Answer:
The plant should reproduce by sexual reproduction.
Step-by-step explanation:
In asexual reproduction, the chances of variation becomes limited which decreases the chances of evolution of a species but in sexual reproduction the chances of variation in species increases which increases the evolution rate in sexually reproducing organisms.
So if a plant growing in an environment where harmful bacteria pathogen is abundant then the plant should reproduce sexually which will allow the production of genetically different offspring which will have a new allele that can resist the bacterial infection which is not possible in asexual reproduction due to lack of or slow variation.