1. Hosts/Symptoms

2. Disease Cycle

3. Environment
     Management    Cultural control   Chemical control  

4. Importance
     United States    India  

5. See also

6. References

Hosts/Symptoms

Buckeye rot of tomato affects tomato plants, although there are many other plants that are affected, including pepper, potato, tobacco, pineapple, and various other hosts.^[4] Upon infection, brown and greyish-green water soaked spots appear on the fruit. These spots develop into lesions that resemble the markings of a bull's eye with alternating dark and light brown concentric rings. These are very smooth lesions, barely raised, unlike the rough lesions found in late blight (Phytophthora infestans), which is a similar pathogen.^[1] Finally, a white fungal-like growth may appear within the lesion.^[2] While fruit rot is the most common symptom, damping off and stem cankers are possible.^[1] The disease does not affect the foliage of the plant, which further helps separate it from late blight .^[2]

Disease Cycle

Environment

Buckeye rot is favored by warm, wet weather. Temperatures between {{convert|75|and|86|F}} are ideal for the fruit rot.^[5] In order for sporangia to be produced, allowing the pathogen to reproduce, the soil must be wet and above {{convert|65|F}}.^[6] Zoospores can only disseminate by swimming in water, so excessive rain and irrigation promote growth of the disease.^[2] Oospores, on the other hand, can be spread across a field by water runoff, farming equipment, and workers.^[6]

Management

Because there are currently no disease resistant varieties, cultural and chemical control are the only management options.^[1]

Cultural control

Once the pathogen is in the soil, avoid fluctuation in moisture, compact soil, and prevent flooding by providing good drainage. Specifically, keep the tops of the bed dry to avoid the fruit rot.^[7]

This will provide a less than ideal environment for the pathogen to survive and grow. Crop rotations every 3 to 4 years can be another alternative to control the disease.^[6] Since the pathogen is found in the soil, avoiding contact of the fruit with the soil can decrease infection. You can do this by using plant stakes or support cages that will hang the plants above the soil.^[8] Another control is mulching with newspapers, plastic, and other materials that will prohibit soil from splashing up on the plants during heavy rainfall.^[8]

Chemical control

Applying fungicides that contain chlorothalonil, maneb, mancozeb, or metalaxyl as the main ingredient on a regular schedule will help to eliminate the pathogen.^[5] You can also apply fungicides containing mefenoxam to the soil surface under the vines around 4–8 weeks prior to harvest.^[1] A third practice to help control the disease is to spray with another fungicide, difolatan, 4 times over a 10-day period.^[9] Soil should be fumigated before anything else is planted in previously-infected soil.^[10]

Importance

United States

One of the first reports of Buckeye rot of tomato occurred in Florida in 1917. Later, in 1921 the first epidemic of it occurred in an experimental field in Indiana. It persisted throughout the summer infecting other hosts as well. It resulted in destroying up to 40 percent of the tomato plants grown. In Maryland, tomatoes are the second most important vegetable crop grown, accounting for 8.6 million dollars in profit. Annually, 25-30 tons of tomatoes are processed in Maryland. Tomatoes are also the second most economically important vegetable in Pennsylvania. Fresh tomatoes account for 2.1 million dollars in cash receipts and 26-28,000 tons are produced by growers every year. Buckeye rot is one of the most important diseases to control in Pennsylvania. Maryland is able to manage it through a combination of chemical and non-chemical treatment, whereas in Pennsylvania, Buckeye rot of tomato is controlled through a three-year crop rotation schedule.^[11][12]

India

In 2013, the Hindustan Times reported that in India, Buckeye rot of tomato has led to damage in 30-40 percent of tomato crops.^[13] In 2012, the price of a tomato in India ranged from 0.20-0.33 dollars per kg; however, in 2013 when the disease hit, the price rose to 0.33-0.65 dollars per kg.^[3]

See also

• Phytophthora infestans
• Oomycete

References

• Acrolophus harpasen
• Acrolophus harpella
• Acrolophus hedemanni
• Acrolophus heinrichi
• Acrolophus heppneri
• Acrolophus hirsutivestita
• Acrolophus hirsutus
• Acrolophus horridalis
• Acrolophus hulstellus
• Acrolophus hypophaea
• Acrolophus icarus
• Acrolophus illudens
• Acrolophus indecora
• Acrolophus infida
• Acrolophus invida
• Acrolophus irrisoria
• Acrolophus jalapae
• Acrolophus juxtatus
• Acrolophus kearfotti
• Acrolophus klotsi
• Acrolophus laetifica
• Acrolophus laminicornus
• Acrolophus languidalis
• Acrolophus latiberbis
• Acrolophus laticapitana