Study On The Effects Of Differert Kinds Of Secondary Macronutriente And Micronutrient Fertilizers On The Yield And Quality Of Navel Orange And Selenium Enriched In The Fruit

Navel orange is an important fruit in China as well as in the world.The fruit yield of Navel orange in China account No.1 in the world.The improvement of navel orange yield and quality plays important roles in navel orange industry.Secondary-macronutrient and micronutrient are essential for plant growth and development,which are important factors affecting the quality of navel orange and play important roles in improving the quality and nutrients efficiency of navel orange.Most of the cultivated land in China suffered from secondary-macronutrients and micronutrients deficiency.Exogenous application of secondary-macronutrient and micronutrient fertilizer has become a basic method in agricultural production.In this study,field experiments were conducted to study the effects of secondary-macronutrient and micronutrient fertilizers,compound fertilizers containing secondary-macronutrient and micronutrient,and selenium fertilizers on fruit yield,fruit quality and fruit selenium content of Newhall navel orange.The main results are as follows.(1)Effects of secondary-macronutrient and micronutrient fertilizers on fruit yield and quality of navel orangeIn the soil lacking of secondary-macronutrient and micronutrient,compared with farmer’s fertilizer practices(FFP),addition of calcium-magnesium fertilizer,boron fertilizer and multi-micronutrient fertilizer increased the number of fruit,single fruit weight and fruit diameter by 8.11% ～ 22.86%,5.08% ～ 18.92% and 1.89% ～ 10.07%,respectively;increased the soluble solid content by 4.38% ～ 8.71%,the soluble sugar content by 0.82%～ 10.16%,the Vc content by 3.37% ～ 8.15%,and the sugar/acid ratio,solid/acid ratio and edible rate by 5.54% ～ 24.37%,8.49% ～ 23.46% and 1.70% ～ 11.29%.,respectively;decreased the soluble acid content by 2.61% ～ 15.17%.In addition,the effect of calciummagnesium fertilizer,boron fertilizer and multi-micronutrient fertilizer on the fruit yield and quality of navel orange were different.(2)Effects of compound fertilizers containing secondary-macronutrient and micronutrient on fruit yield and quality of navel orangeCompared with FFP,the application of compound fertilizer combinations S1 and S3 containing secondary-macronutrient and micronutrient significantly improved the fruit yield of navel orange in the soil lacking of secondary-macronutrients and micronutrients,for example,the number of fruit increased by 46.88%,and the fruit diameter increased by6.73% ～ 7.79%.The application of compound fertilizer combination S2 containing secondary-macronutrient and micronutrient was more effective in improving the quality of navel orange than than of other compound fertilizer combinations.Among the fruit quality parameters,the soluble solid content and Vc content of navel orange increased significantly by 15.54% and 16.01%,and soluble acid content decreased by 39.09%;the sugar/acid ratio,solid/acid ratio and edible rate were significantly increased by 68.08%,89.67% and 7.35%,respectively.In addition,compared with FFP,the application of compound fertilizers reduced the application rate of nitrogen,phosphorus and potassium in different extent,and different compound fertilizer combinations had different effects on the fruit yield and quality of navel orange.(3)Effects of selenium fertilizers and application methods on fruit yield,quality and selenium enrichment of navel orangeIn the soil lacking of available selenium,the single fruit weight,fruit diameter,Vc content and solid/acid ratio increased firstly and then decreased,soluble acid content decreased firstly and then increased,the total selenium content in the fruit of navel orange increased with the increase of selenium fertilizers,but edible rate did not change with the increasing of selenium fertilizers(whether organic or inorganic selenium fertilizers).Foliar application of selenium fertilizers(whether organic selenium fertilizer SE2 or inorganic selenium fertilizer SE4)had the best selenium enrichment effect.Overall,the fruit quality under the treatments of SE2-1,SE2-2,SE4-1 and SE4-2 were better than other treatments,for example,the single fruit weight increased by 13.86% ～ 28.54%;the fruit diameter increased by 4.35% ～ 9.74%,the Vc content of navel orange increased by 15.18% ～ 18.25%,the selenium content of navel orange increased by 430.49% ～ 746.95%;while the soluble acid content decreased by 9.68% ～ 23.15%.Additionally,the solid/acid ratio and edible rate were increased by 19.11% ～ 36.85% and 11.59% ～ 15.14%,respectively.Different application methods of selenium fertilizer had different effects on the fruit yield,quality and selenium content of navel orange.Among them,in the treatment of selenium fertilizer spraying,the single fruit weight significantly increased by 25.80%;soluble sugar,Vc and selenium content increased by 7.86%,11.52% and 369.51%,respectively;while soluble acid content decreased by 10.77%.Additionally,the sugar/acid ratio,solid/acid ratio and edible rate of the fruit under the former were increased by 23.18%,9.63% and 12.66%,respectively.Overall,spray application of selenium fertilizer was better than soil application of selenium fertilizer in the improvement of the fruit yield yield,quality and selenium content.In conclusion,the appropriate application rate of secondary-macronutrient and micronutrient fertilizers,compound fertilizers containing secondary-macronutrient and micronutrient,and selenium fertilizers improved the yield and fruit quality of navel orange,and the appropriate application rate of selenium fertilizers also increased the content of selenium in fruits,and different fertilizers had different effects on improving the yield and quality of navel orange.