High Tunnels as a Unique Theatre for Investigating the Complex Causes of Yellow Shoulder Disorder in Tomatoes

Yellow shoulder disorder (YSD) is characterized by discolored regions beneath the fruit’s epidermis, impacting the ripening process and rendering tomatoes unsuitable for marketing. YSD poses a significant challenge in high-tunnel (HT) tomato production, a system that has gained prominence for its ability to extend growing seasons and enhance crop quality. This review delves into the various factors influencing YSD occurrence, including soil nutritional status, weather, plant variety, and the interactions between these factors, contributing to the occurrence of YSD in HT microclimate. The severity of YSD symptoms, ranging from minor to significant discoloration, highlights the complexity of this disorder. This review highlights research gaps on the effects of temperature, relative humidity, nutrient imbalance, soil water management, clay minerals, and how their interactions influence YSD in HT microclimates, emphasizing the need for comprehensive studies to understand the complex relationships between soil health, nutrient management, and tomato quality in HT microclimates and the need for further research to sustain high-quality tomato production in HTs.