Department of Agronomy, University of Agriculture, Faisalabad 38040, Pakistan.
Department of Agronomy, University of Agriculture, Faisalabad 38040, Pakistan; Department of Agronomy, Muhammad Nawaz Shareef University of Agriculture, Multan, Pakistan.
Ecotoxicol Environ Saf. 2015 Dec;122:352-9. doi: 10.1016/j.ecoenv.2015.08.019. Epub 2015 Sep 20.
Phytotoxic effects of parthenium residues incorporation and parthenium-infested rhizospheric soil on emergence and seedling growth of winter crops (wheat and canola) and weed species (wild oat and canary grass) were examined in different pot studies. In first experiment, parthenium whole plant residues were incorporated at 6 and 8 g kg(-1) soil five days prior to sowing. Pots without residues incorporation were maintained as control. In a second study, parthenium-infested rhizospheric soil collected from different depths (15 and 22.5 cm) and collar regions (horizontal distance away from plant trunk, 15 and 22.5 cm), was used as growing medium. Parthenium-free soil was used as control. Parthenium residues amendment as well as its rhizospheric soil was detrimental for emergence and seedling growth of all test species. Incorporation of parthenium residues reduced the final emergence of canola, wild oat and canary grass by 11-20%, 20-29% and 20-27%, respectively; however wheat emergence was unaffected. Moreover, seedling biomass of wheat, canola, wild oat and canary grass was reduced in the range of 41-48%, 53-61%, 31-45% and 30-45% by parthenium residues incorporation. In second study, soil collected from a rhizospheric depth of 15 cm and collar distance of 15 cm reduced the emergence and seedling growth by 15% and 40%, respectively averaged across different test species. Parthenium residues incorporation and infested rhizospheric soil increased the soil phenolics, electrical conductivity, organic carbon and nitrogen contents over control soils with the exception of pH that was declined. All test species manifested reduced chlorophyll and increased phenolic contents in response to parthenium residues incorporation and infested rhizospheric soil. The inhibition in emergence and seedling growth of all test species was associated with increase in phenolic contents. Parthenium residues incorporation at 8 g kg(-1) soil and upper parthenium-infested rhizospheric soil (15 cm soil depth and 15 cm collar distance) were more phytotoxic for all test species.
在不同的盆栽研究中，研究了部分植株残体的掺入和受部分入侵的根际土壤对冬季作物（小麦和油菜）和杂草物种（野燕麦和雀麦）出苗和幼苗生长的植物毒性效应。在第一个实验中，在播种前五天，将 6 和 8 g kg(-1) 的部分植株残体掺入土壤中。未掺入残体的盆作为对照。在第二项研究中，使用来自不同深度（15 和 22.5 cm）和茎环区域（距植物主干的水平距离，15 和 22.5 cm）的受部分入侵的根际土壤作为生长介质。使用无部分的土壤作为对照。部分残体的添加及其根际土壤对所有测试物种的出苗和幼苗生长都有害。部分残体的掺入降低了油菜、野燕麦和雀麦的最终出苗率 11-20%、20-29%和 20-27%；然而，小麦的出苗率不受影响。此外，部分残体掺入降低了小麦、油菜、野燕麦和雀麦幼苗的生物量，范围为 41-48%、53-61%、31-45%和 30-45%。在第二项研究中，从根际深度为 15 cm 和茎环距离为 15 cm 的土壤中采集的土壤，平均降低了不同测试物种的出苗率和幼苗生长率 15%和 40%。与对照土壤相比，部分残体掺入和受部分入侵的根际土壤增加了土壤中的酚类物质、电导率、有机碳和氮含量，而 pH 值则下降。所有测试物种对部分残体掺入和受部分入侵的根际土壤的反应是叶绿素减少和酚类物质增加。所有测试物种的出苗和幼苗生长受到抑制与酚类物质含量的增加有关。土壤中 8 g kg(-1) 的部分残体掺入和上部受部分入侵的根际土壤（15 cm 土壤深度和 15 cm 茎环距离）对所有测试物种的毒性更大。
