Evaluation of Phosphonate Treatments for Control of Phytophthora Crown Rot of Walnut

Fig. 1. Canker incited by Phytophthora citricola in Persian walnut. The trees were inoculated at either 1 or 7 months after application of preventative phosphonate treatments, and efficacy of the treatments was assessed according to the area of cankers 2 to 3 months after inoculation.



Image from Plant Health Progress article:
Evaluation of Phosphonate Treatments for Control of Phytophthora Crown Rot of Walnut