2, the temperature poinsettia likes warmth and is afraid of cold. When entering the room in the middle and late September every year, it is necessary to strengthen ventilation to make the plants gradually adapt to the indoor environment, and the room temperature should be kept at 15℃ to 20℃ in winter. At this time, the bracts are discolored and the flower buds are differentiated. Spraying Hua Zhuang Di Ling in time can make the flower buds strong, the petals plump, the colors bright, the flowers fragrant and the flowering period prolonged. If the room temperature is below 15℃, the flowers and leaves will be stunted. After1mid-February, it will enter the flowering stage, and it should be gradually ventilated.
3, watering fertilization, poinsettia is not resistant to drought, and it is not resistant to water and humidity, so watering should be flexible according to the weather, pot soil and plant growth. Poinsettia likes fertility. In addition to adding organic fertilizer and horseshoe slices as base fertilizer when changing pots, in the growing and flowering season, dilute fertilizer should be applied in time and new high-fat film should be sprayed to protect fertilizer and moisture.
4. Shaping and pruning: before and after Tomb-Sweeping Day, change the dormant old plants into pots, cut off the old roots and weak branches, and after pruning, apply a callus antiseptic film to the wound to make it heal quickly and promote its germination of new techniques. It is necessary to pick the heart during the growth process, and control the big fat water in the cultivation, especially before the plant is finalized in autumn. When the branches are 20 to 30 cm long, they will be shaped and bent. The purpose is to make the plant short, the flower heads neat and evenly distributed, and improve the ornamental value.
extermination of disease and insect pest
. 1 disease
Poinsettia diseases mainly include gray mold, which mainly occurs in winter and damages inflorescences, bracts, leaves and branches. Generally, water-soaked spots begin to appear from tidbits, then gradually expand into irregular shapes and then expand to branches, resulting in yellowish brown to brown spots; Root rot and stem rot are more likely to occur when the soil water content is high in high temperature season. In the early stage, plants will wither, but infected plants will not be corrupted or hydrolyzed. Later, the disease spots will gradually spread upward and the withering phenomenon will become more and more serious. It can be prevented by improving the cultivation management conditions and reducing the air humidity. If you are sick, you can use 45% chlorothalonil or 15% kemeiling smoke agent, 200 ~ 250 g per 667m2 each time, and you can spray Bordeaux solution or 65% zineb wettable powder 800 times.
.2 Insect pests
Pests mainly include whitefly, tetranychus urticae, etc. Whitefly often congregates on the back of leaves to suck juice with piercing mouthparts, which makes the leaves fade or appear chlorosis spots, which affects photosynthesis and leads to poor plant growth. The optimum control period is in late September, and the spraying time is 6 ~10 in the morning. Tetranychus urticae, also known as red spider, occurs seriously under the condition of high temperature, drought and little rain, and the peak period is from March to June and September to11month. Tetranychus urticae likes to live on the back of old leaves, and the damaged leaves have yellow spots, resulting in a large number of netting hazards, resulting in plant growth stagnation, dry leaves, falling off and plant death. Pests should be prevented immediately once they are found, and can be fumigated with 22% dichlorvos smoke agent, with a dosage of 300 ~ 400 g per 667m2 each time.