Walnut trimming varies with young trees, fruit trees, and aging trees. At the same time, during the fruiting period, fruiting and thinning should be carried out.
1, pruning of young trees. To be different for different varieties of growth and development characteristics, the main cut off the weak branches, cross-branches, overlapping branches, parallel branches and diseased branches, in order to cultivate all levels of the branches and the results of the branches. The specific methods are: controlling secondary branches; controlling leggy branches; handling well-branched vegetative branches; removing overly dense branches and handling the back branches.
2, adult tree pruning. In the walnut trees that have just entered adulthood, the tree shape has basically taken shape, and production has gradually increased. The main pruning task of walnut trees in this period is to continue to cultivate the main and lateral branches, make full use of the early results of auxiliary branches, actively cultivate the result branches, and try to expand the results. The pruning principle is: to stay strong and weak, first put back contraction, zoom in and out, prevent the resulting parts from moving out.
3, pruning fruit trees. During the fruit period, most of the large walnut trees are close to or close to the canopy, and the number of peripheral branches gradually increases, and most of them become the result branches, and due to poor light, some branchlets are dry and bald areas appear behind the main branch. As a result, the site is shifted outwards and it is prone to result in a phenomenon that occurs every other year. Therefore, the main task of pruning during this period is to adjust the relationship between vegetative growth and reproductive growth, continuously improve the ventilation and light transmission conditions within the canopy, and continuously update the resulting branches in order to achieve the goal of high yield and stable production.
4, pruning of aging trees. When walnut trees enter the aging period, the peripheral branches droop and produce a large number of "focal shoots". At the same time, a large number of leggy shoots are sprouted and natural renewal phenomenon occurs, and the yield also drops significantly. In order to extend the results of the year, it can be updated and rejuvenated. The specific pruning method: 1 trunk update (big update) saw the main branches all sawn off, causing it to re-spray and form the main branch. 2 Main branch update (medium update) Retract in the appropriate part of the main branch to form a new side branch. 3 Lateral branch renewal (small update) The first side branch was retracted in place to form a new secondary branch. The advantage is that the new canopy formation and production increase are faster.
The narrowband filter is subdivided from the bandpass filter, and its definition is the same as the bandpass filter, that is, this kind of filter allows the optical signal to pass through in a specific wavelength band, but deviates from the outside of this wavelength band. Optical signals on both sides are blocked, and the passband of the narrowband filter is relatively narrow, generally less than 5% of the central wavelength value.
The narrowband filter is subdivided from the bandpass filter, and its definition is the same as the bandpass filter, that is, this kind of filter allows the optical signal to pass through in a specific wavelength band, but deviates from the outside of this wavelength band. Optical signals on both sides are blocked, and the passband of the narrowband filter is relatively narrow, generally less than 5% of the central wavelength value.
Its main parameters are: center wavelength, half maximum width (bandwidth), peak transmittance, cut-off range, cut-off depth (OD value)
Type: Generally, it can be any wavelength within 350nm~2000nm, the transmittance is greater than 70%, the cut-off wavelength is from 200nm to 3500nm, and the cut-off depth is 1OD~6OD
Let the visible light completely filter out only the near-infrared 940nm light that needs to be used, so that the CCD or CMOS photosensitive chip can form a black and white image. Through the calculation method of the biometric system, the human eye, iris, and face are tested to identify different people. Features, play access control security, hotel, entertainment venue monitoring, factory or office attendance.
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