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Influence of nitrogen and potassium fertilizers on pectic enzyme activity in tomato fruit
Author(s) -
Hobson G. E.
Publication year - 1963
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740140804
Subject(s) - ripening , pectinase , pectinesterase , chemistry , potassium , nitrogen , enzyme , pectin , horticulture , enzyme assay , agronomy , food science , biochemistry , biology , organic chemistry
The influence of nitrogen and, especially, potassium fertilizers on the quality of tomato fruit has raised the question of the mechanisms by which they have their effect. As part of a large‐scale factorial trial, plants were grown in two soil levels of nitrogen combined with two levels of potassium. Good quality fruit from each treatment was analyzed for pectinesterase and polygalacturonase activity, since the pectic enzymes have long been associated with ripening. Results show that an increase in the soil level of nitrogenous fertilisers was always reflected in higher total pectic enzyme activity, but potassic fertilizers gave no consistent trends. More detailed studies on one variety showed that additional nitrogen had the effect of increasing extractable protein in the fruit; potassium stimulated the specific activity of pectinesterase. The probability that the pectic enzymes are connected with the process of ripening is discussed, and the possible pathways by which potassium exerts its strong effect upon fruit quality are examined.