Vegetative Annual Disease Management
By Jane Trolinger, Ph.D., Syngenta Flowers Technical Services
(4/20/12) -- Vegetative annual crops can be affected during production by several different diseases, some of which can be devastating. Recently, two types of pathogens have been problematic for calibrachoa, New Guinea impatiens, petunia and verbena: Botrytis, an ubiquitous fungus known as gray mold; and the tospoviruses, Impatiens Necrotic Spot Virus ("INSV") and Tomato Spotted Wilt Virus ("TSWV"). Here are some tips for managing Botrytis and tospoviruses in the greenhouse. To prevent Botrytis:
- Remove and discard severely affected plants and clean diseased plant parts (e.g., senescing leaves) from healthy plants. Bag and remove from the greenhouse.
- Practice thorough sanitation in the greenhouse, especially debris removal from below the bench and aisles, and daily garbage can removal and cleaning. This will ensure Botrytis is not sporulating on any plant tissues or debris and prevent it from spreading to otherwise healthy plants.
- Avoid injury to plants.
- Avoid excess nitrogen.
- Prevent high humidity conditions by providing sufficient plant spacing and air circulation, and by reducing overhead watering. Botrytis spores need a film of water to germinate, so keeping the leaves as dry as possible reduces the chances of Botrytis being able to thrive.
- Use appropriate fungicides......
Impatiens necrotic spot virus ("INSV") and tomato spotted wilt virus ("TSWV") are transmitted by western flower thrips ("WFT"), so the best way to control these viruses is to control the thrips, which are considered one of the most serious pests on ornamental crops. In addition to vectoring the tospoviruses, WFT damage plants directly by feeding. Generally, INSV is a more frequent problem in greenhouses than TSWV. Key information to prevent tospoviruses:
LINKS:
Tech Tip: Vegetative Annual Disease Management
|
|
