1, observe the branches
In the growing season, the thickness, color, upright status and hardness of branches, the angle and number of natural branches, the length of internodes and whether there are short branches, the shape and fullness of buds on branches are observed;
Observe the size and number of lenticels on branches after defoliation. At the same time, observe the overall growth potential. The overall growth potential of the same variety is consistent in the nursery, and the overall growth potential of different varieties is easy to distinguish in the standardized nursery.
2. Observe the young stems and leaves of new shoots.
From April to May, the color of young leaves and tender stems at the top of seedlings and the amount of fluff were observed in the maternal garden and nursery. The color of young leaves and tender stems varies with varieties, and their red shades are also different.
There are deep red, light red, reddish, etc., and some varieties are extremely light red. There are villi on the front and back of young leaves, and the length and density of villi of different varieties are different. For the same variety, the color of leaves and new shoots of the same age is consistent with the color and density of villi.
3. Observe the mature leaves
From May to September, the leaves were observed in the maternal orchard and nursery. Pay attention to the comparison with the leaves in the same part of the branch. Observe the basically mature leaves. Generally, the size of the leaves is more than 2/3 of the adult area or close to adult leaves. Do not take the aged leaves for observation.
Observe and compare the thickness and shape of leaves, the density of villi and the depth of green, the size, density and shape of serrated leaves, the thickness of waxy layer on leaves, the shape of leaf tips, and the number, color, shape and size of nectaries planted on petioles.
4. Observe the root system
In addition to observing the above characteristics, rootstocks should observe the consistency of their roots after seedlings leave the nursery. Such as the number of fibrous roots, the depth of distribution, the color of epidermis and the meristematic angle, sharpness and softness of main lateral roots.
5, inspect the seedling production unit.
It is also an important factor for selecting high-purity and high-quality seedlings to examine the technical level and production strength of seedling production units, including technical strength, maternal orchard, scion nursery, rootstock breeding nursery, management level and credibility.