Allelopathic Effect of Leaf, Stem, and Root Extracts of Parthenium hysterophorus L. on Wheat (Triticum aestivum L.) Seed Germination and Seedling Growth at Hargeisa, Somaliland

Abstract

Parthenium hysterophorus L. has a latent allelopathic effect on the germination of bread wheat seeds and the growth of its seedlings. Two experiments (Laboratory and pot experiments) were carried out during Jan.-Mar. 2024, at the Ministry of Agricultural Development Hargeisa, Somaliland, with the objectives of studying the leaf, stem and root extract concentrates (10%, 20% and 30%) of Parthenium hysterophorus allelopathic effect on seed germination and seedling growth of bread wheat. The concentrates were prepared from each root, stem, and leaf part of the weed. To each extract 100 ml of distilled water was added and solutions of 10%, 20%, and 30% were prepared with check (0%) which were laid out using a completely randomized design and a randomized complete block design for laboratory and pot experiment, respectively. The analysis showed that there was a highly significant effect the leaf, stem and root extract of the weed on seed germination and seedling growth of wheat. A low germination percentage of wheat seed (66%, 59%, and 26.5%) was recorded from a 30% concentration of root, stem, and leaf extracts, respectively. Similarly, in pot trials, seedling emergence decreased with a 30% concentration of root (67.71%), stem (60.95%), and leaf (42.3%) extracts. ‍ Shoot length was significantly affected by the P. hysterophorus extract parts and concentration levels, as the minimum shoot length was recorded at a 30% concentration level of leaf, stem and root parts. Root growth was also adversely affected by the leaf, stem and root extract parts and different concentrates, with the longest roots recorded at (0% concentration) and the minimum root length at 30% concentration of all the weed  parts.‍ The verdicts of the study concluded that there is a direct relationship between concentration levels and effect magnitude, with higher concentrations leading to greater effects and specifically, the leaf part of P. hysterophorus exhibited a significant effect at a concentration level of 30%. Therefore, further studies are suggested to confirm the allelopathic effect of the weed under field conditions.