Planting

Field Observations Thru May 12

Throughout the growing season I will post information on different pests or issues I am seeing in our fields in Knox County.  This week Mother Nature is finally cooperating, a little, and we are starting to make some planting progress.  Below are a some to observations to keep an eye on.

Alfalfa

Continue to scout fields for Alfalfa Weevil.

Click here for Alfalfa Weevil Scouting Guide

 

 

Corn

Finally, we are planting!  While conditions are not perfect, we are able to get some seeds in the ground!

Most of our early planted corn has sprouted, some has finally begun to emerge.  As you evaluate your plant stand, do not be too concerned, yet – it is still early!

Click here to read the following post from OSU Agronomists Osler Ortez, Laura Lindsey, Alexander Lindsey

Soybeans

Same story as corn.  Early planted soybeans are beginning to emerge. As you evaluate your plant stand, do not be too concerned, yet – it is still early!

Click here to read the following post from OSU Agronomists Osler Ortez, Laura Lindsey, Alexander Lindsey

Wheat

Trapped heads in Wheat.  While rare, I have seen this before. It looks like the heads are trapped in the boot.  This is usually a weather related issue.

Under warm conditions, the heads are pushed out of the leaf sheath quickly, but when it’s cold/cool, the process is slower, causing the heads to get trapped.  This is particularly problematic on awned varieties.  This issue could cause some constriction and affect grain full at the tips of the head, but usually not a major cause for concern.  

Click here for more information

We are still very early, but if crop stands are a concern…

Source: Osler Ortez, Laura Lindsey, Alexander Lindsey

We are still early, but if you planted in April or the first few days of May, soil conditions have been wet and cold in many parts of the state. Early plantings, cold air/soil temperatures, and precipitation cause slow progress in corn and soybean.  Corn and soybean plants slowly emerge from the ground under wet soil conditions.

One of the downsides of planting early is the risk of seeds sitting too long in the field. Seed damage (biotic or abiotic) can lead to reduced stands in planted fields. Factors to consider are imbibitional chilling, frost damage, seed treatment duration/viability, insect/disease damage, soil crusting, and standing water. These factors (or combinations) can negatively affect seedling vigor, plant growth, crop establishment, ultimately reducing crop stands. If reduced stands are a concern, a potential solution is to replant fields. However, we are still early to make accurate assessments of crop stands.

Our 101 recommendation now is to wait… Crop stands should be assessed after ‘stable’ and ‘better’ conditions are achieved (e.g., warmer temperatures, adequate soil moisture conditions):

  • For corn, past work has shown that 50% emergence can be expected following accumulation of 150 soil GDDs (base of 50°F) from planting, about 5-7 days under normal conditions (much longer under cold/wet as areas of Ohio have been).
  • For soybean, assess the stands no earlier than the VC growth stage. Visual stand assessment at the VE growth stage often underestimates the number of plants that will emerge.

Figure 2.

Often, hasty decisions are not the best. When replanting decisions on early planted acres are made, one should be careful about getting more plants than necessary in the field. In the following picture (Figure 2), the first set of soybeans was planted early and took a long time to emerge from the ground. So, a replanting decision was made (replanted at an angle). Once the weather conditions turned better, the first planting and replanting came up, in which case the replant was unnecessary. We suggest caution when replanting decisions are made.

How Deep Should Corn Be Planted?

Source: Dan Quinn, Ph.D., Purdue University

During the heat of planting, one thing that often can be forgotten is thoroughly checking and understanding two items, 1) what seed depth am I planting at? and 2) is my seeding depth consistent, especially across all of my individual row units? We may often be inclined to use the “set it and forget it” approach to seed depth, yet this may not always be the best idea. In order to get corn started off on the right foot, it is important to achieve both rapid and consistent emergence following planting. One aspect of achieving rapid and consistent plant emergence is by choosing the correct seeding depth and ensuring there is adequate and uniform moisture at the chosen seeding depth. The most common seeding depths recommended for corn range between 1.5 and 2 inches deep, and these planting depths can work very well within most conditions, however, certain soil moisture conditions at planting may warrant further examination/change in seeding depth.

A corn seed imbibes soil moisture within the first 24 – 48 hours after planting, therefore maintaining both adequate and uniform moisture at seeding depth (not too wet and not too dry) within the first 48 hours is important. If the soil remains too dry, then the seed may be delayed in emergence until precipitation occurs. Furthermore, if the soil remains saturated after planting, the seed may rot and die. If the soil conditions are dry at planting, then a seeding depth of 2 inches may be too shallow and not place the seed in adequate/uniform soil moisture conditions. Therefore, if the moisture at a 3-inch depth is more adequate and uniform, and no additional rainfall is expected in the next week, then it may be worthwhile planting the seed at a 3-inch depth instead of a 2-inch depth. It is important to remember that corn can physically emerge at seeding depths lower than 2-inches, therefore, planting deeper can help ensure more consistent plant emergence when soil moisture conditions are dry. However, if soil moisture conditions are adequate it is likely ideal to not go much deeper than 2 – 2.25 inches. If planted too deep and soil moisture conditions are adequate, emergence can become delayed, thus further exposing the corn seed to various stresses (e.g., disease, insects, etc.). Furthermore, if corn is planted too shallow <1.5 inches, you can run the risk of poor root development, stand establishment, and lodging.

To further examine the impact of seeding depth on corn emergence and yield, a research trial was established at the Throckmorton Purdue Agricultural Center in Lafayette, IN. The research trial examined corn seedling emergence timing and yield differences across four different seeding depths and two different hybrids. The trial was designed as a randomized complete block design with three replications. Plots measured 30 feet wide (12, 30-inch corn rows) by 400 feet long and the center six rows were harvested with a commercial combine with a calibrated yield monitor. Trial results are presented below:

Results: Continue reading How Deep Should Corn Be Planted? →

Soybean Planter Considerations

Click on the video below to watch Dr. John Fulton discuss soybean planter considerations and recommendations to meet a variety of field conditions we may face this spring.  Dr. Fulton specifically talks about:

  1. Downforce pressure for consistent seed depth
  2. Adjustments due to soil variability
  3. Row-unit settings
  4. Comments on speed tubes

Double Crop Soybean Management Considerations

by:

Wheat harvest is just around the corner, and it’s time to consider double-crop soybean production management. For double-crop soybean to be successful, you need adequate time and moisture for the production of the soybean crop. In southern Ohio, double-crop soybean after wheat harvest is common. In central and northern Ohio, double-crop soybean after winter wheat depends on the wheat harvest date and soybean prices. With high soybean prices, we anticipate interest in double-crop soybean production in central and northern Ohio this year.

Double-crop soybean management considerations.

  1. Soybean relative maturity. Relative maturity (RM) has little effect on yield when soybeans are planted during the first three weeks of May. However, the effect of RM can be larger for late plantings. When planting soybean late, the latest maturing variety that will reach physiological maturity before the first killing frost is recommended. This is to allow the soybean plants to grow vegetatively as long as possible to produce nodes where pods can form before vegetative growth is slowed due to flowering and pod formation.

Table 1. Recommended relative maturity (RM) ranges for soybean varieties planted in June and July in northern, central, and southern Ohio.

  1. Row spacing. Double-crop soybeans should be produced in narrow rows- 7.5 or 15-inch row spacing. The later soybeans are planted, the greater the yield increase due to narrow rows. Soybeans grown in narrow rows produce more grain because they capture more sunlight energy, which drives photosynthesis.
  1. Seeding rate. The soybean plant population at harvest for mid-to-late June plantings should be between 130,000-150,000 plants/acre. The harvest population for early July plantings should be greater than 180,000 plants/acre. Harvest population is a function of seeding rate, quality of the planter operation, and seed germination percentage and depends on such things as soil moisture condition, seed-soil contact, and disease pressure.

Evaluating the Prevent Plant Option

By: Eric Richer & Chris Bruynis, OSU Extension Educators

Planting progress goes differently every year and in each part of the state. This year is no different in Ohio. Some places got in early and are finished. Others had their ‘normal’ planting progress with ‘normal’ Mother Nature breaks, perhaps with some re-plant needed. And still others have not had ideal conditions all spring to plant.  As such, we have received some recent calls regarding the mechanics and economics of utilizing the Prevent Plant through crop insurance this year in certain parts of the state. First and foremost, we are not crop insurance agents, so speaking with your agent is of utmost importance. In this article, we will walk through an example on the economics of electing Prevent Plant.

In Ohio, once you arrive at the final plant date of June 5 for corn (already passed) and June 20 for soybeans, you basically have 3 options in a corn scenario: Continue reading Evaluating the Prevent Plant Option →

Growing Degree Days vs. Calendar Days – How Long Will Emergence Take?

Source: Alexander Lindsey, Greg LaBarge, OSU Extension

When we examine crop emergence post-planting, two factors can impact speed of emergence – soil moisture content and soil temperatures. If soil temperatures are lower, it can take more calendar days for emergence to occur meaning rowing corn may take a little more time. In the Ohio Agronomy Guide, emergence should begin to occur after approximately 100 air GDDs.

A difference in 10 degrees in temperature can dramatically affect how quickly crops will emerge. For example, at a temperature of 60 degrees F heat unit accumulation per day would be 60 F – 50 (base temperature for growth) = 10 GDDs. If it takes 100 GDDs to start to see emergence, at this rate it would take 10 calendar days to see the crop start to emerge. If temperatures are 70 degrees F, heat unit accumulation per day would be 70 F – 50 = 20 GDDs. This would shorten the emergence window to 5 calendar days instead, resulting in more rapid emergence from planting.

Figure 1. Emerged corn on May 6, 2021 planted April 19 near London, OH.

In recent work from Nemergut et al. (2021), researchers from OSU observed emergence starting at 110 to 120 soil accumulated GDDs (base of 50 degrees F) for corn, which equated to first emergence observed in 4 or 5 days after planting. Some of the difference in calendar date for emergence (though GDD accumulation was similar) was because planting depth was changed, and the 1” planting accumulated GDDs faster than the 2” and 3” planting depths. These studies though were planted in May or early June (2019 wet spring delayed planting), and daily accumulated GDDs was higher than we might expect if planted in late April. Soil accumulated GDDs have been discussed above, and these could vary slightly compared to air accumulated GDDs (calculated using air temperatures). In the work referenced above, accumulated air GDDs in the first four days post-planting were 106-118 GDDs, slightly less than the soil accumulated GDDs.

If you want to predicate emergence on your farm, the GDD calculator found at https://mrcc.illinois.edu/U2U/gdd/ is a useful tool. It is a two-step process, first find your location on the map, then enter your planting date. The graph will display accumulated GDD’s for your location. Example output in Figure 2 shows GDD accumulation from an April 19, 2021 planting date near London, OH in Madison County. By May 6 the accumulated GDD was 138 and the emerging corn is shown in Figure 1. The GDD calculator can be used to predict growth stage throughout the growing season. This is a handy to time when scouting and management decisions should be made.

Figure 2. GDD accumulation from April 19 to May 6, 2021 near London, OH.

As the days turn cooler, don’t be surprised if the crops don’t pop out of the ground quickly due to lower soil temperatures. If emergence is still not observed after two weeks, it may be worth checking the field to see if other issues may be affecting emergence.

Soil Moisture & Corn Seed Depth

Source: Dr. Bob Nielsen, Purdue Univ.

Bottom Line: Uniformly adequate soil moisture at seeding depth is important for assuring rapid and uniform germination of a newly planted corn crop. Take time to assess soil moisture at your selected seed depth on the day of planting. If soil moisture is not available or unevenly available at your normal seeding depth, then consider planting deeper than normal if soil moisture is available at those deeper settings.

Uniformly adequate soil moisture at seeding depth is important for assuring rapid and uniform germination of a newly planted corn crop. Take time to assess soil moisture at your selected seed depth on the day of planting. If soil moisture is not available or unevenly available at your normal seeding depth, then consider planting deeper than normal if soil moisture is available at those deeper settings.

Choice of seeding depth for corn is often paid scant attention by growers during the rush of planting their crop. Human nature being what it is, we tend to simply leave the planter’s depth control setting at the same position as it was in previous years. While it is true that a seeding depth of 1.5 to 2 inches is a fairly all-purpose range that works well in most situations, certain conditions merit more attention to seeding depth, the most common factor being soil moisture.

Continue reading Soil Moisture & Corn Seed Depth →