Agronomist Notes

Modern seeding equipment and technology is really awesome, especially when you buy it in the winter. Then spring comes along and seeding begins, hair turns grey, some falls out and tech support guy becomes your new best friend. For many, planting began last week with wheat, barley and peas going into warm, mellow, and relatively moist soil. Actually, the soil conditions this year are some of the best I’ve seen in years.

In my territory, there have been a few rain delays in the east while the west remains fairly dry. I have some producers still waiting for the ground to dry to begin seeding in the heavy clay areas. At the farm we’ve had 1.5 inches of rain plus 6 inches of wet snow so far. The forecast is for rain during the middle of the week with cooler weather and then back up to mid-teen temperatures for the first week of May.

In this week’s issue, I’ll start with a few tips for the week ahead. Next, I’ll give you the low down on when to spray glyphosate after a frost and then give you some post-seed herbicide options given the poor spraying conditions we’ve had lately. I’ll pass along some inter-row seeding observations that may intrigue the speed seeders out there and finally, I’ll update you on our 4WD modification for controlled traffic. We’ll finish with fundamental and technical grain market news.

Agronomy

Steve’s tips of the week

• I’ve seen a jump in weed germination over the past week. Be sure to scout fields that didn’t show signs of weed growth a week ago so you don’t get caught off guard.
• Watch your seeding speed. The mellow soil conditions are causing openers to throw more soil at higher speeds causing fluctuations in seeding depth. Go 4.8 mph on cereals and 4 to 4.3 mph on canola.
• Volunteer canola is starting to emerge, especially under the residue. If your fields look clean, take a look at what’s hiding under the residue to be sure you don’t need a pre-seed herbicide.

Practical Questions on Glyphosate Use

How long do I have to wait to seed after I spray Glyphosate?
If you are targeting annual weeds like stinkweed, volunteer canola, cleavers, flixweed, kochia and wild buckwheat then seeding the same day is fine. Does that mean seeding 1 hour or 12 hours after you spray? Remember that annual weeds have very small root systems so it doesn't take very long to get the glyphosate into the plant. Spraying early afternoon and seeding early evening is fine.

If you are targeting perennial weeds like dandelion, quackgrass and Canada thistle then, ideally, you should wait 3 days before seeding. If weather conditions are good (no frost) and 15-20°C days then you can push the envelope to 2 days before seeding while understanding the risk and guarantees that are foregone by spraying earlier than recommended. The longer you wait the better.

If a frost occurs, can I still spray Glyphosate?
Frost is always a problem in the early part of spring. Often temperatures will reach a low of -2 to -3°C, and then peak the following day to 13-20°C.

Hard Frost (roughly -2 to -3°C for an extended period of time, window scraping in the morning)
Perennials: wait until the warm part of the next day to spray. Wait 24 hours.
Annuals: wait until the warm part of the same day to spray. Wait until daytime temps have reached 10°C for at least 2 hours before spaying. If frost damage is suspected wait 1-2 days to ensure that the weeds recover (they need to be at least 60% green).

Light Frost (temperatures dip briefly below 0°C overnight)
Perennials and annuals: wait until the warm part of the same day to spray. Minimum daytime temperatures should be at least 10°C.

Weeds in order of frost tolerance:

1. Dandelion
2. Winter annuals
3. Quack grass
4. Perennial Sow Thistle
5. Canada Thistle
6. Toadflax
7. Annuals

Source: Syngenta and Monsanto

Post-seed herbicide options

Once again, the weather has been windy during the day when temperatures are right for spraying and frosty at night, reducing the possibility of spraying during the morning when the wind is calm. This kind of weather leaves us with a few options:

• If you’re fields are clean but you’re concerned about flushing weeds like volunteer canola, cleavers, wild buckwheat, wild mustard and chickweed emerging after seeding, remove the florasulam component from the PrePass and apply at 40 ml/ac separately. You’ll be relying on the soil activity to give you the 7 to 14 day residual control depending on conditions. If weeds have emerged, you’ll have to add 2.5L/1000L of a non-ionic surfactant like AgSurf or Agral 90. Save the glyphosate for your RR canola later on or use it for another pre/post seed burn off. You forfeit any product warranty by doing this.
• If your field is clean of grassy/broadleaf weeds but you have a history of problem wild oats, apply Everest at 8.7 grams/ac alone to give you flushing control. If you have left over Everest from last year, this might be an option. You’ll still have to go in with a full rate of Everest or wild oat herbicide in-crop. This tactic helps keep wild oats in check before you hit them in-crop.
• You can apply Express Pro alone with no surfactant or glyphosate if you’re just looking for residual control much like PrePass. Express Pro is weaker on cleavers so if you’re looking for flushing control, choose PrePass or the florasulam component of PrePass. Again, same forfeit of warranty applies. SL

Inter-row seeding blocks soil throw at higher speeds

I had a client call with some interesting observations on soil throw, seeding speed and inter-row seeding. During the set up of their new Case 800 precision drill they did some seeding speed trials of 4.7, 5.0 and 5.2 mph planting barley. There was no difference in seed placement at each speed with this drill but they did notice soil throw increased as they went faster. It’s interesting to note that they are getting a small amount of soil throw even with a ¾ inch opener on 10 inch spacing. Incredible! Can you imagine a 3 or 4 inch opener? I digress.

They also looked at seeding speed and soil throw when the openers were seeding between the stubble and inter-row. Again, this Case 800 opener seen here maintained seeding depth accuracy at 5.2 mph but did start to throw soil at 5.0 and 5.2 mph. The interesting part occurred when they began seeding inter-row at higher speeds. The soil continued to throw but was blocked on both sides by the stubble rows. The soil remained inside the furrow because the stubble blocked the soil from launching on to the next row.

Now, I’m not advocating speed here, I’m just looking for efficiencies. If you could stifle the effects of soil throw at faster speeds by combining a precision drill like the Case 800 with inter-row seeding, you might just find the best of two worlds. Think about it? How often do you read speed and accurate seed placement in the same sentence? Food for thought. SL

Thanks to Spencer Hilton, of Strathmore for sharing his observations.

Converting a 4WD to run on singles: it’s more than a day’s work!

As you know, my in-laws Mitch and Sam Currie and I are currently modifying our equipment to begin controlled traffic farming in 2010. After the tremendous benefits I documented on my overseas travels, I felt there was no time like the present to begin controlled traffic farming in our heavy clay soils. Thankfully, the in-laws were keen enough to see it through and we are now at the final stages of completion. This week, I’ll take you through the modification of our 4WD and how we took it from a dualled tractor to a single wheeled unit running on the outside rims. Enjoy! (We did!)

The first task of converting any dualled 4WD tractor to run on single tires is to find the right load rating. We currently have 23.1-34 bias ply tires with a load rating of 7,500 lbs per tire at 18 psi. The 4WD weighs 30,000 lbs wet so we didn’t have to buy new tires, thankfully! Ideally, we could run radial tires to help carry the load, reduce tire pressure and smooth out the ride. Our budget doesn’t allow for this just yet.

Next, we needed to match the wheel widths on the 4WD, sprayer, air drill, air tank and combine so they would stay inside each others wheel track. By matching the wheel widths on each pience of equipment, we could bring our area of compaction down to just 16.6% of the field. The original plan was to have ten foot center to center tire widths so we would only have to modify the 4WD and back axle on the air tank. The sprayer, combine and front axel of the air tank were already on ten foot centers. After some head scratching, we realized we could only get down to a width of 10 ft 3 inches with our 4WD because we couldn’t bring the outside rims in more than seven inches. The concensus was to go with the 10 ft 3 inch centers on the 4WD and the other equipment tires would fall inside anyhow. The 1.5 inches per side was nothing to sweat about. 

Now, given that our Steiger has outboard planetaries, it makes the modification process more difficult compared to something like a John Deere that has inboard planetaries. Inboard planetaries have axle extentions you can bolt on and allow you to run on the inside rim, which is more structurally sound than the outside rim. Running on the outside rim of an outboard planetary system meant that we’d have to cut the spacers and weld the rims together. Not easy, but totally doable! 

We ripped off the tires, rims and spacers and had them sandblasted. We welded the stress fractures and cracks in the welds and cut four spacers down to 7 inches to fit in between the rims for added stability. The six bolts on each rim were cut down to 26 inches, rethreaded with a new nut welded on one end. We used these bolts to tighten the rims together so we could begin welding the two rims together. Once the welding was completed, each new rim was painted a lovely factory Steiger green on the inside.

The next step was to put the four new rims back on the planetaries after replacing the seals and to finish painting the rims while we could spin them on the hub. Thankfully, all the planetaires were sound on this old girl. Our friends at Kal tire put the tires back on but this time we left the calcium out. We chose not to put calcium back in because the tractor is fairly well balasted from factory and we might have to make a quick tire change if things go south on us!

After an armstrong torque on the wheel nuts with a four-foot snipe, the 4WD modification to singles is complete. I think the old girl looks pretty awesome don’t you? I dare say we’ll get a few looks and few comments under the breath at how nuts we are but such is life in the name of progress. SL