Planter Tips, Seedbed Prep & More
Planter Tips, Seedbed Prep & More
Get tips to help you determine when soil is ready for spring tillage and seedbed preparation. Also find tips on getting your planter ready.
|Seedbed Preparation Tips|
Planting Outcome Effects on Corn Yield
Crop Insights written by Tom Doerge1, Mark Jeschke2 and Paul Carter3
- Uniformity of plant emergence, planting timing, plant population, and evenness of plant spacing are 4 outcomes of planting that can influence final corn yield.
- Research has shown that delayed emergence can reduce the yield of individual plants in a stand; however, the notion that a plant emerging more than 48 hours after its neighbors is a “weed” is clearly not supported.
- Corn yield potential declines as planting is delayed beyond the optimum planting window for a given geography, and the yield penalty tends to be greater in northern areas where the growing season is shorter.
- Optimum plant population can be influenced by factors such as yield level, hybrid, and weather conditions.
- The CoV and singulation readings on the planter monitor are valuable real-time indicators of meter performance but poor predictors of the agronomic consequences of common, realistic non-ideal planting outcomes.
- Within-row plant spacing uniformity does impact grain yield; however, whole-field impacts on grain yield are usually relatively small, averaging about 1% to 2%.
- By far, a skip is the planting outcome that contributes the most to yield loss, whereas occasional doubles have no negative impact.
4 Planting Outcomes for Success
Planning and execution associated with corn planting are critical if growers are to maximize the genetic potential of today's elite corn hybrids. The simple secret for success is to "do everything right." Many of these key management decisions are made well before the planting season, including choice of hybrid, crop rotation, tillage system, nutrient placement, target planting rate, and row spacing.
This Crop Insights focuses on the 4 planting outcomes that are achieved during planting itself. The relative impacts these 4 factors have on grain yield were recently summarized by Dr. Jeff Coulter from the University of Minnesota4 and are presented below.
These goals and their estimated typical impact on yield include:
- Achieve uniform emergence (5-9%)
- Plant within the optimum window (2-5%)
- Achieve the correct population (1-2%)
- Achieve uniform plant spacing (1-2%)
The latest research related to achieving each of these 4 planting outcomes is discussed and, in several cases, suggest the need to rethink conventional wisdom regarding their importance in affecting grain yield.
Achieve Uniform Plant Emergence
A primary goal of corn growers is to achieve stands containing uniformly large-sized plants that consistently produce 1 full-sized ear each. Small, delayed or "runt" plants rarely, if ever, produce full-sized ears. Traditionally, growers have assumed that the primary cause of these smaller, undesirable plants was a delay in the time of emergence. And often the cause for delayed emergence was assumed to be inconsistent seeding depth. Logically, late-emerging plants are less able to compete for limited light, nutrient, and moisture resources with earlier-emerging and larger neighbors. Several studies have indeed documented significant yield loss when the development of plants within the stand was delayed (Nafziger et al., 1991; Ford and Hicks, 1992; Liu et al., 2004a, 2004c). These studies typically used multiple planting dates 7 to 28 days apart to achieve varying degrees of delayed plant growth. These studies are valuable in demonstrating certain aspects of plant-to-plant competition and give some guidance for making replant decisions. But they are of little value in understanding the effects of time of emergence on individual plant yield in stands planted all on the same day, as is typical in commercial corn production. They also do not indicate the relative importance of time of emergence versus other factors occurring after stand establishment or how final plant yield is impacted by each.
Multiple factors shown to affect plant yield
There is widespread agreement that large plants exhibiting well-synchronized silk emergence and pollen shed produce the largest and most consistent-sized ears (Pagano et al., 2007; Kovács and Vyn, 2014). However, these studies have also shown that time of emergence has relatively little effect on plant biomass and final grain yield. In a 2-year study in Indiana, Murua (2002) documented that time of emergence in conventionally-planted corn stands only explained about 4% of the variation in individual plant yield. A similar study by Kovács and Vyn (2014) found that value to be only about 1%.
Other studies from Argentina found that even when corn canopies emerge uniformly, they can develop well-established plant hierarchies as early as the V4 growth stage (Pagano et al., 2007; Maddonni and Otegui, 2004). These differences in plant size within the stand are probably explained by "other" factors such as moisture availability, compaction, soil textural differences, nutrient acquisition or insect damage, and clearly not time of emergence. The notion that a plant emerging more than 48 hours after its neighbors is a "weed" is clearly not supported by these studies. In fact, Kovács and Vyn (2014) further warn, "the importance of ultra-uniform seedling emergence times for adjacent plants within the row can easily be overstated."
How much does uniform emergence affect plant yield?
Determining the exact effect of uniform emergence is difficult, in part because studies have used different ways to measure and express emergence uniformity. Some of the different measures used include calendar or growing degree days from planting to emergence, time to 50% emergence, number of leaf stage growth differences and days of emergence delay after the mean emergence date of the plant stand. Ford and Hicks (1992) measured a 6% yield loss when every second plant had a 1-leaf stage delay and a 5% yield loss when every sixth plant had a 2-leaf delay. Liu et al. (2004a, 2004c) found that yield decreased 2% per day whenever the time to 50% emergence was delayed by more than 3 days. Nishikawa and Kudo (1973) report that per plant yield declines by 5% for every day in emergence delay after the mean emergence date of the plant stand. And finally, Murua (2002) measured an average of 2.3% yield loss for every additional day's delay in emergence of individual plants.
These results suggest that delays in emergence can result in average yield losses in the 5% to 9% range proposed by Coulter. Careful attention to managing planting depth, seed trench compaction, surface crusting, seed furrow closure and surface residue will minimize these yield losses. But beyond that, attention to other factors, such as uniform moisture and nutrient availability, soil compaction and disease and insect protection may be even more important in achieving uniform stands at physiological maturity with low plant-to-plant variability in ear size and maximum grain yield.
Plant within the Optimum Window
Timely planting of full-season hybrids allows the corn crop to take full advantage of the available growing season. Numerous studies have shown that corn yield potential declines as planting is delayed beyond the optimum planting window for a given geography (Coulter, 2012; Farnham, 2001; Myers and Wiebold, 2013; Nafziger, 2008).
Yield reduction with delayed planting
Results of DuPont Pioneer planting date studies conducted over 18 growing seasons show that yield was maximized when corn was planted within the 2-week period around the optimum planting date (Jeschke and Paszkiewicz, 2013). The optimum planting date was April 16 for the central Corn Belt and April 30 for the northern Corn Belt. Yield declined for planting dates following the optimum window and the rate of yield decline increased with delay duration. The yield penalty associated with delayed planting was greater in the northern Corn Belt where the growing season is shorter. Yield of corn planted 4 weeks following the optimum date was reduced by 7% in the central Corn Belt, compared to over 15% in the northern Corn Belt
Figure 1. Planting date effect on corn yield for the central and northern Corn Belt, based on DuPont Pioneer planting date studies conducted at 17 locations over 18 years. (Central Corn Belt locations in Neb., central Iowa, central Ill. and central Ind. Northern Corn Belt locations in northern Iowa, southern and central Minn., southwest S. D., central Mich. and southern Ontario.)
Factors that influence planting timing
The ability to get corn planted within the optimum planting window is largely driven by weather conditions during this time. The number of suitable days can vary greatly from year to year. For example, an analysis of USDA data by Irwin and Good (2014) showed that the number of days suitable for fieldwork in Illinois from 1970-2013 during the 3 weeks spanning April 30 to May 20 ranged from as many as 19 to as few as 4 across these years (Figure 2). On average, slightly over half (11.5) of the days in the 3-week period were suitable for field work.
Figure 2. Number of days suitable for fieldwork in Illinois during April 30 – May 20 from 1970 to 2013.
It is commonly believed that larger planters and improved technology have increased the pace at which the U.S. corn crop can be planted, although examinations of USDA planting data have shown this is not actually the case (Irwin and Good, 2011; Kucharik, 2006). Although larger planters have enabled a single operator to cover more acres in a day than was possible in the past, the total number of planters in use has declined as farm operations have consolidated. Planting data show that, in general, the U.S. corn crop is planted much earlier now than it was 30 years ago; however, the pace at which it is planted has not accelerated, and weather is the primary factor that determines planting progress. Since yield losses only occur on acres planted following the optimum window, typical farm-wide yield losses due to planting delays likely average no more than 2-5%.
Achieve the Correct Population
Unlike planting timing, which is often heavily influenced by weather conditions, plant population is a yield determining factor largely within the control of the grower. Determining and achieving the ideal population to maximize yield is complicated however, as the optimum population in a given situation can be influenced by a number of factors such as yield level, hybrid, and weather conditions.
In general, optimum populations for corn have steadily increased over time. Higher populations accompanied by improved stress tolerance in hybrids have contributed to incremental yield gains. Average corn seeding rates used by growers in the U.S. and Canada have increased from about 23,000 seeds/acre in 1985 to over 30,000 seeds/acre today or approximately 300 seeds/acre per year (Figure 3).
Figure 3. Average corn seeding rates reported by growers in North America, 1985 to 2013. Source: DuPont Pioneer Brand Concentration Survey 2013.
Factors that can influence optimum population
Yield Level: DuPont Pioneer and university studies have shown that corn hybrid response to plant population varies by yield level. The population required to maximize yield increases as yield level increases. When grouped by yield level, results from DuPont Pioneer plant population trials showed that the economic optimum seeding rate increased from approximately 27,000 seeds/acre at yield levels below 130 bu/acre to over 38,000 seeds/acre at yield levels above 250 bu/acre (Figure 4). An Iowa State University study comparing corn yield response to plant population across soils with different corn suitability ratings found similar results. The most productive soils tended to have a higher optimum population for maximum yield (Woli et al., 2014).
Figure 4. Corn yield response to population and optimum economic seeding rate by location yield level, 2006 to 2012.
Hybrid Maturity: Research has shown that early maturity hybrids (< 100 CRM) may require higher populations to maximize yield. Figure 5 shows the yield response of hybrids to plant population grouped by CRM range in DuPont Pioneer trials conducted from 2006-2012.
Figure 5. Yield response to plant population for corn hybrids from 5 maturity (CRM) ranges, 2006 to 2012.
Although this trend can still be detected when examining the response curves closely, it is a smaller difference than in the past. This change may be the result of different genetic backgrounds predominant in early maturities historically vs. currently, or other unknown factors.
Hybrid Genetics: Yield response to plant population can also vary based on hybrid genetics. Figure 6 shows an example of 2 hybrid families with the same CRM that have been shown to differ in their response to plant population in DuPont Pioneer research trials. 1 hybrid family (Pioneer® hybrid P1142) has a plant population response that is typical of current 111 CRM hybrids; whereas the other (Pioneer® hybrid P1151) tends to achieve maximum yield at higher plant populations. DuPont Pioneer offers growers an online planting rate calculator that provides recommendations based on a selected hybrid, grain price, seed cost, and yield level.5
Figure 6. Corn yield response to plant population of 2 hybrid families with similar comparative relative maturity.
Yield impact of high or low population
A plant population that is too high or too low can negatively impact yield. A low population may limit yield potential when growing conditions are favorable, while a high population may result in reduced performance and standability under stress conditions. In general however, modern hybrids tend to have a relatively wide margin of error when it comes to ideal population. For example, both of the hybrid families shown in Figure 6 could be as much as 4,000 plants/acre over or under the optimum population and still have less than 2 bu/acre variation in yield.
1 reason for this is the improvements in stress tolerance that have resulted from decades of targeted breeding. A common stress response of older corn hybrids was "barrenness," or the inability to produce an ear. Even as recently as 30 years ago, some of the best hybrids were prone to barrenness when population thresholds were exceeded. Modern corn hybrids are better able to produce an ear under moisture and density stress, even though ears are progressively smaller under increasing stress. This means that when plant density optimums are exceeded, yields tend to level off rather than drop abruptly. This hybrid characteristic has changed the risk/reward equation in the growers’ favor. Because the risk that excess populations will decrease yields under dry conditions is reduced, growers can more confidently plant higher populations that support increased yields when favorable conditions develop.
Achieve Uniform Plant Spacing
Growers instinctively prefer corn stands with uniform plant-to-plant spacing. A "picket-fence" stand is both aesthetically pleasing and presumably higher yielding.
How is plant spacing uniformity measured?
Seeding specialists and agronomists have long used 2-related statistics, coefficient of variation (CoV) and standard deviation (SD), as the preferred metrics to quantify meter performance and plant spacing uniformity. A SD value of 2.0 inches or the corresponding CoV value of 0.33 are widely cited as the thresholds above which, corn yield loss would be expected (Nielsen, 2001). The CoV is easily calculated by dividing the SD by the average plant spacing. For example, the SD corresponding to a CoV of 0.33 at an average spacing of 6.0 inches is 2.0 inches. More recently, engineers have also devised a "singulation" metric as an indicator of seed spacing uniformity, although there is no industry standard as to how it is calculated.
Spacing metrics poorly correlated to yield
Agronomists have long known that the various planting outcomes that result in increasing CoV and SD, and declining singulation values can have widely different impacts on resulting individual-plant grain yield (Nafziger, 1996; Doerge et al., 2002 and Nafziger, 2006). Thus, the use of easy-to-measure plant spacing metrics that are poorly correlated with individual plant yields has unfortunately created a tradeoff between convenience and accuracy. This has no doubt contributed to inconsistent results in past research seeking to explain the impact of within-row plant spacing on corn grain yield (Krall, 1977; Nafziger, 1996; Nielsen, 2001; Doerge and Hall, 2000; Doerge et al., 2002; Lauer and Rankin, 2004; Liu et al., 2004a, 2004b, 2004c; Nielsen, 2006).
Individual plant yield determinations provide new insights.
Individual plant yield determinations provide new insights
A 2002 DuPont Pioneer study (Doerge et al.) uniquely allows for quantifying the impacts of common and realistic non-ideal planting outcomes on grain yield. This study was conducted in 4 different environments (2 in Iowa, 1 in Missouri and 1 in Minnesota), across a wide yield range of 109 to 206 bu/acre, and using hybrids with 3 very different genetic pedigrees. In this study, within-row spacing measurements and grain yields were determined on >6,000 individual plants.
|1)||As expected, differences in grain yields resulting from common non-ideal planting outcomes were indeed observed and are listed in Table 1.|
|2)||These non-ideal planting outcomes typically, but not always, resulted in lower grain yield. The notable exception is that a double slightly increased yield. But yield losses for all other planting outcomes varied over a rather wide range, from zero to -0.26 lbs. grain for the 2- or 3-plant groupings depicted in Table 1.|
|3)||By far, a skip is the planting outcome that contributes the most to yield loss. Plants adjacent to a skip only partially compensate for the missing plant.|
|4)||In general, yield loss due to misplaced plants is negligible if plants are displaced from their preferred location by no more than ½ of the normal plant-to-plant distance.|
Table 1. Corn grain yields resulting from various planting outcomes. Yield impacts are averaged across 4 study locations.
- The CoV and singulation readings on the planter monitor are valuable real-time indicators of meter performance but poor predictors of the agronomic consequences of common, realistic non-ideal planting outcomes.
- The planting outcome causing the greatest yield loss is % skips. A skip is defined as an in-trench distance between seeds of ≥1.75 times the desired plant-to-plant distance (for example, at 34,848 plants/acre in 30-inch rows, the average distance between seeds or plants would be 6.0 inches, and a skip would therefore be a plant-to-plant distance of ≥1.75 x 6.0, or 10.5 inches).
- Not all skips are caused by the planter. Missing plants resulting from unsuccessful germination or emergence will reduce grain yield just as much as planter skips and are to be equally avoided. Emerged plant spacing, along with population, gives the best prediction of yield performance.
- Occasional doubles do not negatively impact yield. A true planter double, or 2 seeds held in 1 cell of the planter meter, is not necessarily a bad thing. First of all, there is at least enough increase in yield from a double to offset the cost of the extra seed that is being planted. And if having an occasional double (i.e. 1-2%) helps ensure fewer or no skips, then such an outcome would be preferred. This would be the case if adjusting the planter vacuum setting upward could reduce the occurrence of empty cells, even if the higher vacuum setting increases doubles slightly.
Past inconsistent research results explained
There are several explanations for the lack of agreement in the results from past plant spacing studies, which were all conducted by highly-qualified researchers. First of all, different planting outcomes that contribute to SD, CoV or singulation can have completely different effects on individual plant yield (Table 2). Skips are highly detrimental to yield, doubles can be slightly positive, and misplaced plants have no effect on yield until plants are displaced from their preferred location by more than 1/2 the normal plant-to-plant distance. Second, no 2 fields can be expected to have the same amount or combination of non-ideal planting outcomes. Thus, it is no wonder that comparisons from aggregated, plot- or field-wide plant spacing studies are contradictory if the sources of plant spacing non-uniformity are not considered. Unfortunately, this lack of consideration has been true of most plant spacing studies.
Table 2. The contribution of 5 common non-ideal planting outcomes to 2 statistics used to describe seed and plant spacing uniformity, including Coefficient of Variation and Standard Deviation.
Loss or Gain
|1% Seed Misplaced by 1/4||0.04||0.28||0|
|1% Seed Misplaced by 1/2||0.07||0.55||0|
|1% Seed Misplaced by 3/4||0.11||0.83||-0.2|
*Compared to perfect plant spacing.
Plant Population assumed - 34,848/acre or mean spacing - 6.0 in.
Other sources of confounding include the manner in which some field experiments have been conducted. For example, some studies have used highly artificial groupings of plants to achieve predetermined levels of plant spacing variability. In addition to being unrepresentative of "real-world" conditions, they often employ only different levels of misplaced plants (no skips or doubles) to achieve the desired spacing treatments. Table 1 and Table 2 indicate that these types of plant arrangements will have little to no impact on yield. Other plant spacing studies may have been compromised by the use of overplanting and thinning to achieve the desired plant spacing arrangements and populations. These practices are potentially confounding because corn plants can sense the presence of neighboring plants beginning very shortly after emergence due to subtle differences in the ratios of red: far red light they receive (Liu et al., 2009). These light quality differences can act as an early signal of pending competition that can initiate a shade avoidance response in the remaining plants. Thus overplanting and thinning can unintentionally result in plants that have been preconditioned to exhibit less favorable crop architecture and lower grain yield potential.
In contrast, when individual plant yields arising from different planting outcomes are considered, research results have been amazingly consistent. For example, Nafziger (1996) found that 10% skips in 4 Illinois experiments resulted in an average 8.1% decrease in yield (at 30,000 plants/acre) while the findings from the DuPont Pioneer study (Doerge et al., 2002) measured a corresponding 8.9% yield decrease (at a similar plant population). Likewise, the Illinois studies measured a yield increase of 4.2% for 10% doubles while the Pioneer data revealed a 4.7% yield increase. These similarities are notable since the genetics used in these two sets of experiments were released at least a decade apart.
Clearly, the key messages on within-row plant spacing uniformity are:
- it does impact grain yield and can be explained
- whole-field impacts on grain yield are usually relatively small, averaging about 1 to 2%
- growers should work to minimize or eliminate skips and not worry about occasional doubles or slightly misplaced plants
Coulter, J. 2012. Planting Date Considerations for Corn. Minnesota Crop News. Univ. Of Minnesota Extension.
Doerge, T.A., Hall, T. and Gardner, D. 2002. New research confirms benefits of improved plant spacing. Crop Insights, Vol. 12, No. 2. DuPont Pioneer.
Doerge, T.A. and Hall, T. 2000. The value of planter calibration using the MeterMax™ system. Crop Insights, Vol. 10, No. 23. DuPont Pioneer.
Farnham, D. 2001. Corn Planting Guide. Iowa State Univ. Extension. PM 1885.
Ford, J.H. and D.R. Hicks. 1992. Corn growth and yield in uneven emerging stands. J. of Production Agriculture, 5:185-188.
Irwin, S. and D. Good. 2011. Late Corn Planting and Planting Speed. FarmDoc Daily. Univ. of Illinois.
Irwin, S. and D. Good. 2014. Prospects for Timely Planting of the 2014 Corn Crop. FarmDoc Daily. Univ. of Illinois.
Jeschke, M. and S. Paszkiewicz. 2013. Hybrid Maturity Switches Based on Long-Term Research. Crop Insights. Vol 23, No. 5. DuPont Pioneer.
Kovács, P. and T.J. Vyn. 2014. Full-season retrospectives on causes of plant-to-plant variability in maize grain yield response to nitrogen and tillage. Agron. J. 106:1746-1757.
Krall, J.M., Esechie, H.A., Raney, R.J., Clark, S., and Vanderlip, R.L. 1977. Influence of within-row variability in plant spacing on corn grain yield. Agron. J. 69:797-799.
Kucharik, C.J. 2006. A multidecadal trend of earlier corn planting in the Central USA. Agron. J. 98:1544-1550.
Lauer, J. and Rankin, M. 2004. Corn response to within row plant spacing variation. Agron. J. 96:1464-1468.
Liu, J.G., Mahoney, K.J., Sikkema, P.H. and Swanton, C.J. 2009. The importance of light quality in crop-weed competition. Weed Research, 49:217-224.
Liu, W., Tollenaar, M., Stewart, G. and Deen, W. 2004a. Impact of planter type, planting speed and tillage on stand uniformity and yield of corn. Agron. J. 96:1668-1672.
Liu, W., Tollenaar, M., Stewart, G. and Deen, W. 2004b. Within-row plant spacing variability does not affect corn yield. Agron. J. 96:275-280.
Liu, W., Tollenaar, M., Stewart, G. and Deen, W. 2004c. Response of corn grain yield to spatial and temporal variability in emergence. Crop Sci. 44:847-854.
Maddonni, G.A. and Otegui, M.E., 2004. Intra-specific competition in maize: early establishment of hierarchies among plants affects final kernel set. Field Crops Res. Vol. 85:1-13.
Murua, M. 2002. Polymer seed coating effects on feasibility of early planting in corn. Master of Science thesis, Purdue Univ.
Myers, B. and W.J. Wiebold. 2013. Planting Date 2013. Integrated Pest & Crop Management. Univ. of Missouri.
Nafziger, E.D., P.R. Carter, and E.E. Graham. 1991. Response of corn to uneven emergence. Crop Sci. 31:811-815.
Nafziger, E.D. 1996. Effects of missing and two-plant hills on corn grain yield. J. Prod. Agric., 9:238-240.
Nafziger, E.D. 2006. Inter- and intraplant competition in corn. Plant Management Network. Online. Crop Management doi:10:.1094/CM-2006-0227-05-RV.
Nafziger, E. 2008. Thinking About Corn Planting Date and Population. The Bulletin. Univ. of Illinois Extension.
Nielsen, D.L. 2001. Stand establishment variability in corn. Dept. of Agronomy publication AGRY-91-01., Purdue Univ.
Nielsen, D.L. 2006. Effect of plant spacing variability on corn grain yield. 2005 Research Update. Purdue Univ.
Nishikawa, H. and Kudo, M. 1973. Explanation of the appearance of a sterile ear on mechanically cultivated corn (zea mays, L.). Res. Report Tohoku Agric. Expt. Stn. 51-95.
Pagano, E. , Cela, S., Maddonni, G.A., and Otegui, M.E., 2007. Intra-specific competition in maize: Ear development, flowering dynamics and kernel set of early-established plant hierarchies. Field Crops Res. Vol. 102:198-209.
Woli, K.P., C.L. Burras, L.J. Abendroth, and R.W. Elmore. 2014. Optimizing corn seeding rates using a field's corn suitability rating. Agron. J. 106:1523-1532.
1 Corporate Agronomist, Deere and Co.
2 Agronomy Research Manager, DuPont Pioneer
3 Senior Agronomy Sciences Manager, DuPont Pioneer
|Preseason Planter Checklist | Top 10 Preseason Planter Tips|
Preseason Planter Checklist
By Steve Zobrist, Area Agronomist and Jeff Daniels, Seed Technology Manager
From planter singulation to seed furrow creation, use this preseason planter maintenance checklist to help prevent common seeding problems that result from improper setup, maintenance and operation.
|Left (Photo Above)
No-Till Coulters too deep
|Right (Photo Above)
Level your units in the field
|Keeton Seed Firmer down pressure lightened||Must be done in motion.
Have someone help you watch your row unit
|Closing wheel down-pressure lightened||Front of seed box should be 1/2” higher
than back of insecticide box
Correct Toolbar Height
Level Bar Across Entire Planter
Stop and think how much weight is added to the center frame of this planter. Two 50-bushel seed tanks plus a 500-gallon fertilizer tank all riding on the center. Four tires pushing the center of the planter farther down into the tilled soil than the wings.
Seed Transmission Systems
How much vibration do you have in your drive system?Check the following:
Note: Transmissions need to run smoothly. Any vibration in the drive system will end up at the meters and can cause spacing issues. Sprockets, chains, bearings, meter drives and insecticide drives all need to be checked.
Check Shaft Alignment
Shafts must be aligned. If they are misaligned some row units may plant heavier or lighter populations than the main section of the planter.
Seed Furrow Creation
|If using no-till coulters they need to be 1/4" above the openers.
Set deep enough to remove trash and not throw soil. In some cases floating cleaners may help.
Floating vs. Fixed
Floating row cleaners follow contours and are less likely to "trench" or "hover."
JD Opening Disks
Disc Contact Adjustment
Firming point, shown in red circle, should be replaced when opener disks are replaced. The firmer is designed to run in the bottom of the seed trench.
Seed Tubes and Firmers
Bullseye Tube with additional wear allowances (left) Standard Tube (right).
Vibration or bounce of the row unit can cause tumbling and poor seed spacing.
Keeton Seed Firmers
Seed firmers are designed to push the seed to the bottom of the trench. In wet conditions, soil can build up on the firmers and actually move the seed along the trench.
Seed firmers help eliminate a gap between the seed and the bottom of the seed trench, helping create good seed-to-soil contact and uniform depth within the seed trench.
Gauge wheels should slightly rub on the disk openers to help create a good seed trench sidewall and keep the openers clean.
Too much down force creates sidewall compaction.
Gauge wheels should take effort to spin by hand.
In tougher wet soils, spike closing wheels may help prevent sidewall compaction.
Finger Pickup Checklist
- Check finger pickups for wear
- Replace worn knock-off brushes
- Replace worn finger pickups and check finger tension
- Replace worn or grooved faceplates
- Replace seed conveyers with missing ladders
- Use graphite for lubrication
Vacuum Systems - Theories of Operation
Check all types of vacuum systems for air leaks and worn seals around the metering units.
Cell Disk - John Deere Cell Disk
- Seed size sensitive
- Lower vacuum
Flat Disk - Precision Planting eSet
- Seed size independent
- Should have doubles eliminator
- Higher vacuum
Flat disks are more forgiving of different seed sizes than cell disks. Note the different sizes of seed in the cell disk.
Doubles eliminators are used with flat disks. Shown are the Precision, Case and Deere singulators.
Central Fill Systems
Seed Bridging in Seed Tank
Seed Plugging in Seed Hose
Seed Lubricants Reduce Problems
Proper use of talc and graphite may eliminate a lot of potential problems. Use rate may need to increase for large treated seed and when temperature and humidity are high.
Talc and Graphite
- Talc removes static
- Graphite lubricates
Find use rates at Seed Corn Plantability Guide.
Increase use rates for heavily treated seed or when temperature and humidity are high.
Refer to the individual planter manufacturer's manual for complete recommendations.
Top 10 Preseason Planter Tips
Go through this quick checklist before you start planting this spring.
- Level the Planter. Check the hitch height. The tractor hitch height may vary due to the tractor tire size, tractor manufacturer, and the type of planter (Draw bar vs. 2 pt hitch). Refer to the planter operator's manual for set up. Make sure the planter's tool bar is level (vertically) or running slightly up hill. When planters tip down, coulters run too deep and closing wheels run too shallow.
Check Bushings and Parallel Linkage. Worn bushings increase row bounce which increases seed bounce. Stand behind the row unit and wiggle it up and down and back and forth checking to make sure bushings are tight.
- Drive System. Check every chain. Kinked chains cause shock and vibration in the meter. Start with fresh, lubricated chains and check them daily. Include transmission chains, meter drive chains and insecticide box chains.
- Calibrate Corn Meters. Calibrated meters can help add six or more bushels per acre. On finger units check brushes, fingers, springs, back plates and seed belts for wear. On air or vacuum planters check brushes, gaskets and disks or drums for cracks or wear. Replace all worn parts. A good cleaning will also help improve performance. It is recommended having finger units set on a MeterMax¹ planter stand.
Double Disk Openers and Depth Wheels. Test to make sure there is good contact between the double disks. Slide a business card from the top down along the front of the disks until the card won't lower any further. Mark that spot with chalk. Then, take the card from the back and slide it forward until it stops. Mark that spot and measure the distance between the two marks. If it is less than two inches, reship or replace the disks. In general, the disks must be replaced when they loose 1/2 inches in diameter.
Depth wheels - check rubber tires for cracks and wear. Wheels should run tight against double disk openers to ensure seed furrow does not collapse. Reduced inner diameter gauge wheels help to reduce sidewall compaction in wetter conditions such as reduced or no-till.
Brand of Planter New Disk Diameter Replace Disk if Less Than: Case/IH 400 13 ½ inches 13 inches Case/IH 800, 900 & 1200 14 inches 13 ½ inches JD 7000, 7100, 7200,
7300, 1700 & ProSeries Units
15 inches 14 ½ inches White 5100 13 ½ inches 13 inches White 6000 15 inches 14 ½ inches
- Seed Tubes. Inspect seed tubes for wear at the bottom. If the tubes have a small dog ear flap on the left side of the seed tube, replace them.
- Closing Wheel System. Consider an alternative to rubber closing wheels. For cool, moist planting conditions, take a look at running one spike wheel (15 inches) and one rubber wheel (13 inches). The spike wheel can help chop the sidewall improving fracturing and sealing in the tough soil conditions. For no-till, an even more aggressive approach may improve trench closing. Two 13" spike wheels with a drag chain provide the most aggressive action.
- Closing Wheel Alignment. With your planter sitting on concrete, pull ahead about 5 feet. Look at the mark left behind the planter by the double disk openers. The mark should run right down the centerline between closing wheels. If a closing wheel is running too close to the mark, adjust the closing wheels to bring it back to center.
- Row Cleaners. With higher levels of residue and more corn-on-corn, almost any planter can benefit from well adjusted row cleaners. Row cleaners sweep residue from the row, warming the soil around the seed trench, reducing wicking and seedling blight. Make sure row cleaners gently sweep residue - you don't want to move soil, just residue. Watch the row cleaners running. They shouldn't turn constantly. They should gently turn sporadically, especially through areas of thick residue.
- Get Organized. Have your Crop Field Plans by hybrid/variety and populations organized; seed ready, planter monitors working/programmed and tractors/tenders in tune.
¹® MeterMax is a registered trademark of Precision Planting, Inc.
Field Facts written by Jim Boersma, DuPont Pioneer Product Agronomist
Seedbed preparation sets the stage for optimal growth and development throughout the growing season and ultimately has a major impact on yield potential. This fact sheet reviews management decisions regarding when to begin seedbed preparation and how to minimize compaction.
Determining When Soils Are Fit
The following soil test is a quick method to help gauge if soil is ready for spring tillage and seedbed preparation.
Take your trowel and dig down 2 to 4 inches into the seedbed. Grasp a handful of soil from the trowel and squeeze it. Soils are too wet for spring tillage if any of the following are true:
- Does it feel tacky?
- Can you make a ball that sticks together?
- Does it form a ribbon when squeezed between your thumb and forefinger (as shown below)?
Ribbon indicates soil is still too wet for field work.
If soil crumbles when pressed, soil is suitable for field work.
Soil should be dry enough in the top 4 inches that it cannot be formed into a ribbon with normal compression in your hand. Soils in proper condition for seedbed preparation should crumble between your fingers. Soils that crumble easily are ready for spring tillage operations, creating favorable tilth for early growth while minimizing soil compaction.
Improving Seedbeds for Optimum Yield Potential
- Evaluate every field for soil moisture conditions. Use the simple “ribbon” test to determine soil conditions and fitness for seedbed preparation.
- Reduce compaction with proper tire inflation and counter weights for spring tillage and planting equipment.
- Under dry conditions the use of a packer/roller may help improve seed-to-soil contact and germination.
- Select hybrids with above average stress emergence scores for earliest planting dates.
- Wait until soils reach a minimum of 50 degrees at the 2-inch depth prior to starting planting.
Soil moisture conditions can change between the time the seedbed is prepared and planting begins in the field. If soils become wet, be patient and allow them to dry out. Try to work fields as close to planting operations as possible. Planting into wetter soils, or working soils too wet will cause sidewall compaction from the disk openers. This type of compaction is frequently the cause of uneven emergence. In addition, this compacted soil creates a compaction barrier that corn and soybean root systems will have difficulty penetrating. This can reduce moisture and nutrient uptake and yield potential.
Wet soils at planting can lead to smearing of the seed furrow sidewall by the disk openers. This can lead to uneven emergence and restricted root growth.
Wet soils at planting can lead to a compaction barrier that restricts root growth and yield potential.
Proper Tire Pressure
Compaction in the top 6 to 8 inches is related to soil moisture conditions, inflation pressure (psi) and the total axle load of the equipment. One thing that can help prevent soil compaction is ensuring that your equipment has proper tire pressure and counter balance weight. Wet soils at planting can lead to smearing of the seed furrow sidewall by the disk openers. This can lead to uneven emergence and restricted root growth.
Wet soils at planting can lead to smearing of the seed furrow sidewall by the disk openers. This can lead to uneven emergence and restricted root growth.
Most new 4-wheel-drive tractors are equipped with radial tires that should be inflated to 8 to 10 psi. A properly inflated radial tire will have a wider base and will have a noticeable "cheek"; showing in comparison to older bias-belted tires, which were typically inflated to pressures of 20 to 25 psi. It is not uncommon for radial tires to be overinflated to 20 to 25 psi because of previous experience with older bias-belted tires and the fact that a grower may not be accustomed to the look of a properly inflated radial tire. Properly inflating tires will not only significantly improve the ride in the tractor and improve fuel efficiency and pulling power, but will also help prevent compaction. For example, a tractor equipped with 18.4 R42 tires carrying an axle weight of 3,200 lbs would have a footprint area of 272 sq. inches when properly inflated at 8 psi. However, the same tire with an identical axle load would have a footprint area of only 125 sq. inches when inflated to 24 psi. Proper tire inflation more than doubles the footprint of the tire, spreading the load of the tractor across a much larger surface, thereby reducing compaction.
Consider these tips when getting your tractor ready for spring operations:
- Check tire pressure and inflate your tires based on the manufacturer's recommendations. Radial ply tires should be inflated to 8 to 10 psi.
- Always check the inflation pressure early in the morning before you go to the field. For optimum performance check and maintain tire inflation pressures at least once every 2 weeks.
- Use only low pressure gauges to check for inflation to obtain accurate readings.
- Properly inflated (low pressure) radial ply tires will also help reduce power hop problems in most cases.
- Remember that bias ply tires require higher inflation pressures than similarly-sized radial ply tires. Serious tire damage can occur from sidewall buckling if under-inflated.
- Proper ballasting is necessary to obtain optimum performance from your tractor. The amount of ballast and the proper split in weight between the front and rear axle will depend on the type of tractor, the type of implement and soil conditions. Contact your dealer for specific information for your equipment.
Use of Packers to Firm Seedbeds
Adequate seed-to-soil contact is critical for proper germination and nutrient uptake. Under dry conditions, the use of a packer may help firm seedbeds and improve stand establishment. The use of packers under dry conditions has also been observed to aid root interception and uptake of nutrients such as zinc and potassium. However, the use of a packer in wetter conditions can increase bulk density of the soil and reduce soil tilth. The decision to use a packer should be made on a field-by-field basis as current conditions require.
In areas of Minnesota with severe iron deficiency chlorosis, some growers are experimenting with the use of rollers to firm seedbeds. This management technique is in response to the observation that iron chlorosis is often reduced or eliminated in wheel tracks. University of Minnesota Soil Extension Scientist George Rehm has reported significantly lower soil nitrate nitrogen levels in wheel track areas that are green compared to chlorotic areas of the same field. This may lower nitrate levels in legumes growing in the wheel tracks. It is speculated that higher nitrate levels in legumes can block the normal uptake of iron, resulting in chlorosis.
More research is needed to fully understand the impact of nitrate on iron deficiency chlorosis in soybeans and possible management strategies, including the use of packers. For the present, the best management strategy is to select a variety with adequate tolerance to the level of severity of iron deficiency chlorosis for your soil types.
Soil Compaction: What Can You Do? U. of Minn. Extension.
Let the Air Out – Advantages of Properly Adjusted Radial Tire Pressures. Ohio State University Extension.
Tractor Tire and Ballast Management. University of Missouri.
Photos courtesy of Jim Boersma.
Minimize Soil Compaction
Field Facts written by DuPont Pioneer Agronomy Sciences
Soil compaction causes yield loss in crop production by restricting root growth and by reducing air and water movement in the soil. Soil compaction is caused by soil particles being pressed together by mechanical or natural forces. An ideal soil structure consists of 50% soil, 25% water space and 25% air space.
Impact of Soil Compaction
The end result of soil compaction is less yield potential from crop production. Yield loss can vary widely depending on the extent of the compaction of the soil and environmental conditions in which the affected crop is grown in. Favorable growing conditions, such as timely precipitation and high soil fertility can minimize compaction effects. Severe compaction can cause up to 60% yield loss, however, it is estimated that compaction on average reduces yield potential in the 10 - 20% range.
Soils that are above field capacity in moisture have the greatest potential for compaction. Water acts as a lubricant between soil particles that allows soil to be pushed together. As more air space is replaced with water, the potential for compaction increases. There is a point however, when most air space is filled with water (near saturation) that compaction potential of a soil decreases. Therefore, a very wet soil has less compaction potential than a moderately moist soil.
Soil texture (% of sand, silt and clay in a soil) has, to some degree, an effect on compaction. Soils that consist of particles of equal size have less compactive potential than soils that have particles of varying sizes. Smaller particles can fill spaces between larger particles, thereby increasing soil density. A sandy loam soil is the most susceptible to compaction, while pure sands, clays, and silt soils are least.
Soil structure also plays a role in compaction potential. Soil structure is defined as how well a soil breaks up into small, cohesive clumps. Organic matter improves soil structure by creating soil aggregates (easily crumbled soils). Soils higher in organic matter generally have better soil structure and resist compaction better than low organic matter soils.
Types of Soil Compaction
Surface crusting is a form of soil compaction that reduces seed emergence and water infiltration rates. It is caused by the impact raindrops on surface soil particles. Heavy impact causes soil particles to sift together. Rapid soil drying increases potential of surface crusting. Soils with higher organic matter or high in sand content have less potential for crusts to form.
Sidewall compaction is caused by planting into wet soils. The action of the planting disc openers shearing into wet soils can cause seed furrow sidewalls to become hard after planting. The result can be poor crop emergence and poor root development out of seed slice.
Shallow compaction occurs from the surface down to the normal tillage zone. This type of compaction is normally caused by light wheel traffic or animal traffic. Shallow compaction is usually temporary and can be eliminated by normal tillage.
Tillage pan is subsoil compaction only a few inches thick right beneath the normal tillage zone. This type of compaction is caused by types of tillage implements that shear the soil, such as discs, moldboard plows and sweep type tools.
Deep compaction lies beneath the tillage zone and is caused by maximum axle weight load to the soil. Harvest equipment such as grain carts and combines have high axle loads, and most often are the biggest contributors to deep compaction. Deep compaction is the most difficult to eliminate, so prevention is important.
Symptoms and Detection of Soil Compaction
Since soil compaction affects root growth, above ground symptoms can take on many forms. Signs of compaction may include:
- Visible wheel track patterns across field.
- Malformed root growth, including stubby, flat, thin, or twisted roots. Roots growing into a tillage pan can grow horizontal rather than vertical and will have flat, shallow root system.
- Stunted plant growth. Above ground growth is directly related to below ground root growth. If root growth is being impaired, vegetative growth above ground will likely be stunted. Look for specific patterns or areas in field, such as wheel track patterns. In some cases, a specific pattern is not visible. Many times these areas are a result of repeated overlapping of the same areas with different tillage passes that, over time, have an additive affect on areas within the field
- Nutrient stresses on crops can be another sign of compaction. Since roots are the avenues of soil nutrients to the crop, root restrictions can decrease root interception of nutrients in the soil. Phosphorous, potassium and nitrogen deficiencies can be secondary symptoms to soil compaction.
- Standing water or excessive water erosion can be caused by soil compaction. Compaction reduces pore space within soil so water is not absorbed into soils as readily.
- Wilting of plants in certain areas of a field can signal compaction. This can result from shallow root systems preventing the crop from uptake of subsoil moisture.
- Increased power requirements for field operations can be a sign of compaction as well. If field tillage operations encounter certain areas in a field where the tractor "pulls down" and soil is uniform across area, this can signal a compaction area.
Once compaction is suspected, the next step is to verify and isolate compaction areas. Sidewall, surface crusting, and tillage pan compaction are the easiest forms to detect with a shovel or other type of digging device. Deep soil compaction is harder to find since it occurs deeper in the soil.
Cone tipped penetrometers can be used to locate compaction. These have limitations however. Penetration resistance is a function of soil density and moisture content. Compacted and non-compacted soils of equal moisture and texture need to be compared. Therefore, there is no specific numerical value of resistance (psi) that identifies compaction. Comparative values need to be evaluated. Constant rates of push also must be maintained to give accurate readings. Motor drive penetrometers, which penetrate the soil at a fixed rate, give the most accurate readings.
Soil probes are another useful tool. These are also subject to moisture content and soil density. A drier soil will probe harder than a wet soil; clays will probe harder than loam soils for instance. Soil probes can be used effectively to monitor differences in the soil moisture profile. If the top foot of soil is extremely dry, but second foot is very moist, this suggests that crop's roots are not penetrating into the second foot, possibly because of compaction.
The best indicator of compaction is viewing root growth patterns into the soil profile. This is accomplished by using a spade or shovel to dig holes or trenches alongside the existing crop. Holes should be dug alongside the existing crop in suspected compaction areas.
Examining below ground root growth and soil characteristics will tell if compaction exists.
Minimizing Soil Compaction
The best strategy to minimize compaction is to avoid working wet soils, especially in the spring. Elimination of all soil compaction is nearly impossible however. Here are some tips to reduce compaction when forced onto wetter soils.
- Control wheel traffic. Research shows that 80% of wheel traffic compaction occurs on the first pass, so try to limit the number of trips across field and use the same traffic pattern whenever possible.
- Increase surface area of tire to soil contact by using duals, larger diameter tires, radial tires, or decreasing tire inflation. This may increase potential for surface compaction, but will reduce deep soil compaction, which is the hardest form to deal with.
- Alter tillage depths to avoid additive tillage pan effects.
- Avoid excessive tillage. Tilled soils are more easily compacted than non-tilled soils.
Soil Compaction Remedies
- Freeze/thaw and wet/dry cycles are good natural remedies to alleviate compaction.
- When subsoiling (deep ripping tillage) is used, first identify the depth of compaction and subsoil an inch or 2 below affected area. Be sure soil is dry enough - subsoiling when the field has soil moisture at field capacity or above may create more compaction rather than eliminate it. Be careful not to re-compact soil. Ohio research indicates that only 2 traffic passes can quickly compact soil to the level it once was.
- Use deep rooted perennials, such as alfalfa to alleviate deep compaction. Root channels are excellent ways of loosening soil.
- Compensate for decreased nutrient and water availability due to compaction by using row applications of fertilizers to improve nutrient availability. Increase irrigation frequencies to compensate for decreased root availability to the moisture profile.
|Seed Treatments & Seed Lubricants | Optimizing Planter Performance|
Seed Treatments & Seed Lubricants
Excellent planting accuracy and stands can be achieved using all seed sizes with appropriate planter adjustments and calibration. These plantability guidelines are designed to provide management tips that will help growers achieve maximum planter performance and precise planting accuracy with seed of all sizes.
For the most precise recommendations, you can directly access information for individual seed batch numbers and your specific planter type with the Pioneer plantability tool.
A Pioneer plantability app easily scans a seed tag to indicate the planter type, maximizing planter performance and seed-drop accuracy.
The Pioneer plantability app allows users to scan the seed bag tag and select the planter make. The app then generates a customized grid with the suggested plate or disc size, pressure or vacuum setting speed, and the singular setting, in addition to the predicted seed drop for each individual batch and planter combination. This tool is available for iPad®, iPhone® and Android™ devices currently. To download, go to the Apple Store or Google Play on your device.
PPST 250 is the standard treatment for Pioneer® brand seed corn, providing protection against earlyseason fungal diseases and insects. The new seed treatment PPST 250 plus DuPont™ Lumivia™ insecticide seed treatment is available on most newly-advanced hybrids for 2016. Results of internal trials has shown this new treatment to have similar plantability performance to the standard PPST 250 treatment.
Also available is Poncho1250®/VOTiVO® insecticide for enhanced insect control as well as protection against nematodes. Raxil® fungicide is provided on selected hybrids for additional disease protection in certain geographies. All Pioneer Premium Seed Treatments utilize polymer coatings for improved seed flow and plantability while reducing dustoff. Many planter manufacturers recommend adding talc or graphite to the seed to improve plantability. The polymers used as part of seed treatments by Pioneer are not intended as a substitute.
Fluency Agent from Bayer CropScience is available as an alternative for talc, graphite and talc/graphite blended planter seed lubricants. Fluency Agent helps reduce the amount of total dust and further minimizes the amount of active ingredient potentially released in treated seed dust during planting. Add Fluency Agent at the rate of 1/8 cup per 80,000-kernel unit of seed or 4 3/8 cups per 35 bushels. IMPORTANT: Mix the Fluency Agent thoroughly into the seed. When filling large central fill seed hoppers, add the Fluency Agent to seed as it is filling the hopper to assure even distribution. DO NOT USE MORE THAN 1/8 CUP PER SEED UNIT! Fluency Agent can be used in all makes and types of planting equipment that recommend the use of a planter seed lubricant.
Delivery of seed from center-fill hopper to meter may be impacted by several factors. These include planting time, atmospheric environment, use of planter lubricant, ground speed, level of treatment, and seed size. The liberal use of talc, graphite, or a talc-graphite blend, specific by planter type, is critical. Thorough mixing of these lubricants in seed generally produces the best results. High population settings, combined with high ground speed may create challenges. If meters are “starving” for seed, reduced ground speed may provide a solution. The proper fan speed or pressure in the bulk delivery system is an adjustment that can be made to enhance seed delivery. This varies by planter manufacturer. Consult the planter operator’s manual for proper setting. Larger seed, especially with high-rate treatment, can be delivered to the meter and planted accurately if consideration is given to the points above.
*Refer to individual planter manufacturer owners manual for complete recommendations.
Kinze and John Deere Finger-Type Planters
When planting treated seed, use your planter manufacturer’s recommended amounts of dry powdered graphite. To ensure good seed coverage, add graphite at several levels as the hopper is filled, rather than only on the top.
John Deere vacuum-type including ProMAX40 flat disk – Talc lubricant is required for optimum performance of the vacuum meter and CCS system (if equipped). Add talc at the rate of 2.5 ounces per 80,000-kernel unit of seed or 11 cups per 35 bushels or 16 cups per 50-bushel fill. Adjust these rates as necessary so all seeds become coated with talc, while avoiding an accumulation of talc in the bottom or tank or hopper. Double the talc recommendation when planting small seed, large seed, seeds with heavy treatment, or in humid planting conditions. If seed treatment is building up on the disc, use additional talc. Add talc throughout the box while filling, not just on top.
Precision Planting eSet® disk – Use 1/4 cup of the company’s eFlow seed lubricant (or an 80% talc/20% graphite mix) per 80,000-kernel bag. Heavily treated seed may require a higher rate.
Kinze EdgeVac® vacuum planter – Manufacturer recommends mixing 1 tablespoon of powdered graphite into each hopper-fill of seed. Mix thoroughly so all kernels are coated. Adjust graphite rate as needed. Planting in high humidity conditions may require use of talc as a drying agent.
Kinze Air Seed Delivery (ASD) system – Powdered graphite should be added with the seed each time the bulk seed hopper is filled. Use 1½ - 2 pounds per 50 units of seed. Graphite should be added in layers as the bulk seed hoppers are filled. Use of powdered graphite will prolong the life of the seed meter components, reduce buildup of seed treatment on components in the meter and improve seed spacing.
White – Manufacturer recommends mixing 1/2 cup of talc per two-bushel hopper fill, or 1 cup of talc per three-bushel hopper fill. Seed treatments may also affect seed monitor performance and require periodic cleaning of the seed disc.
Case IH vacuum Advanced Seed Meter (ASM) – Graphite is recommended for lubrication. Talc is not recommended as a sole lubricant for the Advanced Seed Meter, though it may be added to graphite to improve flow in bulk delivery of seed.
- On-Row Hopper: Case IH recommends 1/8 cup of graphite per rowunit hopper.
- Bulk Fill System: Case IH recommends 1/8 cup of graphite per two units of seed as a starting point for most seed sizes and treatments. Some seed sizes and treatments may require additional lubrication to flow into the delivery system in high humidity conditions. In such situations, a 50-50 blend of talc and graphite is acceptable within the system.
Optimizing Planter Performance
Planter and meter maintenance are critical to seed singulation, spacing accuracy and planting the targeted population. Even spacing reduces competition between plants and maximizes ear count. Extensive research conducted by Pioneer has consistently shown that with other variables remaining constant, improved plant spacing produces a yield increase. It is recommended that meters be inspected and maintained prior to season to allow for optimal performance. Several opportunities exist for professional assistance with meter maintenance and calibration, including assistance from your Pioneer sales professional.
- The manufacturer’s recommended maximum operating speed is 38 disk RPMs.
- This planter uses vacuum rather than air pressure to hold the seed against the disks.
- 3 disks are available: regular, small, and ProMAX40. The standard corn disk (A50617) will accurately plant seed sizes up to approximately 2,000 seeds per pound. The small disk (A43215) is designed for small seed – usually greater than 2,000 seeds per pound. The ProMAX40 disk (A52391) is designed to plant all seed sizes.
- The ProMax disk may under-populate if vacuum is too low. Set at higher vacuum levels, the ProMax disk is much more tolerant because the doubles eliminator prevents over-population.
- Vacuum levels taken from charts are a starting point. However, high-rate seed treatment, uneven ground conditions and/or faster ground speeds require higher levels of vacuum than indicated. Perform a field check and adjust level to obtain proper population.
- John Deere also recommends adding talc to improve seed singulation and row spacing of all treated seed.
|Recommended Vacuum Setting for John Deere - ProMAX40 Flat Disk (A52391)|
|PPST 250 or PPST 250 plus Lumivia™ Seed Treatment (Vacuum Listed in Inches)|
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|ProMAX40 Disk (A52391): PDF, PDR, F14, R22, R23|
|Review a larger version. (JPG 103 KB)|
|Recommended Vacuum Setting for John Deere - Standard Disk (A50617)|
|PPST 250 or PPST 250 plus Lumivia™ Seed Treatment (Vacuum Listed in Inches)|
|(JPG 101 KB)|
|Standard Disk (A50617): PDF, PDR, F14, R22, R23|
|Review a larger version. (JPG 101 KB)|
|Recommended Vacuum Setting for John Deere - Small Disk (A43215)|
|PPST 250 or PPST 250 plus Lumivia™ Seed Treatment (Vacuum Listed in Inches)|
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|Small Disk (A43215): PDF, PDR, F14, R23|
|Review a larger version. (JPG 101 KB)|
- 1 disk plants all seed sizes.
- Most seed plants at 15” or 18” of vacuum.
- Very large seed may benefit from additional vacuum – up to 22."
- Precision Planting recommends use of their e-Flow™ lubricant, a mix of talc and graphite.
|Recommended Vacuum Setting for John Deere - Precision Planting eSet Disk|
|PPST 250 or PPST 250 plus Lumivia™ Seed Treatment (Vacuum Listed in Inches)|
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|Review a larger version. (JPG 102 KB)|
- 2 corn disks are available for the EdgeVac® meter:
- 39-cell disk (light blue in color)
- 24-cell low-rate disk (light green in color)
Both will plant seed sizes in the range of 35 to 70 lbs. per 80,000-kernel bag (2,286 to 1,143 seeds per lb.).
- For most kernel sizes, set vacuum at 18.” For larger, heavier seed, set at 20” for best plantability. Incrementally increase the vacuum level to improve accuracy as needed on larger, more heavily treated seed.
- Singulator brush settings on this planter range from 1 (least aggressive) to 11 (most aggressive). Manufacturer recommends a range of 5-7 for corn. DuPont Pioneer lab testing suggests a setting of 8 or 9 may improve accuracy for larger seed.
|Recommended Singulator Setting for Kinze EdgeVac® Vacuum Planter|
|PPST 250 or PPST 250 plus Lumivia™ Insecticide Seed Treatment (Singulator Setting)|
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|Review a larger version. (JPG 96 KB)|
- *Refer to manufacturer’s vacuum settings at www.kinze.com.
- The manufacturer’s recommended maximum operating speed is 75 finger RPMs. This corresponds to the maximum suggested ground speed for most sprocket combinations. Ground speed will vary depending on the sprocket combination being used.
- Proper finger and spring tension is important.
- John Deere factory specifications are that fingers should be set at 23 to 25 inch lbs. Consult owners manual for adjustment procedure.
- Kinze factory specifications are 22 to 25 inch lbs. of rolling torque. Consult owners manual for adjustment procedure.
- Worn parts should be replaced. Worn brushes can cause up to 15 percent overplant, especially when using smaller kernel sizes. Grooves worn into the faceplate also can cause overplanting.
Finger mechanism planter meter: Finger mechanism planter meters can accurately plant a wide range of kernel sizes. Finger tension adjustment for large seed sizes such as R22, and small kernel sizes such as PDF® seed may improve drop accuracy. Individual meter calibration, using the actual seed size to be planted, can significantly improve the spacing accuracy of this finger mechanism meter. Increasing field speed increases seed drop on these planter units.
Always check actual field populations to ensure desired accuracy. If desired drop is not achieved, consider the following options:
- Well-maintained planter units experience less variance. Have a qualified technician check planter unit condition and adjustment. Proper calibration using the actual seed size to be planted will help minimize this problem.
- Move sprocket combination up one setting. Population drop will increase by approximately 3%. Consult manufacturer operator’s operation manual.
- Seed coated thoroughly with graphite will provide potential increase in seed drop of 1-2%.
- Plant within the manufacturer’s recommended speed range.
Pioneer has not tested plantability of the precision meter from Precision Planting because it is assumed these units will be custom calibrated by a trained MeterMax® technician. If all seed being planted is large (R23 or R22), Precision Planting makes shims that may be placed under the cam to increase the opening height of the fingers. The standard finger configuration will do an adequate job on large seeds, and is preferred if planting a variety of small, medium and large seed sizes.
- The manufacturer recommends a disk speed of 32 RPMs with suggested disk and air pressure. Adjustments to air pressure can be made depending upon the disk used and the kernel size being planted. Smaller seeds usually require less air pressure.
- Air pressure can be adjusted from 1.0 to 5.0 inches of water. The percentage of skips or doubles is managed with increases or decreases in air pressure.
- The manufacturer does not recommend the use of talc with the seed unless seed coatings interfere with metering.
- A disk (700745799) is now available for planting PDF, F14 and F12 flat seed sizes, 1200 to 2200 seeds/lb.
|Recommended Pressure Setting for White Pneumatic Planters (Small Disk 852436)|
|PPST 250 or PPST 250 plus Lumivia™ Seed Treatment (Pressure Listed in Inches)|
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|Review a larger version. (JPG 104 KB)|
- Manufacturer vacuum range for corn planting is 18-22 inches of water vacuum.
- Seed disk number indicates number of holes and hole diameter. For example, seed disk 4855 contains 48 holes with each hole 5.5 mm in diameter.
- Vacuum level is set by adjusting fan speed control with seed on disk. Setting is in inches of water (inches H20).
- Meter cover indicates baffle setting number. Meter inspection without draining seed can be made when baffle is set to position 0 (fully closed).
- Do not use singulator dial (lever) settings to control gross population; excessive doubles or skips will occur. Higher dial setting decreases singulator interference with seed disk holes.
- Pioneer testing indicates all Pioneer kernel sizes can be planted accurately with this unit. Test results for most seed sizes average within +/- 1% of the expected drop with this equipment.
- Testing conducted at the DuPont Pioneer plantability laboratory suggest vacuum and singulator settings in the manufacturer’s owners manual should be considered as a starting point. Variations may be necessary to achieve optimum plantability, especially for larger and more heavily treated seed.
- Remember to change singulators back after each seed adjustment for larger seed.
|Recommended Singulator Setting for Case-IH ASM Model 1200 (4855)|
|PPST 250 or PPST 250 plus Lumivia™ Seed Treatment (Singulator Setting)|
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|Review a larger version. (JPG 127 KB)|
- *Refer to precision planting recommendations at www.precisionplanting.com/#products/vset/
- The manufacturer’s recommended maximum drum speed is 35 RPMs, with seed metered in a 36-hole drum. Air pressure should be set from 9 to 11 ounces.
- Plant all seed sizes except R22 and R23 using 9 ounces of pressure. Plant R22 and R23 seed sizes at 11 ounces of pressure.
- Adjust the brush to the down position for all seed sizes. For most seed sizes, do not wire the brush down as is done for soybean planting. However, R22 and R23 seed are the exception and may plant best with the brush wired down.
- Replace the entire brush assembly when wear is apparent.
Reduce Planter Down Pressure to Reduce Sidewall Compaction
As some growers watch the calendar they may realize they are headed into fields that may be less than ideal for planting. Wet soils are easily compacted and sidewall compaction during planting can be a problem, especially if the crop is "mudded-in" and a dry spell occurs after planting.
Most sidewall compaction on wet soils occurs when the press wheels/closing wheels are set with too much down pressure, over packing the seeds into the soil. It is important to plant corn 1.75 – 2 inches deep so that the press wheels are creating good seed-to-soil contact around the seed and not below it where the roots may grow if that seed is planted shallower than 1.5 inches. When properly closing the seed-vee, the sidewalls of the furrow should be fractured as the soil closes around the seed, eliminating the sidewalls and providing good seed-to-soil contact.
A good way to provide loose soil for closing the seed-vee is to do it after the seed is placed in the furrow. Spoked closing wheels are available to replace the standard press wheels. These spoked closing wheels till in the sidewall around the seed. Less aggressive spoked wheels provide some seed-to-soil contact and reduce air pockets around the seed. More aggressive spoked closing wheels tend to dry the soil more. These typically require a seed firmer to provide seed-to-soil contact and a drag chain behind them to level the soil.
Watch Down Pressure
Be careful not to have too much down pressure set on some of these spoked closing wheels as they may “till” the seeds out of the seed-vee. To reduce the aggressiveness of the tillage and to provide some soil firming and depth control, some growers will run one spoked closing wheel and one standard wheel. This situation works well in a wide variety of situations.
While the seed furrow closing devices are important, too much down pressure on the depth gauge wheels will also create sidewall compaction as the disk opens the seed furrow. The disk openers may create some sidewall smearing while pushing the soil outward. If there is too much down pressure on the depth gauge wheels, they will pack the soil downward at the same time, causing compaction that may be too dense for the closing wheels to fracture. When this occurs, growers typically put more pressure on the closing wheels trying to close the seed-vee, making conditions worse yet. Down pressure on both the row unit (gauge wheels) and the closing wheels should be reduced in wet soil conditions.
Corn Stress Emergence
What Controls Emergence?
- Seed Quality
Why Corn is Sensitive to Early Season Stress?
- Corn is a warm-season crop – optimal temperature for emergence is 85-90 F – so it is almost always under some degree of cold stress.
- Prolonged exposure to soil temperatures below 50 F promotes seed deterioration and seedling disease.
Modes of Damage in Cold, Wet Soils
Imbibitional Chilling Injury
- Cell membranes are brittle in the cold
- Force of hydration causes membrane rupture
- Leaked cell contents invite pathogens
Water temperature during initial contact is critical.
Most damage occurs during imbibition at < 50° F.
Imbibitional chilling and cold injury (photo above and below.) Note club and corkscrew shapes, and underground emergence in these 2 photos.
- Frost damage can lead to runts and uneven stands
- Multiple events are more damaging than a single frost
- A healthy growing point does not guarantee a healthy stand
- Growth may be blocked by dead tissue
- Growing point needs a healthy coleoptile to push through soil
Flooding damage – note necrotic area of each root above root tip.
Pioneer Stress Emergence Scores
- Genetic potential of hybrids to emerge under stressful environmental conditions (cold, wet soils or short periods of severe low temperatures)
- Avoid planting ahead of a cold event
- Plant into moisture
- Plant well-drained, low-residue fields first
- Use a residue manager
- Use the right seed treatment
- Choose the right hybrids:
- Stress Emergence
- High Residue Suitability