What methods are there to prevent high-temperature damage to flowers?
What measures can reduce the harm of high temperatures to flowers.
People fear high temperatures, and flowers fear high temperatures just the same, so are there any good techniques to reduce the harm of high temperatures to flowers?
Water, air and temperature are essential conditions for flower growth. In summer, high temperatures bring great harm to flower growth. When the air temperature reaches as high as 38°C, many flowers show poor growth, manifested as faster respiration, weakened photosynthesis and blocked nutrient transport. If the temperature exceeds their heat tolerance, they will tend to wither and die. Even flowers accustomed to growing in tropical regions are difficult to grow normally if care is not paid attention to. For this reason, the following management measures are proposed:
1. Shading: Flowers in greenhouses or plastic tunnels should all be shaded with shade nets to prevent direct scorching sunlight from burning the flowers. Those grown in the open field should also be shaded by some means.
2. Frequent watering: Water frequently in the morning and evening to increase humidity and thereby lower the temperature. If sprinkler irrigation or drip irrigation facilities are available, the effect is even better. Usually, the temperature can be lowered by 2-5°C after watering.
3. Frequent ventilation: Add ventilation equipment in greenhouses or tunnels to introduce fresh air and expel indoor hot air and harmful gases.
4. Disease and pest control: Protect against wind and rain, and promptly prevent and control pests and diseases.
(1) Cold damage, also called chilling injury. It refers to the harm to heat-loving flowers caused by low temperatures above 0°C. The affected flowers are mainly those native to tropical or subtropical regions. The most common symptoms of cold damage are discoloration, necrosis and spots appearing on the surface. Woody flowers may also show bud blight, dieback of the top, bark cracking with gum exudation and leaf drop.
(2) Frost damage. When the air temperature or ground surface temperature drops to 0°C, supersaturated water vapor in the air condenses into white ice crystals - frost. The harm to flowers caused by the appearance of frost is called frost damage. After flowers suffer frost damage, the affected leaves become water-soaked in appearance, soften and wilt after thawing, and soon fall off. After the young buds of woody flowers are frozen, they turn black, the floral organs become water-soaked in appearance, and the petals discolor and fall off.
(3) Freezing damage refers to the injury caused by the flower body cooling down below freezing point, causing ice to form in the intercellular spaces. Freezing damage often kills herbaceous flowers outright and causes the bark of some woody flowers to split from freezing, branches to die back or roots to be injured.
The low-temperature damage suffered by flowers depends not only on the external air temperature factor, but also on the ability of the flower variety to resist low temperatures. The same variety has different low-temperature resistance at different developmental stages. Resistance is strongest during the dormant period, intermediate during the vegetative growth period, and weakest during the reproductive stage.