Pseudomonas putida

Pseudomonas putida is a gram-negative soil bacterium that, under certain environmental stress, can act as an opportunistic plant pathogen. While widely recognized in research as a beneficial microbe for soil health, it can occasionally cause bacterial lesions and soft rots in agricultural crops, particularly in intensive cultivation systems.

This pathogen impacts a variety of plant species, ranging from greenhouse vegetables to sensitive seedling stages of cereal crops. Plants grown in hydroponic environments or under high-moisture conditions are particularly susceptible, as the bacterium can colonize the rhizosphere and infiltrate the vascular tissues through natural openings or micro-wounds.

Visible symptoms often start with localized chlorosis, followed by tissue softening and dark, water-soaked lesions on stems or leaves. As the infection progresses, it blocks the plant's vascular system, leading to rapid wilting. In many cases, the presence of a distinct bacterial smell is a key diagnostic feature indicating tissue decomposition.

Development and spread are facilitated by excessive soil moisture, lack of proper aeration, and temperature ranges between 20°C and 30°C. The pathogen easily spreads through contaminated water sources, poorly sterilized potting tools, and infected organic debris. Prevention requires strict adherence to sanitary protocols in both field and greenhouse settings.

To effectively manage and prevent the spread of this bacterial agent, agronomists should implement the following measures:

• ensure proper drainage and aeration in the root zone;
• implement rigorous sanitation schedules for tools and growing media;
• utilize balanced fertilization to avoid excess nitrogen, which can increase susceptibility;
• apply biological control agents to maintain a healthy rhizosphere microbial balance.