The Effect Of Plant Growth Retardant On Amaranthus, Hydrangea And Chrysanthemum

In the course of the modernization production of garden plants, how to control the growth is a serious problem.In modern times, with the developing of landscape, the garden plants were raised higher level for fill the market requirements. So, How to control high and figure of plants to suffice the market is a problem.High, size of flower, length of florescence and some other characters were controlled by DNA. But now , there are three ways to control the characters. First ways, to select individual plant which have some characters in several generation and breed it to gain the excellent offspring; the second , to change the DNA of the plant, and gain some excellent character plants; the third , to use plant growth retardant to control the physiology growth of plants.The advantage of first ways - - all characters which gained by choice and breed are transmissibility. We can obtain a good deal of plants which have same character. But the process is too long, and need a large numbers of plants. Second ways is a powerful method to change the characters, but this method is exorbitant and always used on grain and cash crops. On the production of landscape plant, to control the plant characters by plant growth retardant is a befitting method. It's simple and economical.Experiments and researches prove that, three plant growth retardant—daminozide (B9), chlormequat (CCC), paclobutrazol (PP333) can control the characters of plant. They were influence landscape plants on several aspects such as shape, anatomies configuration, physiology and so on. It is a kind of simple and convenient method with instant effect to use plant growth retardant to control the physiology growth of plants. As to this, already there have been many experiments and studies done at home and abroad. But, because of different horticultural equipments, environmental, condition and cultural modes between areas, it is different to apply those findings to Chongqing directly. So it is significant for improvement of quality of plants and advance of industrialization of plants to study the physiological effects of plant growth retardant on landscape plants pertinently and systematically.In this thesis, Amaranthus (Amaranthus tricolor var splendens. Hort., Hydrangea (Hydrangea macrophylla Ser.), and chrysanthemum (Dendranthema marifolium Tzvel.) which used widely in landscape were choose for experiment material.The result of experiment shows: 1) Amaranthus are treated with daminozide(B9), chlormequat(CCC), paclobutrazol(PP333) on three different concentration. Standard approach to use standard in landscape, daminozide(B9) 1000 mg/L is optimal concentration. This concentration can control the height of plants steadily. But in other aspect, paclobutrazol(PP333) 800 mg/L can make the flower have more excellent appearance. Chlormequat (CCC) 100mg/L～200mg/L can help plants fight back adversity, the survival of plant is uprated. Taking one with another, in this experiment paclobutrazol(PP333) is the best optimal plant growth retardant, and 400～600mg/L is the optimal concentration.2) Hydrangea are treated with daminozide(B9) ,chlormequat(CCC), paclobutrazol(PP333) of three different concentrations by spraying. Standard approach to use standard in landscape, Paclobutrazol(PP333) have stronger reaction than others, But daminozide(B9) is the best optimal plant growth retardant on Hydrangea, Because it can control height and flower steadily and safely. And 1000～2000mg/L is the optimal C. When the concentration is beyond suited, the phytotoxicity of medicament on the plants will happen.3) For chrysanthemum 'Shan cheng zhi guang', Paclobutrazol(PP333) can control the height effectively. Daminozide(B9) 2000 mg/L is effective in reducing the height of the plants, making the leaf color darker and making the flower more bigger and more darker. When the concentration between 1000 mg/L to 2000 mg/L, the increase of flower's length is obvious. Spraying Chlormequat(CCC) and paclobutrazol(PP333) can delay florescence. Spraying same plant growth retardant with same concentration on different variety of chrysanthemum, it put up different refection.More and more studies on the plant growth retardant is compulsory work for apply optimal concentration on production of landscape plants.