By Matt Reese
They say a wet year will starve you to death and a dry year will worry you to death.
Well, with a rough stretch of high temperatures starting in late June combined with limited rainfall around the state, farmers are starting to worry. So far in July, temperatures in Ohio were averaging 2 to 8 degrees F above average in a lengthening stretch of 90-degree days, said Aaron Wilson with Ohio State University Extension. At the same time, Wilson said Ohio had less than 0.25-inch statewide.
“Not only are we falling short on typical rainfall (~1-inch per week), but hot daytime temperatures have led to intense evaporation rates (0.25 to 0.30-inch per day). This has caused rapidly drying soils and decreasing stream flows,” Wilson said in the CORN Newsletter.
Even by July 2, abnormally dry conditions were being reported for roughly 17% of Ohio, largely in the northwest. Wilson said the Ohio outlook through mid-July shows elevated probabilities of above average temperatures and below average precipitation, which could add to dry weather woes and bring about additional worry regarding the “D” word for agriculture.
Ohio State University Extension experts put out a number of resources to help minimize the worry and maximize the potential for success while navigating the dry weather challenges for Ohio’s crops and livestock this summer. In terms of fungicide application decisions, the dry conditions paired with ongoing crop price concerns, makes scouting especially important. OSU Extension plant pathologist Anne Dorrance said for soybeans the key concerns are going to be white mold and frogeye leaf spot.
“Frogeye leaf spot and white mold on susceptible varieties when the environment is favorable for disease easily pay the cost of application plus save yield losses,” Dorrance said in the CORN Newsletter. “White mold is favored in northeast Ohio and down through the central region where fields are smaller and airflow can be an issue. Frogeye has been found on highly susceptible varieties south of 70, but it is moving a bit north, so it is one that I am watching.”
White mold likes a closed canopy, cool night temperatures and high humidity. If the soybean variety has a moderate to low resistance rating for white mold, spraying may be warranted this year, Dorrance said. Frogeye, though, may be less of an issue if the dry weather persists.
“This disease will only move in the canopy when there is regular rainfall, and again only on susceptible varieties,” Dorrance said. “With dry weather, this will sit and hold. The time to scout for this will be at the end of flowering if it can be found in the field. With drought conditions, the disease will not impact the crop.”
For corn, OSU Extension plant pathologist Pierce Paul said hot, dry weather really reduces the need for controlling disease. The big concerns are gray leaf spot and northern corn leaf blight
“Fungicides are not warranted under these conditions; it just does not pay. Although some product labels may mention yield responses under drought-like condition, our data do not support such a benefit,” Paul said. “We see the highest yield responses when fungicides are applied to susceptible hybrids at VT-R1 under disease-favorable conditions. These conditions would include extended periods of dew and high relative humidity, especially during the early- to mid-morning hours.”
Other emerging corn disease concerns in Ohio include southern rust and tar spot, which also require warm, humid conditions.
“Scout fields to see what is out there and at what level before investing in fungicide application,” Paul said.
With Ohio’s wheat harvest wrapping up, the dry weather is also a concern when making double-crop soybean planting decisions. Some farms have found the combination of double-crop beans and manure applications can have benefits. Glen Arnold, OSU Extension manure specialist, is now in his third year of using a drag hose to apply manure in emerged soybeans, flattening them in the process. They do not seem to suffer much damage up to the V5 stage.
“Both swine and dairy manure can be used to add moisture to newly planted soybean fields. It’s important that the soybeans were properly covered with soil when planted to keep a barrier between the salt and nitrogen in the manure and the germinating soybean seed,” Arnold said. “An acre-inch of water is 27,154 gallons. The application of 10,000 gallons per acre of dairy manure would be about 0.37 inches of moisture. The application of 7,000 gallons of swine manure would be about 0.26 inches of moisture.”
The conditions Ohio has been experiencing are also tough on livestock. Clean, fresh water is very important and pasture management can make a big difference moving forward, said David Barker, Ohio State University Extension grazing and forage specialist.
“Unfortunately, without rain or irrigation pastures will not grow, and close grazing will exaggerate this effect,” Barker said in the Ohio Beef Cattle Letter. “As a general rule of thumb, grazing below 2 to 3 inches will accelerate drought effects on pastures, and also, slow recovery once rain does come.”
Barker said endophyte poisoning on tall fescue and perennial ryegrass can be a concern to watch as well in dry conditions. Strategic use of nitrogen early in the recovery from drought can re-gain some drought losses.
Keep on praying for rain as the summer unfolds and try to remember the value of worrying in 2020.
“Who of you by worrying can add a single hour to your life?” — Jesus, Luke 12:25