Do phytotoxic allelochemicals remain in ashes after burning Chrysanthemoides monilifera subsp. monilifera (boneseed)?

Australia is facing challenges in controlling Chrysanthemoides monilifera subsp. monilifera(boneseed). However, burning has achieved some success in this regard. We aimed to investigate the comparative phytotoxicity of boneseed dried powder and ashes(burnt at 450℃ and250℃). Phenolic compounds in powder and ashes were measured using Folin–Ciocalteu assay and HPLC. The phytotoxicity of boneseed powder and ash extracts was assessed through germination bioassay on Lactuca sativa and the phytotoxicity of litter and ashes was evaluated using field soil, both in growth chamber. Burning of boneseed reduced total phenolics in ashes of boneseed organs by 99% and 100% both at high and low temperatures. The four phenolic compounds that were detected in boneseed were either absent or at negligible levels in the ashes,with inversely related to temperature. Both boneseed ash extracts and litter ash-mediated soil significantly reduced phytotoxicity displaying increased germination, biometric and biochemical parameters of test species compared with unburnt powder extracts and litter powder-mediated soil respectively, with greater reduction of phytotoxicity found for ashes produced at the lower temperature. Interestingly, the ash extracts and litter ash-mediated soil were found to stimulate some of those parameters of the test species compared to control. There was no excessive reactive oxygen species(ROS) produced in test species exposed to ash extracts compared with unburnt powder extracts. These findings suggest that burning of boneseed is an appropriate method of weed control and that this approach will reduce phytotoxicity of this species on native plants.     

Comparison effect of feedstock to inoculum ratios on biogas yields of cafeteria,vegetable, fruit wastes with cattle manure using co-digestion process

Cafeteria, vegetable, fruit, and cattle manure are available year around at low cost and have the potential to complement each other for anaerobic digestion (AD). The objectives of this study were to determine the preferred mixing ratios and effects of feedstock to inoculum ratios for the optimal biogas production. The mesophilic digestion tests were performed with five mixing ratios of CW, VW, FW with CM and five feedstock to inoculum (F/I) ratios using batch anaerobic digesters. Co-digestion of CW, VW, FW with CM was carried out at F/I ratios of 1.0, 2.0, 3.0, 4.0, and 5.0. The results showed that the F/I ratio significantly affected the biogas production rate. Increasing the CW, VW, FW in the CM resulted in an increased methane yield by decreasing the F/I ratios in the reactors from 5.0 to 1.0. The highest biogas yields of 591.3, 432.9, and 450.6 L/kg VS_feed were obtained with CW/CM (50:50), VW/CM (25:75), and FW/CM (25:75) ratios, respectively. At five F/Is tested, after 45 days of AD, the total biogas yields were determined to be 629.74, 552.64, 501.87, 464.66, and 396.04 L and 496.93, 460.02, 420.5, 398.14, and 336.20 L, and 455.03, 382.81, 349.78, 340.95, and 298.53 L, respectively. However, the highest average CH₄ contents obtained at an F/I of 1.0 were 62.14%, 60.72%, and 61.08% that are 5.87%, 9.47%, and 10.17% higher than those obtained at F/I ratio of 5.0 for CW/CM (50:50), VW/CM (25:75), and FW/CM (25:75), respectively.     

Pasture diversification to combat climate change impacts on grazing dairy production

Among livestock systems, grazing is likely to be most impacted by climate change because of its dependency to feed quality and availability. In order to reduce the impact of climate change on grazing livestock systems, adaptation measures should be implemented. The goal of this study is to identify the best pasture composition for a representative grazing dairy farm in Michigan in order to reduce the impacts of climate change on production. In order to achieve the goal of this study, three objectives were sought: (1) identify the best pasture composition, (2) assess economic and resource use impacts of pasture compositions under future climate scenarios, and (3) evaluate the resiliency of pasture compositions. A representative farm was developed based on a livestock practices survey and incorporated into the Integrated Farm System Model (IFSM). For the pasture compositions, four cool-season grass species and two legumes were evaluated under both current and future climate scenarios. The effectiveness of adaptation measures based on economic and resource use criteria was evaluated. Overall, the pasture composition with 50% perennial ryegrass (Lolium multiflorum) and 50% red clover (Trifolium pratense) was identified as the best. In addition, the increase in precipitation and temperature of the most intensive climate scenario could significantly improve farm net return per cow (Bos taurus) and whole farm profit while no significant impact was observed on resource use criteria. Finally, the overall sensitivity assessment showed that the most resilient pasture composition under future climate scenarios was ryegrass with red clover and the least resilient was orchardgrass (Dactylis glomerata) with white clover (Trifolium repens).     

Validation and application of an analytical method for determining pesticides in the gas phase of ambient air

A method for determining atmospheric concentrations of eight pesticides applied to corn and soybean crops in Mato Grosso state, Brazil is presented. The method involved a XAD-2 resin cartridge coupled to a low volume air pump at 2 L min^?1 over 8 hours. Pesticides were recovered from the resin using sonication with n-hexane:ethyl acetate and determined by GC-MS. Good accuracy (76–128%) and precision (CV < 20%) were obtained for atrazine, chlorpyrifos, alpha- and beta-endosulfan, endosulfan sulfate, flutriafol, malathion, metolachlor and permethrin. Method detection ranged from 9.0 to 17.9 ng m^?3. This method was applied to 61 gas phase samples collected between December 2008 and June 2009. Atrazine and endosulfan were detected both in urban and rural areas indicating the importance of atmospheric dispersion of pesticides in tropical areas. The simple and efficient extraction method and sampling system employed was considered suitable for identifying pesticides in areas of intense agricultural production.     

Pesticides and Trace Metals Residue in Grape and Home made Wine in Jordan

Sixty home made wine and sixty-four grape samples were collectedfrom five territories in Jordan, where grapes and wine aremostly producted. The collected samples were analyzed for themost used organochlorine pesticides (OCP) and organophosphorouspesticides (OPP) in Jordan, as well as for four heavy metals(Ni, Cu, Zn and Pb). The results showed that OCPs residues weredetected in 73% of the wine samples but no OPPs residue weredetected which is due to generally shorter half life of thelater pesticide. Grapes showed higher incident of contaminationthan wine, however, OCPs and OPPs with both short and longhalf-lives were detected. The OPPs were detected in only8.3% of the analyzed grape samples. Heavy metals showed higher valuesin grapes than in the wine samples and it was attributed toremoval of solids during wine preparation processes or throughcontamination of wine during storage. Most of the samples werebelow toxic limit.