The term resistance or tolerance does not mean that the plant is completely immune to disease. It refers to a plant's ability to overcome to some degree the effect of the pathogen. Also, no variety is resistant or tolerant to all diseases. For instance, the initials VF by a tomato variety indicates resistance to the fungal diseases Verticillium wilt and Fusarium wilt, but does not mean that the variety is also resistant to the common leaf diseases.
If you have had a particular disease problem on a crop in the past, check to see if resistance to this disease is available. Many catalogs clearly list information on resistance or tolerance to specific diseases.
The following list gives some examples of host plants and diseases to which resistance or tolerance is available:
monarda | powdery mildew |
phlox | powdery mildew |
rose | black spot, powdery mildew |
zinnia | powdery mildew |
apple | scab, cedar-apple rust, fireblight, powdery mildew |
asparagus | rust |
beans | powdery mildew, downy mildew, rust, various viruses |
broccoli | black rot, downy mildew |
cucumber | bacterial wilt, powdery mildew, downy mildew, various viruses |
pea | Fusarium wilt, powdery mildew, downy mildew, various viruses |
pepper | Verticillium wilt, various viruses |
sweet corn | rust, smut, Stewart's wilt, anthracnose, other foliar diseases |
tomato | Fusarium wilt, Verticillium wilt, Tobacco Mosaic virus, early blight |
This article originally appeared in the January 13, 1995 issue, p. 6.
Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Horticulture and Home Pest News, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on January 13, 1995. The information contained within may not be the most current and accurate depending on when it is accessed.