TITLE:
Comparative Evaluation of Humic Substances: Effect at Cell Level and Chlorophyll Retention during Accelerated Senescence
AUTHORS:
Tirichy Ganesh Prasad, Joz Liza, Bargur Jayaram Manjushree, Ramarao Nagalakshmi, Kumar Devendra
KEYWORDS:
Biostimulants, Chlorophyll, Compost, Cotyledon, Humic Substances, Hypocotyl, Sedimentary
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.14 No.6,
June
27,
2023
ABSTRACT: The influence of humic substances (HS) formulations derived from sedimentary and compost sources was studied on plant growth at
cell level and chlorophyll retention during accelerated senescence
of leaf tissue. The direct effect of HS formulations was studied on cell
expansion using cucumber and radish cotyledon expansion test. The cucumber hypocotyl
elongation test was used to study the
effect on cell elongation. Chlorophyll pigment retention in excised leaf tissue incubated in dark with high temperature was assessed
to study the effect on leaf senescence.
Explant tissues were incubated directly in the solutions of the formulations at the concentration
recommended for foliar application to the crop plants. HS formulations showed significant variations in their
direct bio-stimulatory effects. Formulations derived
from compost sources were found superior in terms of inducing a direct stimulatory effect on
cell expansion and cell elongation and in maintaining chlorophyll pigment
retention during accelerated senescence. HS from sedimentary sources stimulated
cell expansion and delayed chlorophyll degradation to a lesser extent compared
to HS from compost. However, HS formulations derived from sedimentary sources
used in this study were not effective in inducing cell elongation in the cucumber hypocotyl
elongation test. The direct bio-stimulatory effect of HS formulations
differed significantly between the formulations that were evaluated.