C.O.R.N. Newsletter: 2024-12

Ohio experienced overnight cold temperatures between April 21st and April 22nd . Early planted corn and soybeans were subjected to frost damage with air temperatures lingering under 30ºF for about five hours, with the low reaching 28ºF.

Freeze damage on corn

Corn at the Western Agricultural Research Station was at V1 when temperatures dropped to freezing. At the V1 growth stage, the growing point is about ¾-inch below the soil surface. The growing point is above ground at the V6 growth stage. Damage to the above-ground leaf tissue (Figure 1) is not detrimental to the crop and leaves can grow back as long as the damage did not affect the mesocotyl and crown, below the soil surface. The mesocotyl and crown should be white when healthy and brown when killed by the frost (Figure 2). Air temperatures between 28ºF and 32ºF can result in tissue damage, but soil temperatures of 28ºF can result in plant death. To assess frost damage, evaluate the crop at least 3 to 5 days after the cold temperatures to see if there is regrowth or death of the growing point.

Figure 1. March 25^th planted corn, 24 hours after frost at the Western Agricultural Research Station

Figure 2. Uprooted corn, showing a healthy mesocotyl and crown at the Western Agricultural Research Station.

Freeze damage on soybean

Soybeans are in danger of frost damage with the same temperatures as corn, between 28ºF and 32ºF. However, the soybean growing point is above ground at emergence, and the apical meristem is at the cotyledons. If there is damage above the cotyledons, the crop can put on new growth and survive, but if the damage is below the cotyledons, at the hypocotyl or the crook of the soybean that emerges from the ground first, then the plant cannot recover (Figure 3). To assess damage, look at the hypocotyl to see if there is discoloration. If the soybeans have not yet emerged, then there should be limited damage.

What’s happening in the field?

As seen above, corn and soybean plants had visual injury from recent freeze events. However, the corn had healthy growing points and will likely grow out of the damage and only a few soybeans sustained lethal damage. Other soybean studies planted the same day (March 25th) at the same location sustained much more frost damage, we think because of the difference in soil type and tillage practices.

The Wooster campus was able to plant the first planting date of corn and soybeans on April 22^nd after weeks of saturated soils (Table 1). Table 2 presents the weekly (April 22 to April 28) weather conditions for planting dates one and two at the Western location and planting date one at the Wooster campus. The first planting date at the Northwest research site is forthcoming.

 Table 1. The planting date conditions for planting date one at the Wooster Campus, 2024.

Table 2. Weekly weather conditions for planting dates one and two at the Western location and planting date one at the Wooster campus, with day of planting, soil, air temperature averages, and Growing Degree Days (GDDS) from April 22 to April 28. Information from CFAES Weather System (https://weather.cfaes.osu.edu/).

Climate projections by climatologists suggest that the Midwest will experience wetter and warmer winters and springs and hotter and drier summers. One estimate suggests that by the end of the century, Ohio’s summers will resemble those of current-day Arkansas and winters will resemble those of current-day North-Carolina.  With more intense rain events delivering larger quantities, producers seem to prefer narrower drain spacing than the traditional designs. Can farmland be over-drained with narrow tile spacing leading to unintended consequences when wet springs turn into dry summers?

A research team at The Ohio State University has designed and implemented plot experiments that takes OSU’s long-term drainage research a step further and explores how intense drainage in combination with management decisions will impact crop productivity and economics.  The experiment is located at OSU’s Northwest Agricultural Research Station in Hoytville, OH and begins in 2024.  Formerly known as the drainage-tillage-rotation study, the new experimental design maintains the 40-foot tile drain spacing compared to undrained plots and adds 25-foot tile drain spacing treatment.  Additionally, three different tillage treatments will continue (no-till, chisel plot, and strip till) with the addition of a cover crops treatment.  The crop rotation treatment will ensure that corn and soybean are both grown in each year in an alternate rotation. The 3 drainage x 3 tillage x 2 cover crop x 2 crop rotation treatments replicated twice result in 24 subplots. A pseudo-replication within plots will allow for doubling the number of subplots within each treatment combination. In addition to agronomic monitoring, the team plans to monitor the hydrologic water budget in the plots. A mini research grant supported by the Ohio Soybean Council provided seed funding to initiate monitoring of water table, soil moisture, temperature, and electrical conductivity. Additional financial support came from the Virgil Overholt Drainage Education and Research Program at OSU.

The research team will address the following questions with this long-term experiment: How do changes in tile drain spacing influence trafficability in the early growing season as well as soil moisture throughout the growing season? What are the effects of drainage intensity and land management (i.e., tillage type, crop rotation, cover crop) on soil moisture availability, crop stress, crop yield, and economics?        How do these drainage and land management practices affect soil health in the long-term? Are there differences in the prevalence and abundance of soil-borne pathogens (e.g., phytophthora, pythium, rhizoctonia) under different drainage intensity and land management practices? Do foliar diseases differ across these treatments?

Meet the research team: Dr. Vinayak Shedekar, Assistant Professor in the Department of Food, Agricultural and Biological Engineering at The Ohio State University and serves as the State Extension Specialist for agricultural water management.  Nick Eckel, Agriculture and Natural Resources Extension Educator in the Wood County Extension Office. Mr. Eckel has expertise in agronomy and monitoring crop growth monitoring, scouting for pests and diseases, and sampling of soil and tissue samples.  Matt Davis is the manager of the Northwest Agricultural Research Station in Custar, Ohio. He is responsible for conducting farm operations as per the experimental design and measuring the crop yields in each individual research plot.  Wm. Bruce Clevenger, Ohio State University Extension Field Specialist, Farm Management specializes in economic analysis of agronomic systems and drainage treatments.

Authors: Wm. Bruce Clevenger, Vinayak Shedekar, Nick Eckel, Matthew Davis