Effect of Silicon on the Fruit Quality and Disease Response to Gummy Stem Blight in Cucumber

Gummy stem blight (GSB) caused by Stagonosporopsis cucurbitacearum is the most destructive fungal disease affecting cucumber (Cucumis sativus L.) production. In Thailand, cucumber is one of the most popularly marketed vegetables and the cultivation of cucumbers or Cucurbitaceae often face impact epidemics and insect infestation. Furthermore, global climatic or climate change affects crop production too, which increases the frequency and severity of disease and pest outbreaks. Silicon (Si) enhances plant resistance against insect pests and fungal, bacterial, and viral diseases although Si is not the only beneficial element for plants but also it does play an important role in improving plant health and increasing resistance against pests and diseases. Therefore, the aim of the study was to investigate the effect of Si-application at two levels i.e., 50 ppm, and 100 ppm on yield, yield components, aroma, Si-concentration and disease response of cucumber under greenhouse condition in a randomized complete block design with 4 replications. Results, when compared with control, depicted that the highest fruit weight, marketable yield, fruit length, fruit width, and pith length were found under 50 ppm Si. Moreover, higher Si-levels resulted in increased aroma in rind (exocarp) and increased percentage of Si-concentrations in rind (exocarp), leaves, and shoot. Further in this research, the response of Gummy stem blight disease (GSB) in cucumber was also investigated the response of. The taxonomic identification of Stagonosporopsis cucurbitacearum was confirmed based on the evidence from morpho-molecular analyses and the pathogenicity test was performed to confirm its potential pathogenicity. The results showed that the varying treatments of Si affects the disease development. The 50 ppm Si caused the lowest disease response on cucumber fruits. This study can be used as a guideline for modifying Si-fertilizer application inputs to plants to increase disease resistance and fruit quality.