Sunflower Diseases Remain Rare in California Seed Production Fields Compared to North Dakota

Fig. 4. (A) Basal collar rot caused by Phytophthora cryptogea, showing girdling black lesion at soil line, which differentiates it from Phoma macdonaldii.



Image from Plant Health Progress article:
Sunflower Diseases Remain Rare in California Seed Production Fields Compared to North Dakota