The incidence of stolbur disease and associated yield losses in vegetable crops in South Moravia (Czech Republic)

The study was performed at a vegetable farm from 2006 to 2008 in the intensive horticultural area of Lednice (South Moravia, Czech Republic), where a stolbur (phytoplasma) epidemic had occurred. The study showed that the incidence of stolbur disease reached 15% in both tomato (Lycopersicon esculentum) and pepper (Capsicum annuum), and up to 6.7% in celeriac (Apium graveolens). There were significant yield losses in the stolbur-affected plants; total yield losses were up to 60% in tomato, 93% in pepper, and 100% in celeriac. The mean yield was significantly decreased in stolbur-affected plants, compared to healthy plants (i.e. from 42.79 to 17.21 fruits per plant in tomatoes; from 10.11 to 0.74 fruits per plant in peppers). In the locality studied, it was mainly the weed plants Convolvulus arvensis and Cirsium arvense (which were frequently interspersed among the crops), which tested positive for the stolbur phytoplasma and might have provided a reservoir for the phytoplasma infection.