June 5, 2012

Agronomists Notes

Hello Reader,

Seeding has finally ended and you can say we're just about to launch into spraying season. Peas have been sprayed along with many late April seeded wheat and barley fields. Crops look good overall aside from some frost damaging leaf margins from about ten days ago. Spraying season will be well under way by the end of the week after this cool weather system passes.

Last Thursday was a good day. Armed with refreshments, measuring tapes and shovels, 20 of us toured the countryside to see five precision drills and chat with their operators. It was very worthwhile and undeniably more fun than a stuffy indoor meeting or the sales pitch at a farm show.

In this week’s newsletter, we’ll start with a look at a canola stand establishment inside our CTF and inter-row seeding system. Next, we’ll talk about air diffusers on air drills for improving seed distribution in the furrow. I’ll also provide some tips on herbicide applications and then share some of the finer points on a couple precision air drills. We’ll finish with technical grain market news.
Have a great week.

Picture: Clients touring SeedHawk drill during our precision air drill tour.

Crop Staging

(Calgary to Drumheller to Three Hills)

Seeded    Apr 24-30          May 1-7           May 8-15
Wheat      4-leaf 1 tiller     3-leaf 1 tiller      2-leaf
Canola     4-leaf                3-leaf                2-leaf
Barley      4-leaf 1 tiller     3-leaf 1 tiller      2-leaf
Peas        7th node           5th node           4th node

Steve's tips and tricks of the week

Follow me on Twitter for in-season updates @BeyondAgronomy

Monitor flea beetle pressure. Seed treatment lasts 3 weeks on average so early-May seeded canola is most at risk. The threshold is 25% defoliation.
Scout your frost damaged canola fields for flea beetle pressure. Weak plants attract insects!
Measure plant densities to find out mortality rates. You’d be surprised to see how many thin crops there are after a walk through. The field may look great from the road but less than ideal at closer inspection.
Avoid spraying when temperatures will drop below 5oC at night and begin applying when daytime temps climb above 10oC for optimal weed control and crop safety.
Have you missed a pre-burn herbicide? Apply Express SG + 0.35% v/v non-ionic surfactant to control volunteer canola, wild buckwheat, cleavers, dandelion, and flixweed in 1-leaf or emerging cereals. It works excellent!
Check seeding depth in canola. One of the leading causes of poor establishment is seeding too deep. SL

CTF and inter-row seeding canola shines this year

This spring, canola emergence has averaged 50-60% in spite of warm soil temperatures and rain before and after seeding. Precision drills with on row depth control are achieving 75-85% on average from what I’ve seen. I’ve also noticed, once again, that our canola emergence is hitting 75-85% in our CTF and inter-row seeding system, using a 35-year-old Concord air drill with gang packers.

The three major causes of reduced emergence in my opinion are deep seeding, over-packing and heavy residue. We’re able to address those issues in our system in a couple of ways. We keep stubble height tall and inter-row seed. We reduce packing pressure by dropping tire pressure and placing seed on the outside of the packer wheel. We’re able to keep seeding depth consistent since wheel traffic is reduced which usually creates lumps and skews depth.

The picture above is of our Liberty Link 5440 canola seeded at 4.3 lbs/ac with a 98% germ and 5.12 tkw. At 100% emergence we should see 8.5 plants/ft2 and we’ve achieved 6 plants/ft2 on average. See how nicely the canola is tucked beside its guardian- 10-12 inches of barley stubble? Drying winds after seeding were a non-issue.

To improve emergence and achieve more uniform stands we simply must address the three big issues: deep seeding, over-packing and heavy residue. We’ve been able to make that old Concord sing and if we can achieve 80% emergence rates on canola with old technology, something tells me the CTF and inter-row seeding system is working. SL

Picture: 2 leaf canola planted inter-row in our CTF 3inch offset inter-row seeding system.

Improving seed distribution with air diffusers

I had a lot of feedback about last week’s article on the distribution of seed with today’s metering systems. From Canada to Australia, the consultants and farmers I’ve talked to are just as dissatisfied with the seed distribution in today’s metering systems, especially when you look at the price tag of today’s drills.

Seed spacing within rows is random. Most producers find seed placed in a bunch, usually three seeds, and then a large gap, followed a group of, say, 8 seeds within two inches, then another gap. This creates un-necessary competition in the furrow when seeds are stacked on top of each other and wastes space where large empty gaps exist. Aside from moving to seed singulation with vacuum planters, is there a way to improve today’s air drills with a better delivery system?

The fact that we experience blocked primary lines and poor in-furrow seed placement from seed bounce is due to a design flaw in air delivery systems. Some consultants overseas suggest we use air brakes or diffusers to release some of the back pressure in the seed lines. Back pressure can cause small seeds to bounce around like popcorn before they eventually drop down to the opener. Diffusers allow the seed to travel to the secondary tubes where air pressure is released and seeds of all sizes use gravity and some air to fall the rest of the way. This has been shown to help with seed distribution but as always, not all diffusers are the same.

There is a diffuser in the Australian market called SeedVu which I’m told is one of the better ones. See website and video here. Most diffusers attach to the secondary hoses and are prone to getting plugged up by dust or mud or break off in the field. The SeedVu (shown above) replaces the distributor head from the primaries. I liken it to a grain vac where air is diffused out the top, but in this case the diffused air can be controlled to match your desired air flow.

I’ve included some comments on air diffusers by Andrew Newall of NewAg Consulting from Victoria, Australia. He has a few tips on what to look for:

“Using good quality diffusers that diffuse air consistently and accurately certainly helps. There are some poor ones on the market. One that we use that works really well and is made locally mounts on the distribution head and diffuses around 70-75% of the air. This works very well and gives the seed time to get into some sort of formation before going out the seed tube. (SeedVu pictured above.)
“Some of the more popular diffusers on the market like D Cup Diffusers work very well as they remove all the air but depending on what style of opener you use or fertiliser we found that they caused some issues with fertiliser sticking in the tube and or on JD single disc machines some seed was getting stuck in the boot.
“The best ones on the market are those that only take out 70-75% of the air especially if running a disc as you need some air to fire it into the slot as everything opens and shuts very quickly.”

The seed distribution issue is common among all air delivery systems, no matter how accurately you meter the seed. The issue starts as the seed hits the air line. Seeds of varying sizes do not travel down the air line at the same speed whether its canola, peas or wheat. The more consistent the seed size, the more uniform the distribution will be. Unfortunately, it’s not realistic to size your seed so something else must be done to control seed distribution. I believe in some cases diffusers may drastically improve the distribution of seed in the furrow on some makes of drills. This is certainly something to look into further. SL

Picture: SeedVu air diffuser manifold from Australia.

Herbicide efficacy comments and tips

Frost and cool temperatures can have a significant impact on herbicide performance and increase the risk of crop injury. A crops ability to metabolize herbicide slows during cool conditions or when plants are under stress, which extends the amount of time required to degrade herbicide. Slow herbicide metabolism increases the risk of crop injury and can lead to a reduction in weed control. The following tips may help your specific situation:

When spraying Liberty, the weather that occurs during application and the day after application has a significant impact on Liberty performance. For example, a worst case scenario: You spray late at night and temperature falls below 15 degrees C then cloudy weather follows the next day. You can be sure of very disappointing weed control. Cloudy weather significantly affects the performance of Liberty the day after application.
Grassy weed escapes or re-tillering is likely to occur during prolonged periods of stress with any wild oat herbicide.
Green and yellow foxtail are warm season grasses and may stop growing under cold conditions, resulting in poor control.
There is a high risk of crop stunting in wheat when Achieve Liquid is applied at the 3 to 4 leaf, 1 tiller stage when you spray in the evening and the temperatures fall below 8 degrees C at night.
Products like Achieve Liquid and Centurion are highly susceptible to UV light and will degrade rapidly if applied during mid-day or if left in non-metal spray tanks for an extended period of time. If you are stuck with Achieve Liquid or Centurion in the tank, be sure to park the sprayer in the shade or under cover to avoid the breakdown of the chemical.
If you have Centurion left in the tank for a few days due to a shut-down, top up the Centurion by 10% before you start up again.
If spraying Velocity, be sure to add water to your chem. handler first before adding Velocity A or Velocity All in one. Adding Velocity to an empty chem. handler or tank will create a reaction and product will start to crystallize.
If sprayed during warm, moist conditions, you will see improved performance of Achieve Liquid, Poast Ultra and Centurion when you spray later in the day. The rapid UV breakdown of these herbicides is slowed under low light conditions which allows more time for the herbicide to work. It can also lead to more crop injury, so be cautious with Achieve Liquid.
Cold temperatures, including freezing conditions following application of ALS herbicides (Group 2) and Buctril M, may increase crop injury of labelled crops with little effect on weed control.
Liberty, Basagran and Gramoxzone are less likely to cause crop injury when cold temperatures follow application but less weed control will result.
Products such as 2,4-D, MCPA, dicamba, clopyralid (Lontrel), fluroxypyr (Attain) have adequate crop safety and provide similar weed control across a wide range of temperatures, but weed death is slowed when cold temperatures follow application. SL

Precision drill tour 2012

Assessing performance outside the tradeshow floor

When it comes to assessing precision air drills, there’s no better place to look than in the field just after emergence. You have to wonder how so many drills are sold on the tradeshow floor by someone who’s never operated the drill they’re selling. Last week, I hosted a precision drill tour for my clients and looked at five precision air drills to see which ones performed the best and to find out first hand the pros and cons of each machine.

DISCLAIMER: All precision seed drills do a good job of placing seed in the ground accurately within reason. Compaction, steep rolling terrain and heavy residue will reduce the performance of these machines. Also, packing pressure and seed depth must be adjusted properly to really make these drills perform. Almost every precision drill we viewed in the field had a consistent seeding depth, unfortunately the canola was accurately placed at 1.25 to 2 inches deep, which is less than ideal. I also viewed some canola fields with too much packing pressure that left ½” cement layers above the canola seed. Packing pressure can be changed as field conditions change and so can seeding depth. All in all, with the right adjustments, these drills do provide better seed placement which translates to better emergence. The question is how does it pencil out in the end?

SeedHawk: 72 feet and 800 bushel tank

800 bu/tank offers a 240 bu, 135 bu, 425 bu split which can do 120 ac/fill with a 300 lb/ac fertilizer blend in canola. Wow!
Conveyer is fast loading in 25 minutes but very tough to man handle from the ground.
Frame depth is 15ft from front to back which can be troublesome on steep knolls or depressions. Openers lift out of the ground or dig deep in steep situations.
The Viper monitor doesn’t have enough storage capacity to map fields larger than 300 acres. You have to start a new job every 300 acres or monitor stalls out. Upgrade coming.
Sectional control works excellent and saves a few percent on overlap in each field depending on field shape or the number of wells and sloughs.
Front castor wheels outside the centre section rub against frame and drag tires when filled with mud. There is only ¼” of clearance between wheels and frame. Upgrade coming.
Trash flow is not great on this machine with bunching very common in mildly tough conditions.
Dual fan allows you to reduce air velocity on one fan for canola and crank up fan speed on fertilizer if need be.
Stainless distributor system underneath the air tank is nice and changing rollers is easy.
Height from ground to paralink hinge point is roughly 19” which gives it good trash clearance to ride up the shank but the dual shank seed and fertilizer opener catches residue which then piles up.
Owner mentioned that they had to change fertilizer tubes after one season after putting all 300 lbs of fertilizer down the same fertilizer tubes

Bourgault 3310: 67 ft and 700 bu tank

700 bu/tank offers a 370 bu 95 bu 30 bu 205 bu split which can do 80 ac/fill with a 330 lb/ac blend in canola.
Greases machine seasonally. So far no bushings or bearings wearing after 13,000 acres.
This frame is the second shortest of all from front to back at 10 ft 2 in, second to the Flexicoil design of the Case/New Holland at 7 ft 2 in. This allows excellent ground following capability.
The short frame depth does not make it easy to crawl underneath and check openers for plugging. You really need a helmet!
Mid-row banders don’t like big rocks but what disk does.
Stainless meter augers stay clean longer than original nylon augers.
Packer to seed opener is 10 inches. This leaves room for residue to flow back on to the furrow before the packer versus other precision drills which vary from 4 to 6 inches.
Fill time is 30 minutes and auger is easy to move across this school bus sized air tank.
Height from ground to paralink hinge point is 21 inches roughly which allows it to travel through longer straw or residue.
Single shank design reduces seeding depth variability. Dual shank designs open up furrow with fertilizer knife first and if soil doesn’t close furrow, seeds drop down.
Packer wheel presses soil over top of seed which can create a hard surface above seed but this is the same across all precision drills except the Conservapak.

What I learned most on our tour was that a $2000 pool cue does not make you a pool shark. Meaning, residue issues, seeding depth, packing pressure can all be managed poorly and leave you with an average seeding job no better than a regular hoe drill. It’s the ability to make those subtle but necessary changes that will improve germination and emergence from a precision hoe drill. SL

Picture: SeedHawk and Bourgault shanks.