A 13-year-old Kerry student has reached the finals of SciFest with her natural solution to eliminating the invasive weed Japanese knotweed

Grace Ni Ifearnáin from Ghaelcholáiste Chiarraí in Tralee believes she has found a possible method of eliminating the devastating weed, using the black walnut tree.

Ni Ifearnáin first confirmed a link between the black walnut tree and Japanese knotweed after she noticed there was no Japanese knotweed growing within 150ft of black walnut trees.

Laboratory tests revealed juglone, an organic compound which has poisonous properties, is produced by the black walnut tree, and is spread through its roots.

The second stage of the project involved extracting juglone from the hulls of the black walnut, and adding it to distilled water, methanol and 1% ascorbic acid to make up three solutions for testing.

The final stage of the project saw her spraying the Japanese knotweed with her three test solutions.

She found that the methanol and 1% ascorbic acid had a discolouration effect on the Japanese knotweed, which led the student to believe that the walnut extract did indeed have a negative effect on the Japanese knotweed. These results will be further monitored in the spring.

Ni Ifearnáin has already won awards in the SciFest competition and now heads to the national final, taking place virtually on 26 and 27 November 2021.