Field Notes 05-12-22

A hot and humid weather pattern has spurred fieldwork, gardening and plant development across the state. Unsettled, breezy conditions with highs reaching the 80s and low 90s have prevailed since last week, while scattered showers and storms brought varying amounts of rain. Temperatures in Madison and several other southern and western locations reached the 80s for four days in a row May 9-12, making it the hottest streak since last August.

Crop producers are reporting measurable progress on spring field preparations and planting, with tillage approximately 30% complete statewide (up from 15% last week). Meanwhile, observations from apple growers indicate wide variation in apple tree phenology, ranging from half-inch green in the far north to tight cluster and pink along the Illinois border. In La Crosse, the eastern redbud is in full bloom.

Record highs are expected today, with afternoon heat index values in the upper 80s and 90s, before cooler weather returns next week.

__________________________________

^{Black cutworm larva | Purdue Extension}

Black cutworm development has accelerated with the abrupt mid-May warming trend. Beloit, currently the most advanced location in the state, has accumulated 100 growing degree days (GDDs) of the 300 GDDs needed for the black cutworm to develop from the egg stage to the damaging fourth-instar larval stage. Based on forecast predictions for the next 10 days, and using May 4 as the biofix (the date of the first “intense” moth captures), corn growers can anticipate the peak black cutworm damage window to open May 25 in southern Wisconsin.

La Crosse has accumulated 104 GDDS since the first intense moth flights on May 4 and the peak seedling corn cutting window for the west-central area of the state is expected to open May 26. Near Eau Claire, the projected starting date for the primary cutworm damage season is May 30.

DATCP’s 30 monitoring locations collected 252 moths this week, with a high count of 29 moths recorded at both Grand Marsh in Adams County and Leeds in Columbia County. Pheromone traps have captured a cumulative total of 469 moths since traps were set on April 1. Last season at this time, the count was 927 moths.

__________________________________

^{Eastern redbud full bloom | K. Hamilton DATCP}

^{Having trouble viewing this email? View it as a Web page.}