DefinePK

Research Objective

To provide an insight into the major microbial diseases affecting greenhouse-grown tomatoes, their causal agents, symptoms, risk factors, and recommended control strategies, with an emphasis on alternative biocontrol measures.

Methodology

This study is a review based on a combination of available literature and expert guidance concerning major diseases affecting greenhouse-grown tomatoes, their causal agents, symptoms, risk factors, and control strategies, including structural designs of greenhouses.

Methodology Flowchart

                        graph TD; A[Literature Review & Expert Guidance Gathering] --> B[Identification of Major Greenhouse Tomato Diseases]; B --> C[Description of Causal Agents, Symptoms, and Risk Factors]; C --> D[Review of Greenhouse Structure & Setup]; D --> E[Evaluation of Control Strategies]; E --> F[Emphasis on Alternative Biocontrol & Nanotechnology]; F --> G[Compilation of Insights for Growers]; G --> H[Review Paper Output];                    

Discussion

The review details specific symptoms and risk factors for numerous diseases, such as Clavibacter michiganensis subsp. michiganensis causing bacterial canker under high humidity, and Phytophthora infestans causing late blight in cool, rainy conditions. Greenhouse structural designs influence light transmission and disease susceptibility. Novel control methods, particularly biocontrol agents (like Trichoderma and PGPR) and nanotechnology (nanoparticles and nanoemulsions), offer safer, residue-free alternatives to conventional chemical treatments, though further optimization of these novel formulations is needed.

Key Findings

Greenhouse environments favor the development of microbial diseases (bacterial, fungal, viral, or nematode origin) which adversely affect tomato yield. Major diseases discussed include bacterial spot/speck, canker, early blight, gray mold, leaf mold, powdery mildew, tomato mosaic virus, tomato big bud, and root knot. Conventional control methods exist, but alternative biocontrol measures like Effective Microorganisms (EM), natural antimicrobials (e.g., chitosan), and nanobiopesticides are emphasized for sustainable management. Greenhouse cultivation generally results in significantly higher yields (13.1 kg m-2) compared to open-field cultivation (1.8 kg m-2).

Conclusion

Greenhouse cultivation offers advantages in yield and quality but remains vulnerable to microbial diseases. Effective disease management, increasingly leaning towards biocontrol and nanotechnology, is crucial for sustainable and high-yield tomato production, especially given the potential impact of climate change on disease prevalence.

Fact Check

1. Tomato production in greenhouses is becoming increasingly common as a crop production system. (Confirmed in Abstract)
2. Worldwide tomato production in 2021 attained 189,133,955,040 kg. (Confirmed in Introduction)
3. Mean tomato yield in greenhouses was recorded as 13.1 kg m-2, compared to 1.8 kg m-2 for open-field grown tomatoes. (Confirmed in Causes of Diseases in Greenhouses section)

Mind Map