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The Cropwalker - Volume 2 Issue 9

Always read and follow label directions.


You Don’t Use Soil Samples for Recommendations?

There are several methods of creating a fertilizer recommendation, and using crop removal is one of them. With increasing yields there is a heightened focus on using crop removal as the basis for fertilizer recommendations. But…why continue to soil test if you are using crop removal as the basis for fertilizer recommendations? 1) In lean times, it allows the Agronomist to determine which nutrient is most limiting. This means if you have to cut back it tells you where to cut back with the least impact on yield. 2) It provides a benchmark or scorecard of your soil. Looked at it over time you can see if your soil test levels are increasing, decreasing or staying the same. 3) When adding nutrient sources with a range, it allows the agronomist to see the long-term effect of adding these nutrient sources.

Forage Seeding Depth

A bit early to seed forages but not too early to get ready. The biggest cause of poor forage establishment is seeding too deep. Remember this when you start to plant forages. I like to have at least 5% of the seeds lying on top of the ground. This will mean that most are at the right depth. When preparing a forage seed bed work the ground shallowly. When you walk into the field ― you want the soil to be firm. This means that your shoes should not sink more than ½” into the worked soil. We over-plant forages because of poor seed placement. Normally we need about 20 lbs/ac of seed because of poor seed placement

Sulphur on Alfalfa, Corn, Red Clover, and Wheat

Table gives the rate of various products. There is a ratio of N:S that some use. It boils down to higher yielding crops that use more nitrogen should have higher rates of S. For wheat you need a minimum of 10 lbs actual S per acre. Some growers are applying 15-20 lbs/ac. There are on farm trials showing addition of sulphur on wheat helped the establishment of red clover. The soils most apt to need S are lighter soils. For corn consider using 10 lbs /acre. For alfalfa use 15-20 lbs actual. While we are still learning the best way to apply S consider applying it with your first application of N on wheat and corn. For alfalfa I like to get it on as early as possible.

Table 1 - Sources of Sulphur containing Fertilizers

Elevore vs. Eragon

Elevore is a new active ingredient used in burndowns. The company Corteva are calling it “the fleabane fighter”. In Peter Sikkema’s research it gave similar results to Eragon. Eragon might have been a tad better. Eragon is a group 14 product while Elevore is a group 4. So different groups. If you have been using Eragon for a number of years in the same field consider trying some Elevore. Elevore must be applied 5 days before corn and 7 days before soybeans. The seed must be 4 cm (1.6 inches deep). This means that you have to make sure closing wheels do a good job covering the seed. It must be mixed with a product like Suremix or Turbocharge. The manufacturer strongly recommends glyphosate be added to the mix. Red clover is not on the label but Paul Foran from Corteva says it does a good job controlling red clover.

Acuron By Syngenta

Acuron is a newer corn herbicide from Syngenta. It is a combination of the actives in Dual, atrazine, Callisto, and a new active bicyclopyrone. Bicyclopyrone is not sold as an individual product. According to Leanne Freitag, Syngenta Agronomic Services Manager, Acuron is replacing Lumax. Acuron sharpens broadleaf control compared to Lumax. It has excellent control of waterhemp, suppression of proso millet, and controls bluegrass in 2017 trials. (bluegrass is not on the label) It also controls fleabane up to 4”. It is registered for pre-emergent and up to 6 leaf corn. Use rate is 1.98 L/ac.

2,4-D Ester vs. Eragon LQ, which is the better option for your soybean burndown program?

There may be a few situations where you would rather use 2,4-D Ester than Eragon as part of your soybean burndown program. Here are a few suggestions.

1) You have a field full of dandelions and minimal fleabane. Eragon tends to burn very fast under bright, sunny conditions. In these cases the glyphosate may not translocate from the leaves to the roots, allowing regrowth to occur.

2) You have a lot of volunteer alfalfa. Similar issue to point 1. Plants with large amounts of top growth and a big root system from which to regrow will have issues if the glyphosate cannot translocate.

3) You are planning on tank mixing with a group 14 that contains Valtera. BASF will not support the tank mixing of Eragon with Valtera due to crop injury concerns.

Adding liquid carbon to your crop plan?

Speaking with a supplier rep this winter and some additional reading helped to shed some light on where you would consider using a few of the liquid carbon products that are available ;

1) You have soil organic matter levels below 2%. Anecdotally, those that have tried the products have commented that they get the biggest response on the worst fields or those than have the lowest organic matter.

2) Where or when to apply these products?

a) Humate/Humic Acid – these are long carbon chain materials derived from lignite or peat. One study commented that the best performing were derived from compost rather than lignite or peat. Typically applied to the soil with liquid starter or dry fertilizer.

b) Fulvic Acid – is smaller, lighter molecules that humic acids. Fulvic acid has a better chance of being absorbed by a plant cell compared to a humic acid due to the smaller molecule size. Fulvic is generally preferred over humic for foliar sprays (inclusion with nutrients or pesticides).

3) In one trial I was involved with these products; we did not see any significant yield gain but did see an increase in leaf burn. Be aware that the crop can have an adverse reaction under the right environmental conditions (thin cuticle or extreme temperature swings).

What is the best residual herbicide program for soybeans?

First off, the right question is; what weeds can I not control in-crop if they escaped, and which ones cause the greatest yield loss?

1) Which weeds should I control pre-emerge because of limited in-crop tools?

a) Canada Fleabane (groups 2, 9 and 22)

-Residual products should contain dicamba (Engenia, FeXapan or Xtendimax) or metribuzin (Sencor/Tricor)

b) Waterhemp (groups 2, 5 and 9)

- Residual products should contain a group 15 such as Boundary, Frontier, and Focus/Zidua. Best options include a group 14 with the group 15 i.e. Authority Supreme or Fierce.

c) Giant Ragweed (group 2 and 9)

- A properly timed spring burndown can be quite effective

-Residual products should contain Valtera

2) Which weeds should I control in soybeans because of early season weed competition? Annual broadleaves cause the largest yield loss on per plant basis. These are the 5 biggest offenders;

Eastern Black Nightshade

Group 14 – Authority, Valtera; Group 15 – Boundary, Frontier, and Focus/Zidua

Giant Ragweed

Group 14 – Valtera is your best choice

Lamb’s Quarters

If you have resistance issues to group 2 and 5 – group 14s such as Authority or Valtera are your best options.

Redroot Pigweed

Group 14 – Authority or Valtera; Group 15 - Boundary, Frontier, and Focus/Zidua

Common Ragweed

Group 14 – Valtera is your best choice

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