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The effects of nitrogen, phosphorus, potassium and gibberellic acid on leaf area and cell division in Majestic potato
Author(s) -
HUMPHRIES E. C.,
FRENCH S. A. W.
Publication year - 1963
Publication title -
annals of applied biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 80
eISSN - 1744-7348
pISSN - 0003-4746
DOI - 10.1111/j.1744-7348.1963.tb03737.x
Subject(s) - gibberellic acid , biology , dry matter , phosphorus , nutrient , nitrogen , potassium , botany , plant nutrition , agronomy , horticulture , germination , chemistry , ecology , organic chemistry
SUMMARY Potato plants in a factorial experiment with nitrogen, phosphorus and potassium were sprayed with gibberellic acid. Leaf areas were determined at a‐week intervals and cell numbers in some leaves determined. Total leaf area of main‐stem leaves was affected more by nitrogen than by gibberellic acid. The effects of nitrogen and gibberellic acid on maximum size of main‐stem leaves increased acropetally. Mineral nutrients affected lateral‐stem leaves more than main‐stem leaves, because laterals developed after the soil had been depleted of nutrients. Leaf discs from main‐stem leaves nos. 7, 11 and 15 were macerated with pectinase and ethylene‐diamine‐tetraacetic acid and cells counted. Cell size decreased from leaf to leaf up the stem. Gibberellic acid but none of the mineral nutrients increased cell size. Cell size accounts for only part of the increase in leaf area caused by gibberellic acid, because cell number also increased. In contrast to its effect in an earlier experiment, gibberellic acid increased dry matter of tubers, perhaps because larger pots were used. Potassium increased total dry matter and net assimilation rate. In absence of nitrogen gibberellic acid increased the integral of leaf area and time (the leaf‐area duration) but this increase was not associated with increase in yield. With nitrogen most of the difference in leaf‐area duration caused by mineral nutrition was associated with lateral‐stem leaves. There was a linear relationship between leaf‐area duration and dry‐matter yield, and regression coefficients indicated that I g. dry matter was produced by a leaf‐area duration of 3 or 4 dm. 2 weeks.