C.O.R.N. Newsletter: 2015-09
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Upcoming Weather
April has been a warmer and wetter month across most of the state of Ohio. Temperatures are averaging 3-7 degrees above normal with precipitation ranging from 100-200 percent of normal. The wettest and warmest areas have been across the southern part of the state. Rainfall has been close to normal in the north.
A pattern change is about to begin which will turn the weather cooler than normal for the rest of April into the first week of May. Temperatures will run several degrees below normal. For the rest of April say goodbye to highs in the 60s and 70s and hello to highs in the 40s and 50s. Lows will mostly be in the 30s and 40s but a few days of 20s are expected especially north of I-70.
The main headline for Ohio will be increasing frost and freeze risk at the end of our typical frost and freeze season. The most likely days of lows in the upper 20s and lower 30s will be Thursday and Friday, April 23/24, and again Sunday April 26.
Rainfall will average about normal each week into early May at around 0.75 inches.
After the first week of May, indications are a return to above normal temperatures and normal rainfall.
The latest 2 week rainfall outlook by the National Weather Service can be found on the Ohio River Forecast Center website at:http://www.erh.noaa.gov/ohrfc/HAS/images/NAEFS16day.pdf
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Identifying Feekes Growth Stage 6: Jointing
1- Pull, or better yet, dig up, several clusters of tillers with roots and soil from multiple locations in the field;
2- Identify and select three to four primary tillers from each cluster – usually the largest tillers with the thickest stem, but size can be deceiving;
3- Strip away and remove all the lower leaves (usually small and yellowish or dead leaves), exposing the base of the stem;
4- Now look for the first node anywhere between 1 and 2 inches above the base of the stem. This node is usually seen as a slightly swollen area of a slightly different (darker) shade of green than the rest of the stem.
If the first node (and only that node) is seen at the base of the stem, then your wheat is at Feekes growth stage 6. Click on the links below for information on management practices that are recommended (or not recommended) at this growth stage:
http://corn.osu.edu/newsletters/2015/2015-06/wheat-is-starting-to-green-up
http://corn.osu.edu/newsletters/2015/2015-08/wheat-management-by-growth-stage
Here is a link to a video on staging wheat on the OSU Extension Agronomic Crops Team website. The file is very large does not play from the website. It needs to be downloaded so expect a delay.
https://agcrops.osu.edu/photo-library/multimedia/staging-wheat-feekes-gs-6
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Corn Planting Progress in Ohio: A “Historical” Perspective
How much corn is typically planted in Ohio by the third week of April? According to the National Agricultural Statistics Service (http://www.nass.usda.gov/Statistics_by_State/Ohio/Publications/Crop_Prog...), for the week ending April 13 no appreciable acreage of corn had been planted in Ohio (1%), which compared to 0% last year and 7% for the five year average.
The table below shows corn planting progress (percentage of acres planted) in April and May for the past 15 years. This historical data shows that the percentage of corn acres planted by April 15 is usually very limited averaging 2% and ranging from 0 to 10%. By April 20, the percentage of corn acreage planted was 10% or greater in only four of the 15 years, and by April 25, it was 10% or greater in only seven of the 15 years. By April 30, the percentage of corn acres planted was 10% or greater in nine of the 15 years but in only 3 of the 15 years did the % acreage planted exceed 50%. In 2005, 55% of the corn acreage was planted by April 25 but snow and freezing rains in late April resulted in considerable replanting in early May.
The data also show that in most years, even those with slow starts due to persistent cold weather in April, 60 percent or more of corn acres were planted by May 10, which is within the optimal planting date window. The recommended time for planting corn in northern Ohio is April 15 to May 10 and in southern Ohio, April 10 to May 10.
Progress of corn planting, Ohio 2000-2014.
Date
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
-------------------------------------------------------% corn planted------------------------------------------------------
April 10
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2
1
0
0
0
0
1
0
0
0
0
4
0
0
April 15
2
3
2
2
2
0
2
1
0
1
4
0
10
0
0
April 20
3
3
2
4
11
26
6
3
0
2
17
0
27
1
0
April 25
5
7
4
18
30
55
19
10
6
4
45
1
44
1
2
April 30
7
22
7
43
44
59
43
22
18
9
58
1
60
2
4
May 5
33
64
11
83
57
66
68
35
33
16
69
1
73
7
9
May 10
62
85
15
85
65
76
79
82
46
22
77
3
82
46
35
Source: USDA/NASS, Annual Statistics Bulletins, 2000-2013; USDA/NASS, Crop Progress and Condition Reports, 2000-2014
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Black Cutworm and Armyworm Counts on the Rise
Last week, both Purdue University and the University of Kentucky reported high black cutworm catches. In addition, UKY caught a large number of armyworms in one of their traps. Both of these moth species migrate into our area, lay eggs, and the developing larvae can be significant pests of corn and wheat.
Black cutworm—Females like to lay eggs in fields with heavy weed cover; weeds like chickweed are especially favored by black cutworm. As these weeds are killed by tillage or herbicide, the larvae move to emerging corn. Unfortunately, there aren’t good “pre-control” options. Although there are some hotspots for egg laying, these predictions are far from exact. Insecticidal seed treatments do not offer much protection, and tank-mixing an insecticide with early burn-down has limited efficacy if scouting has not been done to see if larvae are present. Instead, we recommend rescue treatments which are very effective in controlling damage. If more than 3% of corn are showing damage, corn is in the V2-V6 stage, and larvae are less than 1 inch, treatment may be needed. We will provide updates over the next few weeks as planting begins (hopefully…) and if damage is reported.
Armyworm—Females like to eggs in grasses, especially wheat, where egg hatch occurs over a couple of weeks. As the larvae develop, they can defoliate wheat plants, leading to yield loss. If corn is planted into wheat fields or other grassy cover, then, like black cutworms, armyworms can also move onto corn. Again, like black cutworm, the best way to control armyworm is scouting and rescue treatments. We rarely see economic damage from armyworm, except in outbreak years and it is too early to know if this year is an outbreak. We will provide updates over the next few weeks.
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Soybean Planting Date, Seeding Rate, and Row Width
Planting date. Planting date (both too early and too late) can reduce soybean yield potential. In 2013 and 2014, we conducted a planting date trial at the Western Agricultural Research Station near South Charleston, Ohio. In both years, soybean yield decreased by 0.6 bu/ac per day when planting after mid-May. The greatest benefit of planting May 1 to mid-May is canopy closure which increases light interception, improves weed control by shading out weeds, and helps retain soil moisture.
Planting too early (before field conditions are adequate) comes with a risk. Factors such as damping-off and pressure from bean leaf beetle are concerns to keep in mind, as well as the possibility of a late spring frost. (Our early May planting date in northern Ohio in 2013 was damaged by bean leaf beetle and two frosts that occurred mid-May.)
Before heading to the field, consider the conditions you will be planting into. Soybean germination begins when soil temperatures reach 50°F and moisture is present at the planting depth of 1-1.5 inches. With these conditions, emergence can typically be expected 2-3 weeks after planting. Do not plant early if the soil is excessively cold or wet. Slower germination and compaction can negate the benefits of the earlier planting date. Timely planting is critical for maximizing yield in soybeans, but using good judgement on field conditions plays a role that is equally important to determining yield potential.
Seeding rate. What is the optimum soybean seeding rate? On-farm research conducted by the AgCrops Team from 2004-2014 indicates that 116,000 plants/acre at harvest resulted in a relative yield of 90% (i.e., If 100% yield is 50 bu/ac, 90% yield is 45 bu/ac) when soybeans were planted in May. In the seeding rate figure, the relationship between yield and final stand is a relatively flat line indicating that soybean can yield well over a wide range of seeding rates. (Note: All of the seeding rate work was conducted in either 15- or 7.5-inch row width.) Seeding rate research is on-going, and we will be conducting trials at three locations this year.
Row spacing. According to the USDA National Agricultural Statistics Service survey data, in 2014, approximately 94% of Ohio farmers planted soybean in row widths ≤ 15 inches. Soybeans grown in narrow rows (≤ 15 inches) tend to out-yield soybean produced in wide row width (30 inches) due to increased sunlight interception in narrow rows. Row width should be narrow enough for the soybean canopy to completely cover the interrow space by the time the soybeans begin to flower.
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Considerations Before Interseeding Soybeans into Wheat this Spring
Modified Relay Intercropping (MRI) is the planting of soybeans into standing wheat versus double cropping soybeans that are planted after wheat is harvested. Vyn et al found that relay intercropping of soybeans yielded better than double cropping of soybeans north of I-70 in Indiana. 2014 Ohio research showed a 10 to 25 bushel advantage to MRI over double cropping at OARDC Western and Bucyrus, Ohio respectively. Budgets also show MRI to have $150 gross advantage over other grain operations or a $50 advantage over monocrop soybeans.
Prochaska et al showed that in the past 16 years of replicated trials in North Central Ohio, MRI wheat has averaged 74 bushels per acre and soybeans 31 bushels per acre. Wheat that was planted close to the fly free date in favorable growing conditions has exceeded 90 bu/acre and soybean field averages have been over 54 bu/acre.
Successfully seeding MRI soybeans into a growing wheat crop requires planning at wheat planting time to minimize wheel traffic damage. Usually tram lines are utilized in 10 inch wheat rows to allow for the tractor and planter to drive in the wheat field without damage. Wheat row spacing’s in MRI have varied from 10 to 22 inches but wheat yields may decline with wider rows (http://corn.osu.edu/newsletters/2011/2011-27/wheat-variety-yield-in-15-i...). Even in wide row wheat, special equipment may need to be designed to fit down the 15 inch wheat rows without using tram lines.
While utilizing an existing piece of equipment on the farm is always the most economical way to start interseeding, many successful producers have built special three point interseeders to minimize the wheel trams through the field to allow all tires to follow the tractor.
The Best Management Practices for MRI soybeans include: Planning and setting up equipment for interseeding in the fall before wheat is planted. If the wheat is sown and you are building an interseeding tool bar, taking the equipment out first thing in the spring before wheat Feekes 5 and testing wheel and unit alignment to save time during planting. If any of your wheels or units happen to fall on a wheat row at this time, you won’t damage the wheat. Seeding generally occurs between Feekes 10.1 and 10.5, generally between June 1st and the 20th. Some producers have had success interseeding when wheat is in the boot stage in wide row wheat that has enough sunlight reaching the ground that the soybeans are not stretching to find the sun. Current seeding rate recommendations are between 200,000 and 250,000 / acre, depending on soil moisture, timing and the ability of your planter to penetrate the ground and close the seed trench.
For more information on different MRI practices, visit: https://agcrops.osu.edu/on-farm-research
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We have Nematodes in our Corn Fields
Editor's note: Abasola Simon is also an author on this article.
A total 425 corn fields were surveyed for plant-parasitic nematodes during the 2013 and 2014 growing seasons. In each year, soil samples were collected from 15-16 fields in each of 28 counties, across 6 soil regions, and nematodes were identified and counted.
Ten major morphological types were found, with populations ranging from 0 to 1,164 nematodes per 100 cm3 of soil. Spiral, lesion, lance, dagger, stunt, pin, ring, stubby-root, cyst, and tylenchid nematodes were each found in at least one field. Spiral and tylenchid nematodes were the most frequent, being detected in more than 93% of the fields (that is more than 395 out of 425 fields). The lesion nematode, one of the most economically important groups, was detected in 80% of the fields, while the lance, stunt, and pin nematodes were found in approximately 50% of the fields. Some fields had predominantly one type of plant parasitic nematode, while other fields had as many as 9 of the 10 types. More than 85% of the fields had between 4 and 9 different types of plant parasitic nematodes.
Nematode presence and populations varied among soil regions and also among fields under different tillage and crop rotation practices. Dagger and ring nematodes tended to be more common in soil region 6, whereas lance, stunt, stubby-root, and spiral nematodes were more common in soil regions 1, 2, 3, 4, and 5 than in region 6. In addition, one or more types of nematodes tended to reach higher, and potentially more damaging, population levels in soil regions 1, 2, 3, 4, or 5 compared to region 6.
In terms of crop rotational schemes, spiral, lance, and pin nematodes were more common in fields under corn-soybean or corn-soybean-wheat rotation than under continuous corn, while the other types of nematodes were equally present in continuous corn fields as well as fields under 2- or 3-crop rotation. Lance and stubby-root nematodes were more common, and the lance nematode population tended to be higher, in fields under no-till, vertical tillage, and minimum tillage. Nematode populations also varied with soil pH and texture.
As pH increased from 4 to 9, spiral nematode populations also increased, but lance and pin nematode populations decreased. Lance and lesion nematode populations were higher in soil with low silt content. Research in this area will continue and the focus will be to gather data from counties not sampled in 2013 and 2014; to better understand what these nematodes really represent in terms of damage to our corn crop; and to evaluate different strategies for their management if warranted.
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Cover Crop Spring Strategies Field Day *Minor* Location Change
The Cover Crop Spring Strategies Field Day scheduled for Wednesday, April 22nd will be held at the St. Marys Township House, 10752 SR 364, southwest of St. Marys, OH. This is less than 1/8th of a mile north of the field itself, but will allow for *inside* discussion away from the mud and the rain.
Presentations will be held at 2:30p, 4:30p, and 6p at the Township House. Presenters and Hosts will be on hand from 2p to 7p to answer questions. This Field Day is being sponsored by OSU Extension Shelby, Mercer, and Auglaize Counties and VanTilburg Farms of Celina.
Crop Observation and Recommendation Network
C.O.R.N. Newsletter is a summary of crop observations, related information, and appropriate recommendations for Ohio crop producers and industry. C.O.R.N. Newsletter is produced by the Ohio State University Extension Agronomy Team, state specialists at The Ohio State University and the Ohio Agricultural Research and Development Center (OARDC). C.O.R.N. Newsletter questions are directed to Extension and OARDC state specialists and associates at Ohio State.
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Disclaimer
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