| The experiment was carried out in the fruit tree experimental station of Shandong Agricultural University from September,2015 to November,2016,which include three experients.The effects of different substrates(conventional substrate;mushroom compos;cow-dung;rice-husk:vermiculite=3:1;peat:perlite=3:1;mushroom-compos:vermiculite=3:1;cow-dung:peat=3:1;sludge:perlite=3:1;sludge:perlite:vermiculite=6:3:1),different sizes of containers(diameter of 50 cm,height of 40cm;diameter of 50 cm,height of 50cm;diameter60cm,height of 40cm;diameter 60 cm,height of 50cm;diameter 70 cm,height of 40cm;diameter 70 cm,height of 50cm)and different time and angle(in July,August and September,the branches were pulled to 90 degrees,110 degrees,130 degrees and 140 degrees)of branches on Fuji apple were studied.The main results are as follows:1.The difference of soil physical and chemical properties between different substrate treatments and had great influence on the growth of apple.The results showed that,the content of invertase,neutral phosphatase and urease in soil was the highes of trice-husk:vermiculite=3:1(D),Peat:perlite=3:1(CK)was the lowest;Soil enzyme activities directly affect nutrient absorption of apple root.Soil enzyme activities directly affect the nutrient uptake of apple roots.Under different treatments,the index of apple leaf photosynthetic characteristics,the total chlorophyll content,tree height and total biomass of D was significantly higher than that of other treatments.In CK,Apple was the weakest,the chlorophyll a,chlorophyll a+b,total biomass,tree height,the highest and lowest compared respectively increase 54.46%,43.14%,41.37%,22.26%,The net photosynthetic rate of apple,intercellular CO2 concentration and stomatal conductance were 9.42%,11.88%,4.76% higher than the minimum treatment.The tree stem diameter of C4(cow-dung:peat=3:1)is the largest,the minimum is E(conventional matrix),C4 treatment was 41.67% higher than E treatment.The best substrate was rice husk: vermiculite =3:1.2.The experimental results showed that the net photosynthetic rate and intercellular CO2 concentration,stomatal conductance,chlorophyll content,plant height,stem diameter and total biomass were increased with the increase of vessel diameter increased.However,there was no significant difference between the indexes of the same height and diameter.Under the experimental conditions,the height of containeris of 40 cm has to meet the needs of apple growth.The two treatment of diameter 50 cm,height 40 cm and diameter 50 cm,height 50 cm limited the vegetative grow of apple.The follow index in the vessel diameter 60 cm and 70 cm has little difference between the two treatments,but with the diameter 50 cm were significantly higher than those of apple;The apple root,root length,root surface area,root volume and root number were increased with the diameter of the container,only the diameter difference between the two types of 60 cm container root growth index is significant,the rest of the same diameter with no significant difference.This may be because the vessel diameter is too small,which limited the apple root horizontal line extension,causing the root absorption of nutrients decreased,that It can decrease the transportation ability of nutrients,and then affect the vegetative growth of the tree.Therefore,the vessel diameter 50 cm,the two containers with the height of 40 cm and 50 cm performed best.3.Branch can enhance the photosynthetic characteristics of leaves in each month,with branch angle increased,the content of chlorophyll a,chlorophyll b and chlorophyll a+b was significantly increased,and the treatment in August leads to the most significant effect.The net photosynthetic rate,intercellular CO2 concentration,stomatal conductance,stem diameter,and total biomass became slight decreased or changed little in the branch angle greater than 130degrees;with the branch angle increased,the height of tree decreased,the branch angle is 110 degrees and 130 degrees when the index is minimum.The most obvious change is in August.The results showed that the branch could slow down the growth of the top of the tree,transport the nutrient to lateral branch.The number of medium-short branches in Apple was significantly increased,and the number of long branches was reduced.It is beneficial to the culture of the branch and flower bud differentiation.The distribution law of nitrogen is mainly reflected in the medium-long shoots,trunk,leaves and short shoots.When the branch opening angle less than 130 degrees,with the increase of branch angle,the content of15 N in long shoots and trunk distribution isdecreased,when itis increased in leaves,medium-short branches,and the content of 15 N in roots decreased slightly.When Branch angle is less than 130 degrees,with the increase of branch angle,the distribution of 13 C in apple leaves and medium-short branch distribution is increased,and the distribution of 13 C in trunk,long shoots,root is decreased.The results showed that the amount of photosynthesis products that transport to the underground decreased,and the storage of photosynthesis products of leaves and shoots increased.When the branch angle is greater than 130 degrees,C,N distribution showed opposite trend in various organs,It may be due to the excessive pulling branch angle,which can lead to the damage degree of the branches,the transportation of nutrients,minerals,and water is also severely blocked,thus affecting the growth of tree. |
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