8/27/26 - When is Black Rot not Black Rot?

Find full show notes at https://www.extension.iastate.edu/commercialhort/82726-notes-what-weather

00:00:32 Iowa weather history: Heavy thunderstorms in 1903 produced extraordinary rainfall totals across southern Iowa, including an unofficial 14.61 inches at Woodburn.

00:01:26 Weather trivia: What causes the reddish, coppery appearance of the Moon during a lunar eclipse?

00:02:00 Weekly forecast: A quieter storm track overall, better rain chances Saturday, slight chances early next week, and temperatures about 5 degrees above normal.

00:02:33 Climate outlook: A warmer-than-normal start to September is favored, while precipitation is expected to be near normal statewide. Southern Iowa faces a slight risk of extreme heat during the September 3–9 period.

00:04:28 Seasonal outlook and El Niño discussion: The hosts examine the September–November outlook, the developing Pacific signal, and how climate models use analogs and trends.

00:06:08 Past-week weather recap: Pleasant temperatures, cool nights, limited rainfall in parts of Iowa, and a reminder to credit the Iowa Environmental Mesonet and Daryl Herzmann when using IEM data. https://mesonet.agron.iastate.edu/onsite/features/cat.php?day=2026-08-27

00:07:52 Iowa temperature and precipitation extremes: Rock Rapids reached 90°F, while Spencer Municipal Airport and Lake Park fell to 47°F; Boone recorded the week's highest precipitation total.

00:08:59 Lunar eclipse viewing: Details on the August 27 deep partial lunar eclipse, including peak viewing at 11:12 p.m. Central Time and 96.3% coverage at maximum eclipse.

00:10:19 Specialty crop impacts: Powdery mildew management, late-season pumpkin guidance, and a diagnosis of Xanthomonas leaf spot in Lacinato kale.

00:12:52 Managing Xanthomonas leaf spot: Resistant cultivars, copper-based treatments, removal of affected leaves, sanitation, crop rotation, and hot-water seed treatment for brassicas.

00:14:33 Wet-season crop challenges: Dan discusses troubleshooting difficult field conditions for a northeast Iowa grower and compares the challenging 2026 season with 2025.