β-amino-butyric acid induces resistance against Asian citrus psyllid, Diaphorina citri, in citrus

Beta-aminobutyric acid (BABA) is known to broadly induce resistance to several microbial pathogens, nematodes and insects in several plant species. The objective of this study was to determine whether BABA induces resistance to Asian citrus psyllid, Diaphorina citri, in citrus under greenhouse conditions. This investigation examined the effect of five concentrations of BABA applied as root drenches to citrus plants, on the performance of D. citri. The number of eggs, nymphs and adults produced per plant were quantified on treated and control plants. Survival of D. citri eggs, nymphs, and adults was reduced on BABA-treated plants compared with controls. In addition, leaf-dip bioassays confirmed that BABA was not directly toxic to D. citri. Our results indicate that systemic application of BABA to citrus induces resistance and that this affect is not explained by direct toxicity.