The Preparing Conditions Of Weakly Acidic Electrolyzed Water And Its Application In Greenhouse Vegetables

This work evaluated the effect of the concentration of sodium chloride andhydrochloric acid, flow rate and decomposition voltage on the indexes of Weakly Acidic Electrolyzed Water(WAEW) prepared by electrolysis using sodium chloride and dilute solution of hydrochloric acid. Stability of WAEW under four kinds of storage conditions include exposure with light, exposure without light, seal with light, seal without light were analyzed. Differences of physicochemical indexes of theelectrolysed water prepared from two kinds of solution(sodium chloride and hydrochloric acidsolution, potassium chloride and hydrochloric acidsolution, respectively) were compared. The WAEW was used to evaluate its effects on greenhouse cucumber and tomato. Growth indexes of cucumber(Plant Height, Stem Diameter, Overground part and Dry Weight of Root, Fresh Weight, Root Shoot Ratio and Per Fruit Mass), fruit appearance quality(Bow Height, Diameter at the Equatorial Section, Fruit Length and Peduncle Length), physicochemical properties(the content of Vitamin C, Soluble Solid, Soluble Protein, Soluble Sugar, Titratable Acid, Imidacloprid and Flusilazole), fruit quality, growth and effect of the yield of tomato were measured. Finally the control efficiency on powdery mildew and downy mildewof cucumber was monitored, the studyresultsare as follows:The concentration of sodium chloride, hydrochloric acid and flow rate have a significant impact on the pH value of WAEW( p<0.01). In addition, the concentration of hydrochloric acid, flow rate and decomposition voltage have a significant impact on the ORP of WAEW( p<0.01) and the concentration of sodium chloride and the flow rate have a significant impact on the ACC of WAEW( p<0.01). The flow rate has a more significant impact on pH value and ORP than the concentration of sodium chloride and hydrochloric acid and the decomposition voltage. Meanwhile, the concentration of sodium chloride affect ACC greater than the flow rate, the decomposition voltage and the concentration of hydrochloric acid.The WAEWpH value decreased and the ORP and the content of ACC of WAEW increased with increasing hydrochloric acidconcentration of original electrolyte. The ORP decreased and the pH value and ACC of WAEW increased with increasing sodium chlorideconcentration of original electrolyte. The voltage of diaphragm pump had a linear regression relationship with the flow rate. The flow rate increased with increasing voltage of diaphragm pump and the pH value and the content of ACC decreased while the ORP increased with increasing flow rate. The pH value and the content of ACC increased and the ORP decreased with increasing bath voltage. The WAEWs prepared by sodium chloride and potassium chloridehad no significant difference. The response surface model showed a good prediction ofthe physicochemical indexes of WAEW.The pH value, ORP and ACC of WAEW remained about the same stored for one month under seal without light condition, therefore seal without light is the optimal condition for storing WAEW, and it was easily resolved under light condition.The growth of cucumber promoted and the fruit appearance and nutritional qualityimproved and the risk of pesticide residues decreased with the spraying of WAEW. WAEW prepared by potassium chloride and hydrochloric acid performed best at 8 indexes such as fresh weight of root, dry weight, per fruit mass, bow height, the content of Vitamin C. WAEW had a lower control efficiency on the cucumber disease than pesticide group. WAEW had no negative effects on the growth of tomato and it could improve the tomato production. Water decreased root shoot ratio of tomato better than pesticide.