Spring may feel far away, but vegetable garden planning begins during the cold months of winter. Seed catalogs, store displays, and online retailers present a number of different options. However, successful production begins with the selection of the right seeds for each garden. Gardeners often have preferences towards certain cultivars or varieties, but if plant diseases have plagued plants in the past then it may be time to consider a change.
Selection of a disease tolerant or resistant cultivar is one way to prevent or limit the impact of plant diseases in the vegetable garden. A number of cultivars are labeled as tolerant, which means that while plants may become diseased, plants still yield sufficient amounts of produce. Resistant cultivars do not become diseased, and therefore produce higher yields than those that are susceptible to disease.
While no single cultivar is resistant or tolerant to all plant diseases, use of resistant cultivars can reduce or elevate the need for additional plant disease management practices, such as fungicide sprays. Gardeners should choose cultivars that are tolerant/resistant to the diseases of greatest concern in their garden. It is advisable to keep a garden journal of cultivars that have been grown in the past, as well as a record of disease issues. Proper diagnosis of plant diseases is important for future disease management. If issues arise in the vegetable garden, contact a local county Extension agent for assistance.
Select a tolerant or resistant cultivar by reviewing information on websites, seed packets, or seed catalogs. Note that disease names may be abbreviated, or a coding system may be used to indicate resistance or tolerance to specific diseases. Varieties with resistance/tolerance to common vegetable disease issues are detailed below. Additional information about resistant/tolerant varieties can be found in Vegetable Cultivars for Kentucky Gardens (ID-133) or by contacting a local county Extension agent.
Tomato
Early blight is the most common disease of tomatoes in Kentucky, and often co-occurs with Septoria leaf spot. Tomatoes with some resistance to early blight are ‘Jasper,’ ‘Matt’s Wild Cherry,’ ‘Mountain Magic,’ and ‘Sun Gold’ (small cherry tomatoes), ‘Indigo Rose,’ ‘Plum Regal,’ and ‘Verona’ (Roma size), and ‘Defiant,’ ‘Iron Lady,’ ‘Mountain Fresh Plus,’ ‘Mountain Merit,’ and ‘Stellar’ (slicing size).
Pepper
The bacterial spot pathogen causes the most common disease of peppers. There are at least ten races of the pathogen, and pepper resistance is race-specific. Commonly occurring races can vary by location, so it is recommended to choose cultivars with resistance to as many races as possible. Some suggested cultivars include: ‘Boca,’ ‘Ninja,’ ‘Outsider,’ ‘Playmaker,’ ‘Samurai,’ and ‘Tracer.’
Cucurbits (Cucumber, Squashes, Muskmelon, Watermelon, Pumpkin & Zucchini)
Many powdery mildew resistant cultivars of picklers, slicers, pumpkins, and squash are available.
Cultivars that are less susceptible to bacterial wilt include the pickle cukes ‘Cross Country’ and ‘County Fair,’ ‘Howden’ pumpkins, and ‘Waltham Butternut’ squash. Manage cucumber beetles for best management of bacterial wilt. All watermelons have natural resistance to bacterial wilt.
Leafy Greens
Many lettuces have been bred for resistance to downy mildew. Consider head lettuces ‘Kweik,’ and ‘Pirat,’ green leafed lettuces ‘Black Seeded Simpson,’ and ‘Nevada,’ and red leafed lettuces ‘Galactic,’ ‘Red Zin,’ and ‘Rustica’ for their additional resistance to bacterial disease and/or white mold (drop).
Powdery mildew-resistant lettuces include ‘Jericho’ and ‘Super Jericho’ (romaines), ‘Sandy’ (oakleaf), ‘Loma,’ ‘Red Salad Bowl,’ and ‘Skyphos’ and ‘Red Cross’ (red butterheads).
‘Regal’ and ‘Samish’ spinaches are resistant to downy mildew and white rust.
Kale, collards, turnip greens, and mustards are naturally less susceptible to many diseases.
Legume Vegetables (Beans & Peas)
Many French and green beans have been bred for resistance to anthracnose, but resistance in other types of beans is unavailable.
‘Caprice,’ ‘Espada,’ ‘Kentucky Blue,’ ‘Romano II,’ ‘Volunteer,’ and ‘Goldkist’ are fungal leaf spot and/or rust resistant bean varieties, with additional resistance to various viral diseases (viruses are not common in Kentucky).
‘Green Arrow,’ ‘Cascadia,’ ‘Sugar Daddy,’ and ‘Oregon Sugar Pod II’ are pea cultivars suggested for their resistance to powdery mildew, Fusarium wilt, and Verticillium wilt.
Cole Crops (Cabbage, Broccoli, Cauliflower, Kohlrabi & Brussels Sprouts)
Black rot is the most common disease of cole crops in Kentucky. Cabbage cultivars ‘Bilko,’ ‘Blues,’ ‘China Pride,’ ‘Blue Vantage,’ and ‘Bronco’ carry resistance to a broad range of diseases, such as downy mildew, Fusarium yellows, and/or black rot.
Broccoli cultivars ‘Emperor,’ ‘Pinnacle,’ and ‘Green Magic’, as well as cauliflower cultivar ‘Majestic’ are resistant to downy mildew and/or black rot.
‘Grand Duke’ kohlrabi is resistant to black rot.
Categories: Kentucky, Rural Lifestyle