Managing populations of cyst-forming nematodes in agroecosystems of field crops

Abstract

Cyst-forming nematodes have been known since the second half of the 19th century as one of the causes of "soil fatigue" and highly harmful agricultural pests. In Ukraine, the sugarbeet cyst nematode Heterodera schachtii Schmidt, 1871; cereal cyst nematode H. avenae Wollenweber, 1924; golden potato cyst nematode Globodera rostochiensis Wollenweber, 1923; clover cyst nematode H. trifolii Goffart, 1932; alfalfa cyst nematode H. medicaginis Kirjanova & Krall, 1971; hop cyst nematode H. humuli Filipev, 1934 are currently economically significant species. Their distribution mainly coincides with the traditional cultivation of sugar beets, grain cereals, potatoes, clover, alfalfa and hops. Long-term studies of the impact of abiotic, biotic, and anthropogenic factors on their populations made it possible to identify the dominant species and improve the set of protective measures. Anti-nematode crop rotations are the main limiting factor in preventing mass reproduction of cyst-forming nematodes, provided there is scientifically justified crop rotation. To prevent the mass accumulation of alfalfa and clover cyst-forming nematodes, the maximum share of perennial grasses in crop rotations should not exceed 30% (crops under cover of grain cereals + perennial legumes – one-two-year use); oat nematode – 40% of grain cereals; beet nematode – 20% of Chenopodioideae and cruciferous crops; golden potato nematode – 20% of potatoes (10% susceptible + 10% resistant varieties). The rational saturation of modern crop rotations with intermediate crops makes it possible to reduce the level of crop weediness caused by potential host plants of cyst-forming nematodes and to increase their anti-nematode effectiveness in general. The developed ecologically oriented system of phytosanitary control provides mandatory measures, which must be applied regardless of the level of initial population density, and additional measures specific to each culture and species of cyst-forming nematodes. Considering the current high specialization of crop production, the use of biological preparations in modern systems of integrated plant protection will contribute to the greening of agricultural output. Pre-planting treatment of tubers with metabolic biological preparations (Streptomyces avermitilis) of multifunctional action ensured the achievement of a higher (79.2–91.7%) efficiency of biological cleaning of the soil from the golden potato nematode, compared to the use of only potato-resistant varieties. A logical combination of various anti-nematode measures makes it possible to effectively keep the density of populations at an economically insignificant level and prevent crop yield losses.