# Characterization of finger millet extracts and evaluation of their nematicidal efficacy and plant growth promotion potential

## TL;DR

Finger millet extracts can kill plant-parasitic nematodes and promote plant growth, offering a natural solution for crop protection.

## Contribution

The study identifies specific bioactive compounds in finger millet extracts that effectively control nematodes and enhance plant growth.

## Key findings

- Finger millet extracts achieved up to 98% nematode mortality in vitro.
- Extracts reduced nematode populations and reproductive factors in greenhouse conditions.
- Treated plants showed enhanced seed weight and phytochemical activity.

## Abstract

Plant‐parasitic nematodes pose a significant threat to finger millet crops, potentially causing yield reduction of up to 70%. Extracts derived from finger millet varieties contain potent bioactive compounds that can mitigate nematode damage and promote plant growth. This study aimed at isolating and characterizing bioactive compounds from the finger millet varieties Ikhulule, Okhale‐1, and U‐15; evaluating the impact of Ikhulule and U‐15 extracts on the mortality of the root lesion nematode Pratylenchus vandenbergae; assessing the growth promotion effects of Ikhulule and U‐15 extracts on the finger millet variety Okhale‐1; and determining the efficacy of these extracts in managing plant‐parasitic nematodes under greenhouse conditions. Extracts were obtained from both leaves and roots and tested in vitro for nematode mortality and in vivo for growth promotion and nematode control. The results showed that finger millet extracts exhibited strong nematicidal properties in vitro, achieving a mortality rate of up to 98% against P. vandenbergae nematodes. Applying these extracts to finger millet shoots significantly reduced nematode populations in both soil and roots and decreased the reproductive factor to below one (1), indicating an effective nematode control. The study attributes the enhanced nematicidal effects of finger millet extracts to their bioactive compounds, particularly dodecanoic acid, phytol, 1,1,4a‐trimethyl‐6‐decahydro naphthalene, 2,3‐dihydro‐benzofuran, 2‐methoxy‐4‐vinylphenol and ethyl ester, and hexadecanoic acid. These findings suggest that finger millet‐derived extracts offer a natural solution for nematode management and broader agronomic benefits, ultimately contributing to overall plant health and productivity.

Finger millet has a diverse set of phytochemicals. These chemicals can kill nematodes directly after 72 hours of soaking. Indirectly, phytochemicals can enhance the weight of seeds, indicating that extract‐treated plants have larger seeds than the control plants.