Persistence of spiromesifen in soil: influence of moisture, light, pH and organic amendment

Abstract

Persistence of spiromesifen in soil as affected by varying moisture, light, compost amendment, soil sterilization and pH in aqueous medium were studied. Degradation of spiromesifen in soil followed the first-order reaction kinetics. Effect of different moisture regimes indicated that spiromesifen dissipated faster in submerged soil (t 1/2 14.3-16.7 days) followed by field capacity (t 1/2 18.7-20.0 days), and dry soil (t 1/2 21.9-22.9 days). Dissipation was faster in sterilized submerged (t 1/2 17.7 days) than in sterilized dry (t 1/2 35.8 days). Photo spiromesifen metabolite was not detected under different moisture regimes. After 30 days, enol spiromesifen metabolite was detected under submerged condition and was below detectable limit (<0.001 μg g(-1)) after 90 days. Soil amendment compost (2.5 %) at field capacity enhanced dissipation of the insecticide, and half-life value was 14.3 against 22.4 days without compost amendment. Under different pH condition, residues persisted in water with half-life values 5.7 to 12.5 days. Dissipation in water was faster at pH 9.0 (t 1/2 5.7 days), followed by pH 4.0 (t 1/2 9.7 days) and pH 7.2 (t 1/2 12.5 days). Exposure of spiromesifen to different light conditions indicated that it was more prone to degradation under UV light (t 1/2 3-4 days) than sunlight exposure (t 1/2 5.2-8.1 days). Under sunlight exposure, photo spiromesifen metabolite was detected after 10 and 15 days as compared to 3 and 5 days under UV light exposure.

Residue level and dissipation pattern of spiromesifen in cabbage and soil from 2-year field study

“…(Shahgholi and Ahangar 2014). Spiromesifen dissipation was faster in soil with high moisture content (Mate et al 2015). The high rainfall during the current study periods could have facilitated faster dissipation of spiromesifen in soil as it was not detected in the field soil at harvest.…”

Zinc in Soil Environment for Plant Health and Management Strategy

“…Zinc applications have been realized at the following growth stages: (1) stem elongation and booting stages, (2) milk and dough stages, (3) booting and milk stages and (4) booting, milk and dough stages. Once the micronutrient content of the seed is improved by any bio-fortification technique, say agronomic bio-fortification, it has several agronomic advantages besides improving human nutrition [35,36,37]. Fertilizer studies focusing specifically on increasing Zn concentration of grain (or other edible parts) are, however, very rare, although a large number of studies are available on the role of soil and foliar applied Zn fertilizers in correction of Zn deficiency and increasing plant growth and yield.…”

“…The highest increase in grain yield was obtained with soil, soil + foliar and seed + foliar applications. When a high concentration of grain Zn is aimed in addition to a high grain yield, combined soil and foliar application is recommended [37]. Alternatively, using seeds with high Zn concentrations at sowing together with foliar application of Zn is also an effective way to improve both grain yield and grain Zn concentration.…”

Metallothionein from Wild Populations of the African Catfish Clarias gariepinus: From Sequence, Protein Expression and Metal Binding Properties to Transcriptional Biomarker of Metal Pollution

“…Some fish of the Salmoniformes family and Notothenoids have two MT genes [ 36 ] (also see Figure 2 b for respective proteins), but most likely C. gariepinus only possesses a single MT gene, like Ictalurus punctatus , for which a sequenced genome is available [ 83 ]. The CgMT protein ( Figure 2 b) displays features typical of vertebrate MTs in general [ 29 , 30 , 35 ], and fish MTs in particular [ 36 , 84 ]. Its predicted molecular weight (excluding metal ions) is 6138.16 Da, typically low as for the vast majority of MTs.…”