Effects of two kinds of flower-inducing agents on the flower dnducing of Tainong No.4 pineapple
Ethephon,a plant growth regulator,was used to induce flowering for Tainong No.4.In common practice,calcium carbide is used to induce the flowering,which is a complicated practice and unfavorable for green and safe production.Fruiting characteristics and fruit quality of pineapple treated with different concen-trations of ethephon and calcium carbide were detected and compared.The results showed that Tainong No.4 pineapple was highly sensitive to ethephon for flowering induction.Even treating with ethephon at a very low concentration(30 mg/kg),the flowering induction rate still exceeded 99%.However,at higher concentra-tions(960 mg/kg and 480 mg/kg),there was no significant difference in the average single fruit weight be-tween ethephon(40%)and calcium carbide treatments,both exceeded 1.08 kg.On the other hand,at low concentrations(240,30 mg/kg),a 40%ethephon treatment led to a decrease in fruit weight.Regarding to the fruit appearance,a high concentration of ethephon(480,960 mg/kg)significantly increased the proportion of cylindrical-shaped fruit of Tainong No.4 than other treatments to more than 94%,which was 32%higher than that of the treatment with 1.25%calcium carbide for two times.In intrinsic fruit quality,compared with calcium carbide,the ethephon treatment significantly increased the vitamin C content,total sugar content,sugar-to-acid ratio,and soluble solids of pineapple fruit.The correlation analysis results indicated extremely significant positive correlations between the concentration of ethephon and the vitamin C content,total sugar content,sugar-to-acid ratio,and soluble solids of pineapple fruit,but extremely significant negative correlation with citric acid content.Considering fruit shape,yield,and quality,the most effective flowering induction for Tainong No.4 was 960 mg/kg ethephon combined with 0.2%urea,with induction rate of 99.69%,cylindri-cal fruit rate of 99.38%,average single fruit weight of 1.22 kg,vitamin C content of 40.45 mg/100 g,soluble solids of 17.93%,total sugar of 17.84%,citric acid of 0.61%,and a sugar-to-acid ratio of 19.71,which is a better alternative to traditional calcium carbide flowering inducing agent.
Tainong No.4pineappleethephonflower forcingcalcium carbidecylindrical-shaped fruit rate