrogen application. Maverick cautions about possible leaf burn and reduced growth and states that weed control is more consistent when applied with water as the carrier.

Wheat Nutrition – Adding an Extra Touch

Wednesday, March 26th, 2008

Richard Taylor, Extension Agronomist; rtaylor@udel.edu

With the current wheat price, many producers may be thinking of adding extra nitrogen (N) to push yield potential to the maximum. The high cost of N actually could limit any gain from this approach since we know that in most cases what limits yield are the environmental (water-primarily-and temperature) conditions during grain fill and not N availability. Wheat yield, like corn, responds to additional N in a way that for each additional pound of N applied the incremental increase in yield becomes smaller and smaller until the point of maximum economic yield (MEY). After the MEY point, although more N may increase yields slightly, the extra N actually reduces net profit per acre. (more…)

Nitrogen Applications to Wheat in a Cover Crop Program that Restricts Fertilization Until Mid-March 2008

Wednesday, March 26th, 2008

Richard Taylor, Extension Agronomist; rtaylor@udel.edu

A number of fields were seeded this past fall to winter wheat after being enrolled in cover crop programs that excluded fall applied nitrogen (N). Some fields were seeded quite early in the fall and tillered profusely while other fields were seeded late enough or in dry soil so fall growth, and especially tiller production, was very limited. As late-planted or untillered fields begin to emerge from winter dormancy, N availability will be critical to encourage rapid growth and tiller development in the spring of 2008 for those fields that will be allowed to be harvested for grain. Virginia Tech’s publication entitled “Intensive Soft Red Winter Wheat Production” provides some valuable information to assess the N status of wheat fields in early spring. (more…)

Irrigating Wheat

Wednesday, March 26th, 2008

 Gordon Johnson, Extension Ag Agent, Kent Co.; gcjohn@udel.edu

Wheat irrigation is a subject of considerable discussion. Does it pay? When should wheat be irrigated? How much should wheat be irrigated? When should you stop irrigating wheat? The following are some thoughts on the subject.

  • Irrigation does not always show an increase in yield. In fact, irrigation at the wrong time could potentially reduce yields. On average, a 3-7 bushel increase in yield has been seen with irrigation looking at yield maps. At today’s prices, a 7 bushel increase would be over $60 more per acre. This must be weighed against the cost of irrigation. Fuel costs alone to apply 1.5 inches of water would be $19 per acre.

  • Wheat water use is minimal until jointing, when the plant has some height to it. At jointing, wheat will use between 0.2 and 0.25 inches of water per day. At boot and heading stages, wheat is using around a quarter of an inch a day, and during grain development through the milk stage, wheat will use about 3 tenths of an inch a day. Once wheat hits the dough stage, water use drops off considerably.

    (more…)

Septoria and Stagonospora Diseases

Wednesday, March 26th, 2008

Bob Mulrooney, Extension Plant Pathologist; bobmul@udel.edu

The following article was reprinted with modifications for Delaware from Ohio State University Extension Fact Sheet, Plant Pathology, “Septoria tritici Blotch and Stagonospora nodorum Blotch” by Patrick E. Lipps and Dennis Mills, The Ohio State University.

Septoria and/or Stagonospora diseases can be found in nearly every wheat field in Delaware at some time during the growing season. These diseases have the potential to cause serious losses if the environmental conditions are favorable for their spread during May and early June. In years when wet and windy weather prevails during mid to late spring, losses can be as high as 20 to 30%. Greatest yield losses occur when the flag leaf and the two leaves below the flag leaf become infected by the time the wheat flowers in May. If these leaves are killed before the soft dough stage, the grain will be lightweight and shriveled. Septoria (Stagonospora) glume blotch is a leading cause of poor quality wheat seed in Delaware. It affects germination of seed and causes seedling blight when infected seed are planted without an appropriate seed treatment fungicide. (more…)

Powdery Mildew Questions and Answers

Wednesday, March 26th, 2008

Bob Mulrooney, Extension Plant Pathologist; bobmul@udel.edu and Gordon Johnson, Extension Ag Agent, Kent Co.; gcjohn@udel.edu

Powdery mildew has been a major disease in wheat in DE. However, we have seen relatively little in the last 2 years. Why?
The reason is the lack of favorable weather for infection and subsequent disease development. The weather has been drier and the relative humidity in the spring has been lower due to windier weather.

In what types of growing seasons should we expect more powdery mildew?
The seasons when powdery mildew is troublesome are those that are favorable for luxuriant fall growth followed by cool, wet springs.

What impact can powdery mildew have on yield if left untreated?
Powdery mildew can have a tremendous negative impact on yield if the disease is able to infect a high percentage of the leaf area on the three topmost leaves.

(more…)