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Video: Thorny Nightshade. A Dangerous Weed. A Harmful Plant. Thorn. Agrotechnical Control Measures. A Photo
The plant belongs to the family Solanaceae Solanaceae Juss., Genus Solanum L.
Synonym: Solanum rostratum Dun.
Biological group: Spring annual
Morphology and biology: Plant 30-100 cm tall, densely pubescent with stellate hairs. The stem, branches, petioles and veins of leaves, peduncles and calyx are also planted with strong, subulate, straw-colored thorns 5-12 mm long. The stem is cylindrical, woody, highly branched, grayish-dusty in color. On one freely growing plant, up to 70 branches can form, the diameter of the bush reaches 70 cm.The root of the taproot, branched, penetrates to a depth of 3 m.The leaves are alternate, long-petiolate, lyre-shaped, deeply double pinnate, 5-10 cm long. Flowers are 5-membered, first collected at the end of a short (2-3 cm long) peduncle, later, due to the lengthening of the latter, they are arranged in the form of a brush. Corolla yellow, 2-3 cm in diameter, with lanceolate-ovate lobes. Calyx with ovate-lanceolate lobes,when fruit grows to an almost spherical and tight-fitting berry. The plant blooms in June-September, bears fruit in August-October. The fruit is a unilocular, spherical, semi-dry berry. When ripe, the fruit cracks. One plant can form up to 180 berries, each berry contains 50-120 seeds. Seeds are dark brown or black, rounded kidney-shaped, flattened from the sides, their surface is reticulate, wrinkled. Freshly ripe seeds of prickly nightshade do not germinate, they are in a state of biological dormancy for 5-6 months, germinate only after overwintering in the soil. The viability of seeds in the soil lasts for 7-10 years. The dying off of seeds in different layers of the arable horizon is uneven. So, for three years at a depth of 5 cm, the number of nightshade seeds decreases by 83%, and at a depth of 30 cm - only by 9%.The minimum temperature for seed germination is 10-12 ° C, the optimum is 22-25 ° C. Seeds are able to germinate from a depth of 1-15 cm, seeds germinate best from a depth of 3-5 cm, when seeding seeds deeper than 15 cm, seedlings do not appear. Thorny nightshade propagates only by seeds, after the seeds ripen, the plants easily break off from the root and are rolled over long distances by the wind. Seeds of prickly nightshade, after falling to the ground, can be carried by the wind, on the wheels of cars along with mud. After germination, nightshade grows very slowly. It takes 3-4 weeks to form 3-4 true leaves, and branching of the main stem begins in 30-40 days. At this moment, the root system of the nightshade develops intensively. It grows 5-6 times faster than the stem. Depending on the growing conditions, nightshade can develop a powerful ground mass,forming up to 30 branches and often reaches a height of one meter. The nightshade taproot can penetrate up to 3 meters.
Distribution: North America, as an invasive plant in Central Europe, Mediterranean, Australia, South Africa. The potential area can reach 60 ° N. An alien weed, native to Mexico and southwestern North America. Distributed in the European part b. USSR, Caucasus, Kazakhstan, Far East.
© S.Yu. Larina, I.A. Budrevskaya.
Ecology: Very thermophilic plant. Thorny nightshade grows on all types of soils, but best on loose, alkaline loamy or clayey soils. Prefers well-lit areas. Lack of light, especially in the initial phases of development, negatively affects its growth. So, in the sowing of spikelets with a normal density of standing of cultivated plants, the development of nightshade is suppressed and by the time the grain is harvested it has time to form only a few leaves.
The most favorable conditions for the growth and development of beak-shaped nightshade are in the crops of row crops, orchards and vineyards. By the time of harvest, nightshade has time to form seeds and clog the soil with them. With insufficient care for these crops, a sharp increase in soil contamination with nightshade seeds is observed. Nightshade grows abundantly on wastelands, roadsides and other uncultivated lands. Often, in this case, all herbaceous vegetation is replaced by nightshade.
Economic value: Noxious quarantine weed. Infests crops of tilled and spring grain crops, vegetable gardens, orchards and pastures. As a ruderal plant, it is found along roads, in garbage places, on uncultivated lands. Due to the deep and branched root system, S.cornutum successfully competes with cultivated plants for nutrients and moisture, in areas infested with solanaceous crops, crop yield losses reach 40-50%, and in some cases the crop may die completely, which causes its high harmfulness. The leaves of the nightshade prickly are poisonous to animals. The thorns of this plant, getting into hay and straw, damage the oral cavity and gastrointestinal tract in animals. Straw that is heavily littered with nightshade is not suitable for use even on bedding. Thorny nightshade is a host plant for some pests (Colorado potato beetle,potato moth) and pathogens (tobacco mosaic virus, Verticillium albo-atrum) of nightshade crops.
Agrotechnical control measures:
- The complex of agrotechnical measures in the fight against prickly nightshade includes a system of advanced technologies developed by research institutions and recommended for use in the Russian Federation.
- When placing crops in a crop rotation, fields heavily infested with prickly nightshade should be allocated for sowing continuous crops - winter and spring crops, perennial and annual grasses, peas and legumes.
- To prevent the development of nightshade plants, in the fields that emerged from under the ears immediately after harvesting, stubble plowing should be carried out, followed by soil cultivation as a semi-fallow. The system of measures for semi-steam tillage ensures the complete destruction of all vegetative plants of nightshade, as well as newly emerged seedlings. With the systematic destruction of nightshade plants, before the formation of seeds, within 3-4 years, the arable soil layer can be cleared of its seeds by 90-98%.
- Plowing plowing for sowing spring crops should be carried out at a depth of 27-30 cm. At the same time, some of the seeds planted deeply do not germinate at all, and some of the germinated seeds will not sprout, as a result of which the weediness of crops can be reduced by 80%.
- On uncultivated lands, nightshade is systematically destroyed by plowing, peeling, and cultivation. If these techniques are not possible, the nightshade is destroyed by periodic mowing. To prevent seeding of nightshade plants, at least three mows are required per growing season. It is necessary to mow nightshade during the period of budding - flowering, before the formation of seeds.
Chemical control measures:
To protect plants from prickly nightshade, chemical, biological and other agents certified in accordance with the established procedure, passed mandatory state tests and recommended for use by specialized research institutions included in the list of pesticides and agrochemicals permitted for use in the Russian Federation, are used. These are such drugs as roundup or hurricane, or glyphosate with a consumption rate of 4–6 l / ha.