User:Solanummelongena/sandbox

Description
Fruits are approx. 3.5 mm long with 2-3 mm long pappus bristles. [This sentence should be added between the last and the second-last sentence of the existing "Description" chapter.]

Weed in arable crops
Centaurea cyanus is considered a noxious weed in arable crops, especially cereals and rapeseed. In winter wheat, one plant per m2 can cause a yield loss of up to 30 kg / ha. Centaurea cyanus produces around 800 seed per plant, which are either shed shortly before the harvest of cereals, or they are threshed together with the cereal grains, contributing to the further spread of the species by the harvesting machinery and contaminated seed. The occurrence of Centaurea cyanus strongly decreased during the last decades due to improved seed cleaning, more intensive nitrogen fertilization and herbicide use. However, Centaurea cyanus has become more common in cropland due to an increase in crop rotations dominated by winter cereals and rapeseed and the use of more selective herbicides with a low effectiveness against Centaurea cyanus. In addition, the emergence of resistance against the herbicide class of sulfonylureas has been reported recently. Due to its strong roots, Centaurea cyanus is difficult to control mechanically in spring.

Fodder for insects and birds
The pollen of Centaurea cyanus is used by several different insect species. Insects of the orders Hymenoptera and Diptera are particularly attracted by the flower. As Centaurea cyanus is a self-incompatible species, it needs external pollination. The nectar of Centaurea cyanus is very sweet with a sugar content of 34 %. Due to its high sugar production of up to 0.2 mg sugar per day and flower, the species is highly appreciated by beekeepers.

The seeds of Centaurea cyanus are one of the favourite foods of the European goldfinch. [This information should be relocated here from the existing "Uses" Chapter]

Control of insect pests
Centaurea cyanus was found to produce volatiles attracting Microplitis mediator, which is a major parasitoid of the cabbage moth (Mamestra brassicae), which is the most important pest of cabbage (Brassica oleracea) in central Europe. Planting "Centaurea cyanus" in cabbage fields was thus suggested as an alternative to the widespread use of insecticides for the control of Mamestra brassicae. Field experiments showed that planting "Centaurea cyanus" in cabbage filds at a density of 1 plant / m2 can result in a significant increase in parasitation of [Mamestra brassicae] larvae, predation of Mamestra brassicae eggs (e.g. by carabid beetles or spiders) and ultimately cabbage yield.

Soil and climate requirements
Centaurea cyanus requires full sun and neutral (6.6-7.5) to mildly alkaline (7.6-7.8), moist and well-drained soil. However, Centaurea cyanus is quite tolerant to drought once established.

Sowing
For summer-blooming plants, sowing should be executed in late spring. In moderate climates, however, it is also possible to sow Centaurea cyanus in early fall. In this case, plants will already start to flower in the following spring. Recommended spacing between plants is approx. 20 to 30 cm. Centaurea cyanus can germinate from up to 10 cm depth, but the best result is obtained at 1 cm sowing depth. Germination occurs quickly after sowing.

Fertilization and cultural practices
High phosphorus fertilization in mid-summer will increase flower production. Mulching is recommended to prevent drying out of the soil and exposure of the root system to the sun.

Pests and Diseases
In general, Centaurea cyanus is not very susceptible to pests and plant diseases. However, it may be affected by stem rot and stem rust if grown too tightly or by powdery mildew (Best Plants 2020). Furthermore, aphids and leafhoppers can cause relevant damage to Centaurea cyanus.

Genetics and Breeding
''This is how I would change the "Genetics" section which AlCropsCT suggested to add to the existing article. Please note that it contains some information that should be relocated here from the existing "Cultivation" section (as mentioned above).''

Genetics
Centaurea cyanus is a diploid flower (2n = 24). The genetic diversity within populations is high, although there could be a future decline in diversity due to fragmentation of population and intensive agriculture. In general, Centaurea cyanus is a self-incompatible species. However, selfing still occurs occassionally, but results in inbreeding depression.

Breeding goals
As for all ornamental plants, important goals of Centaurea cyanus breeding include the induction of phenotypic variation (e.g. in flower coloration, size and shape, foliage charcteristics or plant height), higher flower yield, resistance to pests and diseases as well as tolerance to abiotic stress (e.g. extreme temperatures, drought or salinity).

Uses
I would suggest to add the following sub-section about phytoremediation to the end of the draft of the "Uses" chapter written by AlCropsCT:

Phytoremediation
Centaurea cyanus has been evaluated for phytoremediation of soils contaminated with lead. Inoculation of the contaminated soil with Glomus spp. (fungus) and Pseudomonas spp. (bacterium) would significantly enhance the biomass production and lead uptake of Centaurea cyanus. Solanummelongena (talk) 12:12, 22 November 2020 (UTC)