Spent mushroom substrate extracts as natural-substance biostimulants: effects on growth, chlorophyll and root architecture of cucumber.

Authors

Grzegorz Izydorczyk, Katarzyna Chojnacka

Published in

Plant science : an international journal of experimental plant biology. Pages 113431. Sep 05, 2026. Epub Sep 05, 2026.

Abstract

Spent mushroom substrate (SMS) is an abundant agro-industrial by-product rich in transformed organic matter, nutrients and potentially bioactive compounds, which makes it a promising raw material for biostimulant production. However, the plant-growth-promoting potential of chemically obtained alkaline SMS extracts, particularly under different application routes, remains insufficiently investigated. This study tested whether an alkaline extract of spent button mushroom substrate stimulates the growth and physiology of cucumber (Cucumis sativus L.). SMS was extracted with 10% potassium hydroxide, and the extract was compared with a commercial humic-based product. Both were applied to cucumber as a foliar spray or a soil drench at 0.1, 0.25, 0.5 and 1.0% organic carbon (Corg). Growth, biomass, chlorophyll content, root architecture and oxidative markers were measured, and the extract was profiled by LC-MS/MS and GC-MS. The SMS extract promoted growth relative to the untreated control, with the strongest responses at 0.5-1.0% Corg. Foliar application increased chlorophyll content and stem length, which rose by about 26% at 1.0% Corg, whereas soil application produced the largest root response, with root length and root volume reaching about 72% and 74% above the control at 1.0% Corg, and raised dry biomass by up to 30%. Hydrogen peroxide content, lipid peroxidation and catalase activity did not change significantly, indicating no detectable oxidative stress under the tested conditions. Chemical profiling revealed a multicomponent matrix of humic-like substances together with microbial peptide-like and indole-related metabolites, phenolics and organic acids, a plausible basis for the growth and chlorophyll responses. Part of the response may be nutritional, because the extract supplies potassium and nitrogen; effects on fruit yield and quality were not measured and remain to be confirmed. Alkaline SMS extracts merit further development as waste-derived biostimulants for horticulture.

PMID:
42700889
Bibliographic data and abstract were imported from PubMed on 06 Sep 2026.

Read full publication at:
Please sign in to see all details.

Stats

1-terrible, 9-excellent. How would you rate this publication? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.