Manganese Deficiency of the Andosol in Northern Part of Gifu Pref. Caused the Yellow Spot in Spinach in Takayama City, Takane-cho

Abstract

Yellow spotting between the veins of spinach leaves has hindered the cultivation of spinach in the Andosol in Takane-cho district in Takayama city. This symptom was frequently seen in this district, although the degree of spotting varied. We sampled and analyzed the leaves of the plants with yellow spots (yellow leaves) and the leaves of normal green plants (green leaves) as well as the soil in the same field. The component with the lowest content in the yellow leaves as compared with that in the green leaves was manganese, and this was also the case in the soil. When the spinach with yellow leaves were sprayed with 2g L^-1 manganese sulfate solution, the yellow spot symptoms disappeared four days later. Moreover, the easy reductive manganese content of the soil in the field where yellow spots were observed was much lower than that of the soil in another district where soluble phosphatic manure was applied in large quantities, or where yellow spots had not been observed. On the other hand, spinach with yellow spots often appeared on the soil whose manganese content was about 60 mg kg^-1 in this district. Therefore, it was considered that the cause of yellow spotting in spinach in Takane-cho, Takayama city was the lack of manganese in the soil. The reason why yellow spots often appear even in the spinach grown on the soil with 60 mg kg^-1 easily reducted manganese may be the strong adsorption ability of the Andosol.