African Journal of
Agricultural Research

  • Abbreviation: Afr. J. Agric. Res.
  • Language: English
  • ISSN: 1991-637X
  • DOI: 10.5897/AJAR
  • Start Year: 2006
  • Published Articles: 6574

Full Length Research Paper

Study on twenty-five percent pymetrozine-thiamethoxam suspension concentrate as an insecticide against rice planthopper

Zhuo Chen1, Song Bai1, Zhenchao Wang1, Song Zeng1, Feng Zhu2, Jia-xiang Zhuang3, Rong Guo4 and Deyu Hu1*    
1State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang 550025, P. R. China. 2Plant Protection Station of Fujian Province, Fuzhou 350003, P. R. China. 3Plant Protection Station of Jiangsu Province, Nanjing 210013, P. R. China. 4Research and Extension in Agricultural Development International Center, Beijing 100125, P. R. China.      
Email: [email protected]

  •  Accepted: 27 June 2012
  •  Published: 28 August 2012

Abstract

A blended pesticide, 25% pymetrozine-thiamethoxam suspension concentrate (SC), was evaluated for its insecticidal activity against rice planthoppers in a greenhouse and field. The results of the seedling-dipping and rice-stem-dipping methods used in the greenhouse indicated the excellent activity of the SC against the brown rice planthoppers, with the lethal concentration causing 50% mortality (LC50) values reaching 3.27 and 3.79 μg/ml, respectively. The co-toxicity coefficient (CTC) value >120 indicated that the obtained SC had a synergistic effect. The results from the field efficacy trials revealed that the controlling effect of the proposed reagent on rice planthoppers was better than (or comparable with) commercial insecticide-25% pymetrozine SC and 2.2% abamectin-imidacloprid emulsifiable concentrate (EC) at comparable doses and differential time intervals. The proposed reagent had low toxicity from the data of acute oral, acute dermal, eye irritation and skin irritation. These characteristics suggested 25% pymetrozine-thiamethoxam SC as a potential candidate insecticide.

 

Key words: 25% pymetrozine-thiamethoxam suspension concentrate, rice plant hopper, toxicological test, field efficacy.