Amaranthus Retroflexus Research Articles

Značaj suzbijanja korova i roka sjetve u proizvodnji kivana (Cucumis metuliferus E. Meyer Ex. Naudin) na području istočne Slavonije

Seed germination, growth, flowering and yields of kiwano (Cucumis metuliferus E. Meyer Ex. Naudin) were examined in eastern Slavonia during 2021 growing season. The objective of this study was to determine agro-morphological diversity within kiwano growing under different weed management practices and sowing time. The experiment was arranged as a 3 x 3 factorial design with three replications. Factors included three weed management options (wheat straw mulch, cultivation and un-weeded control) and three planting dates (early, mid and late May). A typical summer weed community that develops during experiment dominated with bristly foxtail (Setaria verticilata (L.) P. Beauv.) and redroot pigweed (Amaranthus retroflexus L.) while the others were with lower relative density and frequency per unit area and with the lower impact on the crop. Weed control was very effective compared to weedy check. However, sowing date appears as a critical factor in kiwano production, influencing not only emergence, growth and flowering, but also fruit number and size. This study concluded that mid sowing time and cultivation as a weed control measure has a highest agronomic potential for a kiwano production following by mid and early sowing time with mulch as a weed control measure.

Alelopatski potencijal biljnog ekstrakta zelenih plodova oraha (Juglans regia L.)

The aim of this study was to test the allelopathic effects of the plant extracts isolated from immature walnut fruits on the germination and early seedling growth of two weed species (Amaranthus retroflexus and Chenopodium album), and its phytotoxic effects on the germination and early seed growth of maize, Zea mays. Additionally, the goals was to also conduct an analysis of the plant extracts and determine its antioxidant properties. Antioxidant activity of the plant extracts were determined via its ability to neutralize DPPH (2,2-diphenyl-1-picrylhydrazyl) radicals and by testing their potential for iron reduction using the FRAP method. The inhibition of the measured parameters (total germination and seedling length) decreased proportionally, with the reduction of concentrations of plant extracts isolated from immature walnut fruits. Also, the seedling length parameter has shown greater sensitivity when compared with the parameters of total seed germination in both weed species. Even though the results of both biotests with seeds show a high inhibitory effect on the germination and early growth of the tested weed species, they also point to phytotoxicity in early growth of Z. mays seeds. Future research will be focused on the HPLC analysis of the plant extracts isolated from immature walnut fruits and their allelopathic effects on the early growth of plants of the tested species.

Korovi u proizvodnji suncokreta u Hrvatskoj i njihovo suzbijanje

Sunflower is the most important oil crop in the Republic of Croatia. In the last two decades, it has been grown on average on 33,506 ha with a average grain yield of 2.66 t/ha. Weeds represent one of the most important causes of biotic stress, and their action is reflected in the competition for nutrients, water, light and space. The weed flora in sunflower crops in Croatia is extremely diverse, and we will most often meet: Polygonum persicaria L., Polygonum lapathifolium L., Ambrosia artemisiifolia L., Chenopodium polyspermum L., Amaranthus retroflexus L., Solanum nigrum L. emend Miller, Abutilon theophrasti Medik, Datura stramonium L., Xanthium strumarium L., Convolvulus arvensis L., Cirsium arvense (L.) Scop., Echinochloa crus-galli (L.) Pb., Setaria glauca (L.) Pb., Setaria viridis (L.) Pb., Digitaria sanguinalis (L.) Scop., Panicum spp. and Sorghum halepense (L.) Pers. For many years, weed control was based on the intensive use of chemical preparations, which were most often used after sowing and before emergence, in double or triple combinations. In addition to a number of advantages of using chemicals in sunflower production, the problem of broadleaf weeds was not satisfactorily solved until the advent of Clearfield, Clearfield plus and Express sun technology, i.e. hybrids tolerant to herbicides from the group of imidazolinone (imazamox) and sulfonyl-urea (tribenuron-methyl) at the beginning of this century. Integrated plant protection, including integrated weed management, with its holistic approach and greater application of direct and indirect non-chemical measures, is only environmental quality solution for controlling weeds in sunflowers.

Auxin‐based herbicide program for weed control in auxin resistant soybean

AbstractSoybean [Glycine max (L.) Merr.] cultivars resistant to synthetic auxin herbicides have provided another mode of action for the postemergence broadleaf weed control. This field study was conducted at three South Dakota locations [Northeast, NERF; east‐central, ARF; and Southeast, SERF) in 2019 and two locations (ARF and SERF) in 2020. The Enlist E3 and Roundup Ready 2 Xtend cultivars were planted at three dates (early, mid‐, and late season) to examine weed control, agronomic characteristics, nodulation, and yield. Preemergence (PRE) treatment was flumioxazin + metribuzin + S‐metolachlor + glyphosate + pendimethalin. Two postemergence (POST) treatments, based on cultivar, were compared with PRE‐only. The PRE‐only treatment had numerous grasses {including green foxtail [Setaria viridis (L.) P. Beauv.] and yellow foxtail [S. pumila (Poir.) Roem. & Schult.], volunteer corn (Zea mays L.), barnyard grass [Echinochola crus‐galli (L.) Beauv.], large crabgrass [Digitaria sanguinalis (L.) Scop.], woolly cupgrass [Eriochloa villosa (Thunb.) Kunth]} and broadleaf weeds (including redroot pigweed [Amaranthus retroflexus L.], common lambsquarters [Chenopodium album L.], waterhemp [Amaranthus rudis Sauer]) with high density and biomass. POST treatments controlled most of the broadleaf species, although some grasses remained. Yields were similar within a location and year, although differences occurred among planting dates. In 2019, planting date did not influence final yield at ARF (average yield 3,084 kg ha−1). Yield was greatest for the early (NERF) and mid‐planting dates (NERF and SERF) compared with late‐season planting. In 2020, dry conditions occurred, and yields at ARF and SERF were lowest for the late‐season plantings (ranging from 37 to 73% lower depending on cultivar) compared with the early season planting. In 2020, dicamba + glyphosate treatment of the Xtend cultivar had 10% (ARF) and 20% (SERF) greater yield than the acifluorfen + clethodim treatment.

Effectiveness of Some Herbicides and Herbicide Combinations Applied to Chickpea (Cicer Arietinum L.) Culture

The purpose of this work is to establish the effectiveness of herbicides or combinations of herbicides under the influence of different climatic conditions in the study years (2019-2021). In this regard, ARDS Teleorman has established an experiment with the application of herbicides and combinations of herbicides, applied in different doses, in different application periods, placed according to the method of randomized blocks in three repetitions, on a chernozem cambic soil with clay content over 42%. The Burnas variety, a chickpea variety created by ARDS Teleorman, was used. Based on the frequency, the following specific problems were identified: Digitaria sanguinalis, Echinochloa crus-galli, Setaria spp., Amaranthus retroflexus, Chenopodium album, Solanum nigrum, Hibiscus trionum, Polygonum convolvulus, Sinapis arvensis, Stellaria media, Veronica spp., Xitalicum Cirsium arvense, Convolvulus arvensis, Sonchus arvensis. On average, over the three years of experimentation, the combination of herbicides applied to the V8 variant [312.5 g/l S-metolaclor; 87.5 g/l terbutilazin applied in a dose of 4.0 l/ha in pre-emergence + isoxaflutol 240 g/l Ciprosulfamida (safener): 240 g/l applied in a dose of 0.3 l/ha in pre-emergence] 98%, variant V5 [960 g/l S-metolaclor isoxaflutol 240 g/l applied in a dose of 1.2 l/ha in pre-emergence + isoxaflutol 240 g/l Ciprosulfamida (safener): 240 g/l in a dose of 0.2 l/ha in pre-emergence] 96.4% and in variant V3 [50g/l quizalofop-p-ethyl at a dose of 1.2 l/ha post-emergence + isoxaflutol 240 g/l Ciprosulfamida (safener): 240 g/l at a dose of 0.15 l/ ha post-emergence] 96%. Of all the tested variants, the variant with the application of 312.5 g/l S-metolaclo; 187.5 g/l terbutilazin herbicides (4.0 l/ha) + isoxaflutol 240 g/l; Ciprosulfamida (safener): 240 g/l (0.3 l/ha) in pre-emergence, with a high level of production, which does not allow its recommendation in weed control in chickpeas.

Vegetation structure of bio-belts as agro-environmentally-climatic measures to support biodiversity on arable land: A case study

<abstract> <p>Loss of biological diversity is one of the greatest challenges that our civilization must face nowadays. Reaction to the diminishing biodiversity of agricultural landscapes is various measures promoting free-living organisms. The study deals with the vegetation composition and structure of agro-environmental-climatic measures applied on arable land in operating conditions (intensively farmed regions of the Czech Republic). Additional study focus was applied to a popular measure of the feeding bio-belts. Bio-belts are not only hiding places for free-living animals but can provide them a rich food offer in the period from the harvest of main crops until winter. Thanks to the bio-belts, the landscape gains in biodiversity, and sloping sites can be protected from soil erosion. The vegetation of land parts used as bio-belts was assessed using phytocoenological relevés. Dominant plant species sown in the bio-belts were <italic>Avena sativa, Panicum miliaceum</italic>, <italic>Brassica oleracea</italic> var. <italic>acephala, Fagopyrum esculentum, Phacelia tanacetifolia</italic>, and <italic>Pisum arvense</italic>. Apart from the sown plants, there were also weeds occurring in the bio-belts, of which the most abundant were <italic>Chenopodium album</italic>, <italic>Amaranthus retroflexus</italic>, <italic>Setaria verticillata</italic>, <italic>Cirsium arvense</italic>, <italic>Equisetum arvense</italic>, etc. Risks connected with the realization of feeding bio-belts in respect of weeds occurring on arable land are negligible. Weeds from bio-belts have only a limited potential to spread to adjacent arable land. A potential spreading of weeds from the bio-belts to adjacent arable land was not demonstrated. On the contrary, thanks to its composition, the vegetation of bio-belts has the potential to extend the food offer for animals. Thus, bio-belts are useful for supporting biodiversity in regions intensively used for agriculture.</p> </abstract>

Identification of Weeds in the Greenhouse Production Lands of Kirsehir, as well as their Prevalence and Densities

Turkey has a higher greenhouse potential than the rest of the Mediterranean countries. In greenhouses, yield and quality losses arise at varying levels due to abiotic and biotic factors. Within the scope of this study, surveys were conducted in the vegetation period of 2021 to determine the weed species that have become a problem in soil greenhouses in Kırşehir Province, as well as their densities and prevalence. In the 16 greenhouses where the study was conducted, 28 weed species were identified, including 5 monocotyledons, 1 parasitic, and 21 dicotyledons from 16 families. It was determined that 64.28% of the identified weed species were annual, 24.42% were perennial, 7.14% were annual/biennial, 3.57% were parasitic, and 3.57% were biennial. Chenopodium album L. (2.94 pcs/m2), Amaranthus retroflexus L. (1.59 pcs/m2), and Solanum nigrum L. (1.03 pcs/m2) were determined to have the highest density in the greenhouses. The prevalence of weeds in the greenhouse lands was A. retroflexus (93.75 %), C. album (81.25 %), S. nigrum (75 %), and Portulaca oleracea L. (50 %), respectively. Consequently, it was observed that the control of these weed species, which are common and dense in Kırşehir greenhouse cultivation lands, was primarily necessary.

Korovi zasada jabuke i njihovo suzbijanje

Floristic composition of the weed community in apple orchards differs, depending on the type of management - extensive or intensive. In extensive orchards, weedy-ruderal-grassland species are dominant. On the other hands, in intensive orchards the inter-row can be dominated by annual (therophyte) weed species, if mechanically cultivated, or grass species, if grasses are used as cover crops, while the rows are dominated by perennial weed species (geophytes, hemicryptophytes). The floristic composition of the weed communities is also dependent on the age of the orchard. In younger orchards row crop weeds are dominant, while as the orchard ages, the community gets a more weedy-ruderal-grassland character. The most common weed species in apple orchards in Serbia are: Amaranthus retroflexus, Ambrosia artemisiifolia, Chenopodium album, Convolvulus arvensis, Carduus acanthoides, Cynodon dactylon, Erigeron canadensis, Hordeum murinum, Lamium purpureum, L. amplexicaule, Medicago lupulina, Setaria spp., Stellaria media, Stenactis annua, Sonchus arvensis, Taraxacum officinale, Veronica spp. and Vicia spp. Weed control in apple orchards can be done using agrotechnical (soil cultivation), physical (mowing, mulching), thermic, chemical, biological measures, and by growing cover crops. In practice, weed control in apple orchards is dominantly done by herbicides, based on the following active substances: napropamide, glyphosate, 2.4D, flazasulfuron, flurochloridone, cycloxydim, fluazifop-p-butyl, clethodim, diquat, fluroxypyr-meptyl, and pyraflufen-ethyl. Given that nowadays the production of healthy and safe food is an imperative, also demanded by the international market, it is expected that bioproducts will be prioritized over classical synthetic herbicides. Moreover, non-chemical measures are also becoming more important as part of integral weed control measures of weeds in apple orchards.

Allelopathic Effect of Aqueous Extracts of Stinkwort (Dittrichia graveolens L.) on Germination and Growth of Some Weed Species

The experiment was implemented by CRD design with three replications and lasted for 40 days, from 5 October until 15 November 2020. Four extract concentrations of D. graveolens 0, 2, 6, and 10% were used. The concentration of 0% was considered as control. The allelopathic effect has been studied on five weed species; Amaranthus retroflexus L., Portulaca oleracea L., Lolium multiflorum Lam., Sorghum halepense L., and Cuscuta campestris Yunck. The research also aimed to determine the effect of Stinkwort extract on the growth of tomato seedlings. All concentrations affected seed germination for all studied weeds. The concentration of 10% was more influential in growth-related indicators compared to other concentrations. The seeds of L. multiflorum and rhizomes of S. halepense were more tolerant to D. graveolens allelochemicals in germination rate than A. retroflexus, P. oleracea, and C. campestris. All concentrations led to a reduction in the weed heights and the wet and dry weights compared with the controls. The effect of the extract with various concentrations was catalytic for the growth of tomato seedlings, as the average height of tomato seedlings was in direct proportion to the concentration.

Allelopathic Effect of Aqueous Extracts of Stinkwort (Dittrichia graveolens L.) on Germination and Growth of Some Weed Species

The experiment was implemented by CRD design with three replications and lasted for 40 days, from 5 October until 15 November 2020. Four extract concentrations of D. graveolens 0, 2, 6, and 10% were used. The concentration of 0% was considered as control. The allelopathic effect has been studied on five weed species; Amaranthus retroflexus L., Portulaca oleracea L., Lolium multiflorum Lam., Sorghum halepense L., and Cuscuta campestris Yunck. The research also aimed to determine the effect of Stinkwort extract on the growth of tomato seedlings. All concentrations affected seed germination for all studied weeds. The concentration of 10% was more influential in growth-related indicators compared to other concentrations. The seeds of L. multiflorum and rhizomes of S. halepense were more tolerant to D. graveolens allelochemicals in germination rate than A. retroflexus, P. oleracea, and C. campestris. All concentrations led to a reduction in the weed heights and the wet and dry weights compared with the controls. The effect of the extract with various concentrations was catalytic for the growth of tomato seedlings, as the average height of tomato seedlings was in direct proportion to the concentration.

Assessment of weed root extracts for allelopathic activity against Orobanche and Phelipanche species

Broomrapes (Orobanche and Phelipanche species) are holoparasitic weeds that infect roots of crop hosts from Asteraceae, Brassicaceae, Apiaceae, Fabaceae, and Solanaceae. The parasitic weeds are difficult to control selectively without crop damage once attached to their roots. Identification of natural compounds with herbicidal activity against pre-attached broomrape stages can provide control alternatives. With the aim to identify plant species with efficacy for broomrape control, organic and residual aqueous phase extracts from roots of seventeen weed species common in south Spanish broomrape-infested fields were assessed as potential inducers of suicidal broomrape germination and as inhibitors of broomrape radicle growth. Assessments were carried out in vitro using seeds and seedlings of four noxious broomrape species, Orobanche crenata Forsk., Orobanche cumana Wallr., Orobanche minor Sm. and Phelipanche ramosa (L.) Pomel. While root extracts from all the weed species did not induce suicidal germination on O. crenata seeds, most of the extracts induced germination of P. ramosa except for those obtained from Amaranthus albus L., Amaranthus retroflexus L. and Convolvulus arvensis L. Moderate levels of germination activity were induced in O. cumana and O. minor seeds by some of the root extracts tested, with strongest induction obtained from Heliotropium europaeum L. on O. cumana seeds, and from Silybum marianum (L.) Gaertn. on O. minor seeds. For root extract inhibition of broomrape radicles, the extract from C. arvensis roots strongly inhibited radicles of all the broomrape species. While extracts from the other weed species induced low or negligible inhibition of O. cumana and O. crenata radicle growth, many inhibited P. ramosa and O. minor radicles. Exceptions were root extracts from Datura stramonium L., Heliotropium europaeum L., Malva sylvestris L., Solanum nigrum L. and Urtica dioica L., which did not inhibit P. ramosa radicles, and those from A. retroflexus, Datura stramonium L., Malva sylvestris L., Portulaca oleracea L. and S. nigrum, which did not inhibit O. minor radicles. Among the active organic extracts assessed, those showing promising chemical profiles were selected for future studies to characterize natural compounds with potential herbicidal activity on early stages of broomrape growth.

The Effect of the Timing of Manure Application in Combination with Mineral Fertilizers and Planting Density on the Weediness of Potato Plantings

Potatoes are one of the most responsive crops for grooming techniques since in the period from seedlings before closing rows are easily suppressed by weeds that take away nutrients, water, light from it. The factor that causes high harm to potatoes is weed. By absorbing a large number of nutrients and moisture from the soil, weeds inhibit the growth and development of plants, reducing their potential productivity. The purpose of the study was to establish the effect of the timing of the introduction of bedding manure in conjunction with mineral fertilizers and planting density on the weediness of potato plantings. Studies were provided to identify the impact of the timing of bedding manure together with mineral fertilizers and planting density for weed planting potatoes. Experiments were laid by the systematic method with a tiered arrangement of variants in the experiment with a 3-fold repetition. We used cattle manure on straw bedding for autumn-winter harvesting. The following types of fertilizers were used: ammonium nitrate, double superphosphate, potassium chloride. Determination of the amount and biomass of weeds in potato plantings was carried out in the flowering phase and before harvesting. The application of manure was accompanied by an increase in the number and weight of weeds. Annual weeds predominated in potato plantings: Amaranthus retroflexus L., 1753 and Amaranthus blitoides S. Watson, 1877, Chenopodium album L. Chenopodium album L., 1753, Setaria P. Beauv, 1812 and Setaria viridis (L.) P. Beauv, 1812, Echinochloa crus-galli (L.) BEAUV., 1812 and others, perennials included Cirsium arvense (L.) SCOP. 1772 and Sonchus arvensis L., 1753, (Elytrigia repens (L.) DESV. ex NEVSKI, 1933 and others. Planting density also has a definite effect on the development of weeds. When manure was applied in autumn under the plow, the number of weeds increased in comparison with other options, where only mineral fertilizers were applied. The application of manure over frozen plow and in winter over snow leads to a slight decrease (2.3-2.5 pcs/m2) of weeds. The greatest number of weeds is observed during the spring application of manure for plowing the fall plow. Nevertheless, studies aimed at clarifying the composition and structure of weediness, the number and weight of weeds in potato plantings are of great practical importance for local agricultural producers. These data should contribute to the development of an effective weed control system and high yields of potatoes in the region

Efficacy of herbicides in sunflower sowings in the conditions of the western Forest-Steppe of Ukraine

Purpose. Determinе the species composition of weeds and the most efficient system of weed control in sunflower sowings.
 Methods. Field, laboratory, mathematical and statistical.
 Results. The species composition of spring weeds in sunflower sowings was mainly represented by dicotyledonous species Amaranthus retroflexus L., Chenopodium album L., Galinsoga parviflora Cav., Matricaria inodora L., Thlaspi arvense L., Polygonum convolvulus L., Sinapis arvensis L., Xanthium strumarium L. and cereal weeds Setaria glauca L., Echinochloa cruss-galli L. The efficiency of the use of herbicides Challenge 2.5 l/ha + Harness 1.5 l/ha on the 30th day after application, against the total number of weeds, was 89.7%. Meanwhile, the use of the herbicide Challenge is the application rate of 2.0 l/ha appeared more effective with the efficiency rate of 95.6%. The herbicides, regardless of their application scheme, did not caused thinning of the sowing density; however, plant suppression did occur. This was evidenced by reduced plant height during the anthodium formation and flowering stage compared to control.
 Conclusions. The dominant weed species in sunflower crops were Amaranthus retroflexus with the share of 15%, Chenopodium album 8%, Setaria glauca L. 23% and Echinochloa cruss galli 10%. Application of herbicide Challenge 2 l/ha in the 2 to 4 leaf stage of sunflower appeared the most effective as weed control method with the efficiency rate of 92.8%. Herbicides Challenge (2.5 l/ha) + Harness (1.5 l/ha) were milder to crop plants, which ultimately contributed to the formation of sunflower yield of 3.47 t/ha in hybrid ‘NK Condy’ and 3.04 t/ha in hybrid ‘Atilla’.

Phytotoxic effects of essential oils from Nepeta glocephalata Rech.f. and N. ispahanica Boiss. on se-lected weed species

In the present study the bioherbicidal activity of essential oils hydrodistilled from Nepeta glocephalata Rech.f and N. ispahanica Boiss were investigated on four weed species (barnyard grass (Echinochloa crus-galli (L.) Beauv), redroot pigweed (Amaranthus retroflexus L.), lambsquarters (Chenopodium album L.) and canary grass (Phalaris canariensis L.)). A total of 37 components were identified from the essential oils of N. glocephalata and N. ispahanica constituting approximately 98.61 % and 96.1 % of the oils, respectively. In laboratory bioassay different concentrations (0, 1, 2, 4 and 8 μl ml-1) of two Nepeta essential oils on germination, root and shoot length were studied. Results showed by increasing the concentration of oils, all studied traits of the weeds were decreased compared with control. In a glass house bioassay post-emergence application of Nepeta essential oils (1.25 %, 2.5 %, 5 % and 10 %, v/v) on 3-week-old weed plants caused visible injury (7-days after spray) ranging from chlorosis to necrosis of plant weeds. In foliar application under glasshouse conditions, both Nepeta essential oils reduced the seedling dry mass and concentrations of chlorophyll a chlorophyll b. The study concludes that Nepeta essential oils have phytotoxic effects and could be used as bioherbicides but the selectivity of these compounds should be considered also.

Weed Control in Sunflower (Helianthus annuus L.) with Soil-applied Herbicides Affected by a Prolonged and Limited rainfall

The field trials were carried out in the Bitola and Titov Veles regions during two sunflower growing seasons (2018 and 2019) to estimate a weed control in sunflower with the soil‒applied herbicides, influenced by a prolonged and limited rainfall. Polygonum aviculare L., Solanum nigrum L., Chenopodium album L., Amaranthus retroflexus L., Portulaca oleracea L., and Echinochloa crus-galli (L.) P. Beauv. were the most dominant weeds in both regions. The efficacy of PRE-em herbicides varied among the weed species, treatments, periods of efficacy estimation, regions, and years. The overall performances of the PRE-em herbicides were correlated with weather and soil conditions. The inconsistent weather patterns between the two years of the study likely influenced the weed control. All weeds in 2018 in the Bitola region were poorly controlled (<77% and <62%, 28 and 56 days after application, respectively) due to a higher amount of rainfall (57 mm) during the 10 days of the 1st decade after herbicide application. The herbicide efficacy has only produced a marginal control of weeds in 2019 in the Titov Veles region as well (<68% and <59%, 28 and 56 days after application, respectively), due to the drought conditions observed in this region in early spring and in mid-spring. A PREem application followed by a heavy rainfall resulted in a sunflower injury in the Bitola region in 2018, ranging from 9 to 28% across the PRE-em treatments seven days after emergence. The injuries by oxyfluorfen and dimethenamid-P were more serious (24 and 28%, respectively). The sunflower achene yields for each treatment in both regions generally reflected an overall weed control and crop injury.

Influence of basic tillage, fertilizers and herbicides on weediness of pea crops for grain in stationary crop rotation

Goal. To establish the influence of the methods of basic tillage, fertilization system and herbicides on the weediness of pea crops for grain during cultivation in a stationary steam-grain-row crop rotation of the eastern part of the Forest-Steppe of Ukraine.
 Methods. The research was carried out by route surveys of pea crops for grain in the field crop rotation.
 Results. According to the research of 2016—18, 52 types of weeds and contaminants (spring early and late were 54%; wintering, winter and biennials were 23%; perennials were 23%) were found in pea crops for grain after spring cereal crops (spring barley, spring wheat, spring triticale) as forecrop. The largest number of them was noted on the organic-mineral background (manure aftereffect, 30 t/ha + N30P30K30) for the application of fertilizers for plowing (33 species) and chisel tillage (35 species). The weeds found in the pea crops for grain belonged to 20 families, of which the aster family (17 species) was the most represented. The main weeds in the crops were Setaria glauсa (L.) Beauv., Echinochloa crus-galli (L.) Roem. et Schult., Chenopodium album L., Amaranthus retroflexus L., Solanum nigrum L., Ambrosia artemisiifolia L., Stachys annua L., Xanthium strumarium L., Galium aparine L., Viola arvensis Murr., Cirsium arvense (L.) Scop., Sonchus arvensis L. and Convolvulus arvensis L. The use of herbicides and their compositions in the cultivation of peas for grain has significantly influenced the dominance and subdominance of certain weed species in the years of research. The fertilization system and the methods of basic tillage in crop rotation had a significant impact on the type and level of weediness of crops. The type of weed control crops (without fertilizers) differed significantly from organic and organo-mineral fertilizer backgrounds. For the most part, the version with chisel tillage had a higher level of weeding compared to plowing.
 Conclusions. Methods of basic tillage, fertilizer system and herbicides significantly affect the weediness of pea crops for grain in steam-grain-row crop rotation, which should be taken into account by farmers when developing methods of its control in the eastern part of the Forest-Steppe of Ukraine.

Weed control in maize crops with various schemes of herbicide application

Goal. Carry out a comparative evaluation of the effectiveness of different schemes of application of modern herbicides in maize crops.
 Methods. Field, phenological, statistical. Conducted spraying of corn crops to seedlings (ВВСН 00) with herbicides Adengo 465 SC, hp (thiencarbazone-methyl, 90 g/l + isoxaflutol, 225 g/l + cyprosulfamide, 150 g/l), 0.5 l/ha, Primextra TZ Gold 500 SC, (S-metachlor. 312.5 g/l + terbuthylazine, 187.5 g/l), 4.5 l/ ha, Merlin Flex Duo 475 SC, (isoxaflutop, 50 g/l + cyprosulfamide, 50 g/l + terbuthylazine, 375 g/l, 2.0 l/ha. After germination in the phase of 4—5 leaves (ВВСН 14—15) applied insurance herbicides Milagro 040 SC, (nicosulfuron, 40 g/l), Basis 75 v.g. rimsulfuron, 500 g/kg + thifensulfuron-methyl, 250 g/l), MаisTer Power OD (foramsulfuron, 31.5 g/l + iodosulfuron-methyl sodium, 1.0 g/l + thiencarbazone-methyl, 10 g/l + cyprosulfamide, 15 g/l), Laudis 30 WG, VG (tembotrione, 200 g/kg + isoxadifen-ethyl, 100 g/kg) and Stellar, RK (topramezone, 50 g/l + dicamba, 160 g/k) in the recommended consumption rates. The experimental plots were 1000 m2 in the first experiment, the recurrence of 3-fold and 25 m2 in the second experiment, the recurrence of 4-fold. Observations were made for meteorological indicators. Statistical processing of the results was performed according to computer «Statgraphic plus» programs. 
 Results. Mixed type of segetal vegetation prevailed in the experimental plots. Among the perennial weeds dominated by Sonchus arvensis L., Cirsium vulgare Savi Ten., Convolvulus arvensis L., among annuals — Setaria glauca L., Setaria viridis L., Echinochloa crus-galli L., Polygonum convolvulus L., Calinsoga parviflora L., Stellaria media (L.) Vill.), Chenopodium album L., Raphanus raphanistrum L., Thlaspi arvense L., Amaranthus retroflexus L. The application of pre-emergence herbicides effectively inhibited the growth and development of weeds. 60 days after application, the effectiveness of herbicides was 87—97% against cereals and 89—98% against dicotyledonous weeds, which did not require the application of insurance herbicides. During the critical periods of maize development, a sufficient level of soil moisture was recorded during the research years. After 60 days, the effectiveness of herbicides applied after crop germination was 65—95% against dicotyledonous and 65—92% against cereal weeds. The highest effect in killing weeds was provided by MaysTer Power, 1.5 l/ha, Laudis 30 WG, VG, 0.5 kg/ha + surfactant Mero, 2.0 l/ha and Stellar, RK, 1.25 l/ha + surfactant Metholate, 1.25 l/ha. The application of herbicides has significantly reduced the aboveground mass of weeds and increased crop yields. Maize grain yield from weed-protected areas was at the level of 8.0—9.7 t/ha against 4.1—4.9 t/ha in the control.
 Conclusions. Both herbicide application schemes under favorable weather conditions provide effective weed control of maize crops The efficiency of pre-emergence herbicides was at the level of 87—98%, post-emergence — 65—95%. At the same time, the reduction of aboveground mass of weeds was 75—95%, and crop yields increased by 1.6—2.2 times depending on the drug.

Allelopathic effect of herbal formulation containing Ferula assa-foetida L. essential oil and castor oil (Ricinus communis L.) as an herbicide on Amaranthus retroflexus L. seed germination

Allelopathic effect of herbal formulation containing Ferula assa-foetida L. essential oil and castor oil (Ricinus communis L.) as an herbicide on Amaranthus retroflexus L. seed germination

Plant invasions in Ukraine

Abstract We present a comprehensive review of the plant invasions of 42 alien species and their impact on vegetation cover in Ukraine. Among these species, those currently posing the greatest threat to the environment have been identified. The structural features of this group were analyzed. In the life form spectrum the phanerophytes and therophytes are dominant, in the ecological spectrum the mesophytes are dominant, and kenophytes predominate at the time of immigration. Among the examined species, plants of North American origin predominate, agriophytes prevail by their degree of naturalization, and ergasiophytes are predominant by their way of entry. The participation of invasive species in natural and anthropogenic plant communities and biotopes was analyzed. These species are a stable component of grasses, scrub and forest habitats. Most of these invasive plants (33 species) are observed in anthropogenic habitats (I). Slightly fewer species of the studied group prefer habitat types E (25), F and G (22 each), although the largest invasions are observed exactly in these biotopes. Invasive species are characterized by eurytopicity. Four species have the greatest ecological plasticity, each of these is found in six types of habitats: Ailanthus altissima (B, F, G, I, J, H), Amaranthus retroflexus (C, E, F, G, I, J), Opuntia humifusa (B, E, F, G, H, I) and Xanthium albinum (B, C, E, F, G, I). Erigeron canadensis is found in five habitat types (C, E, F, G, I). The studied group is characterized by an insignificant regional specificity of the species composition, high invasive potential and stability of population reproduction.

Эффективность применения комбинированного гербицида Акрис, СЭ на основе диметенамида-Р и тербутилазина в посевах подсолнечника

Trials with a herbicide Acris, SE (280 g/l of dimethenamid-P + 250 g/l of terbuthylazine) were carried out in the Astrakhan, Krasnodar and Altai regions. The aim of this work is studying biological and economic efficiency of pre-emergence treatment with the combined herbicide Acris, SE on sunflower. The treatment with the herbicide Acris, SE (2.0–3.0 l/ha) made it possible to prevent many annual dicotyledonous weeds: Chenopodium album, Amaranthus retroflexus, Fagopyrum tataricum, Abutilon theophrastii and Solanum nigrum. Ambrosia artemisiifolia, found in the Krasnodar region, is less sensitive to this herbicide. The herbicide Acris, SE was highly effective in suppressing annual monocotyledonous weeds: Echinochloa crusgalli and Panicum miliaceum. Efficiency of the herbicide ACRIS was at the level of the standard Gardo Gold, and at the maximum application rate (3.0 l/ha) exceeded the standard one. Pre-emergence soil treatment with the herbicide Acris, SE did not have a negative effect on the germination of sunflower. Significant increase of sunflower yield was noted in all regions of trials. The most significant values were observed on varieties Flagman and R 453 in the Krasnodar region (8.7–9.2 and 7.0–7.5 quintal/ha, respectively). The lowest yields of sunflower in untreated control (10.2 and 11.0 quintal/ha) were observed in the Altai region, but the relative increase in yield in variants with the herbicide Acris, SE application was maximum (from 29.1 to 67.6% in relation to yields in untreated control). In the Astrakhan region, application rates of the herbicide Acris, SE of 2.5 and 3.0 l/ha were characterized by statistical significance (increases up to 2.5 and 3.2 quintal/ha, respectively).