Studies On The Strains Comparing And Improving Fruit Quality Technologies Of Citrus Cultivar Cv. Huangguogan

With the experiment materical of Citrus cultivar cv. Shimian Huangguogan, a natural citrus hybrid in China, this paper investigated the different strains and the biological characteristics of Shimian Huangguogan. Base on the investigation, it studied the techniques of improve the fruit quality by soil testing and formulated fertilization, bagging on the fruitage, mulching on the garden ground.The main results were as flollows:(1) The Shimian Huangguogan had the three strains by fruit shape:'flat fruit-base'big shape,'convex fruit-base'big shape and small shape. The'flat fruit-base'big type fruit weight was 143g, polardiameter was 64.6mm, suture diameter was 65.3mm.'Convex fruit-base' big shape fruit weight was 142g, polardiameter was 74.7mm, suture diameterwas was 65mm. The small shape fruit weight was 91.6g, polardiameter was 55.9mm, suture diameter was 54 mm.With comparison, the'flat fruit-base'big shape was the best strains by production. It's TSS 11.4%, sugar 8.56g/100ml, acid 0.76g/100ml, VC 23.06mg/100ml, protein 3372.09ug/gFW.(2) The reducing sugar was more than the sucrose in the fruitage sugar content. The average temperature was only 8.8℃between the best cold days in winter. The sugar content and protein content declined fast in those days.The showed that the low temperature had the notable influence to the fruit quality.(3) Past test the nutrient content in soil and nutrient element content in leaves from the garden, we could find that the soils and leaves lacked organic matter, phosphate and potassium.The formulated fertilization was N 1.13 kg, P2O50.765 kg, K2O 1.44 kg per tree. Fertilizing the tree three times per year in the last ten days of January, in the first ten days of June and in the middle ten days of August. Fertilizing in the soil or on the leaves. Pay attention to using the organic fertilizer.(4) Bagging with the yellow type increased the surroundings'temperature 0.27℃and 20.74% humidity in the bag between the best cold days. The TSS, reducing sugar, sucrose, VC, protein increasd and organic acid declined by bagging. The yellow type bag was the best choice, and bagging in the first ten days of December, taking off the bag in the 15 to 30 days before pick. (5) Mulching on the garden ground could increase the ground temperature from 0.5℃to 3.2℃between the best cold days. The glisten plastic film could improve the illumination in the crown of a tree. The TSS, sugar, VC, protein increased and organic acid declined by mulching. The glisten plastic film and black plastic film were the best choice when mulching, and mulching the first ten days of December, taking off the plastic film before pick.