Agronomy

2020 Western Bean Cutworm Monitoring Program: Farmer Participation Needed

By Clint Schroeder – OSU Extension Allen County

OSU Extension will be monitoring for Western Bean Cutworm (WBC) moths again during the 2020 growing season. Western bean cutworm moths overwinter in the soil and emerge as adults in late June or early July. Adults then mate and lay eggs in clusters on the top surface of the upper third of a corn plant. The eggs require five to seven days to develop, during which time the egg color changes to tan and then to purple immediately before hatching. As the eggs hatch the larvae will look to feed on the exposed tassels and then make their way into the husks to feed on the developing corn ear. Scouting is critical as larvae that hatch prior to tasseling have a low survival rate, and larvae that have entered the husk will be protected from insecticide applications.

Western Bean Cutworm Moth

Continue reading →

Winter Application of Manure – Remember Setbacks

By:  Glen Arnold OSU Extension Field Specialist

Winter manureSome Ohio livestock producers will be looking to apply manure to farm fields frozen enough to support application equipment.  Permitted farms are not allowed to apply manure in the winter unless it is an extreme emergency, and then movement to other suitable storage is usually the selected alternative. Thus, this article is for non-permitted livestock operations.

In the Grand Lake St Marys watershed, the winter manure application ban from December 15th to March 1st is still in effect.  Thus, no manure application would normally be allowed from now until March 1st.

In the Western Lake Erie Basin (WLEB) watershed, the surface application of manure to frozen and snow-covered soils require there to be a growing crop in the field.  This could be a pasture, alfalfa, clover, ryegrass or a rape crop.  There must be enough vegetation visible to provide a 90% cover of residue and growing vegetation.  Radishes and oats would not qualify as a growing crop as both are typically winter killed.  Manure can be applied to fields without growing crops if the manure is incorporated at the time of application or incorporated within 24 hours of application. Continue reading →

What’s That Smell?

Using a penetrometer to test soil compaction in a field with tillage radishes.

By Clint Schroeder OSU Extension

It’s becoming a common occurrence across the state. Small towns and rural areas plagued by a mysterious smell during the winter months. Natural gas? Raw sewage? Dead Animals? Nope, just radishes.

The radishes are planted as a cover crop by farmers in an effort to eliminate soil compaction and hold nutrients on their farm fields. Unlike the radishes you might see at the supermarket, these tillage radishes are white, and in the tuber stage they can grow up to 2 feet deep and 6 inches wide. Farmers are growing these root crops to replace tillage passes in the hopes of building organic matter in the soil and reducing erosion. When everything goes to plan the radishes winter kill after a stretch of temperatures around 20 degrees Fahrenheit. They then start to break down slowly. When temperatures rise to the upper 40’s and low 50’s the process is sped up and the decomposing crop can release a rather rancid odor.  The smell is often times reported to fire departments and utility companies as a gas leak. The only real way to stop the smell is a return to colder temperatures. As more farmers adopt cover cropping into their operation there will be a learning curve as to best management practices. Planting a mixture of covers such as oats and vetch along with radishes might be a way to help reduce the odor in future years.

Help OSU Extension Document the Yield Impacts of the 2019 Planting Delays

By: CFAES Ag Crisis Taskforce

Normal planting dates for Ohio range from mid-April to the end of May. This season was quite different when planting for both crops was delayed until late May and stretched into June and even July across many parts of Ohio. We found ourselves grasping for any information we could find including 1) how much of an effect late planting dates would have on yield, and 2) what, if anything, we should change in management of these late planted crops. The historical planting date information we did have was somewhat helpful, but we did not have any data on what could happen when planting is delayed into the second half of June nor July. Continue reading →

Soybean Cyst Nematode Sampling

By:  Stephanie Karhoff OSU Extension

A female soybean cyst nematode, stained with a bright pink stain, has set up her feeding site within the soybean root. Her body will fill with eggs and become a bright white cyst visible on the soybean root.

A female soybean cyst nematode, stained with a bright pink stain, has set up her feeding site within the soybean root. Her body will fill with eggs and become a bright white cyst visible on the soybean root. Photo: OSU Extension.

Soybean cyst nematode (SCN), Heterodera glycines, is a small roundworm that parasitizes soybean roots, stealing vital nutrients from the plant. Even if you are not seeing above-ground symptoms, SCN is likely still reducing your yield. To make matters worse, certain SCN populations are now becoming “resistant to the resistance.”  In other words, a portion of the nematodes now have the capability of feeding and reproducing on soybean varieties previously thought to be resistant. The main reason for this, is that more than 95% of all SCN-resistant varieties for the past two decades included resistance gene(s) from the same breeding line, Plant Introduction (PI) 88788. Just like herbicide-resistant weeds, relying on the same SCN resistance source for the past 20 years has led to SCN populations adapting to, and overpowering the resistance. Continue reading →

Ohio Certified Crop Adviser Pre-Exam Training Seminar

The Certified Crop Adviser (CCA) Exam Training program, sponsored and delivered by the OSU Agronomic Crops Team, will be offered at the Shelby County Ag Building, 810-820 Fair Rd, Sidney, Ohio 45365 on January 8th and 9th beginning at 9:00 a.m. on the 8th and adjourn by 5:00 p.m. on the 9th. This is an intensive two-day workshop somewhat directed toward the local exam – to be used as a reminder on what best to study in preparation for the CCA exams. Exams will be given in 2020 on February 7th and August 7th. Register for the exams at least six weeks before the exam date: https://www.certifiedcropadviser.org/exams. The exams are not given during the preparation class. Continue reading →

Allen County Weed Survey

By Clint Schroeder OSU Extension

Each fall Ohio State University Extension conducts a survey of the different types of weeds present in soybean fields, as well as, the level of infestation. Weed Science State Specialist Dr. Mark Loux leads this study and uses the information gained to help develop future weed management programs. This study is conducted in each county where there is an Ag and Natural Resources Educator. The educator selects a route 80-100 miles long through the county and takes notes on one soybean field in each mile.

Allen County 2019 Weed Survey Results

Continue reading →

Corn Ear Rots: Identification, Quantification and Testing for Mycotoxins

By Pierce Paul OSU Extension

Ear rots differ from each other in terms of the damage they cause (their symptoms), the toxins they produce, and the specific conditions under which they develop. So, a good way to determine whether you do have a major ear rot problem this year is to quantify the disease in your field and get suspect samples tested for mycotoxins. And the best way to tell the difference among the ear rots is to know the types of symptoms they produce.

TRICHODERMA EAR ROT – Abundant thick greenish mold growing on and between the kernels make Trichoderma ear rot very easy to distinguish from Diplodia, Fusarium, and Gibberella ear rots. However, other greenish ear rots such as Cladosporium, Penicillium and Aspergillus may sometimes be mistaken for Trichoderma ear rot. Like several of the other ear rots, diseased ears are commonly associated with bird, insect, or other types of damage. Another very characteristic feature of Trichoderma ear rots is sprouting (premature germination of the grain on the ear in the field). Although some species of Trichoderma may produce mycotoxins, these toxins are usually not found in Trichoderma-affected ears under our growing conditions.

DIPLODIA EAR ROT – Diplodia causes a thick white mass of mold to grow on the ear, usually initiating from the base of the ear and growing toward the tip. Eventually the white mold changes to a grayish-brown growth and infected kernels appear glued to the husk. Infected ears are usually lightweight and of poor nutritional value. When infections occur early, the entire ear may become moldy. When infections occur late, only a fine web of fungal growth appears on and between the kernels.

Continue reading →

Considerations for 2019 Wheat Planting

By:  Andy Michel, Laura Lindsey, and Pierce Paul, Ohio State University

growing wheatWith the autumn rapidly approaching, wheat planting is likely to begin soon. Planting after the Hessian fly free date remains the best chance to avoid issues with insects and diseases, as well as helping ensure good agronomic quality.  Some benefits of the fly free date:

Hessian Fly: Adults of the Hessian fly lay eggs in emerging wheat. These eggs then hatch into small larvae that feed before spending the winter as a flaxseed. The early autumn feeding will stress the young wheat plant right before the winter, resulting in stunted and wilted plants.  Very little egg laying occurs after the fly free date, which helps to limit infestation. Wheat varieties with resistance against the Hessian are available, in addition to seed treatments, which can help limit damage.

Aphids: Two main aphids infest wheat in Ohio: the English grain aphid and the bird cherry-oat aphid.  These aphids rarely cause economic injury on wheat from feeding. However, they can transmit several viruses that can severely impact wheat including Barley Yellow Dwarf virus.  These aphids do not only feed on wheat, but several other grasses that serve as natural sources of viruses.  If wheat is planted too early, and emerges before the aphids overwinter or stop feeding, they can be early transmitters of viruses.  Although seed treatments could help kill the aphids, they may survive long enough to transmit the virus to the plant.  Any transmission in the autumn would likely serve as a local source in the following spring.

Other foliar diseases: Although not directly related to the Hessian Fly, planting after the fly free date also helps to reduce the early establishment of leaf diseases like Stagonospora leaf blotch and powdery mildew. Planting date is indirectly linked to spore production by fungi that cause these diseases and infection of young plants. The earlier you plant, the more spores are available, and the more suitable (warmer) conditions are for infection. Fall infections often leads to more damage and greater yield loss in the spring, especially of susceptible varieties are planted and not protected with a fungicide at Feeks 8 (flag leaf emergence). As conditions become cooler after the fly free date, pathogens that cause leaf diseases become last active, and as such, are less likely to infect plants.

Unusual Ears Appearing in Corn Fields

By: Peter Thomison OSU Extension

Last week, I received reports of several ear oddities showing up in corn fields including the following:

Shortened husk leaves with normal ears protruding beyond the husks

Most corn fields have a few ears with exposed tips. In extreme situations, a high proportion of ears outgrow husks by 1/3 to 1/2. According to Aldrich et al., 1986, Modern Corn Production, observed this where “… extreme [drought] prevailed during the time of ear set with abundant rainfall and good growing conditions thereafter.”

With corn at so many different stages of growth in Ohio this year, it is likely that some corn was subject to heat and drought earlier in the season during husk formation followed by cooler and wetter conditions. Ears protruding beyond the husks are likely to be more susceptible to bird and insect damage followed by molds that may produce mycotoxins. It is advisable to harvest earlier and dry corn down to minimize these potential problems. Avoid hybrids prone to ear tip exposure. However, ear tip exposure problems may be more the result of environmental conditions or an interaction of a particular hybrid with environment than genetics per se.

https://u.osu.edu/mastercorn/files/2015/02/Exposed-Ear-Tip-2-1wdv47i-225x300.jpg

Fig. 1. Ears with exposed ear tips at maturity.

 

“Barbell” or “Dumbbell” Ears

Barbell ears (Fig. 2) are characterized by kernel formation at the base and tip of the ear but absent from the middle of the ear.

The barbell ears I have heard about this year were observed in sweet corn fields. Barbell ears have been associated with chilling injury during ear formation and seem to be more common in certain sweet corn genetic backgrounds. Some agronomists have suggested that low temperatures disrupt normal kernel development resulting in anomalous ear growth.

Barbell ears also appear to be a glyphosate injury symptom in non-GMO corn. It has been observed when non-GMO corn hybrids are sprayed with a low level of glyphosate in spray tank contamination.

Fig. 2.  Sweet corn ears exhibiting barbell deformity. Source: Kevin Black, 2019.

In 2016, agronomists at the University of Nebraska reported the widespread occurrence of dumbbell shaped ears and short husks in certain dent corn hybrids (https://cropwatch.unl.edu/2019/corn-ear-formation-issues). They concluded that the widespread nature of the symptoms suggests a weather-related stress event interacting with genetics and management practices. They also attributed the problem to loss of the primary ear node followed by development of a secondary malformed ear.

For more on ear development problems and others ear abnormalities, check the following: “Troubleshooting Abnormal Corn Ears” available online at http://u.osu.edu/mastercorn/