Hazardous Weather Outlook – Isolated Severe Thunderstorms Possible 4/14/2025: Be Prepared to Apply Streptomycin Tomorrow if You Get Hail
TO ALL LOCATIONS WITH THE POME FRUIT IN VIRGINIA: Even though there is no risk in NEWA EIP model for fire blight infection, there is a warning issued this evening for isolated severe thunderstorms predicted for Virginia locations in most of the Shenandoah Valley and Blue Ridge Mountains that have a chance to bring small to large size hail and wind gusts that can trigger trauma blight. Trauma blight are infections on green and woody tissues due to mechanical injury by hail and wind. Wind can move fire blight and allow spread to other locations. If you get hail, please apply streptomycin up to 24 h after a hail storm started.
Fire blight EIP values in NEWA as of today, are low and there are no reported flower infections – but this applies only if a “normal” rain is in question. We have potential hail and damaging gusts predicted and protection is needed if hail occurs.
EMERGENCY SPRAY OPTION: Harbor, or Agrimycin 17 WP, or FireWall 17 WP at 1.5 to 3 lb per acre (24 – 48 oz/A) plus LI 700 at a penetrating rate or use Regulaid instead of LI700. Based on the Regulaid label, you could use 2 pints penetrating rate. FireWall changed its formulation to FireWall 50WP and the rate to use this higher concentrated material is 8 – 16 oz/A. If hail occurred ally this antibiotic up to 24 h after the start of the rain or hail storm today (the sooner after rain the better). Application of streptomycin in mix with Regulaid or LI700 up to 24 h after the infection rain event started allows absorption of antibiotic in green tissue and triggers so called “kick-back” mode of action – killing just established infection during the rain that started hours before with start of rain or hail. Add mancozeb to this application and a single site fungicide for scab and rust.
If you used captan recently, DO NOT add Regulaid or LI700 to streptomycin for this spray. Keep in mind that hail can damage not only fruit but bark on twigs, shoots, branches and trunk, opening wounds that can be infected with fire blight and lead to trauma blight. If you had a recent history of fire blight and storm does occur on your location, this spray is essential. Please examine hail warnings for locations along and south of I-66/US-50 (Source: https://forecast.weather.gov/):
Hazardous Weather Outlook
Hazardous Weather Outlook National Weather Service Baltimore MD/Washington DC 652 PM EDT Mon Apr 14 2025 MDZ003>006-503-505-507-VAZ025>031-036>040-050-051-501-502-505>508- 526-WVZ050>053-055-152300- Washington-Frederick MD-Carroll-Northern Baltimore- Northwest Montgomery-Northwest Howard-Northwest Harford-Augusta- Rockingham-Shenandoah-Frederick VA-Page-Warren-Clarke-Nelson- Albemarle-Greene-Madison-Rappahannock-Orange-Culpeper- Northern Fauquier-Southern Fauquier-Western Loudoun- Eastern Loudoun-Northern Virginia Blue Ridge- Central Virginia Blue Ridge-Northwest Prince William-Hampshire- Morgan-Berkeley-Jefferson-Hardy- 652 PM EDT Mon Apr 14 2025 This Hazardous Weather Outlook is for portions of eastern West Virginia, northern and central Virginia, and central and western Maryland. .DAY ONE...Tonight A Severe Thunderstorm Watch is in effect until 1AM for locations along and south of I-66/US-50. Elsewhere, showers and thunderstorms are expected this evening. A line of thunderstorms may develop, and could produce damaging wind gusts especially along the Interstate 64 corridor, and west of the Blue Ridge Mountains south of Highway 50 and Interstate 66. Several instances of large hail and a tornado or two are also possible. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday A Wind Advisory is in effect from 10 AM to 8 PM on Tuesday for most of the Shenandoah Valley and Blue Ridge Mountains. Strong winds may cause isolated damage to trees and power lines Tuesday through Wednesday, especially in the higher elevations. .SPOTTER INFORMATION STATEMENT... Spotter activation will likely be needed this evening. $$