EFFECT OF SOIL DRENCH WITH RESISTANCE INDUCING COMPOUNDS ON CONTROL CUCUMBER DOWNY MILDEW DISEASE

The objective of this research was to determine the efficiency of beta- Amino butyric acid (BABA) and Salicylic Acid (SA) as a resistance chemical agents in cucumber against Pseudoperonospora cubensis (Berk. & Curt.) Rostow. the causal agent of downy mildew. Both acids were used as soil drench at different concentrations 2 days before the artificial inoculation with fungal suspension. Results of this experiment indicated that there was a significant effects of both acids in decreasing the percentage of infected leaves, Disease Index (DI) and the rate of disease increase (r) compared to control plants. The occurrence of disease symptom of plants growing in soil drench treatment was delayed 1 week compared with control. Results also showed that the use of BABA at 100 mu g/ml and SA at 150 mu g/ml were decreased the percentage of leaves infection which were 4.16% and 8.66% in plants growing in treated soil for both acids respectively compared with 38.4% for control plants as a mean of 5 weeks recorded data. Results also revealed that BABA and SA have a curative