Control plant height of poinsettia by using plant growth regulator
Regarding many poinsettia varieties, plant growth regulator will be used for the dwarf treatment of plant height in the cultivation process so as to achieve height consistency of merchandise flower. In addition, it is also very important to keep the consistency of diurnal temperature, which should be tracked and monitored all the time. When the temperature difference between day and night has exceeded 3 degrees Celsius, spray 750-1000ppm CCC 1-4 times after pinching so as to inhibit stalk excessive growth.
If the temperature is higher than 26.7 degrees Celsius in the daytime and lower than 21.1 degrees Celsius at night, spray the mixed liquor of 1000ppm CCC and 1500ppm B9 1-3 times after 1-4 weeks of pinching as well as can also spray 5ppm-10ppm MET. This is because the proper growth regulating measure and hard light will have important effect on inhibiting plant internode growth as well as promoting tight crown diameter and plump plant type after punching. However, B9 and MET dwarf agent should not be sprayed after flower bud differentiation.
Below we will respectively introduce the application conditions of several dwarf agents. 500ppm ethephon can be sprayed 3-5 days before punching, 5-7 days after the internode elongation as well as lateral branch growth period, thus it can reduce the injury degree of stalk cleft and promote plump plant shape. In order to improve the using effect of ethephon, a certain substrate wetting nutrition agents can be added in the early morning so as to promote the development of plant root system.
As low concentration MET solution can control coloring, lead to curl bract or smaller the bract, 0.05ppm-0.1ppm MET solution can be sprayed before half the number of leaf coloration after flower bud differentiation.
In order to moderately increase internode length, 2ppm-3ppm gibberellin and plant growth regulator (1ML/10L) can be sprayed in the early October. After 1-2 weeks, the internode maximum elongation can reach 5-10cm, which will certainly have close relationship with variety and temperature.