Spring and summer are good times for people to choose to go outing. Before going outing, it is necessary to have a little understanding of some common allergens. Even one of them, the pollen of Ambrosia, has great harm to the human body. So how can we identify Ambrosia?
【Ecological Identification of Ambrosia】
Ambrosia is an annual herbaceous plant, 20-250 cm tall. The stem is upright, with edges and multiple branches, green or dark purple, and covered with white hairs. The leaves are opposite, with the upper leaves alternate, triangular in shape, green on the surface, and grayish-green on the back.
The head-like inflorescence is unisexual, with male and female flowers on the same plant; the achene is inverted-ovate and enclosed in a hard involucre. The leaves contain bitter substances and essential oils. Cattle feeding on them can deteriorate the quality of milk, which is accompanied by an unpleasant odor.
It grows in wasteland, roadside, ditches, around fields, or in farmland. This grass has strong vitality, wide adaptability, high seed yield, high water and nutrient consumption, vigorous growth, covering and suppressing crops, and hindering agricultural operations.
Ambrosia is native to North America and is now a common weed in Northeast China, North China, and the Yangtze River Basin. Ambrosia is the main allergen of pollen allergy in its original place.
【Harm of Ambrosia】
Ambrosia is a dangerous weed, and its main harm is that its pollen can cause allergic reactions in humans.
During the pollen dispersal period from July to September, people without antibodies, once they inhale air containing Ambrosia pollen, will experience symptoms such as asthma, nasal congestion, sneezing, clear nasal discharge, throat itching, urticaria, chest tightness, dizziness, and insomnia. Severe cases cannot lie flat and may even have other complications, ultimately leading to death.
Ambrosia grows rapidly and can overpower other annual plants, dominating the land, destroying plant diversity, causing serious grassland degradation in farmland, and resulting in poor crop yields.
Ambrosia invades China's original wild vegetation, causing the decline and reduction of popular wild vegetables such as mustard greens, broomrape, lettuce, and pigweed, and greatly damaging the green environment. Therefore, it is imperative to eliminate Ambrosia.
【Prevention and Control Measures of Ambrosia】
1. Agricultural control: The main measures are manual removal and cutting. According to the different growth of Ambrosia caused by climatic differences in different regions, the suitable period for eradication can be determined, which is before Ambrosia blossoms and bears fruit. However, manual removal is labor-intensive, difficult to completely eliminate, and improper handling can easily cause the danger of human carrying and spreading.
2. Chemical control: Different regions of non-farmland and farmland can be sprayed with herbicides such as glyphosate, dalapon, 2,4-D, or fluorosulfuron to kill Ambrosia.
3. Biological control: Introducing Ambrosia natural enemies such as Ambrosia leaf-curling moth and Ambrosia flea beetle for biological control has good effects.
4. Plant substitution: Using Chinese scholar tree, early-maturing fodder grass, etc. for substitution and control; eliminating wasteland, planting crops, and diligent management. These methods have good control effects on Ambrosia.
If the effect of using one method in a large area is not significant, multiple methods can be used together for comprehensive management.
