The estimation of vitamin C and carotin in the vegetable has hitherto been carried out by many investigators. Their results can be looked upon as an average and sufficiently valuable for practical use, because the plants were prevailingly analysed through their growing period. It may however, be very intresting, from point of view to the crop production if the vitamin C content in the plant is influenced by fertilizer. Some field experiments were planed by the author for the inquiring into the true state of the affair. Spinach ("Land sp." "Hollandia")was selected as material of the experiment, for its rapid growth and the considerable large content of vitamin C. The ascorbic acid content of leaves was determined by the titration method of Tillman and Birch et al. with 2,6-Dichlorphenol indophenol in acid medium. The chlorophyll and carotin content was also measured by colorimetric method. The results are summerized as follows : (1) The vitamin C, carotin and chlorophyll contents of the spinach largely depend on the amount of fertilizers in the soil. (2) A lager amount of the nitrogen result is greater vitamin C carotin and chlorophyll contents, and these contents were markedly low in the leaves of the nitrogen-deficient plants. (3) The effect of phosphorous and potassium in the vitamin C, carotin and chlorophyll contents was much smaller than that of the nitrogen. (4) Generally the increase in vitamin C content is most distinct in the plant grew up on the soil, which contained of the larger nitrogen. Under the conditions, the influence of phosphorous and Potassium salts upon the vitamin C content is less.
抄録全体を表示