Apply plant resistance inducer, such as Actigard (Syngenta) if you are using moderately resistant cultivars (i.e., FL 7514). Actigard enhances resistance against this disease if it is used in combination with moderately resistant cultivars.
Chloropicrin was suggested as the most promising chemical for reducing tomato bacterial wilt when it was used as soil fumigant before transplanting (Enfinger et al., 1979).
Unfortunately there is no cure for fungal wilt diseases, so infected plants should be removed and discarded, but do not place diseased plants in the compost pile.
Pesticides such as algicide (3-[3-indolyl] butanoic acid), fumigants (metam sodium, 1,3-dichloropropene, and chloropicrin), and plant activators generating systemic resistance on the tomato (validamycin A and validoxylamine) have been used to control bacterial wilt.
Prochloraz and bromuconazole were the most effective fungicides against the pathogen both in vitro and in vivo, followed by benomyl and carbendazim. All other fungicides were less effective.
Treatment with chemical fungicides especially prochloraz, carbendazim, propiconazole, thiabendazole, benomyl, thiophanate, fuberidazole and benzimidazoles considerably reduce the wilt incidence in tomatoes [7, 8].
Synthetic fungicides are widely used to control wilt diseases. Thiophanate-methyl was found to be effective against Fusarium wilt disease when applied as a soil drench and a seed dresser3.
There is no effective fungicide or other cure for Fusarium wilt. The pathogen nearly always kills infected hosts. Prevention and exclusion are the only effective management strategies. Avoid this problem by replanting at that site using species from different genera than plants previously infected there by Fusarium.
Unfortunately, there is no cure for fusarium wilt. The only option is preventing fusarium in your plants. Once your plants are infected, they must be removed and destroyed.
The major differences in these wilts are: 1) The fungi proceed slowly in the host relative to bacteria and produce more uniform symptoms through the plant. 2) In bacterial wilt, symptoms appear from the top down, whereas in Fusarium and Verticillium wilt, symptoms begin at the bottom of the plant and progress upward.
Symptoms and Signs
Initially, symptoms of Fusarium wilt of tomato appear as one-sided wilting of only half of the plant, branch, or leaflet. At first, the plant will appear to recover from the wilt, but as the disease progresses, it will become permanent regardless of temperature or water status.
It's not unusual for a tomato plant to appear vigorous and thriving one day and then be a limp collection of stems and leaves the next. Wilt is a sign of stress that needs to be addressed quickly to save the plant. Unfortunately, wilt is often not curable, but it can be prevented.
Both fungi invade the plant through the fibrous root system and disrupt water and mineral uptake within the plant. Infection and disease development in Fusarium wilt are favored by warm soil temperatures (80° F) and low soil moisture, while Verticillium wilt develops best at relatively cool (55-75 F) soil temperatures.
It is important to note that there is no cure for bacterial wilt, and infected plants will need to be removed and destroyed.
Chemical Control
Once infected with the virus, there are no treatments against the infection. Control the whitefly population to avoid the infection with the virus. Insecticides of the family of the pyrethroids used as soil drenches or spray during the seedling stage can reduce the population of whiteflies.
In general, however, Fusarium wilt diseases are best controlled by using resistant or tolerant cultivars, not by using soil applied fungicides. Liming soils and using nitrate nitrogen fertilizer have been effective for management of F. oxysporum on chrysanthemum, aster, gladiolus, cucumber, tomato, and watermelon.
Use of calcium nitrate fertilizer instead of ammonium nitrate can reduce Fusarium disease severity in some soils. In acidic soils, raising the soil pH to 7 can help to control disease.
Avoid over-watering: Over-watering can increase the chances of Fusarium Wilt because the fungus thrives in moist soil.
How to Control Fusarium Wilt: Once fusarium wilt infects a plant, there is no effective treatment. Remove and dispose of affected plants immediately; don't compost this garden refuse. Whenever possible, remove and replace fusarium-infected garden soil.
Chemical Control
Prothioconazole is the only commercially available fungicide with proven efficacy. Azoxystrobin, prothioconazole and thiophanate-methyl led to the highest values for reduction of Fusarium wilt and did not cause phytotoxicity in watermelons.
Fungicides that are labeled for Fusarium wilt of watermelon include: Proline 480SC®-active ingredient prothioconazole (FRAC group 3); 12-hour REI; 7-day PHI–This product was one of the first fungicides to be labeled for Fusarium wilt of watermelon, based partly on data from Purdue University.
The resistance of Fusarium species to most antifungal agents results in high mortality rates in immunocompromised patients. Natamycin is active against Fusarium species and, with voriconazole, is the mainstay of treatment for Fusarium keratitis.
You can reduce the spread of Fusarium wilt by limiting overhead watering, sanitizing equipment and planting resistant cultivars. Infected seeds and transplants are also common vectors of the disease, so know your sources or take proactive measures to sterilize plants before introducing them into the growing area.
Use an effective fungicide. These include: metconazole (Caramba®), prothioconazole + tebuconazole (Prosaro®), prothioconazole (Proline®), and adepidyn (Miravis Ace®). Apply an effective fungicide at the correct time. The most effective application window is from flowering (anthesis; Feekes 10.5.