Development of an In Planta Monitoring System of Phosphorus Content in Tomato

Tomato (Lycopersicon esculentum), is an important vegetable crop in the world for fresh and processing consumption. In order to increase fruit yield and improve fruit quality, and avoid injury from typhoons, torrential rain, pests, and disease, most farmers in Taiwan use greenhouse cultivation for growing tomato. Overfertilization and lack of leaching by rain in greenhouse cultivation often leads to increased cost and an accumulation of salt in the soil. Reasonable fertilization is one of important approach for solving the above problems. To achieve the purpose of reasonable fertilization, it is essential to measure the nutritional status in plants. However, the commonly used methods for analysis of soil and plant material to assess fertilizer requirement is time-consuming, requires expensive equipment, and high techniques. Furthermore, in the case of phosphorus, a high amount of phosphorus detected in the soil is usually unavailable for plants, resulting in deficiency. Phosphorus plays an important role in the initial growth and flowering stage of tomato, thus phosphorus deficiency will reduce the growth rate and final yield of tomato plants. To achieve the goals of reasonable fertilization, decreased cost of fertilizer, and protection of ecological environment, we developed an in planta method for the convenient and quick assay of phosphate (Pi) status in tomato.