# Pre-treatment of Cucurbita maxima ‘Hokkaido orange’ by Viscum album aqueous extracts in search of allelopathic potential

## TL;DR

This study explores how extracts from Viscum album, a parasitic plant, affect the growth of Cucurbita maxima seeds, suggesting potential eco-friendly applications.

## Contribution

The study introduces VA extracts as a novel source of allelochemicals for regulating plant growth.

## Key findings

- VA extracts showed a direct effect in 62.3% of cases on plant growth parameters.
- Effects varied based on host tree species and pre-treatment duration.
- VA extracts' effects are not fully explained by polyphenol content or antioxidant activity.

## Abstract

Viscum album L. (VA) is a unique plant with regard to its biological content. It is rich in many different metabolites with high potential in various spheres of human activity. We conducted a pilot study with 5 VA aqueous extracts of different host-tree species for pre-sowing treatment of Cucurbita maxima ‘Hokkaido orange’ seeds. We set the following objectives consisting of hypotheses (1) H01 is based on different effects of tested VA extracts depending on host trees and time of pre-treatment; (2) H02 focuses on the allopathic properties of the tested extracts affecting the plant growth and development by dose–response relationship; (3) A01 considers highly biologically active compounds of VA extracts also containing allelochemicals that can be used to regulate plant growth processes and create eco-friendly and resilient cities. The analysis of the stimulatory allelopathy index for 7 parameters demonstrates the direct effect of VA extracts in 62.3% of cases. The variability of the broad spectrum of effects of VA extracts of different host trees on the ontogenesis of C. maxima plants shows the presence of potential allelochemicals, resulting from the vital products of the host-parasite relationship. These effects are not fully explained by total polyphenol content and antioxidant activity as in previous studies of other mistletoe species. The authors consider this work a pilot study that expands the areas of application of VA extracts and knowledge about potential sources of allelochemicals.