Clubroot Control in Chinese Cabbage

The greenhouse experiment was performed from March to May 2021 under controlled conditions: 30/18°C day/night temperature and 10/14 h light/dark photoperiod (Zhang et al., 2022b (link)). The pots (24 × 18 cm diameter) were filled with 3.5 kg/pot of diseased soil heavily infected with clubroot pathogen collected from the field (Xiadabai County, Kunming, China). Lime and ammonium bicarbonate were added to each pot at the ratio 1:1,300 (m/m), mixed thoroughly with the diseased soil, covered with plastic film (0.08 mm), and placed in a greenhouse at >35°C. The experiment was performed under four different conditions: NB; soil fumigation with lime (2.69 g/pot), N; soil fumigation with ammonium bicarbonate (2.69 g/pot), LNB; soil fumigation with combined ammonium bicarbonate (2.69 g/pot) and lime (2.69 g/pot), and GZ; no soil fumigation as control. After 15 days of anaerobic soil fumigation, Chinese cabbage seedlings were transplanted in pots (5 plants/pots). In addition, fertilizer was applied in each pot before the transplantation of seedlings to overcome the nutrient deficiency (Wei et al., 2021 (link)). The experiment was repeated three times with 15 plants per replication (in total, 45 plants/treatment) and was accomplished using a completely randomized design.