Greenhouse-Grown Tomatoes: Microbial Diseases and their Control Methods: A Review

The cultivation of tomatoes in greenhouse structures is becoming increasingly common as a crop production system. However, the environmental conditions inside a greenhouse favour the development of microbial diseases. These diseases have an adverse effect on the tomato yield and can lead to serious economic losses. This review will give an insight into the major diseases affecting greenhouse-grown tomatoes, the respective causal agents and recommended control strategies. Some of the major diseases are of a bacterial, fungal, viral or nematode origin and include bacterial spot and speck, bacterial canker, early blight, gray mold, leaf mold, powdery mildew, tomato mosaic virus, tomato big bug and root knot. For each disease, the symptoms and risk factors responsible for disease development are described. In addition, the different structural designs and set-ups of tomato greenhouses are covered along with their advantages and limitations, especially any adverse effects on yield and susceptibility to disease. Although conventional control measures are discussed, greater emphasis is laid on the use of alternative biocontrol measures that include Effective Microorganisms, natural antimicrobials and nanobiopesticides. Moreover, information gathered in this review is based on a combination of available literature and expert guidance. This compilation is hoped to be instructive for tomato growers opting for greenhouse farming and assist them in the application of timely and more effective control measures