Corn Tar Spot (Phyllachora maydis) is showing up in Southwest/Central Ohio in Preble and Madison counties. Corn that is tasseling or reaching silking stages with warm, humid, foggy, cloudy and wet weather create favorable conditions for corn tar spot to develop. Tar spot looks like small raised black spots on corn leaves when air temperatures are 64°F - 73°F, high humidity (>75%), and long periods of leaf wetness. Once the tar spot reaches the upper leaves during grain fill, photosynthesis is reduced and it decreases kernel development and grain yield. Tar spot is a corn disease originated in Central America and is spreading rapidly by wind into corn growing states. Corn will mature early with reduced ear weight, poor kernel fill, stalk rot, and possibly lodging with yield losses ranging from 0-60 bushel per acre, depending upon disease severity. There are several ways to combat tar spot. No corn hybrid is totally resistant but some varieties (especially early maturing) are mo...

As summer progresses, not only do the crops grow, but also the Ohio Field Days multiply. Here are some field days coming up. July 22: Maria Stein, Ohio, Manure Science Review, 9 AM–3:30 PM The event focused on the latest research, technologies, and best practices in manure management and water quality. Hosted at Homan, Inc., 6915 Olding Road, Maria Stein, Ohio. Topics: Comparisons between manure and commercial fertilizer, nutrient best management practices, updates on water quality and Lake Erie, H2Ohio initiatives from the Ohio Department of Agriculture. For more information, visit: ocamm.osu.edu or waterqualityextension.osu.edu August 5: Allen Dean Farm, Soil Health Field Day, ½ Mile North of RT 6 on CR 13, Bryan, Ohio 43506. 1 PM–8 PM with a Gourmet Meal. $25 per person. Call or text Shelley: 419-533-6844. Speakers are Dr. Elizabeth Rieke on Soil Microbiome and Brain Rath, Soil Health Institute. August 13: Planter & Technology Field Day, 9 AM–1 PM includes lunch. Precision Agri ...

  As wheat and barley harvest progresses, farmers often ask what should they do with wheat straw? Should I keep the straw on the field to build soil organic matter (SOM) or should I sell it? What is the value of the wheat straw and how many nutrients are being lost? Does straw residue hurt the next crop? Straw is a valuable resource in high demand for bedding or mulch and livestock farmers are even using straw to add fiber to their livestock rations. Fewer farmers are growing wheat today and a little barley is being grown. At a minimum, straw sellers should consider the value of nutrients leaving the farm plus the value of the lost organic material plus the harvesting cost. The nutrient value of straw varies but 9-12 pounds of nitrogen (N), 3-4 pounds of phosphorus (P2O5) and 25-45 pounds of potassium (K2O) per ton can be lost on fields that yield 1-2 tons straw per acre. Based on N-P-K values of $.60-$.90-$.40 per pound, the nutrient value per ton varies for N from $5.40-$7.20, fo...

New research show that microbes, especially bacteria and now fungi are the best at pulling moisture from the sky and making it rain. Dust and dirt particles can help it rain, but they are not as efficient as microbes. A recent article in Science Advances shows how the rain cycle works. Most rain starts as atmospheric water vapor and has to freeze into ice crystals before it comes down, turning into rain. Water in the atmosphere does not always freeze at 32OF. In fact, atmospheric water can stay liquid down to -40OF below zero. Temperatures are much lower at cloud level so clouds can stay full of moisture till it gets cold enough and attaches to something to freeze to cause ice crystals and then turn to rain. “Supercooled” water is a liquid cooler than normal freezing water because it has nothing to hold onto. For clouds to make snow, ice, or rain, it needs a “seed”, a tiny particle for the water molecules to grab onto to form an ice crystal before it falls from the sky as rain. Dust, s...