Nutrient Deficiency Affects the Growth and Nitrate Concentration of Hydroponic Radish

Masaru Sakamoto,Yoshiki Komatsu,Takahiro Suzuki

doi:10.3390/horticulturae7120525

Abstract

In hydroponics, a continuous supply of mineral nutrients is essential for plant growth. However, constitutive nutrient-rich conditions also increase the nitrate content in the plants, which can be harmful to human health. Here, we investigated the effect of nutrient deficiency on the growth and component composition of hydroponic radish by changing the timing of nutrient removal from the hydroponic solution. Radish plants that were 14 days old were transferred to four different nutrient conditions for 14 days: nutrient deficiency for 14 days (WW), full nutrient for 14 days (NN), nutrient deficiency for the last 7 days (NW), and nutrient deficiency for the first 7 days (WN). After the treatments, the NW plants had similar taproot growth to NN plants. In contrast, the WN plants significantly reduced taproot growth. The WW plants reduced the shoot and taproot weight and their water contents. The nitrate content in the taproots was reduced in the NW and WW plants. The WW plants contained lower total phenol and higher ascorbic acid and sugar contents. These results suggest that the uptake of nutrient minerals at the young growth stage is important for the growth of radish taproot. Nutrient deficiency management can be one of the most effective tools for regulating radish growth and composition.

Highlights

Hydroponics is a soilless cultivation method that uses a nutrient solution that contains all of the essential minerals for plant growth [1]
The WN and WW plants showed a lower increase in taproot growth compared to the nutrient for days (NN) and NW plants in the first 7 days after the start of treatment (DAT)
The plants were harvested at 14 DAT, and the growth and components were examined

Summary

Introduction

Hydroponics is a soilless cultivation method that uses a nutrient solution that contains all of the essential minerals for plant growth [1]. This method was originally introduced in indoor farming, where the plant cultivation environment can be optimally controlled. This method makes it possible to grow crops in areas without soil and regardless of soil conditions. Several nutrient solution formulations have been developed that optimally contain the major and micronutrients that are essential for promoting nutrient intake and plant growth [3]. The regulation of nutrient supply might be needed to provide optimal growth while managing the nutrient content of the edible parts of hydroponic plants

Methods

Results

Conclusion