Hurricane Beryl left a lasting mark on rice fields across Missouri’s Bootheel region, where the sudden explosion of fall armyworm populations is threatening this year’s crop.

According to a press release from the Missouri Department of Agriculture, winds associated with the hurricane likely spread the pest, affecting an estimated 60,000 acres of rice. To control movement and prevent damage, farmers should consider insecticide applications.

MDA director Chris Chinn declared a Crisis Exemption through Section 18 of the EPA’s Federal Insecticide, Fungicide, and Rodenticide Act. The measure received EPA concurrence, allowing the use of Intrepid 2F Insecticide from Corteva to mitigate armyworms in Missouri rice.

The Crisis Exemption took effect July 18 and remains through Sept. 30 for the following Missouri counties: Butler, Stoddard, Pemiscot, Bollinger, Dunklin, Scott, New Madrid, Cape Girardeau, Mississippi, Perry and Ripley.

Farmers can apply Intrepid 2F at rates of 4 to 8 fluid ounces per acre, with up to two applications per rice field during the exemption period.

Assess damage from fall armyworm

Fall armyworm larvae threaten rice plants, primarily feeding on the leaves of young rice plants, destroying large amounts of tissue.

Researchers at Louisiana State University Extension say severe stand loss can occur with seedlings potentially pruned to the ground. LSU offers the following tips for rice growers dealing with fall armyworms this year:

Scout fields. Conduct weekly inspections for larvae on rice plants. Mature larvae are about 1 inch long and have a distinct inverted “Y” on the head.

Monitor bird activity. Birds are often attracted to fields infested with armyworms. Large flocks of birds around a field should prompt increased scouting.

Sample plants. Inspect rice plants every 10 feet along a line across the field, then repeat this process in a second and third area of the field. An average of one armyworm per two plants warrants treatment.

UNIQUE MARK: To scout, pay special attention to this pest’s head (bottom), as a “y” is present on fall armyworms. (Photo courtesy of Missouri Department of Agriculture)

Importance of rice to state

Missouri is ranked fourth among rice-producing states in the country, according to MDA.

The USDA National Agricultural Statistics Service reports 205,000 acres planted to rice this year, up 31% from 2022. Expected yield was at 7,990 pounds per acre or 16 million cwt.

The 2023 value of Missouri rice production was more than $246 million.