Influence of Fly Ash and Sewage Sludge Application on Cadmium and Lead Sorption by an Acidic Alfisol

The safe recycling of fly ash (FA) and sewage sludge (SS) in the agricultural processes comprises an important environmental technology on waste management. Soils amended with FA and SS may change their ability to adsorb heavy metals due to either increase of soil pH or decomposition of sludge-borne organic matter. Thus, Cd and Pb sorption was investigated by 1-month incubation under soil moisture content at field capacity and room temperature with an acidic Typic Haploxeroalf from central Greece amended with varying amounts of FA and SS. Batch experiments were conducted by equilibrating the soil samples with CaCl2 solutions containing 0-400 mg Pb L-1 or 0-100 mg Cd L-1. The results showed that the Freundlich equation described well the Cd and Pb sorption. Distribution coefficient (Kd) values of Pb were higher than those of Cd in all the treatments of this study. Application of FA increased Kd values for Cd and Pb to 8.2 and 2.3 times more than the controls, respectively. Simultaneous applications of FA and SS caused a Kd increase of 3.8 and 2.1 times compared to the treatments that received only SS for Cd and Pb, respectively. Treatment of SS alone did not significantly change Cd and Pb sorption compared to the controls. The sorption reactions seemed to be mainly affected by soil pH, which was revealed by the significant correlations of Cd and Pb sorption with soil pH. These suggested that fly ash was very useful as a low-cost adsorbent for Cd and Pb and could be used as an ameliorant for biosolid-amended acidic soils.

Influence of fly ash and sewage sludge application on wheat biomass production,nutrients availability,and soil properties

The influence of fly ash(FA)applied alone and/or with sewage sludge(SS)on wheat(Triticum vulgare)grain yield,biomass production and soil properties was studied in a field experiment.The results showed that both FA and SS significantly increased grain yield and plant biomass.FA applied alone increased significantly soil pH and EC while FA applied together with SS did not significantly affect them compared to mono FA treatment.Soil pH and EC values increased with time in FA and FA-SS treatments.SS increased soil organic matter and total N content and SS applied together with FA increased also available soil B.From the plant nutrients tested only tissue N concentration was increased significantly in all treatments compared to control.Copper,Zn,Mn,Ni,and Pb at both available and total concentrations are significantly affected.

Determination of Heat Stress and Ultra Low Oxygen in Chestnut Storage under Control and Modified Atmospheres

The effects of heat stress (HS) and ultra low oxygen (ULO) in controlled (CA) or modified (MA) atmosphere on chestnut (Castanea sativa L. cv. Rodiana) fruit quality and storability were investigated. Chestnuts exposed to ULO (1% O2 for 1 h) or dipped in water bath (at 55?C for 15 min) and then stored to CA or MA conditions at 6?C for up to 90 days. The HS dipping and storage in CA or MA increased sprouting (up to 60%) as well as mould severe on chestnuts com-paring with the control. In MA conditions, HS and ULO increased respiration rate. Total starch content increased (up to 30%) in MA-HS and MA-ULO treatments comparing with the control the first 60 days of storage. The first 30 days of CA and MA storage, chestnut moisture content decreased. No major differences observed in total sugar, total fat and total phenolic content as well as in the incidence of hole with or without worm in chestnut fruit. Following sensory evaluation, 57% of panelist marked differences among treatments, while the greater preference (67%) observed in chestnut treated with HS and stored in MA. Additionally, MA-HS enhanced (up to 30%) the chestnut appearance while no difference observed in aroma, sweetness and texture among treatments and storage conditions. Thus, the impacts of HS on chestnuts maintain fruit quality, with benefits in CA storage, as increased panelists’ preference.

Assessment of the Bemisia tabaci C YP6CM l vQ transcript and protein levels in laboratory and field-derived imidacloprid-resistant insects and cross-metabolism potential of the recombinant enzyme

Over-expression of the cytochrome P450 CYP6CM1 gene has been associated with imidacloprid resistance in a number of Q and B biotype Bemisia tabaci laboratory strains from distinct geographical origins worldwide. We recently demonstrated that the Q biotype version of the CYP6CM 1 protein （CYP6CMlvQ） is capable of metabolizing imida- cloprid. Here, we show that the levels of BtCYP6CMlvQ were also elevated in laboratory- resistant strains and field-derived populations, with variable imidacloprid resistance levels, collected in Crete. High levels of CYP6CMlvQ transcripts were also determined in survivors of a heterogeneous field population, after exposure to discriminating imidacloprid dosage. Using peptide antibody-based detection assays, we demonstrated that in line with transcriptional data, the CYP6CMlvQ protein levels were higher in imidacloprid-resistant insects, which further implicates the gene as the causal factor of resistance. Finally, assess- ment of the cross-metabolism potential of CYP6CMlvQ against additional neonicotinoid molecules used for B. tabaci control revealed that clothianidin and thiacloprid, but not acetamiprid or thiamethoxam, are metabolized by the recombinant enzyme in vitro.

Insecticide resistance in Bemisia tabaci from Cyprus

A comprehensive study on the Bemisia tabaci （biotype B） resistance to neonicotinoid insecticides imidacloprid, acetamiprid and thiamethoxam, and pyrethroid bifenthrin was conducted in Cyprus. The resistance level to eight field-collected B. tabaci populations was investigated. The activities of enzymes involved in metabolic detoxification and the frequencies ofpyrethroid and organophosphates target site resistance mutations were determined. Moderate to high levels of resistance were detected for imidacloprid （re- sistance factor [RF] 77-392） and thiamethoxam （RF 50-164） while low resistance levels were observed for acetamiprid （RF 7-12）. Uniform responses by the Cypriot whiteflies could be observed against all neonicotinoid insecticides. No cross-resistance between the neonicotinoids was detected as well as no association with the activity of the P450 microsomal oxidases. Only imidacloprid resistance correlated with carboxylesterase activity. Low to extremely high resistance was observed for insecticide bifenthrin （RF 49 1 243） which was associated with the frequency of the resistant allele in the sodium channel gene but not with the activity of the detoxification enzymes. Finally, the F331W mutation in the acetylcholinesterase enzyme acel gene was fixed in all B. tabaci populations from Cyprus.