and Integrated Pest Management - part - usaid

PES'TICIDI"RSIDCES INTI'l 1 P1 III.PIS:s 357
Table 1. Residues (mg/kg) of diazinon and med'yl parathion in string bean
samples taken from a farmer cooperator. Cavite, 1981.
Diazinon Mcthyl Parathion
P IF­
(davs) unwashed washed % rcduction unvashed washed % rcduclion
3 hrs 1.8 1.3 26 2.1 1.1 49
1 0.2 0.1 32 1.0 0.8 20
2 0.2 0.1 33 0.3 0.3 33
3 0.05 0.04 20 0.2 ND
5 tr:lces NDI) 0.03 ND
7 ND ND
" PIl 1= Preharvest interval; ) ND = not detectable at minimum detection level of
0.01 mng/kg; MRL = 1.0 mg/kg for methyl paratLhion.
Table 2. Residues of some organophosphate insectiides in string bean samples
at lifferent preharvest intervals at the recommended dose of 2-3
bsp/191.. UPLB, 1981.
PP-ll Mevin- Monocro- Malathion Methyl Tetra- Triazo­
(days) phos tophos Parathion chlor- phos
vinphos
3 hrs ND b ) 1.8 0.1 0.5 1.6 6.8
1 1.6 ND 0.3 1.4 2.2
2 ND 0.1 1.2
3 0.01 0.1 1.5
5 ND ND 0.9
7 ND NI)
;1 1I = Preharvest interval; b ND = not detected at minimum detection level of
0.01 nig/kg for methyl parathion and mevinphos, 0.04 mg/kg for malathion and
tetrachlorvinphos and 0.05 mg/kg for monocrotolhos and triazophos; MRLs =
0. 1 mg/kg for mevinphos, 0.2 mg/kg for nonocrotophos, anti 1.0 mg/kg for
methyl parathion.
samples from various markets in Metro Manila, only 15 were found to contain
insccticile residues. Since the samples were not washed, about 20% to 50% of
residues were expected to be removed by washing. The samples were positive
for diazinon, methyl parathion and mevinphos.
Green Beans
The residue data in Table 3 for the four insecticides tested on green beans
Phascotus vulgaris L. (Tejada et al. 1977) show tli-t they are all readily lost