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EFFECT OF POTASSIUM NUTRITION ON LEAF ANATOMY AND NET PHOTOSYNTHESIS OF PHASEOLVS VULGARIS L.
Author(s) -
O'TOOLE J. C.,
TREHARNE K.,
TURNIPSEED M.,
CROOKSTON K.,
OZBUN J.
Publication year - 1980
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.1980.tb04776.x
Subject(s) - photosynthesis , potassium , biology , nutrient , horticulture , botany , chemistry , ecology , organic chemistry
S ummary Low levels of potassium (K + ) nutrition resulted in a decrease in dry wt of leaves, stems and roots of two contrasting bean cultivars, Michelite (M‐62) and Redkote (RK). A decrease in eel! size and compaction of cells per unit area, resulting in decreased leaf thickness, and degradation of chloroplasts, and loss of cell wall integrity accompanied the decrease in percent K + of leaf tissue. Net photosynthesis rate decreased below a threshold level of about 1% K + in the leaf tissue with corresponding nutrient solution levels of between 1·2 and 0·3 mequiv. K + 1 ‐1 . Below this critical level, both stomatal and mesophyll diffusion resistances to CO 2 increased markedly. Varietal differences for these responses suggests differences in efficient utilization of the element rather than differential ability to absorb K + .