Study On Nutritional Deficiency Symptom And Nitrogen Nutrition Of New Guinea Impatience

In this paper,cultivars 'Orangel' and 'Orange2' of Java Series of New Guinea Impatiens was chosen as materials.Firstly,the effect on growth and development was studied when lacking N,P, K,Fe,Ca,Mg,combining with the nutritional deficiency symptom and analysis of plant nutrition to diagnose;Secondly,N nutrition of New Guinea Impatiens was studied and effect on growth and development and nutrient absorption under different N levels and N forms were discussed,the main results were summarized as follows:1.Summing up the nutritional deficiency symptoms when lacking N,P,K,Fe,Ca,Mg through the nutrient deficiency experiment,both of two cultivars all showed typically deficient symptoms under N,P,K treatments,'Orangel' showed obvious symptom of Fe-deficiency.2.Combining N level experiment with changes in leaf color,flowering quality,chlorophyll content and nutrient analysis,the concentration limits of N nutrition malnutrition and appropriate scope of concentration to their growth.Were explored.(1)When N concentration provided was lower than 90mg/L,the two cultivars showed typical symptoms of lacking N,firstly,the lower old leaves showed significant yellowing symptoms; secondly,the upper new leaves showed significant differences in color.(2)When N concentration was 90-240mg/L,the color of leaves was normal.Results of N levels-improved experiment showed that:the plant could grow and develop normally when the N concentration was 150-210mg/L,and flower quality was good at 180mg/L treatment which could be recognized as a better level of treatment.(3) When N concentration provided was upper than 240mg/L,the flower quality decreased, the lower leaves performed normally but upper leaves showed difference in color,'Orangel' changed from bronze to green,'Orange 2' changed from yellow-green to dense green,showing symptoms of N excess.3.As for different N forms proportion experiment under the N concentration of 100mg/L, through the regulation of ratio of NO₃-N and NH₄-N to discuss effects on growth and development of New Guinea Impatiens under different rate of N forms.(1) Under single NO₃-N and NH₄-N treatment,plants could normally grow and bloom, flower quality performed better when NO₃^-:NH₄⁺=3:7;when NO₃^-:NH₄⁺=5:5,the plant grew and developed better;as the ratio of NO₃-N was inhanced,colors of upper leaves showed abnormality,when NO₃^-:NH₄⁺＞5:5,varying degrees of the yellowing phenomenon happened in upper new leaves.(2) Dry weigh of root,root length,root surface area and root volume were the smallest under single NO₃-N treatment compared with other treatment,root system grew better when NO₃^-: NH₄⁺=3:7-5:5.