Residues and Half-Life Times of Pyrethrins on Peaches after Field Treatments

Abstract

The behavior of pyrethrins and piperonyl butoxide (PB) on peaches has been studied after field treatment. Three experiments were carried out at 1, 5, and 10x the concentration recommended by the manufacturer. In all experiments, the initial deposition was below the maximum residue level (MRL), and the half-life time calculated in the 10x experiment for total pyrethrins within 2.3 days was in agreement with the preharvest interval (PHI) recommended. In a model system, the photodegradation rates of the pyrethrins in three commercial products were compared with pyrethrum pale (PP), with and without the presence of peach waxes. The pyrethrins in formulations containing PB showed higher half-life times but were not influenced by the presence of waxes, whereas in the case of PP that does not contain any PB, photodegradation was significantly affected by the presence of waxes.

Chemical and biological comparisons on supercritical extracts of Tanacetum cinerariifolium (Trevir) Sch. Bip. with three related species of chrysanthemums of Sardinia (Italy)

“…The insecticidal properties of the chrysanthemum flowers were first reported in the early 1800s; the active ingredient consists of six esters called pyrethrins and identified as pyrethrin I and II, cinerin I and II, and jasmolin I and II, which are obtained from the combination of chrisanthemic acid and pyrethric acid with three alcohols: cinerolone, pyrethrolone and jasmolone (Angioni, Dedola, Minelli, Barra, Cabras, & Caboni, 2005). The relative amount of each compound vary depending on the plant type and the region where the plants are grown.…”

Field efficacy of insect pathogen, botanical, and jasmonic acid for the management of wheat midge Sitodiplosis mosellana and the impact on adult parasitoid Macroglenes penetrans populations in spring wheat

“…The lack of individual effects of B. bassiana or pyrethrin applications on larval populations or other studied parameters could be due to mode of action and presumably with these biopesticides inability to reduce the daily fecundity of wheat midge adults. Furthermore, abiotic factors (e.g., sunlight, temperature) may have contributed to their lack of effect, since the previous studies have shown that fungus or pyrethrin half-life can decline rapidly (2 h to 3 d) in outdoor environments (Inglis et al, 1995;Angioni et al, 2005;Jaronski, 2010).…”

Natural Pesticides and Future Perspectives

“…Pyrethrum is a mixture of six esters, pyrethrins I and II, (the most abundant), cinerin I and II, and jasmoline I and II. Sunlight photodegradation is the main factor influencing the rate of it disappearance after the application at ten times the dose recommended by the manufacturer disappearance time was 2.3 days (Angioni et al, 2005). Pyrethrum was the only botanical included in the Annex I after the fourth stage of re-evaluation.…”