The Allelopathic Effects of Sunflower and Wheat Root Exudates on Sinapis arvensis and Sinapis alba

Abstract

In this study, we aimed to investigate the allelopathic effects of sunflower and wheat root exudates on the common weeds such as wild mustard and white mustard in our region. The root exudates which were obtained by soaking 8 weeks old sunflower and wheat seedlings (20 or 40 seedlings) in 100 mL of distilled water for 3 days were applied to the leaves of wild mustard and white mustard. In order to compare the allelopathic effect, the recommended dose (1 g.da -1 ) and twice the recommended dose (2 g.da -1 ) of Gromstor (Tribenuron-methyl), a herbicide preferred by farmers for the chemical control of these weeds was also applied. The allelopathy was performed for wild mustard and white mustard seedlings by the measurement of different physiological and biochemical parameters, such as chlorophyll a, chlorophyll b, total chlorophyll, carotenoid, proline, total protein amounts and superoxide dismutase enzyme activity. The amounts of total chl and carotenoid in wild mustard leaves decreased in all treatment groups compared to control. The highest decrease in total chl (50.93%) and carotenoid (46.69%) was oberved in the treatment of 40 wheat seedlings. 100 mL -1 distilled water. In the white mustard leaves, the amount of total chl in all treatment groups except the treatment group of Gromstor 2 g.da -1 and carotenoid in all treatment groups increased compared to the control. The highest increases again were observed in 40 wheat seedlings. 100 mL -1 distilled water treatment. The proline amounts in wild mustard and white mustard increased in all treatment groups. The highest increase was observed for the treatment of 20 wheat seedlings. 100 mL -1 distilled water in wild mustard (459.69%) and 40 sunflower seedlings. 100 mL -1 distilled water in white mustard plant (104.70%). In superoxide dismutase enzyme activities, treatments decreased activity except treatment of 40 sunflower seedling root exudate in wild mustard, while increased activity outside commercial herbicide treatment in white mustard. The results showed that sunflower and wheat root exudates have allelopathic effects on wild mustard and white mustard weeds. It is thought that the study will be a reference for new studies that will enable the use of plant root exudates as bioherbicides or foliar fertilizers and will contribute to the fight against weeds in organic agriculture. Materials and Methods MaterialsThe wild mustard (Sinapis arvensis L.) seeds collected from the fields in Imamoglu district of Adana province were assessed according to the Flora of Turkey and the East Aegean Islands [16]. The white mustard (Sinapis alba L.) seeds were purchased from Mersin Kemal Cuce Tarim Transport Food Construction Trade Industry Limited Company. The seeds of Sems sunflower (Helianthus annuus L.) and Sarıbasak wheat (Triticum aestivum L.) were obtained from the Eastern Mediterranean Agricultural Research Institute. All chemicals used in the study were purchased from Sigma-Aldrich and Merck companies. Obtaining the Root ExudatesThe sunflower and wheat root exudates were...

Potential Allelopathic Effect of Wheat Straw Aqueous Extract on Bermudagrass Noxious Weed

“…On the contrary, both extract concentrations showed a significant increase in the contents of free amino acids, total proteins and soluble carbohydrates, especially with the 100% concentration. In line with our results, Unal et al [81] reported a concentration-dependent increase in total protein content in white mustard leaves in response to the treatment with sunflower and wheat root exudates. Similarly, the increase in free amino acid content has been reported in several plant species; P. oleracea leaves after the treatment with Rumex dentatus leaf extract [82] and R. dentatus as a result of Withania somnifera root extract treatment [83].…”

“…Meanwhile, only high extract concentrations (75% and 100%) induced a significant decline in the enzymatic activities of both CAT and APX. The stimulation of CAT and APX by the low concentrations and their inhibition by the high ones could be explained by the hormesis phenomenon, where allelochemicals induce hormesis (growth enhancement) at low doses [14,100], which is supported by the results of Unal et al [81], Hua et al [101] and Hong et al [102]. It is also commonly believed that allelochemicals enhance the content of non-enzymatic antioxidants [103].…”