To prevent the distribution of new weeds of the genus Erigeron L.

Abstract

Goal. The purpose of the research was to determine the biological characteristics of species of the genus Erigeron, their distribution, harmfulness and methods of control.
 Мethods. The studies were conducted during 2006—2018 on the territory of the steppe zones of Ukraine in segetal and ruderal vegetation. The determination of the frequency of occurrence and spread of weeds was carried out in agrophytocenoses and uncultivated lands according to generally accepted methods. Evaluation of the harmfulness of weeds was carried out in the Left bank province of the Steppe zone of Ukraine. The soils are chernozemic soils ordinary meddle loamy. Latin plant names are listed on the Catalogue of Life international database.
 Results. All species of the genus Erigeron in the steppe zones of Ukraine differ in biological and ecological indicators, habitats, weediness and reaction to various methods of control. Erigeron annuus (L.) Pers. (Phalacroloma annuum (L.) Dumort., Stenactis annua (L.) Cass.) — wintering, less often spring weed. It occurs scattered or in groups, often forms thickets. It grows in meadows, gardens, parks, fallow, littered places, along the canals. It is identified in the fields of maize, sunflower, sorghum, melon crops and vegetable gardens. Erigeron strigosus Muhl. ex Willd. (Phalacroloma strigosum (Muhl. ex Willd.) Tzvel., Stenactis strigosa (Muhl. ex Willd.) DC.) — spring, wintering or biennial weed. It occurs as single individuals in meadows, littered places, edges of fields, near perennial grasses under irrigation. Erigeron strigosus var. septentrionalis (Fern. & Wieg.) Fern. (Phalacroloma septentrionale (Fern. & Wieg.) Tzvel., Stenactis septentrionalis (Fern. & Wieg.) Holub) — yearling, biennial or weed. It is found scattered or in groups on meadows, fallows, littered places, in populated areas, flower beds. It is identified in the fields of corn, sunflower, sorghum, fodder crops and vegetable gardens. Small tillage promotes Erigeron`s dissemination and resettlement, the abandonment of complete fallow, and the reduction of chemical protection. The grain yield with an average weediness of crops decreased by 23—28%, vegetable crops — by 16—19%, fodder crops — by 11—18%. An effective method of controlling weeds of the genus Erigeron is intensive autumn tillage. The use of herbicides in the autumn is impractical. In the spring, pre-sowing harrowing, cultivation and herbicides are used.
 Conclusions. Early detection of weeds of the genus Erigeron at the initial stages of invasion, effective control through intensive tillage in the autumn, the use of harrowing, cultivations and herbicides in the spring, fully prevents their distribution and resettlement in the steppe zones of Ukraine.