Abstract

Abdel-Monaim M. F.,Gabr M. R., El-Gantiry S. M., Shaat M. N. and El-Bana A. A.

Four chemical inducers viz. Benzoic, ferulic, malic, and oxalic acids at different concentrations (50, 100 and 200 ppm) were applied on lupine plants in the frame of leaf blight caused by Bacillus megaterium management study. All the tested chemicals clearly retarded disease development on lupine plants treated with chemical inducers (especially in case of higher concentration, 200 ppm) compared with the untreated plants. Oxalic and malic acids were the most effective chemical inducers as they greatly reduced disease severity, while ferulic and benzoic acids were the least effective compounds. Also, the in vitro effect of these chemicals on bacterial growth was weak or moderate at higher concentration when compared with the control. Assessment of peroxidase, polyphenoloxidase, phenylalanine ammonia lyase and phenol compound contents in lupine treated plants indicated great increase in their activities in chemical inducers treated plants. Lupine plants treated with oxalic and malic acids recorded the highest of all the tested enzymes and total phenol compounds, while ferulic and benzoic acid gave the lowest ones in this respect