Stripe Rust Alert April 2022

Stripe rust has appeared in eastern North Carolina. It was found yesterday in field plots of DG Shirley in Washington County. A stripe rust epidemic can develop much quicker than a leaf rust epidemic. If scouting reveals stripe rust in your field a fungicide should be applied as soon as possible to preserve yield. Wheat varieties rated susceptible (S) and moderately susceptible (MS) should be scouted immediately.  Resistant (R) or moderately resistant (MR) varieties are at low risk. Apply fungicides to fields containing multiple stripe rust foci first before moving on to fields with less noticeable infections. A stripe rust focus is pictured in Figure 1B.

A: grass leaf with orange rust streaks; B: cereal field with patchy yellowing
Figure 1. A) Stripe rust is characterized by yellow to orange lesions arranged in stripes on wheat leaves. Heads can become infected if the disease is severe. B) Stripe rust foci in a wheat field. Fields with multiple foci should be treated with fungicide first. Images courtesy of Barry Lewis (A) and Tim Britton (B).

When choosing a fungicide pay close attention to harvest restrictions on the label. Table 1 is abbreviated from NCERA 184 Fungicide Efficacy for Control of Wheat Diseases to include only fungicide products with an excellent stripe rust rating. The fungicides Prosaro, Caramba, and Folicur provide excellent protection against a stripe rust epidemic. Generic versions of the same active ingredient will provide equivalent control. These fungicides have a 30-day pre-harvest restriction so use caution when applying to fields nearing harvest. Stobilurin-only products such as Aproach and Headline are less effective when used alone after a stripe rust infection has occurred.  Aproach Prima also provides excellent protection against stripe rust; however, this fungicide has a 45-day pre-harvest restriction and should only be applied to varieties that are still in boot and not yet heading. As a reminder Feekes 10.5 is heads fully emerged from the boot and Feekes 10.5.1 to 10.5.4 is the flowering stage.

Table 1. Abbreviated from NCERA-184 Fungicide Efficacy for Control of Wheat Diseases

Class Product Rate/A  (fl. oz) Stripe rust Harvest Restriction
Strobilurin Aproach SC 6.0 – 12.0 E3 Feekes 10.5
Headline SC 6.0 - 9.0 E3 Feekes 10.5
Quadris 2.08 SC 4.0-12.0 E Feekes 10.5.4
Triazole Caramba 0.75 SL 10.0 - 17.0 E 30 days
Folicur 3.6 F5 4.0 E 30 days
Prosaro 421 SC 6.5 - 8.2 E 30 days
Mixed Modes of Action Aproach Prima SC 3.4-6.8 E 45 days
Nexicor EC 7.0 - 13.0 E Feekes 10.5
Quilt Xcel 2.2 SE5 10.5 - 14.0 E Feekes 10.5.4
Trivapro SE 9.4 - 13.7 E Feekes 10.5.4 & 14 days
Topguard EQ 4.0 – 7.0 E Feekes 10.5.4 & 30 days


3Efficacy may be significantly reduced if solo strobilurin products are applied after stripe rust infection has occurred.