Total Phenolic Exudation and Allelopathic Potential of Sunflower Residues as Sustainable Weed Management

Abstract

Total releasing phenolic compounds and allelopathic potential of the three sunflower genotypes Helianthus annuus L. residues were evaluated under open field conditions on weed flora associated with the proposed crops; wheat, broad bean and flax which are cultivated usually after the sunflower crop as successive crops. After getting seed from the sunflower crop. After getting seeds, sunflower plant parts were chopped and incorporated with field soil using a rotavator. Regarding the phenolics, total phenolic compounds released from sunflower residues were increased in-field soil and reached the highest concentration in the fourth week after mixing with soil. Significant suppression of weed flora was observed when the weed density and weed dry matter were reduced. Sakha sunflower genotype had the most effect, while Ishaqi genotype had the least amount of phenolic compounds. The residue of the Sakha genotype effectively suppressed over 80% of targeted weeds. The results indicate that the allelopathic potential of sunflower residues can cause suppression of weed flora which can be useful as an attractive alternative natural way to reduce synthetic herbicides as sustainable weed management.

Critical Period for Weed Competition in Sesame under Iraqi Irrigated Areas

“…The number of capsules per plant was directly proportional to the increase in removal periods, Removing weeds for three, four, and five weeks came at the same level of significance with the weedy-free treatment. These results support previous studies, which confirmed that increasing the weed removal periods leads to improving yield components, including the number of capsules per plant [6,12,14]. As for sesame varieties, Had variety excelled with the highest average for this trait 178.3, which did not differ significantly from the Wadaa variety, which recorded the number of capsules per plant at 169.8.…”

“…The acceptable final seed loss rate was estimated based on previous studies [10,11]  Statistical Analysis: The SASS 9.0 version was used to conduct a statistical analysis of the data by the experimental design and the least significant difference test (L.S.D.) was employed to compare the arithmetic means of the data at a significance level of 0.05 [12].…”

Investigating the Phytotoxic Potential of Helianthus annuus on Germination and Seedling Morphological Parameters of Two Target Poaceae Species: Spring Barley and Spring Wheat

“…Substances released by plants with allelopathic properties can suppress the germination and development of nearby or succeeding plants [7,8]. Sunflowers are one of the most widely known allelopathic plants, so new data on the behaviour of these plants among other plants are sought [3,4,9,22,27,28]. Sunflowers accumulate water-soluble allelochemicals in their above-ground organs and roots [9,11,19].…”