Crop Pest Update - 17 Jun 2022

Summary

Insects: Flea beetles levels are at quite high levels in many areas. Some growers have applied up to three insecticide applications for flea beetles, and there has been some reseeding. Some fields of small grains and sunflowers have been sprayed for cutworms. Hatch of the potential pest species of grasshoppers is occurring; some control has occurred in the Central region.

Diseases: It has been wet lately. That is probably an understatement for many areas. As spring crops struggle to emerge and as fall crops move into the reproductive phase, unfamiliar symptoms are noticed by growers and agronomists. We provide a couple of examples of recent inquiries and challenge readers to put forward their best diagnoses.

Weeds: Good weather last week saw great seeding progress and sprayers were keeping up with burnoff before crops started to emerge. Heavy rains in the last couple of days have halted all operations including weed control. Perennial weeds and winter annuals have taken advantage of the moisture from last fall and this spring. Dandelions are flowering and setting seed, Canada thistle are 4 inches or more in size. Stinkweed and shepherds purse are flowering and setting seed. Annual weeds like round-leaf mallow, wild buckwheat, kochia, lambsquarters and red root pigweed are getting large. Warm season grasses like green and yellow foxtail and barnyard grass are emerging and growing rapidly. We’re seeing lots of biennial wormwood this year, which despite its name acts like an annual weed. We will discuss biennial wormwood later in this report.