Ralstonia solanacearum Race 3 Biovar 2 Descalgar la guía descriptiva al formato PDF
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Management

Some level of bacterial wilt control on potato and tomato is possible using resistant A cultivar is a cultivated plant that has been selected and given a unique name because it has desirable characteristics (decorative or useful) that distinguish it from otherwise similar plants of the same speciescultivars. However, resistance in these host plants may vary across locations, according to variation in temperature. Similarly, the use of antibiotics (streptomycin, ampicillin, tetracycline and penicillin) and soil fumigation has shown little efficacy on R. solanacearum.

As a consequence, there are a number of alternative methods for control of R. solanacearum race 3 biovar 2. In regions where the disease is Endemic, in a broad sense, can mean "belonging" or "native to", "characteristic of", or "prevalent in" a particular geography, area, or environment; native to an area or scopeendemic, cultural control methods appear to be effective in some conditions for reducing bacterial populations of R. solanacearum and subsequent Disease Incidence is a measure of the risk of developing the disease within a specified period of timedisease incidence: crop rotation can be particularly effective for controlling R. solanacearum race 3 biovar 2, since the pathogen exhibits a fairly narrow host range. The length of time for crop rotation can vary, but rotations of at least two to five years involving several different non-host crops may be used for significant disease reduction; intercropping can be effective for small farmers as cultivation of beans or maize was shown to significantly reduce disease incidence; control of weeds, which have the potential to serve as inoculum reservoirs, in conjunction with crop rotation can also be effective in reducing disease incidence. Control of root-knot nematode populations and cultural practices that minimize root damage can also reduce disease severity.

Some other cultural strategies that might be used to reduce bacterial populations of R. solanacearum race 3 biovar 2 or decrease disease incidence on different hosts include: planting in uninfested production sites, removal of long-term survival sites, selection of appropriate planting and harvest times, deep plowing of crop residues, ensuring satisfactory soil drainage, or early- and late-season irrigation management.

Chemical treatment by soil fumigation has been used to control soil infestation by R. solanacearum race 3 biovar 2, but the method is environmentally destructive, expensive, and difficult to apply, and results are often unsatisfactory. Several different plant essential oils were successfully used as soil fumigants to reduce bacterial populations of R. solanacearum in tomato. Application of stable bleaching powder in conjunction with deep ploughing can also be used as it showed significant reduction in bacterial populations of the pathogen in greenhouse and field trials in several geographic areas. However, soil disinfection appears to be soil dependent and not universally applicable. Modification of soil pH by use of acidified nutrient solution or a combination of organic amendment and fertilizers was shown to be very effective in reducing bacterial wilt diseases on diverse hosts. Heat treatment by solarization when used in combination with other control strategies is another method that was shown to reduce R. solanacearum populations in soil. Efficacy of heat treatment on control of the bacterium may vary according to soil moisture content, heat temperature and duration of heat application. Application of Plant resistance inducers are natural or synthetic chemical compounds that apparently act by stimulating the natural defense response in the plantplant resistance inducers, such as acibenzolar-S-methyl, might be used to enhance host resistance against R. solanacearum race 3 biovar 2, as it was recently shown to work for broad host range strains of the pathogen on tomato. On geranium, application of phosphorous acid as a drench was recently shown to protect host plants from infection by the bacterium. Finally, use of A suppressive soil is one that possesses some level of control of a disease forming organism. All soils have a natural level of disease suppressive activities. In most soils long term management can either reduce or increase this level of suppressionsuppressive soils was shown to slow infection of tomato seedlings by R. solanacearum and reduce bacterial wilt incidence in nurseries.

Initial studies on Biological control is defined as the reduction of pest populations (including insects, mites, weeds and plant diseases) by natural enemies. Biological control agents of plant diseases are most often referred to as antagonistsbiological control of R. solanacearum gave promising results. The use of numerous diverse bacterial strains antagonistic to R. solanacearum as control agents gave positive results in the greenhouse or in strictly controlled field tests. Similarly, antagonists that are closely related to or derived from the wild type of R. solanacearum itself, such as spontaneous or genetically engineered avirulent mutants of the bacterium, were shown to confer protection against bacterial wilt disease on potato and tomato under greenhouse conditions. Such antagonists may be able to colonize and survive asymptomatically on the host without reducing yield. The use of these strains as antagonist agents for control of R. solanacearum under true field conditions has to be evaluated.

In the United States and other areas where R. solanacearum race 3 biovar 2 is not known to be established, the first strategy is to prevent introduction and inadvertent spread of the pathogen. This can be achieved by the establishment of exclusionary and sanitary practices, along with governmental regulations.

A “New Pest Response Guidelines” (USDA-APHIS-PPQ) and a "Recovery plan for Ralstonia solanacearum race 3 biovar 2" (USDA-ARS) give the most accurate available information for detection, control, containment, and eradication of R. solanacearum race 3 biovar 2.

In areas where the pathogen is present but not yet established everywhere, it is critically important to observe good cultural sanitation practices to keep uninfested areas clean. These include planting only certified disease-free seed potatoes or cuttings, disinfesting all equipment before moving from field to field, and never using surface water for irrigation. Even where R. solanacearum race 3 biovar 2 is present in soils (as in many parts of the African highlands), use of disease-free seed potatoes can significantly reduce disease incidence and allow growers to harvest a profitable crop. Effective health management of brown rot of potato, Southern wilt of geranium and bacterial wilt of tomato caused by R. solanacearum race 3 biovar 2 will be possible through establishment of specific strategies and practices adapted for each of these diseases.

A “Minimum sanitation protocols for offshore geraniums cutting production” document was developed by APHIS-PPQ in 2004 to be used by off-shore geranium suppliers. It defines minimum standards and requirements for greenhouse structure and material.

Regulation

In the United States, R. solanacearum race 3 biovar 2 is listed as a Select Agent, a designation under the Plant Protection Act (7 CFR Part 330) and the Agricultural Bioterrorism Protection Act of 2002 (7 CFR Part 331) that defines the possession, use, and transfer of Select Agents and Toxins.

State diagnostic laboratories receiving suspect infected plant material or cultures are required to have permits from the USDA-APHIS-Plant Protection and Quarantine (consult the APHIS-PPQ permit website). Laboratories possessing, using, or transferring Select Agents such as R. solanacearum race 3 biovar 2 are required to be registered with the PPQ. Diagnostic laboratories that are not registered and identify R. solanacearum race 3 biovar 2, or receive positive feedback from the USDA Laboratory, from a suspect sample are required to immediately notify the APHIS Select Agent Program within seven calendar days, and either destroy or transfer the agent to a registered laboratory within seven days.