Fate of azadirachtin A and related azadirachtoids on tomatoes after greenhouse treatment.
The degradation of the main azadirachtoids on tomatoes was studied after greenhouse treatment. These experiments were carried out at 1 and 5x the concentration recommended by the manufacturer. In all experiments the deposition of azadirachtin A (AZA-A) was below the maximum residue level (MRL). Even if at the highest dose, AZA-A half-life time calculated as pseudo first order kinetic was 1.2 days in agreement with the recommended preharvest interval (PHI) of 3 days. Experiments with a model system showed that sunlight photodegradation is the main factor influencing the rate of disappearance of AZA-A after greenhouse treatment while tomato epicuticular waxes doubled the photodegradation rate of AZA-A in a commercial formulation.
Caboni
Pierluigi
P
Dipartimento di Tossicologia, Universita di Cagliari, Cagliari, Italy. caboni@unica.it
Sarais
Giorgia
G
Angioni
Alberto
A
Lai
Francesco
F
Dedola
Fabrizio
F
Cabras
Paolo
P
D002851:Chromatography, High Pressure Liquid; D005524:Food Technology; D006207:Half-Life; D007306:Insecticides / Q000378:metabolism* / Q000528:radiation effects*; D007700:Kinetics; D000077222:Limonene; D036701:Limonins / Q000378:metabolism / Q000528:radiation effects*; D018551:Solanum lycopersicum / Q000378:metabolism* / Q000528:radiation effects*; D010782:Photolysis / Q000528:radiation effects*; D021241:Spectrometry, Mass, Electrospray Ionization; D013472:Sunlight; D014315:Triterpenes / Q000378:metabolism / Q000528:radiation effects
D007306:Insecticides; D036701:Limonins; D014315:Triterpenes; C105836:salannin; D000077222:Limonene; C008621:nimbin; C010329:azadirachtin; C476490:azadirachtin B