Determination of chlorophyll and carotene in plant tissue

The Carotene and Ascorbic Acid Concentration of Vegetable Varieties

“…Carotene was determined by a slight modification (11) of the PETERING, WOLMAN, and HIBBARD procedure (12) and ascorbic acid by an adaptation (10) of the STOTZ xylene modification of the 2,6 dichlorophenolindophenol method. A Coleman Universal Spectrophotometer was used for both determinations.…”

The Growth and Competitive Ability of Contrasting Natural Populations of Trifolium Repens L. on Calcareous and Acid Soils

“…These observations are reflected in the chlorophyll determinations, by the method of Petering et al (1940), presented in Table 3. The intensity of the symptoms was similar in the two populations during most of the experiment, although in the early stages the acidic population appeared to be slightly more affected.…”

Nutrient Interrelations in Lime-Induced Chlorosis

“…Chlorophyll was determined on fresh or frozen material by-a slightly modified procedure of PETERING, WOLMAN, and HIBBARD (23). A red filter was used in the colorimeter (Wratten #29, with two pieces of ground glass to reduce light intensity).…”

“…In table IX are presented the results obtained from the analyses of leaves that had become green after leaves lower down on the same branch had been dipped in iron citrate solution. The dipping was performed on May 23, 1941, ancd leaf samples were taken on August 23,1941. These data may be eompared with the August samples in the two previous tables (VII, VIII).…”