NDSU Extension Service - Cavalier County

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6/19/2014

Wheat Development/Leaf Stage
Seed Date                            Stage

4/21                                        Flag leaf visible
5/1                                          7 leaf
5/15                                        6 leaf - jointing
5/20                                        4-5 leaf - tillering
5/26                                        3.5 leaf - tillering
5/31                                        2-2.5 leaf
6/5                                          1 leaf

Crop stands?
Excellent crop stands are a common site this year so if you see bare or thin patches, start diagnosing!  Scout for insects (cutworms, wireworms, flea beetles, etc.), diseases (root rots), herbicide carryover (residues), environmental (wind, soil moisture), weed escapes, soil compaction, etc.

Volunteer Crops!
Volunteer crops are weeds and compete with the planted crop for nutrients and water and sunlight.  Volunteer canola seedlings are untreated and can introduce diseases and/or break down the disease resistance of a certain varieties. In non-canola years, volunteer canola provides a host for blackleg and clubroot, reducing the effectiveness of crop rotation for managing these diseases.

Canola growers must keep on the lookout for clubroot as it was confirmed locally in 2013.  In Alberta, Canada, the few varieties they have with resistance to the clubroot found in 2003 is not the answer as they now have a different clubroot pathogen with no commercially available resistance.  Kind of scary – for help in identifying clubroot stop by or call my office for photos and literature.  This disease will move with soil so field sanitation is critical when moving from field to field with equipment as well as by foot!

Topdressing nitrogen and sulfur
A nitrogen top dress can make financial sense for crops with very high yield potentials (excellent stands) and or where all the fertilizer needs weren’t supplied prior to or at planting.

The following are some additional notes on topdressing that review and/or add additional comments to the ones I included in the May 30th Ag Alert.   Most of these comments on topdressing are from the Canola Council of Canada – Canola Watch!

When should topdressing be done?
The earlier the better, and before the 4- to 6-leaf stage of canola and by the 5th leaf stage of wheat For canola this is pre-bolting stage just before buds form and plants begin to elongate. For canola, maximum rates of nitrogen uptake occur from about the 5-leaf stage to full bloom. Nitrogen must be applied well before that period because rainfall is required to move the fertilizer into the root zone and make it available for uptake.  For wheat application later than the 5-6th will increase protein but will not add yield.

What nitrogen source to use:
Nitrogen options for in crop application are urea (dry), UAN (liquid) or ammonium sulphate (if sulfur top-dress is needed but leaf burn is likely with liquid AMS when sprayed over the top) UAN dribbled on the surface is less prone to losses than dry urea broadcast on the surface, but both surface applications require rain soon after application to move the fertilizer into the soil and limit volatilization losses.

If using a granular fertilizer, apply when leaves are dry to make sure prills roll off onto the ground and don’t cause leaf burn.  If using liquid, the ideal is to apply when leaves are moist from early dew or a light rain so liquid nitrogen fertilizer runs off quickly. Applying when hot and dry can increase absorption of liquid into the plant, increasing the amount of burn. Consider adding some extra water to the tank in these conditions.

Broadcast spreading of urea or surface dribble banding of UAN are the most common and fastest methods. But these methods can also result in the highest losses if rain doesn’t come quickly. (Losses with UAN tend to be lower than with urea.) Agrotain helps to minimize these losses.

Fertilizer placement in the soil, as opposed to on the surface, greatly minimizes losses from volatilization and immobilization and enhances overall nitrogen fertilizer recovery. This may be difficult to achieve in practice because spoke wheel applicators are hard to find these days.

Tank mixing liquid nitrogen with herbicide and applying through the sprayer is not recommended for a few reasons. This method can provide only a few pounds of actual nitrogen per acre — which isn’t enough to make a difference. Leaf (foliar) applications are highly inefficient, as plants take up nutrients through their roots..

Sulfur
Peak sulfur uptake for canola occurs later than peak nitrogen uptake, so a sulfur top up can occur a little later than nitrogen top up. Post-emergence sulfur can be applied up to early flowering and still provide a yield benefit.

When doing an in-crop application, growers could target only those areas — such as hill tops — that tend to be sulfur deficient.

A sulfur top dress can make financial sense for canola if: Growers could not put the desired rate on at seeding.  Yield potential improved and growers want to add sulfur to their nitrogen top up. If field conditions have been excessively moist, sulfur may have moved lower in the soil profile. As canola plants grow, their roots will extend into these reserves. For that reason, growers who have been applying recommended rates of sulfur may not see as much economic return from a sulfur top up compared to a grower who has cut sulfur rates in recent years.

Sulfur deficiency symptoms include purpling and cupping of leaves.  With sulfur deficiency, yellowing and leaf cupping tend to occur on new leaves first. Purpling of leaf edges can show up when deficiency is fairly severe. In fields short of sulfur crops can usually find enough to get past the early rosette stage without visible symptoms. Deficiency symptoms often show up at flowering. 

Application just prior to rainfall is best. Surface applied ammonium sulfur requires rain to move it into the root zone. Sulfur is not volatile like nitrogen fertilizer, so while dry conditions may delay availability to the crop, losses will be minimal if rain is not immediately forecast.

Phosphorus top dress rarely effective
Phosphorus needs to be in the soil and as close to the seed as possible for maximum benefit. Canola plants continue to take up phosphorus as biomass increases, but phosphorus fertilizer tends to provide its greatest economic benefit very early in the season. As the soil warms up, phosphorus conversion in the soil increases and the crop can tap into existing phosphorus

IDC soybeans: Keep in mind Foliar sprays do not translocate in the soybean plant.  They may green up the soybean plant but do not contribute to yield. 

Non-proven products are being promoted throughout the area.  Make sure to check if there is actual research results on the product before purchasing (Don’t get mislead by one or two research trials that show a positive return as there may be another dozen trials that show no return). Try the product on a limited basis where yield comparisons can be made.  Then repeat the use next year on a limited basis until research results have proven the product. 

Application for Field Inspection deadline for grains, edible beans, soybeans and sunflowers, were due June 15.  You may still apply but will have a $1.00 per acre late fee applied.  Applications are available at our office. Applications will be accepted through early crop heading and can be canceled if lost to environmental conditions.  

Langdon Research Extension Center's 2014 Field Day in cooperation with Northern Canola Growers Association - Thursday, July 17, 2014  (8:00am-Noon).  The new Groundwater Management Research and Extension tiling project will be in the process of being installed at that time also so it will be a great time to take a look at how the project is laid out.   The scope of this project is one of a kind and the only one on public land in the state!  The advantage with being on state land is that it is not a one shot 2-3 year project but will be on station and working for everyone involved in farming for many, many years. The project will have liners placed between research plots that will be replicated for the most accurate and unbiased data possible.  There will be water control structure (wells) on site. 

A special “Thank you” to all businesses that donated to this project including your Crop Improvement Association as well as individual farmers.  A list of all donors will be put together as we finalize the project this next week.  

.North Dakota State University does not discriminate on the basis of age, color, disability, gender expression/identity, genetic information, marital status, national origin, public assistance status, race, religion, sex, sexual orientation, or status as a U.S. veteran. Direct inquiries to the Vice President for Equity, Diversity and Global Outreach, 205 Old Main, (701)231-7708.

 

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