Seed Supply Update--Sprayer Tip Review  01/26/17 2:54:33 PM

It was good to see many of you last night (Tues. Jan. 24th)  at our customer appreciation dinner!


Key Dates

March 8th—Spring Agronomic Mtg.—Cass Co. Fairgrounds

Yield Info.—2016 Yield Grids are complete! Visit the lobby for the complete genetics X environment version or our website for the summaries.


Seed Supply Update—A residual question/issue of the winter still circles around seed supply of corn from a number of brands.  This brings up the question of where are we on a supply standpoint?  From a DeKalb standpoint, some of the “newer” hybrids that had outstanding performance in 2016, are now out of supply.  (See below for the reasons why are out).  This again happens every year to some degree. I have ample supply of hybrids such as DKC52-61 and DKC61-79, DKC61-88, DKC63-55, DKC64-89, and DKC67-58 that have continued to perform well.



DKC70-27 – 73% in the Top 3 and 91% in the top half (it’s the #1 hybrid in 55% of the plots it’s in) – total dominance in nearly all plots, (also shows tough acre strength). Incredible plant health

DKC64-34 – 58% in the Top 3 of very plot and 89% in the top half –looking very strong in all plots, (even the challenging conditions plots). Incredible plant health

DKC60-87 – 49% in the Top 3 of every plot and 83% in the top half – looking very strong in all plots. Place this toward the higher yielding acre and let DKC61-55, DKC61-79, or DKC61-88 carry the load in the lower yield environments. Better plant health than the rest of its RM range

DKC68-26 – 35% in the Top 3 of every plot and 68% in the top half – this was the incredibly dominant hybrid from last year’s plots. Still looking great, but better products and a more stressful season kept it out of the top three this year. Place on high fertility, better ground.


Asgrow soybean supply is generally good of proven performers such as AG36X6, AG3432 and AG4034.  (See below)



AG36X6 – 73% in the Top 3 of every plot and 100% in the top half (it’s the #1 variety in 36% of the plots it’s in) – looking very strong in all plots. I haven’t seen this dominance since AG4034’s first year in plots. This looks to be a bean that can go on any and every acre.

AG4034 – 50% in the Top 3 of every plot and 73% in the top half – consistent--had another great year and will continue to be a great choice in the future.

AG3432 – 36% in the Top 3 of every plot and 77% in the top half –still a “go to” variety We have not seen this one disappoint when it comes to yield ability.


Spraying Tips--Much has been written/reviewing regarding this topic over the years.  It is now a current topic again now that the RR2Xtend technology is available.   It again seems to be a timely topic for a few of reasons. 

1—In Post-emergence weed control--RR2Xtend is now an in crop option—IF NEEDED 

2--Many herbicide labels are now recommending specific tips/nozzles for their products to comply with EPA requirements.

3—There is a contingent of tank mixes with Roundup Ready applications in which off-target drift is a concern yet again. 

Prior to 1996, we worried about off-target drift with every treatment that was applied—some treatments more than others (growth regulated and auxin treatments—2,4-D/Banvel).  Roundup Ready applications lessened that concern as volatilized (vapor) movement of the treatment wasn’t a large concern.   Now, we are in the midst of tank-mix partners being widely added to the Roundup treatment which re-verts back to some of the pre 1996 concerns regarding herbicide drift.  We think this is true with ALL types of post-emergence treatments.



SO here is our simplified review 

Spray-droplet diameters are measured in micrometers. A micrometer is approximately 1/25,000 of an inch and is usually referred to as a “micron.” For reference, the thickness of a human hair is approximately 100 microns. Drops smaller than 150 microns in diameter (smaller than the diameter of a sewing thread) usually pose the most serious drift hazard. Drift is far less likely to be a problem when droplets are 200 microns and larger in size. A study indicated that spray particles less than 50 microns in diameter remain suspended in the air indefinitely or until they evaporate. This should be avoided because there is no way to control deposition of very small droplets.

Spray Drift--There are two kinds of drift:

·         Particle drift is off-target movement of the spray particles.

·         Vapor drift is the volatilization of the pesticide modules and their movement off target.

A Mississippi State University study analyzed data from more than 100 studies involving drift from ground sprayers. Of the 16 variables considered, three were most important.

Spray when the wind speed is 10 mph wind or less.

1.      Wind Speed. I realize that there are not many days in the application season when sustained winds are below 10 mph.   We realize that this does not happen very often in Nebraska, in June.  However, remember that this is far more of an issue with post-emergence applications than with pre-emergence.  Keep in mind that when wind speed was doubles, there is almost a 700% increase in drift when the readings were taken 90 feet downwind from the sprayer.   

2.      Boom Height. When the boom height was increased from 18 to 36 inches, the amount of drift increased 350% at 90 feet downwind.

3.      Distance Downwind. If the distance downwind is doubled, the amount of drift decreases five-fold. Therefore, if the distance downwind goes from 100 to 200 feet, you have only 20% as much drift at 200 feet as at 100 feet and if the distance goes to 400 feet, you only have 4% of the drift you had at 100 feet.  Check wind direction and speed when starting to spray a field.

·         Start spraying one side of the field when the wind is lower.

·         Spray only part of the field because of wind speed, wind direction, and distance to susceptible vegetation. The rest of the field can be sprayed when conditions change.

Spray Pressure and Sprayer Speed--Pesticide drift also can be reduced by using one of the new types of tips and by adjusting spray pressure. Higher spray pressures produce smaller droplets which are more susceptible to drift. If using a rate controller, be careful of increased speed. Since most rate controllers increase the pressure to maintain the same gpa when the speed increases, try to maintain the speed within 10%. For example, if you're applying 20 gpa at 8 mph at 40 psi and you increase the speed to 11 mph, the pressure will be 75.5 psi which will produce small particles prone to drift. Also, this pressure will be above the operating range of most tips. Drift reduction agents may be helpful.

New spraying technology such as the "blended pulse" can decrease the risk of drift by allowing flow rate to be controlled independently of spray pressure.

Nozzle Tip Selection--It is important to select the nozzle tip and pressure that delivers the spray particle size needed to give good efficacy with the pesticide. Always consult the pesticide label for information on application. This may include carrier rates, nozzle types, spray particle size, pressure, drift, additives, etc.  Our preference is a GreenLeaf medium pressure TurboDrop XL Venturi nozzle which delivers excellent drift control along with excellent coverage for most all of our post-emergence ground applications.  With RR2Xtend applications it is important to select nozzles that possess a coarse droplet size category (500+ microns) such as the TTI tips.

Table 1. Distances spray droplets travel with various wind speeds from 3-foot boom height.

Droplet Size

Wind Speed


5 mph

10 mph

15 mph

20 mph


Distance traveled in feet


























Droplet Size. All nozzle tips produce a range of droplet sizes with low-drift nozzles reducing the number of small droplets (fines). Droplets less than 150 to 200 microns are most susceptible to spray particle drift. Nozzle tips come in several sizes within a given type of nozzle. Smaller nozzles designed to give a lower output will also produce a higher percentage of small droplets compared to larger tips. If the air-induction spray nozzle tips produce the spray particle size needed for the pesticide and application method being used, they may be the best choice. Most of the standard air-induction spray tips give the best performance when used at about 70 psi. Check with the manufacturer to get their recommendations. Extended range air-induction tips are best used at around 40 psi. Again, check with the manufacturer for their recommendation.

You can manage spray drift damage.

1.      Recognize and adjust for the factors that affect it:

·         wind speed (spray when it's less than 10 mph)

·         nozzle height

·         spray nozzle tip

·         pesticide selection

·         spray additive used

2.      Keep spray a safe distance from susceptible vegetation.


Courtesy of

Robert Klein
Extension Western Nebraska Crops Specialist




John W. McNamara


Wiles Bros. Inc.

606 Wiles Road

Plattsmouth NE. 68048

(402) 298-8550--Office

(402) 499-3870--Cell

(402) 298-7174--Fax



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