Feng Zheng1,2, Hui Jiang1,2, Jinliang Jia1,2, Ruifei Wang2, Zhixiang Zhang1,2, Hanhong Xu1,2. 1. State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, Guangdong, China. 2. Key Laboratory of Natural Pesticide & Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou, China.
Abstract
BACKGROUND: Monolepta hieroglyphica (Motschulsky) is a primary pest of maize. The effect of dimethoate on controlling a M. hieroglyphica infestation was studied using drip irrigation. Field trials were conducted to determine the most effective application rate and water volume for dimethoate treatment in arid and semi-arid regions. The absorption, distribution and dissipation of dimethoate in maize and soil were examined. RESULTS: Field trials showed that dimethoate at a rate of 2.70 kg a.i. ha-1 and water volume of 200 m3 ha-1 was the most effective treatment for controlling M. hieroglyphica. Dimethoate via drip irrigation showed longer persistence than dimethoate applied via artificial or unmanned air vehicle spraying. Different parts of the maize plant had a hysteresis effect on dimethoate absorption. Dimethoate was absorbed from the roots, transported upward, and enriched in the leaf. Dimethoate was mainly concentrated within a certain range near the emitter after drip irrigation. Terminal residues of dimethoate in maize grain were below detectable levels 42 days after treatment. CONCLUSIONS: Dimethoate treatment via drip irrigation can control M. hieroglyphica infestation on maize. Results showed that dimethoate is safe for maize and the environment. This study provides guidance for the application of pesticides in arid and semi-arid areas.
BACKGROUND:Monolepta hieroglyphica (Motschulsky) is a primary pest of maize. The effect of dimethoate on controlling a M. hieroglyphica infestation was studied using drip irrigation. Field trials were conducted to determine the most effective application rate and water volume for dimethoate treatment in arid and semi-arid regions. The absorption, distribution and dissipation of dimethoate in maize and soil were examined. RESULTS: Field trials showed that dimethoate at a rate of 2.70 kg a.i. ha-1 and water volume of 200 m3 ha-1 was the most effective treatment for controlling M. hieroglyphica. Dimethoate via drip irrigation showed longer persistence than dimethoate applied via artificial or unmanned air vehicle spraying. Different parts of the maize plant had a hysteresis effect on dimethoate absorption. Dimethoate was absorbed from the roots, transported upward, and enriched in the leaf. Dimethoate was mainly concentrated within a certain range near the emitter after drip irrigation. Terminal residues of dimethoate in maize grain were below detectable levels 42 days after treatment. CONCLUSIONS:Dimethoate treatment via drip irrigation can control M. hieroglyphica infestation on maize. Results showed that dimethoate is safe for maize and the environment. This study provides guidance for the application of pesticides in arid and semi-arid areas.