First, we found complementary evidence from experiments in the field and greenhouse that there is genetic resistance to Phomopsis cane and leaf spot among plant genotypes representative of segregating families, based on observations of symptoms on different grapevine organs (canes, shoots, and clusters). Our findings of Phomopsis susceptibility in powdery mildew-resistant breeding materials makes it clear that cessation of fungicide use to minimize the latter could exacerbate the former. Understanding the genetics of resistance to Phomopsis cane and leaf spot on these organs could facilitate better strategies for its management in diverse environments, such as the east and west coasts of the USA, where the pathogens of both diseases are a problem.