Causal Agent:
Bacterium (Pseudomonas corrugata)
Characteristic Symptoms: | |
Infected plants may display chlorosis of the upper leaves with associated wilting. | |
Affected stem and petioles have brown lesion and stem pith are hollow. | |
Infected plants show profuse formation of adventitous roots. | |
Conditions for Disease Development: | |
The bacterium is soil-borne and waterborne. It is considered a weak pathogen on tomatoes growing too rapidly. | |
High nitrogen fertilization, cool night temperatures, high relative humidity increase disease incidence and severity. Once the weather warms up, the plants tend to be able to outgrow the problem. | |
The disease frequently occurs when the first fruit set is close to mature green. | |
The disease appears to be quite difficult to spread by hand, clothing or pruning tools. | |
The pathogen may be seed-borne. | |
Management and Control: | |
Avoid excessive nitrogen application, especially when night temperature is cool. | |
Remove infected plants as soon as symptoms are observed to minimize spread of disease from plant to plant. | |
Avoid conditions that lead to vigorous plant growth and wet plants. | |
Control root-knot nematode and root-feeding insects since they may help in disease establishment and spread. | |
Biofumigation of soil using chopped mustard leaves can help suppress bacteria in the soil. | |
References: | |
Tomato Pith Necrosis (http://www.aces.edu/pubs/docs/A/ANR-0864/ANR-0864.pdf; http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/prm2859) | |
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