Study on the dynamic growth of the new shoots and leaves of Prunus salicina × armeniaca in Southern Xinjiang

Abstract:【Objective】Continuous observation of the growth of branches and leaves of Prunus salicina×armeniaca in an arid areas, in order to understand the growth and development of the tree. The dynamic micro change of the trunk diameter was an important index to study the water and growth status of plants. Themicro variation of the trunk diameter and its response to environmental factors were discussed, which provided a scientific basis for the micro changes of the stem diameter to guide precision irrigation. The studyaimed to investigation the growth dynamic of new shoots, leaves, and trunks in arid areas, so that we can ef-fectively guide the production of fruit trees. Utilizing local take corresponding cultivation and managementmeasures, scientific fertilizer and water management, allows us to do a good job in the management of theorchard, and thereby providing some theoretical basis for high-quality cultivation of Prunus salicina×armeniaca.【Methods】When the new shoots and leaves grew, they were measured and recorded every 5 days.The leaf area was measured by the“Yaxin-1241 leaf area meter,”and the leaf weight was determined using a portable electronic balance. Continuous automatic monitoring of the plant stem diameter growth by us-ing a plant growth measuring instrument, and two growth measurement instruments DD1, DD2, DD3, DD4 were installed in the ground more than 100 cm from the North-South trunk, utilizing the tin foil protectivetreatment. The selection was about 5 cm in the middle of the test tree canopy. Before the installation, we used a blunt knife to scrap the trunk skin, to ensure that the instrument frame was solid and that the probeand the main contact were good. The probe was wrapped in foil, to prevent the direct effects of wind, tem-perature and rainfall on the probe. The measuring probe was fixed on the side near the base position moni-toring. Regularly checking was done to ensure whether the instrument was loose, and we also performedtimely calibrations. Our test selection consisted of 3 experimental trees, with each tree being set up with 1sensor. The automatic data acquisition system was set every 5 min for automatic measurement of the diame-ter of the data. Under different growth stages, weather and water conditions, the growth of the new shoots,leaves and stems of the different varieties of Prunus salicina × armeniaca were regularly measured, andtheir changing rules and the relationship between them were analyzed. We also did an analysis of their variation law and mutual relationship.【Results】The average annual growth rate of the new shoot lengths forPrunus salicina×armeniaca‘Fengweihuanghou',Prunus salicina×armeniaca‘Weidi', Prunus salicina×armeniaca‘Weiwang'and Prunus salicina×armeniaca‘Weihou'were 7.28, 8.84, 7.92, 6.38 cm, respec-tively. The average values of the new shoot growths were 3.18, 4.08, 3.92 and 3.57 mm, respectively. Theaverage annual growth rates of the individual leaves were 7.28, 7.86, 6 and 6.26 cm, respectively. The aver-age growth rates of the single leaf widths were 3.02, 3.62, 2.54 and 3.34 cm, respectively. The annualgrowth periods of a single leaf were 28, 36, 35 and 26 d, respectively. When the leaves were stable, the av-erage leaf areas of the individual leaves were 18, 25.1, 12.3 and 13.5 cm², respectively. The mean leafweights of a single leaf were 2.57, 3.35, 4, 2.85 g, respectively. The new shoots slow growth period forPrunus salicina×armeniaca‘Fengweihuanghou', Prunus salicina×armeniaca‘Weidi', Prunus salicina×armeniaca‘Weiwang'and Prunus salicina×armeniaca‘Weihou'were between April 10 th to April 16 th,and mid May to early June. The stem exuberant period was between May 10 th and April 14th; the trunk di-ameter of the slow growth period appeared in early April to mid May, and late June to late August. Thestem exuberant period was between mid May to mid June. The daily change of the trunk diameter showed aclear day and night regularity. The first stage: the contraction stage. From about 8:00 in the morning thetrunk diameter gradually decreases, and the trunk diameter of about 16:00 reached the minimum value in aday; the second stage: the recovery stage. When the trunk diameter reached the minimum value, it gradual-ly increased in 1-2 hours, until 21:00 when it was restored to the stage before the contraction. This distance was the maximum shrinkage of the trunk diameter. The time required for the restoration of the daywas RT; the third stage: the growth stage. The stem diameter gradually increased from 21:00 to about 8:00in the morning of the second day, and then reached the maximum value of the stem diameter for the day.From April to August, the Prunus salicina×armeniaca‘Weihou'trunk diameter showed a rise-fall-rise-fall trend, and the trunk diameter growth in May reached the maximum, with the minimum value being inApril. The stem diameter of the growth in May was 2.43 times that in April. From May to August, the maxi-mum daily shrinkage(MDS) and the daily increase(DI) on sunny days were greater than cloudy days. InMay: sunny MDS(205.42 μm) > cloudy MDS(143.39 μm),sunny DI(46.17 μm) > cloudy DI(30.29 μm);In June: sunny MDS(69.06 μm) > cloudy MDS(65.89 μm),sunny DI(31.35 μm) > cloudy DI(14.90 μm);In July: sunny MDS(182.84 μm) > cloudy MDS(49.85 μm),sunny DI(42.00 μm)>cloudy DI(4.72 μm);InAugust: sunny MDS(113.27 μm) >cloudy MDS(84.35 μm), sunny DI(13.00 μm) >cloudy DI(11.48 μm)。The MDS(98.92 μm) of the trunk diameter after irrigation was significantly smaller than that of MDS(184.77 μm) before irrigation, and 46.46% lower than that of MDS before irrigation. DI(104.30 μm) afterirrigation was significantly larger than that of DI(48.28 μm) before irrigation, 116.03% higher than that ofDI before irrigation.【Conclusion】The new shoots, leaves and trunks of Prunus salicina×armeniaca haveobvious alternations in the Akesu area. The growth and development of different organs not only have nutri-ent competition, but they also promote each other. The daily change of the trunk diameter of Prunus salicina×armeniaca‘Weihou'showed a clear day and night regularity, it can be roughly divided into three stag-es: contraction stage, recovery stage and growth stage. The growth of the trunk diameter was the biggest during the whole growth period in May. The diurnal variation of the stem diameter was affected by the weather,and the MDS and DI in sunny days were larger than that in cloudy days. The diurnal variation of the trunkdiameter was also affected by the soil water condition, and the MDS was lower than that before irrigation,but the DI was significantly larger than that before irrigation.