Induction of Systemic Resistance in Cucumber(cucumissatssivus)against Scab with BION,an Activator of Systemic Acquired Resistance

The cucumber scab caused by Cladosporium cucumerinum Ell. is one of the most important diseases of cucumber in the PR. of China and elsewhere. Recently, wider acceptance of under glas culture exacerbates the problem. Both in greenhouses and in free fields in the Northern China pose a challenge in the control of this disease, because there are no effective fungicide to be used. Induced resistance with chemicals may be an ideal way to protect cucumber against this disease , if there are no resistant cultivars to be used. This paper reports the effect of BION, a new activator of SAR, on the induction of resistance to cucumber scab using two treatment methods (seed treatment and foliar spray) at different concentrations (10,20,40, 80, 160 mg. mL- 1). The results showed that the number of diseased plants was decreased drastically in BION - treated plants, the disease incidence was 35 %, whereas it was 75 % in control plants. The disease severity of plant with BION treatment by foliar spray was 2 and it was 1.5 if used as seed treatment, whereas it was 3 and 3.1 in control plants respectively. Moreover it has no phytotoxic effect to be observed at concentrations used in the experiment.