Effects of several Plant growth hormones on promoting Bud and Bud

In the various growth and development processes of orchid germination, growth and flowering, good results can be obtained by using plant growth hormone to treat different parts of orchid plants. In particular, it plays a special role in the preservation, continuation and development of some rare or endangered species, and also plays an extraordinary role in speeding up breeding, enhancing species exchanges with the outside world, and improving economic benefits.

① breaks dormancy and stimulates the germination of latent buds of pseudobulb (Reed head). The old false bulbs that remained year by year were separated from the plant, and the connected 2-3 bulbs were taken into a group, then the remaining old leaves were cleaned and washed to dry, but the latent bud eyes should not be injured in the whole process. The step of hormone treatment is to drip the latent bud eye with 0.05% (500PPm) gibberellin (GA3), and then treat the residual root cap and the base of the pseudobulb with 0.1% (1000PPm) indolebutyric acid (IBA). After treatment, it was implanted into the pot according to the conventional cultivation methods according to different varieties. The trial showed that the number of sprouting plants of orchid plant was significantly higher than that of the control.

② promotes the rapid growth of multiple plants. At present, the main way to improve the reproduction coefficient of rare and excellent varieties is through ramet. Only a few new plants of Dacong orchid can produce new seedlings in the previous year, but there are no or few new seedlings in the old plants for many years, and the propagation of individual plants will affect the growth potential, and the new plants become smaller, even lead to the death of the mother plant. Through the treatment and regulation of plant growth substances, new plants can be induced and growth can be promoted. The practice is to remove the orchid bushes from the basin, rinse the soil between the remaining roots and plants, and dry them until the fleshy roots become soft or brittle; separate them one by one with a sharp knife, then soak them in 0.08% (800PPm) carbendazim solution for a while; still slightly dry, dip cotton into 0.01% (100ppm) 6-benzyladenine and coat the pseudobulbs; then soak from the root cap to the root with 0.1% (1000ppm) indolebutyric acid. The application practice shows that the combination of the three treatments can reduce the death of pseudobulbs, increase the number of plants and improve the growth potential.

③ promotes budding and flowering. The flower bud differentiation of orchids is not only restricted by cultivation management (including light hours, carbon-nitrogen nutrition ratio of plant life cycle, ramet degree, fertilizer and water status, etc.), but also plays an important role in the regulation of variety characteristics and exogenous hormones.

Taking Cymbidium as an example, under normal conditions, the growth of orchid plants has gradually matured by the end of July and the beginning of August. Spraying 0.03% (300ppm) paclobutrazol (PP333) on orchid leaves at this time could promote pseudobulb expansion and provide material basis for flower bud differentiation in August and September. Cover the basin when spraying leaves with paclobutrazol, let alone irrigate the soil directly. From the actual use, the orchid leaves sprayed with paclobutrazol only thickened and darkened, and it had no effect on controlling the leaf length; but if the liquid was sprayed to the soil, the flower stem was obviously shorter than the normal, thus losing the appreciation value of the orchid.

When using plant growth hormone, we must pay attention to the following two points:

The use of plant growth hormone in ① should be carried out in the growing season and the physiological development stage of the action site, so as to facilitate the transport and metabolism of substances. The temperature during treatment is not lower than 15 ℃.

② plant growth hormone can only regulate the growth and development of plants, and can not replace management and fertilizer. Only by applying plant growth substances in fine management conditions and reasonable fertilization measures can we get twice the result with half the effort. (Zhejiang-Chen Hantao, Yu Huaiyun)