Aster robusta is born on the roadside or invades cotton, soybean, sweet potato field and lawn, with small occurrence and light harm, and is classified as a general weed. According to the investigation, Aster robusta has strong saline-alkali tolerance and can grow healthily in weak alkaline soil, forming a single dominant community. The area of a single dominant community surveyed ranges from several square meters to tens of square meters, with the largest community area of 50 meters, the number of plants being 30-80/square meter, and the average fresh weight per plant being 280 grams. The growth of Osmunda tatarinowii leaves consumes a lot of soil nutrients, making it difficult for other plants to survive, and only a small amount of Leymus chinensis and crabgrass are accompanied by the edge of the community.
Hazard assessment Aster crassifolia is listed as a common weed among invasive plants in Compositae. According to the investigation, among the invasive plants of Compositae in northern China, Leymus chinensis has the most occurrence, the widest distribution and the most serious harm. Second, aster drilling leaves are widely distributed and occur in large quantities.
Because of allelopathy and weed characteristics, Aster grandiflora is potentially harmful as an invasive weed, so the control of Aster grandiflora should be strengthened. Dynamic investigation on the distribution of exotic plants should be strengthened.
The allelopathy of the leaves of Aster tatarinowii on crops is from strong to weak in order of rape → wheat → mung bean. Compared with the germination rate, the vigor index can better reflect the ability of seeds to emerge in the field, so under natural conditions, when there are more residual plants of Aster grandiflora in the soil, it has obvious inhibitory effect on the germination and growth of wheat, mung bean and rape.
Bougainvillea is another name for bougainvillea and bougainvillea. Alias: bougainvillea, clover, bougainvillea, azalea, bougainvillea, bougainvillea, Papua, bougainvillea, mirabilis jalapa, safflower bougainvillea (Tonganhong), etc. It is an evergreen climbing shrub. Jasminum, Phyllanthus urinaria.
Like warm and humid climate, not cold-resistant, like plenty of light. Stems stout, branches drooping, glabrous or sparsely pilose; Leaf blade papery, ovate or ovate-lanceolate; Among the three bracts of the top branch of the flower, the pedicel is attached to the bract midvein, and a flower is born on each bract; Bracts are leaflike, purple or magenta, oblong or oval, style lateral, linear, margin expanded into thin slices, and stigma pointed; The base of the disc is unified into a ring, and the upper part is torn. The flowering period is between winter and spring (Guangzhou, Hainan and Kunming), and it blooms in greenhouse cultivation in the north from March to July.