| Abstrakt: |
Shallots are essential vegetables in horticulture, but there is insufficient information available on the effects of drought stress on different growth stages and the inoculation of plant growth-promoting rhizobacteria (PGPR) on their photosynthetic characteristics. This study aims to investigate the effects of drought stress at different growth stages (vegetative growth phase, bulb initiation phase, bulb development phase, and maturation phase) and PGPR inoculation (Pseudomonas Pb04 and Bacillus Pb03) to mitigate the negative impact of drought stress on photosynthetic characteristics, chlorophyll content, and shallot yield. The results showed that the optimal photosynthesis rate, chlorophyll content, and yield of shallots were most tolerant when the plants experienced drought stress in the maturation phase compared to other growth phases. During the maturation phase, the reduction in photosynthesis rate at PPFD 900 µmol·m-2s-1 is only 19.1% compared to plants without drought stress. Drought stress during the bulb growth phase takes the longest to recover conditions after stress, leading to inhibited growth when stress occurs during this phase. In the bulb growth phase, the decrease in photosynthesis rate is 34.8% compared to the treatment without drought stress. PGPR can mitigate the sensitivity of plants to drought stress. Pseudomonas Pb04 predominantly suppresses the impact of drought stress during the vegetative growth phase, while Bacillus Pb03 has a more dominant effect on drought stress occurring during bulb initiation, bulb development, and maturation phases. [ABSTRACT FROM AUTHOR] |
