Premium
Influence of Potassium Nutrition on Net CO2 Uptake and Growth in Maize ( Zea mays L.) 1
Author(s) -
Estes G. O.,
Koch D. W.,
Bruetsch T. F.
Publication year - 1973
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1973.00021962006500060038x
Subject(s) - dry weight , zea mays , potassium , carbon dioxide , agronomy , zoology , chemistry , liter , horticulture , biology , organic chemistry , endocrinology
A heavy dependence on K fertilization in the northeastern U. S. coupled with the luxury accumulation of this element in plants suggest a need for further research. The objective of this greenhouse experiment was to relate CO 2 uptake, determined by a radioactive carbon method, and yield of maize ( Zea mays L., var. Wisconsin 335A') with K concentration and content of tissue. Plants were grown at substrate levels of K from O to 9 m M /liter of K in hydroponic culture. A significant correlation existed between both concentration and content of K and dry weight of plants. There was a curvilinear relationship between both leaf (youngest fully expanded) and plant K percentage and net CO 2 uptake. Leaf content of K between 0.75 and 1.0% was considered critical (42‐day‐old maize) because CO 2 fixation was seriously reduced at lower concentrations. There was a close agreement between CO 2 assimilation and dry weight over the range in substrate K concentrations, .50 to 9.0 m M /liter. An increase in dry weight at the K level of 0.25 m M /liter was not accompanied by an increase in CO 2 fixation. Uptake of CO 2 increased nearly 60% between K concentrations of 0.25 and 0.50 mM/liter but at a much slower rate between 0.50 and 9.0 m M /liter.