Investigating the impacts of airborne dust on herbicide performance on Amaranthus retroflexus.

Dust pollution poses environmental hazards, affecting agriculture through reduced sunlight exposure, photosynthesis, crop yields, and food security. This study explores the interference of dust pollution on herbicide efficacy to control weeds in a semi-arid region. In a factorial experiment conducted in 2019 and replicated in 2020, the interaction of dust and various herbicide applications, including bentazon, sulfosulfuron, tribenuron-methyl, aminopyralid + florasulam, foramsulfuron + iodosulfuron + thiencarbazone, 2,4-D + MCPA, and acetochlor, in controlling Amaranthus retroflexus L. were assessed. Dust induced a 9.2% reduction in the total chlorophyll content of A. retroflexus, while herbicide application independently led to a 67.5% decrease. Contrary to expectations, herbicides performed better in dust, except bentazon, which caused a 28% drop in plant height and a 29% decrease in total biomass compared to non-dust conditions. Both herbicides and dust exerted suppressive effects on A. retroflexus's leaf and stem weights and overall biomass. Despite dust presence, tribenuron-methyl (95.8%), aminopyralid + florasulam (95.7%), sulfosulfuron (96.5%), and foramsulfuron + iodosulfuron + thiencarbazone (97.8%) effectively controlled A. retroflexus. These findings indicate that dust's effect on herbicide efficacy is herbicide-dependent but except bentazon, dust generally increased herbicide efficacy and amplified the control of A. retroflexus.

Preparation and characterization of chloridazon-loaded alginate/chitosan nanocapsules.

In addition to the detrimental environmental effects of herbicides, including the pollution of soil, atmosphere, groundwater aquifers and run-off water, the lack of caution and direct or indirect exposure to these products can cause short-term and long-term human health effects. However, nanotechnology, with its many applications, can be very helpful in improving agriculture and reducing the side effects of chemicals used in agriculture. Nano-encapsulation of chemicals used in agriculture is one of the strategies to improve precision agriculture. Nano-encapsulated herbicides are controlled membrane systems in which the active ingredient is coated with semi-permeable membranes, which may be organic or inorganic polymers. In our study, chloridazon herbicide was selected as the active ingredient for Nano-encapsulation. Like many other agricultural herbicides, the major problem with this herbicide is environmental pollution and its adverse health effects. The ionic gelation method was used to synthesize nanocapsules consisting of alginate and chitosan for chloridazon encapsulation. Alginate-chitosan nanoparticles were prepared in a two-step process involving the ionotropic pre-gelation of an alginate core and then the formation of a chitosan polyelectrolyte complex. The alginate-chitosan nanocapsules containing chloridazon were synthesized at a size of 253 nm with a polydispersity index (PDI) of 0.266 and a zeta potential of -1.43 mV. The loading capacity and entrapment efficiency of these nanocapsules were 14% and 57%, respectively. The study of chloridazon release from formulated alginate-chitosan nanocapsules was performed using dialysis tube testing and UV spectroscopy. The results of our study showed controlled release of chloridazon from loaded alginate-chitosan nanocapsules. In general, alginate-chitosan nanocapsules as a Nano-carrier, have the potential to become a commercial formulation for chloridazon encapsulation. On the other hand, controlled release and increasing the duration of action of chloridazon, along with reducing the required dose, is promising in reducing the adverse health and environmental effects caused by chloridazon and improving precision agriculture.

Comparison of Myagrum perfoliatum and Sophora alopecuroides in phytoremediation of Cd- and Pb-contaminated soils: A chemical and biological investigation.

Phytoremediation is one of the most cost-effective and environmentally friendly ways to reduce adverse effects of cadmium (Cd) and lead (Pb) in the environment. The present study was conducted to investigate the bioaccumulation factor (BF) and translocation factor (TF) of Cd and Pb in muskweed (Myagrum perfoliatum) and foxtail sophora (Sophora alopecuroides). The impact of contamination on some growth responses of plants and soil biological indicators was also evaluated. A non-contaminated soil sample was divided into several subsamples: one subsample was left as control (without contamination) and the others were separately contaminated with three levels of Cd (3, 5, and 10 mg kg-1) and Pb (100, 300, and 600 mg kg-1). Pot experiments were performed under greenhouse conditions. The BF values of Cd were greater than 1 at all contamination levels indicating the potential of muskweed and foxtail sophora for the uptake and phytostabilization of Cd. The only TF > 1 was obtained for Cd in muskweed grown at the highest Cd contamination level. The TF values of Pb were much lower than those obtained for Cd indicating that Cd was more translocated from root to aerial parts of muskweed and foxtail sophora compared to Pb. The highest contamination levels of Cd and Pb did not significantly affect growth responses of muskweed and foxtail sophora. Furthermore, the cultivation of muskweed and foxtail sophora reduced the impact of Cd and Pb contamination on biological indicators including carbon mineralization ratio (CMR), substrate-induced respiration (SIR), microbial biomass carbon (MBC), and metabolic quotient (qCO2).

Effect of irrigation with detergent-containing water on foxtail millet shoot biomass and ion accumulation.

Water shortage leads farmers to use sewages for irrigation. Sewages contain a large amount of laundry detergent. In this study the impact of irrigation by contaminated water on shoot biomass and seed germination of foxtail millet (Setaria italica) was investigated. The research was conducted as laboratory and pot experiments. Iso-potentials (- 0.042, - 0.077, and - 0.415 MPa) of polyethylene glycol (PEG, water deficit treatment) and laundry detergent (contamination treatment) made the laboratory experiment treatments. The pot experiment included contamination factor (0, 0.1, 1, and 10 g L-1 of laundry detergent) and deficit irrigation factor (irrigation interval of 1, 2, and 3 days). Results of this study showed that at the iso-potential, laundry detergent had more negative effect on seed germination traits when compared with PEG. There was no germination at - 0.415 MPa of laundry detergent. Both drought and contamination reduced dry forage yield, plant height, leaf number, leaf area, leaf dry and fresh weight, stem dry, and fresh weight. Detergent concentration of 10 g L-1 with irrigation interval of 3 days had a forage yield reduction of 63% compared to control (laundry detergent concentration of 0 g L-1 with irrigation interval of 1 day). Detergent concentration of 10 g L-1 with irrigation interval of 1 day had a sodium increase of 1847% compared to control. Based on the results of this study, it is recommended not to irrigate foxtail millet farm by contaminated water with laundry detergent higher than 1 g L-1.