Correlation Analysis Between Incidence Rate of Eggplant Bacterial Wilt and Ecological Factors in the Field

In order to analyze the relationship between the incidence of eggplant bacterial wilt and the ecological factors in the field, the field data observation equipment of agricultural habitat was installed in the typical area of eggplant bacterial wilt in Tong’an of Xiamen. Then, the data of ecological factors such as air temperature, ground temperature, relative humidity, rainfall, solar radiation, photosynthetically active radiation, illuminance, CO₂ concentration and soil volumetric water content were collected. And the incidence of bacterial wilt and the distribution characteristics of pathogens for bacterial wilt in eggplant were investigated during the vegetative growth and generative growth stages. The results showed that the air temperature (28.6℃), ground temperature (30.1℃) and relative humidity (66.17%) in the vegetative growth period of eggplant were suitable for the occurrence of bacterial wilt. The incidence (7.90%) and disease index (5.40) of eggplant in the vegetative growth period were higher than the incidence (3.43%) and disease index (2.47) in the generative growth period. The distribution of Ralstonia solanacearum was the highest in the plants in the second stage of disease and their rhizosphere soil, which were 81.80×10⁵ cfu·g⁻¹ in the vegetative growth period and 99.31×10⁵ cfu·g⁻¹ in the generative growth period. The distribution of Ralstonia solanacearum with high pathogenicity in the diseased plants and rhizosphere soil was more than 10⁴ cfu·g⁻¹ and 10⁵ cfu·g⁻¹, respectively. The incidence of bacterial wilt in eggplant was significantly positively correlated with air temperature, ground temperature, relative humidity, rainfall, illumination radiation and carbon dioxide concentration (P＜0.01), and was significantly positively correlated with illuminance and soil volumetric water content (P＜0.05). The research results provided the basis for the establishment of the prediction and forecast technology of bacterial wilt and the effective prevention and control of the disease.