Species composition of weeds in strawberry and raspberry plantations in Belarus

Yu. N. Pereverzeva, N. A. Dmitruk, V. S. Komardina

Introduction. In Belarus, the total area of berry plantations is 13.3 thousand hectares, with garden strawberry plantings accounting for about 10 thousand hectares, and summer raspberry for about 2 thousand hectares. One of the most important factors limiting yield growth under conditions of crop intensification is the high weed infestation of plantations. In the first years after planting, crops compete poorly with weeds, resulting in the stunted growth of the crop plants, and sometimes their death. The damage caused by weeds to the berry harvest reaches 10–20%, and in cases of high infestation, yield losses can reach 28%. Weeds not only significantly reduce the harvest and quality of berries but also facilitate the spread of pests and diseases, increase maintenance costs, and complicate harvesting.

On plantations of summer raspberry and garden strawberry in Belarus, more than 300 species of weed vegetation are found, of which about 40 species are the most common. The lowest species composition is observed in plantations on dry sod-podzolic and sod-calcareous soils of light mechanical composition.

Targeted studies on the species composition of weed plants in summer raspberry and garden strawberry plantations in the republic have not been conducted to date; the literature contains only fragmentary information on their prevalence. In view of the above, the goal of our research was to study the species composition of weeds in summer raspberry and garden strawberry plantations, which, in turn, will serve as a basis for forming an assortment of the most effective herbicides.

Materials and methods. The assessment of weed infestation in garden strawberry and summer raspberry plantations was carried out in 2021–2023 at the following agricultural enterprises: Minsk region – RUE "Institute of Fruit Growing", SE "Voskhod", and "Antey Sad" farm; Grodno region – JSC "V.V. Kremko", JSC "Plemzavod Ross", and the "Porechanka" branch of JSC "Grodno Meat Packing Plant"; Brest region – LPK "Krachevskogo"; Vitebsk region – RUE "Tolochin Cannery".

Species composition and the number of weed plants were determined in each plantation up to 5 hectares diagonally by placing 4 sampling frames with an area of 0.25 m2.

The population density (of individual species, their groups, and all weeds) was determined as the number of plant stems per unit area (1 m2) and calculated using the formula: a

S, where A is the population density of weed plants, plants/m2; a is the number of encountered plant stems; S is the total sampling area, m2.

Botanical and biological characteristics of the weed plants were determined according to taxonomic keys.

Research results. The species diversity of weeds in summer raspberry and garden strawberry plantations was represented by 36 species; the species composition of weeds differed depending on the crop.

In garden strawberry plantations, the average density of weeds over the three years of research was 358.0 plants/m2, of which 197.1 plants/m2 were perennial and 160.9 plants/m2 were annual. The dominant species over the three years were: common dandelion (61.9 plants/m2), couch grass (46.0 plants/m2), white clover (40.0 plants/m2), barnyard grass (37.0 plants/m2), purple deadnettle (31.8 plants/m2), and annual bluegrass (20.3 plants/m2). Weed infestation was lower for common chickweed (17.7 plants/m2), round-leaved geranium (17.0 plants/m2), field horsetail (15.0 plants/m2), and common lambsquarters (11.7 plants/m2). The population density of the remaining weed species ranged from 0.9 plants/m2 (common groundsel) to 8.2 plants/m2 (field bindweed).

Table – Species composition and population density of weed vegetation in summer raspberry and garden strawberry plantations (route surveys, 2021–2023)

Population density of weed plants (number of stems/m2)

Garden strawberry Summer raspberry

Perennial Germander speedwell (Veronika chamaedrys L.) 4.5 7.0 Field bindweed (Convolvulus arvensis L.) 8.2 Tufted vetch (Vicia cracca L.) 3.4 0.5 White clover (Trifolium repens L.) 40.0 Stinging nettle (Urtica dioica L.) - 2.2 Common toadflax (Linaria vulgaris Mill.) 7.1 Common dandelion (Taraxacum officinaleWigg.) 61.9 13.0 Field sowthistle (yellow) (Sonchus arvensis L.) 1.0 4.2 Creeping thistle (Cirsium arvense (L.) Scop.) 2.3 1.0 Common tansy (Tanacetum vulgare L.) - 0.5 Wormwood (Artemisia absinthium L.) - 7.3 Mugwort (Artemisia vulgaris L.) - 3.5 Couch grass (Elytrigia repens (L.) Nevski) 46.0 27.2 Common yarrow (Achillea millefolium L.) - 2.0 Field horsetail (Equisetum arvense L.) 15.0 Great water dock (Rumex confertus Willd.) 5.0 0.5 Sheep's sorrel (Rumex acetosella L.) 2.7 Total 197.1 68.9

Annual Gallant soldier (Galinsoga parviflora Cav.) 3.1 Round-leaved geranium (Geranium rotundifolium L.) 17.0 Cut-leaved geranium (Geranium dissectum L.) - 0.5 Redshank (Polygonum persicoria L.) 3.3 White campion (Silene pratensis (Rafn) Godr.) - 13.3 Common chickweed (Stellaria media (L.) Vill.) 17.7 Common groundsel (Senecio vulgaris L.) 0.9 Common lambsquarters (Chenopodium album L.) 11.7 Canadian horseweed (Erigeron canadensis L.) 6.5 2.6 Annual bluegrass (Poa annua L.) 20.3 38.7 Field forget-me-not (Myosotis arvensis (L.) Hill.) - 3.7 Shepherd's purse (Capsella bursa-pastoris (L.) Medik.) 1.4 16.9 Cleavers (Galium aparine L.) - 3.0

Weed density (pcs., stems/m²)

Effective plant protection for berry plantations requires precise knowledge of the weed phytocoenosis structure. According to field survey data conducted in 2021–2023, the species composition and weed infestation density of strawberry and summer raspberry plantations show fundamental differences. A total of 36 weed species belonging to 16 families were identified in these crops. Understanding these specifics helps the agronomist accurately select an herbicide application scheme and plan mechanical tillage.

• Strawberry weed infestation (max.) — 358.0 pcs./m²
• Raspberry weed infestation (max.) — 175.0 pcs./m²
• Share of dicotyledons in strawberry — 76.8%
• Share of dicotyledons in raspberry — 62.3%

Garden strawberry: predominance of perennial dicotyledonous species

In garden strawberry plantations, weeds are mainly represented by perennial dicotyledonous species. In the overall weed structure, dicotyledons account for 76.8%, of which 24.0% are taproot perennials and 22.0% are root-suckering perennials. Annual dicotyledonous weeds account for 28.0% (with a prevalence of summer annuals — 15.6%). Monocotyledonous species account for 11.3% (mostly annual summer grasses with a dominance of barnyard grass), and spore-bearing weeds account for 4.2%.

The Asteraceae (7 species) and Poaceae (3 species) families are characterized by the greatest species diversity in strawberries. The Polygonaceae family is represented by three species (curled dock, sheep sorrel, redshank), while the Fabaceae (white clover, tufted vetch) and Plantaginaceae (germander speedwell, common toadflax) families are represented by two. At the same time, the Violaceae (field pansy) and Caryophyllaceae (common chickweed) families are represented by only one species each.

Summer raspberry: predominance of annual overwintering weeds

In summer raspberry plantations, the maximum weed infestation is 175.0 pcs./m², with annual species prevailing — 106.1 pcs./m² (perennials account for 68.9 pcs./m²). The dominant group remains dicotyledonous weeds (62.3%), in the structure of which annuals account for 38.5%, and perennials — 23.8%. Among perennial dicotyledons, taproot species were recorded (9.4%). At the same time, among monocotyledonous weeds, overwintering species prevail, accounting for 22.1%.

The Asteraceae family in raspberries is represented by 9 species, and Poaceae by 2 species. The Violaceae (field pansy, field violet) and Caryophyllaceae (common mouse-ear, white campion) families are represented by two species each, while the Fabaceae (tufted vetch), Polygonaceae (curled dock), and Plantaginaceae (germander speedwell) are represented by only one. The number of rare species varies from 0.5 pcs./m² (tufted vetch, common tansy, curled dock, cut-leaved crane's-bill) to 4.2 pcs./m² (perennial sowthistle).

• Annual bluegrass (38.7 pcs./m2)
• Couch grass (27.2 stems/m2)
• Shepherd's purse (16.9 pcs./m2)
• Field violet (15.6 pcs./m2)
• White campion (13.3 pcs./m2)
• Common dandelion (13.0 pcs./m2)

A high share of dicotyledonous weeds (62.3%) was identified. The obtained data on the species diversity of weeds in garden strawberry and summer raspberry plantations will serve in the future to form a range of potentially effective herbicides.

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