Factors affecting content and bioefficacy of neem (Azadirachta indica A. Juss.) phytochemicals used in agricultural pest control: A review

Neem-based products including traditional preparations and formulations have been used extensively for the control of insect pests attacking agricultural crops. Content of phytochemicals extracted from different parts of the neem plant varies considerably due to abiotic and biotic factors from collection of the raw material to extract preparation and product formulation. Likewise, effectiveness of crude or synthesized material used in the field or laboratory may be influenced by storage conditions, content of active ingredient (especially azadirachtin), insect species and its growth stage, type of formulation and synergism of products with other control measures. In this paper, the direct and indirect actions of neem phytochemicals on insect pests are described and practical implications for future pest control strategies are discussed. (C) 2014 Elsevier Ltd. All rights reserved.