Analysis Of The Quality Of Alternate Bearing Fruit Of

Satsuma mandarin is one of the citrus type that is widely planted in China. Its high rough fruit incidence is prominent problem in current production. The rough fruit is similar in shape of gourd, and it has thick and rough peel, less flavour, and it has no mastication which results in their sales difficulties and lower price. The rough fruit of Satsuma mandarin are mainly at the trees in off year, the top of fruit tree and the branch which has less fruit. Usually we adapt two methods to reduce the rough fruit incidence, one is to keep as more as fruits, the other method is to weaken the tree. But at the same time, the methods may bring some another problems such as the less fruit in next year、 more rough fruits and sever plant diseases and insect pests. The alternate bearing technology is to divide the Satsuma mandarin production into on year and off year. Therefore, the rough fruit incidence is descended in the on year and the tree vigour can get recovered in off year, even the production is not decreased.In the paper, the test materials were Citrus unshiu Marc.cv. Kamei No.25which were planted in alternate bearing technology and conventional bearing technology, moreover, the alternate bearing technology had two ways—field and row. The production habits and quality of fruits were compared between the alternate bearing and conventional bearing. The main results were as follows:1. The productionThe average production of off year(2010) and the on year(2011) were3937.5kg/mu, and the average production of conventional bearing was2800kg/mu. Therefore, the alternate bearing increased40.6%of the production.2. The investigation of habits of alternate bearing and conventional bearing(1) bearing base shoot:The alternate bearing had the most autumn shoots as its main bearing base shoots, the proportion was78%; the conventional bearing had spring shoots as its bearing base shoots, the proportion was76%.(2)the length and coarseness of bearing base shoot:In both of the alternate bearing ways,the length and coarseness of bearing base shoots were more than15cm and5mm respectively; the length of bearing base shoots in conventional bearing were less than10cm or more than15cm, and the coarseness of bearing base shoots were between3mm and5mm。(3)Fruit grading:The diameter of85%of alternate bearing fruits was less than55mm, but that in conventional bearing was only32%, there were58%of the conventional bearing fruits whose diameter was between55mm and65mm.(4) Fruit shape index:There were50%of the alternate bearing fruits whose shape index was between0.8and0.9, but there were63%of the conventional bearing fruits whose shape index was between0.9and1.0, even the18%of conventional bearing fruits’ shape index was over1.0.3. The outward quality of alternate bearing and conventional bearing fruits(1)The fruit weight:The alternate bearing technology can obviously reduce the fruit weight. In the field type, the alternate bearing fruit weight is16g less than that in conventional bearing; the reduction in row type was29g.(2)The diameter of fruit:In the field type, the average diameter of alternate bearing fruit was61.16mm, and65.24mm in conventional bearing fruit:In the row type, the average diameter of alternate bearing and conventional bearing were64.56mm and69.16mm.(3)The equator and the base of fruit pericarp thickness:In the field type, the equator and the base of fruit pericarp thickness were3.55mm and2.7mm in alternate bearing and4.42mm and3.5mm in conventional bearing; In the row type, the equator and the base of fruit pericarp thickness were2.29mm and2.2mm in alternate bearing and2.88mm and2.85mm in conventional bearing.4. The inward quality of alternate bearing and conventional bearing fruits(1)TSS and TA content:There was no difference in alternate bearing and conventional bearing in two types in TSS content. The TA content was reduced from 0.86%in conventional bearing fruits to0.65%in alternate bearing in field type; the TA content was also reduced from0.72%in conventional bearing fruits to0.58%in alternate bearing in row type.(2)The mastication of fruit:Firstly, The segment membrane thickness was reduced from3.72mm in conventional bearing fruits to2.55mm in alternate bearing in field type; the segment membrane thickness was reduced from4.57mm in conventional bearing fruits to3.51mm in alternate bearing in row type. Secondly, the stretching force of segment membrane was reduced from440g in conventional bearing fruits to174g in alternate bearing in row type; the stretching force of segment membrane was reduced from609g in conventional bearing fruits to357g in alternate bearing in row type。 Thirdly, The fruit hardness was reduced from7.28kg in conventional bearing fruits to6.57kg in alternate bearing in field type; the fruit hardness was reduced from975g in conventional bearing fruits to738g in alternate bearing in row type.Otherwise, we compared the quality of fruit in different sizes of alternate bearing and conventional bearing, and also discussed the probability of alternate bearing and its type, fruit quality and its mastication.