Dissipation of the fungicide hexaconazole in oil palm plantation.
Hexaconazole is a potential fungicide to be used in the oil palm plantation for controlling the basal stem root (BSR) disease caused by Ganoderma boninense. Therefore, the dissipation rate of hexaconazole in an oil palm agroecosystem under field conditions was studied. Two experimental plots were treated with hexaconazole at the recommended dosage of 4.5 g a.i. palm(-1) (active ingredient) and at double the recommended dosage (9.0 g a.i. palm(-1)), whilst one plot was untreated as control. The residue of hexaconazole was detected in soil samples in the range of 2.74 to 0.78 and 7.13 to 1.66 mg kg(-1) at the recommended and double recommended dosage plots, respectively. An initial relatively rapid dissipation rate of hexaconazole residues occurred but reduced with time. The dissipation of hexaconazole in soil was described using first-order kinetics with the value of coefficient regression (r (2) > 0.8). The results indicated that hexaconazole has moderate persistence in the soil and the half-life was found to be 69.3 and 86.6 days in the recommended and double recommended dosage plot, respectively. The results obtained highlight that downward movement of hexaconazole was led by preferential flow as shown in image analysis. It can be concluded that varying soil conditions, environmental factors, and pesticide chemical properties of hexaconazole has a significant impact on dissipation of hexaconazole in soil under humid conditions.
Analytical and Quality Development Unit, Product Development and Advisory Services Division (PDAS), Malaysian Palm Oil Board (MPOB), No. 6, Persiaran Institusi, Bandar Baru Bangi, 43000, Kajang, Selangor, Malaysia. maznahz@mpob.gov.my.
Zainol
Z
Maznah
Analytical and Quality Development Unit, Product Development and Advisory Services Division (PDAS), Malaysian Palm Oil Board (MPOB), No. 6, Persiaran Institusi, Bandar Baru Bangi, 43000, Kajang, Selangor, Malaysia.
Muhamad
M
Halimah
Faculty of Science and Technology, School of Environmental and Natural Resource Sciences, Universiti Kebangsaan Malaysia (UKM), 43600, Bangi, Selangor, Malaysia.
Sahid
S
Ismail
Ganoderma and Diseases Research for Oil Palm Unit, Biology Research Division, Malaysian Palm Oil Board (MPOB), No. 6, Persiaran Institusi, Bandar Baru Bangi, 43000, Kajang, Selangor, Malaysia.
Abu Seman
AS
Idris
D001711:Biotransformation; D000069601:Crop Protection; D005659:Fungicides, Industrial / Q000378:metabolism*; D032902:Ganoderma; D006207:Half-Life; D000073878:Palm Oil; D010938:Plant Oils; D018517:Plant Roots / Q000382:microbiology; D018547:Plant Stems / Q000382:microbiology; D012987:Soil / Q000737:chemistry; D014230:Triazoles / Q000378:metabolism*
D005659:Fungicides, Industrial; D010938:Plant Oils; D012987:Soil; D014230:Triazoles; D000073878:Palm Oil; C409722:hexaconazole
Dissipation; Ganoderma; Hexaconazole; Oil palm; Preferential flow