Carrot leaf blight
Alternaria dauci
Symptoms of A. dauci appear first as greenish-brown, then water-soaked, and finally necrotic lesions 8–10 days following an infection event. These lesions will appear on carrot leaflets and petioles, and have a characteristic chlorotic, yellow halo. The lesions can be irregularly shaped, and will often appear on older leaves first. Older leaves are the most susceptible to infection; when approximately 40% of the leaf surface area has become infected by Alternaria dauci, the leaf will completely yellow, collapse, and die. It is during extended conditions of warm, moist weather that lesions can coalesce and cause entire tops of carrot plants to die off, a phenomenon that is sometimes mistaken for frost damage.
Pesticides
Amistar Top
intensity: ★★★
Aprisco 900 WG
intensity: ★★★
Bravo
intensity: ★★★
Bravo Weather Stik
intensity: ★★★
Bulls-eye
intensity: ★★★
Cavalry Weatherguard
intensity: ★★★
Cherokee 900
intensity: ★★★
Conan 500
intensity: ★★★
Conan 720 SC
intensity: ★★★
Cupro Isagro 375 WG
intensity: ★★★
Divino 250 EC
intensity: ★★★
FMC Chlorothalonil 720
intensity: ★★★
FMC Chlorothalonil Bond 720
intensity: ★★★
Ospray Copper Oxychloride-WP
intensity: ★★★
Rotam Aprisco
intensity: ★★★
Ace
intensity: N/A
Arysta LifeScience Copper Oxychloride WP Fungicide/Bactericide
intensity: N/A
Barmac Zineb
intensity: N/A
Barrack 720
intensity: N/A
Barrack Betterstick
intensity: N/A
Chlornil 720 SC
intensity: N/A
Chloronil Pro
intensity: N/A
Chlorothalonil
intensity: N/A
Clash Dry 900 WG
intensity: N/A
Clash Storm Guard 720 SC
intensity: N/A
Copper Oxychloride
intensity: N/A
Echo 720
intensity: N/A
Isagro Neoram 375 WG
intensity: N/A
Pacific Echo 500 SC
intensity: N/A