Comparison of tebuconazole and trifloxystrobin residue levels on paddy grains and paddy straw harvested from paddy fields applied with knapsack sprayer, motorised knapsack sprayer or drone application

Ngan C. K.¹*, Chong T. V.² and Khairatul A. M.³

Abstract
A study on comparison of pesticide residue concentrations on paddy grain and paddy straw that were treated using three application methods, namely knapsack sprayer, motorised knapsack sprayer and drone sprayer, was conducted in a paddy field. Nativo (containing active ingredient of tebuconazole and trifloxystrobin) was applied once on a paddy field at 21 days before harvest. On the harvesting day, paddy grain and paddy straw were sampled from the plots that were treated with the three respective three application methods. Tebuconazole was detected in paddy grains (<0.01 - 0.371 mg/kg) and paddy straw (<0.01 - 0.171 mg/kg) at concentrations near to Limit of Quantification (0.01 mg/kg). The concentration ranges of trifloxystrobin in paddy grain and paddy straw were <0.01 – 0.025 mg/kg and <0.01 – 0.011 mg/kg, respectively. In ascending order, residue concentrations from plot treated with drone was the lowest, followed by motorised knapsack sprayer and knapsack sprayer. Spray drift factor may have contributed to the observed magnitude of residues in the treatment plots. Detected residues were within Maximum Residue Limits of tebuconazole and trifloxystrobin on rice. Except for tebuconazole concentration in paddy grain, drone application did not cause concentrations that were significantly differ from the conventional application method.

Keywords: pesticide residues, paddy field, knapsack sprayer, motorised knapsack sprayer, drone

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