Cucumber leaves have been sprayed with a solution of hydrogen peroxide (H202) or Pharmaplant-turbo combined with organic or inorganic fertilizers under plasic house. Under the influence of H202, leaves exhibited resistant against Podoshaera fusca fungus, the causal agent of cucumber powdery m...ildew. H202 (15 mM) was able to decrease the disease severity from 90.4% to 12% in two experiments conducted in two seasons. Pharmaplant-turbo (Turbo) is new chemical compound and used as an antifungal compound. Turbo in 1 ml/L was able to decrease the disease severity from 90.4% to 11.5% in the both experiments as well. Both of H202 and Turbo were combined with organic treatment (compost + compost tea + seaweed extracts) which showed significant effect against cucumber powdery mildew fungus and strongly suppressed it as compared to control leaves. Organic treatment produced higher vegetative growth characters and greater early and total yields as compared to inorganic treatment, also organic fruits produced the lower nitrate content and the higher ascorbic acid content as compared to inorganic fruits. Our study have indicated that, H202 and Turbo combined with organic fertilizers play a role in the resistance of cucumber against powdery mildew by decreasing the disease severity. We suggest to give more attention to the direct application of H202 in low concentration and Turbo against powdery mildew diseases and other plant diseases.
The effect of STS and 1-MCP on the postharvest quality of carnation and rose cut flowers was studied. Cut flowers of Dianthus c..aryophyllus L. cv. Asso and Rosa hybritia cv. Baroness were treated with silver thiosulfate (STS) at 0.4 mM with sucrose at 50 g 1-t and 1-methylcyclopropene ( I -MCP) at 0.5 g m<...sup>-3 for 611.
Pretreatment with STS and 1-MCP significantly extended the vase life and minimized the % loss of initial weight of carnation and rose cut flowers comparing to the untreated control. The two chemicals applied inhibited the chlorophyll degradation and carbohydrate loss and hence, significantly improved the postharvest quality of carnation and rose cut flowers comparing to the control. Ethylene production by cut flowers was inhibited as a result of using these chemicals. In general, there were no differences between STS and (-MCP but the later does not have the heavy metal implications of STS treatment, and hence, using 1-MCP pretreatment for extending the vase life of carnation and rose cut flowers was recommended.