Veronica Persica Research Articles

여름어리표범나비(Mellicta ambigua (Menetries))의 생태적 특성에 관한 보고

ABSTRACT Recently the number of the butterflies, Mellicta ambigua, had been decreasing rapidly, and already disappeared at manyhabitat. In this studies, we investigated ecological environment of Mellicta ambigua for preparing of primary researchdata recovering habitat, and studied on bionomical characteristics. Two different habitat, Jindo and Inje, were selectedfor investigation of ecological environment. We investigated four times during 3-month, from June to August in 2012.In Jindo, we observed more than 100 butterflies and a lot of host plants, Melampyrum roseum var. japonicum. But only5 butterflies and only a few host plants, Veronicastrum sibiricum were observed in Inje. We could not observe the eggs,the larva and pupa on the host plants at all. For finding of bionomical characteritics, we reared butterflies at natural con-ditions. Collected 3-female butterflies from Jindo laid 465 eggs on the leaves of 3-host plants, Veronicastrum sibiricum.120 ~ 186 eggs per each female were laid in the shape of cluster. An egg was globular shape, 0.6 mm diameter and0.7 mm height. The egg periods were 9.96± 0.4 days after ovipositioning, and the hatchability was 95.% at natural con-dition. The larval periods were 4.1 ±0.6 days (1st instar), 2.11.0 days (2nd), 8.1± 0.7 days (3rd), 239.2± 10.9 days(4th), 12.3 ±1.3 days (5th), 17.1 1.1 days (6th), 10.5± 1.0 days (7th) each other. The larva of 4th instar overwinteredin the nest that had been made into the leaf of host plant with secreted thread as a group until early March next year.In the early March next year, overwintered larva went around their nest in search of host plants, and went to other hostplants, Veronica persica and Plantago asiatica, sometimes. The overwintered larva of Mellicta ambigua could grow upon two other host plants normally. In the following experiment, the butterflies of Mellicta ambigua laid eggs on theleaves of Plantago asiatica, but the 1st instar larva from eggs died all. The headwidth of each developmental larval stagewere 0.28 ±0.02 mm (1st), 0.45 ±0.02 mm (2nd), 0.58 0.02 mm (3rd), 0.75 0.03 mm (4th), 0.89± 0.05 mm (5th),1.23 ±0.06 mm (6th), 2.13± 0.11 mm (7th). The pupal ratio was 92.0%. The pupal period were 9.11.6 days, andthe emergence rate was 88.6%. As a result we determined that Mellicta ambigua can rear at natural conditions. Butindoor-rearing is considered to be difficult and not useful industrially, because they have long term larval stage and onlyone life cycle per an year.Key words : Mellicta ambigua, Habitat, Bionomical characteristics, Host plant, Rearing

Image‐based thresholds for weeds in maize fields

SummaryRecent development of site‐specific weed management strategies suggests patch application of herbicides to avoid their excessive use in crops. The estimation of infestation of weeds and control thresholds are important components for taking spray decisions. If weed pressure is below a certain level in some parts of the field and if late germinating weeds do not affect yield, it may not be necessary the spray such places from an economic point of view. Consequently, it makes sense to develop weed control thresholds for patch spraying, based on weed cover early in the growing season. In Danish maize field experiments conducted from 2010 to 2012, we estimated competitive ability parameters and control thresholds of naturally established weed populations in the context of decision‐making for patch spraying. The most frequent weed was Chenopodium album, accompanied by Capsella bursa‐pastoris, Cirsium arvense, Lamium amplexicaule, Tripleurospermum inodorum, Poa annua, Polygonum aviculare, Polygonum persicaria, Stellaria media and Veronica persica. Relative leaf cover of weeds was estimated using an image analysis method. The relation between relative weed leaf cover and yield loss was analysed by nonlinear regression models. The competitive ability parameters and economic thresholds were estimated from the regression models. The competitive ability of weed mixtures was influenced by the increasing proportion of large size weeds in the mixtures. There was no significant effect of weeds which survived or established after the first herbicide application, indicating that early image analysis was robust for use under these conditions.

In the beginning: phenotypic change in three invasive species through their first two centuries since introduction

Previous studies have demonstrated that most introduced species go through rapid phenotypic change during their first decades to centuries of being introduced to a new range. However, little is known about the trends these phenotypic changes follow through time. Using herbarium specimens we track changes in the leaf area, leaf shape and plant height of three species (Epilobium ciliatum Raf., Senecio squalidus L. and Veronica persica Poir.) through their first ~200 years since introduction to the United Kingdom. All three species showed fluctuating direction and strength of phenotypic change through time. Then, we asked whether invasive species showed an initial lag phase in phenotypic change. Contrary to some expectations, we found that none of our species underwent a lag phase for the first 100 years after introduction. This is probably because the strongest selective pressures are exerted on them at the very beginning of their invasion, when the mismatch between their traits and the optimum for the new environment is greatest. Finally, we asked whether invasive species were still changing, or whether they had reached a new equilibrium, finding that all three species were still changing in at least one trait more than a century after their introduction. Our results suggest that some invasive species are yet to demonstrate their full potential as invaders. Overall, our study shows that species are labile in the face of environmental change. Identifying the long term trajectories of invasive species’ phenotypic change during invasion provides important clues for their appropriate management.

Habitat Preferences of Some Neophytes, with a Reference to Habitat Disturbances

The spread of species far from their native range is an important component of global changes. Investigating the ability of alien plants to invade different habitats is one of the most important approaches in the analysis of biological invasion mechanisms.The study was based on floristic research carried out in 1998–2002 in the north-western part of Poland. The habitats sampled were classified according to the EUNIS classification. A dataset of 2638 naturalized neophyte records was compiled based on a total of 2132 floristic lists. Species entries were supplemented with data on taxonomic position (family), origin, frequency, life form and number of habitats a particular species colonises. Ordination analyses showed the level of disturbance in individual habitats to be important in species-habitats relationships. Some of the species (e.g. Chamomilla suaveolens, Galinsoga parviflora, Veronica persica) occurred mainly in man-made, heavily disturbed habitats, while others (e.g. Impatiens parviflora, Padus serotina, Quercus rubra) were present primarily in natural habitats, less affected by humans. The species with the broadest habitat ranges identified included, i.a. Conyza canadensis, Impatiens parviflora, Epilobium ciliatum, and Oxalis fontana. Most of them, however, had different “core” habitats. Some species, e.g. Juncus tenuis, Elodea canadensis, Veronica persica were associated with one or a few habitats. The ability of species to invade numerous habitat types did not depend on their invasive status. The most successful aliens are those which spread dynamically along forest paths as well as those penetrating forest communities. The phytocoenotic role of each naturalized neophyte in plant communities requires a detailed study.Each individual habitat supports well-established alien species whose traits fit its characteristics and the disturbance intensity. Analysis of alien species traits, local distribution, habitat preferences and range makes it possible to reliably assess potentially successful invaders.

The Importance of some weeds for the survival of Fusarium oxysporum Schl. f.sp. lini (Boll.) Snyd.

The studies were caried out to determine the importance of some weeds occurrence in the flax monoculture the survival of <i>Fusarium oxysporum</i> f. sp. <i>lini</i>. It appearet that the roots of <i>Veronica persica, Stellaria media, Lamium purpureum, Capsella bursa-pastoris</i> and <i>Sonchus arvensis</i> were colonized by <i>Fusarium oxysporum</i> f. sp. <i>lini</i>. <i>V. persica</i> especially has, a profitable influence on the survival of <i>F. oxysporum</i> f. sp. <i>lini</i>. However. <i>C. hursa-pastoris</i> and <i>S. arvensis</i> stimulate the growth of fungi of the genera <i>Trichoderma</i>. which limites the occurrence of <i>F. oxysporum</i> f. sp. <i>lini</i> in the soil.

경기도 안산시 대송갯벌 습지에 분포하는 관속식물상

This study is carried out to offer the raw data for conservation and management of tidal flat ecosystem by surveying and analysing the flora distributed in Daesong tidal flat wetland, Ahnsan-si, Gyeonggi-do coast, Korea. The results of surveying the flora were recorded as 186 taxa including 45 families, 121 genera, 170 species, 14 varieties and 2 forms. The halophytes checked around this site were 20 taxa including Atriplex gmelinii, Salicornia europaea, Suaeda glauca, Suaeda japonica, Phragmites communis, Carex scabrifolia and so forth. Polygonum bellardii that species had ecological value was the specific plant by floristic region. The growth locations of halophytes were 11 taxa of upper, 4 taxa of high tide line and 5 taxa of lower. The naturalized plants were 42 taxa including Phytolacca americana, Chenopodium glaucum, Melilotus alba, Veronica persica, Bidens pilosa, Leptochloa fusca and so forth. Because Aster subulatusand Leptochloa fusca grew a upper tidal flat wetland, they had the characteristics of halophytes. The focuses on the management of Daesong wetland were halophytes and naturalized plants. Firstly, to maintain a halophytes communities, we will sow the halophytes seeds and plant the individuals. And In-Situ conservation was applied to Polygonum bellardii habitat. Secondly, to prevent the genesis of naturalized plant, we will don't disturb around the wetland environment. The invasive alien plant, Lactuca scariola, was removed by periodic monitoring and purification activity.

Population survey of phytoseiid mites and spider mites on peach leaves and wild plants in Japanese peach orchard

A population survey of phytoseiid mites and spider mites was conducted on peach leaves and wild plants in Japanese peach orchards having different pesticide practices. The phytoseiid mite species composition on peach leaves and wild plants, as estimated using quantitative sequencing, changed during the survey period. Moreover, it varied among study sites. The phytoseiid mite species compositions were similar between peach leaves and some wild plants, such as Veronica persica, Paederia foetida, Persicaria longiseta, and Oxalis corniculata with larger quantities of phytoseiid mites, especially after mid-summer. A PCR-based method to detect the ribosomal ITS sequences of Tetranychus kanzawai and Panonychus mori from phytoseiid mites was developed. Results showed that Euseius sojaensis (specialized pollen feeder/generalist predator) uses both spider mites as prey in the field.

Impact of Fertilizing Pattern on the Biodiversity of a Weed Community and Wheat Growth

Weeding and fertilization are important farming practices. Integrated weed management should protect or improve the biodiversity of farmland weed communities for a better ecological environment with not only increased crop yield, but also reduced use of herbicides. This study hypothesized that appropriate fertilization would benefit both crop growth and the biodiversity of farmland weed communities. To study the effects of different fertilizing patterns on the biodiversity of a farmland weed community and their adaptive mechanisms, indices of species diversity and responses of weed species and wheat were investigated in a 17-year field trial with a winter wheat-soybean rotation. This long term field trial includes six fertilizing treatments with different N, P and K application rates. The results indicated that wheat and the four prevalent weed species (Galium aparine, Vicia sativa, Veronica persica and Geranium carolinianum) showed different responses to fertilizer treatment in terms of density, plant height, shoot biomass, and nutrient accumulations. Each individual weed population exhibited its own adaptive mechanisms, such as increased internode length for growth advantages and increased light interception. The PK treatment had higher density, shoot biomass, Shannon-Wiener and Pielou Indices of weed community than N plus P fertilizer treatments. The N1/2PK treatment showed the same weed species number as the PK treatment. It also showed higher Shannon-Wiener and Pielou Indices of the weed community, although it had a lower wheat yield than the NPK treatment. The negative effects of the N1/2PK treatment on wheat yield could be balanced by the simultaneous positive effects on weed communities, which are intermediate in terms of the effects on wheat and weeds.

Weed infestation of spring barley (Hordeum vulgare L.) depending on the cover crop and weed control method

<p>The aim of this 3-year field study was to evaluate the effect of some stubble crops and weed control methods on the species composition, number and air-dry weight of weeds in a spring barley crop grown in short-term monoculture. The study was conducted in the period 2009–2011 at the Uhrusk Experimental Farm, on mixed rendzina soil classified as very good rye soil complex. It included stubble crops which were ploughed under in each year (control treatment without cover crop, white mustard, lacy phacelia, a mixture of legumes – narrow-leaf lupin + field pea) and 3 weed control methods used in spring barley crops (mechanical, mechanical and chemical, chemical weed control). <em>Veronica persica </em>was the weed species that occurred in greatest numbers in the spring barley crop sown after stubble crops. All cover crops reduced the numbers of <em>Avena fatua </em>which was the dominant species in the control treatment. Chemical as well as chemical and mechanical weed control significantly reduced the numbers of <em>Avena fatua</em> compared to the treatment where only double harrowing was used for weed control. The stubble crops did not reduce weed infestation of spring barley. Compared to the control treatment, the ploughing-in of white mustard and the mixture of legumes reduced the dry weight of weeds by 49.1 and 22.7%, respectively. Mechanical weed management proved to be less effective in reducing the number and dry weight of weeds compared to the other weed control methods. A significant negative correlation was found between the dry weight of weeds in the spring barley crop and the dry weight of the ploughed-in white mustard cover crop under the conditions of chemical weed control as well as in the case of the mixture of legumes when complete mechanical and chemical weed control was used.</p>

Effects of the penetration of Artemisia vulgaris L. into maize crops as a result of the use of reduced tillage

In recent years, a significant increase in weed infestation of agricultural crops with <em>Artemisia vulgaris </em>has been observed in the south-western region of Poland. The ease of migration of this expansive species results from the fact that it does not face competition from segetal weeds and therefore poses a great threat to the ecological balance. During the period 2008–2011, a floristic study was carried out using the Braun-Blanquet method in an abandoned field adjacent to a maize monoculture grown under two tillage systems: plough and ploughless tillage. These observations allowed an evaluation of the actual risk of spread of <em>Artemisia vulgaris </em>depending on tillage system. The vicinity of the abandoned field had a significant effect on the penetration of <em>Artemisia vulgaris </em>into maize crops. Higher numbers of individuals of this species were found under ploughless tillage compared to plough tillage, regardless of the distance from the field edge, and its increased competitive effects on <em>Viola arvensis </em>L. and <em>Veronica persica </em>L. could be observed. The lowest grain yield was obtained under ploughless tillage where the strong competitive effects of <em>Artemisia vulgaris </em>were observed even in the plot most distant from the abandoned field adjacent to the maize crop.

Promene u zastupljenosti i pokrovnosti invazivnih korovskih vrsta na području Pančevačkog rita tokom desetogodišnjeg perioda

The number of invasive species is increasing worldwide, and certain habitats, such as ruderal areas, are especially susceptible to invasion, highlighting the practical importance of ruderal flora and vegetation research. The aim of this research was to analyze ruderal flora of the Pančevački rit area, after a ten-year period, in order to ascertain the emergence of new and spread dynamics of already present invasive species. Field research was carried out in the area of Glogonjski rit, Padinska Skela and Kovilovo, followed by a comparison of the data gathered with the results of the previous research, done during the 1999-2002 period. The results confirmed the presence of potentially, sporadically and highly invasive plants in the area studied. The increase in the number of records was registered for the species: Amorpha fruticosa, Amaranthus retroflexus, Cuscutta sp., Echinocystis lobata and Veronica persica. The results have also shown changes in the cover of species A. fruticosa, A. retroflexus and Sorghum halepense. A presence of two so far, on this area, unregistered invasive species: Ailanthus altissima and Eleusine indica, was also confirmed.

Lamium amplexicaule (Lamiaceae): a weed reservoir for tomato yellow leaf curl virus (TYLCV) in Korea

After the first identification of tomato yellow leaf curl virus (TYLCV) in the southern part of Korea in 2008, TYLCV has rapidly spread to tomato farms in most regions of Korea. From 2008 to 2010, a survey of natural weed hosts that could be reservoirs of TYLCV was performed in major tomato production areas of Korea. About 530 samples were collected and identified as belonging to 25 species from 11 families. PCR and Southern hybridization were used to detect TYLCV in samples, and replicating forms of TYLCV DNA were detected in three species (Achyranthes bidentata, Lamium amplexicaule, and Veronica persica) by Southern hybridization. TYLCV transmission mediated by Bemisia tabaci from TYLCV-infected tomato plants to L. amplexicaule was confirmed, and TYLCV-infected L. amplexicaule showed symptoms such as yellowing, stunting, and leaf curling. TYLCV from infected L. amplexicaule was also transmitted to healthy tomato and L. amplexicaule plants by B. tabaci. The rate of infection of L. amplexicaule by TYLCV was similar to that of tomato. This report is the first to show that L. amplexicaule is a reservoir weed host for TYLCV.

Discriminating Crop, Weeds and Soil Surface with a Terrestrial LIDAR Sensor

In this study, the evaluation of the accuracy and performance of a light detection and ranging (LIDAR) sensor for vegetation using distance and reflection measurements aiming to detect and discriminate maize plants and weeds from soil surface was done. The study continues a previous work carried out in a maize field in Spain with a LIDAR sensor using exclusively one index, the height profile. The current system uses a combination of the two mentioned indexes. The experiment was carried out in a maize field at growth stage 12–14, at 16 different locations selected to represent the widest possible density of three weeds: Echinochloa crus-galli (L.) P.Beauv., Lamium purpureum L., Galium aparine L.and Veronica persica Poir.. A terrestrial LIDAR sensor was mounted on a tripod pointing to the inter-row area, with its horizontal axis and the field of view pointing vertically downwards to the ground, scanning a vertical plane with the potential presence of vegetation. Immediately after the LIDAR data acquisition (distances and reflection measurements), actual heights of plants were estimated using an appropriate methodology. For that purpose, digital images were taken of each sampled area. Data showed a high correlation between LIDAR measured height and actual plant heights (R2 = 0.75). Binary logistic regression between weed presence/absence and the sensor readings (LIDAR height and reflection values) was used to validate the accuracy of the sensor. This permitted the discrimination of vegetation from the ground with an accuracy of up to 95%. In addition, a Canonical Discrimination Analysis (CDA) was able to discriminate mostly between soil and vegetation and, to a far lesser extent, between crop and weeds. The studied methodology arises as a good system for weed detection, which in combination with other principles, such as vision-based technologies, could improve the efficiency and accuracy of herbicide spraying.

경상북도 경주시 금곡산에 분포하는 관속식물상

The purpose of this study is to collect the raw data for conservation of plant ecosystem by surveying and analysing the flora of Mt. Geumgok located in Gyeongju-si, Gyeongsangbuk-do, Korea. The flora were summarized as 453 taxa including 91 families, 298 genera, 397 species, 4 subspecies, 46 varieties and 6 forms. The rare plants designated by Korea Forest Service were 3 taxa such as Eranthis byunsanensis B.Y.Sun, Potentilla discolor Bunge and Iris odaesanensis Y.N.Lee. The Korean endemic plants were 6 taxa such as Carpinus laxiflora (Siebold & Zucc.) Blume, Eranthis byunsanensis B.Y.Sun, Philadelphus schrenkii Rupr., Lespedeza maritima Nakai, Vicia chosenensis Ohwi and Weigela subsessilis (Nakai) L.H.Bailey. The specific plants by floristic region were 36 taxa such as Pinus koraiensis Siebold & Zucc., Salix chaenomeloides Kimura, Anemone raddeana Regel, Chloranthus japonicus Siebold, Euphorbia pekinensis Rupr., Ilex macropoda Miq., Ajuga multiflora Bunge, Saussurea odontolepis Sch.Bip. ex Herd, Viola orientalis (Maxim.) W.Becker, Betula davurica Pall., Vitex negundo var. incisa (Lam.) C.B.Clarke and Cimicifuga heracleifolia Kom.. The naturalized plants were 36 taxa such as Fallopia dumetorum (L.) Holub, Lepidium apetalum Willd., Robinia pseudoacacia L., Trifolium repens L., Euphorbia supina Raf., Ipomoea purpurea Roth, Veronica persica Poir., Bidens pilosa L., Carduus crispus L., Xanthium canadense Mill., Bromus unioloides H.B.K. and Festuca arundinacea Schreb.. The invasive alien plants were 2 taxa such as Ambrosia artemisiifolia L. and Aster pilosus Willd.. The ratios of the urbanized index(UI), the naturalized index(NI) and the disturbed index(DI) were 11.2%, 7.9% and 18.2% each.

Effect of fertilization patterns on the assemblage of weed communities in an upland winter wheat field

Aims Understanding the response of farmland weed community assembly to fertilization is important for designing better nutrient management strategies in integrated farmland ecological systems. Many studies have focused on weed characteristics, mainly crop-weed competition responses to fertilization or weed communities alone. However, weed community assembly in association with crop growth is poorly understood in the agroecosystems, but is important for the determination of integrated weed management. Biodiversity promotes ecosystem productivity in the grassland, but whether it applies to the agroecosystems is unclear. Based on an 11-year field experiment, the cumulative effects of different fertilization patterns on the floristic composition and species diversity of farmland weed communities along with wheat growth in a winter wheat-soybean rotation were investigated. Methods The field trial included five fertilization patterns with different combinations of N, P and K fertilizers. Species composition and diversity of weed communities, aboveground plant biomass and nutrient accumulation of weeds and winter wheat, light penetration to the ground surface and wheat yield were measured at each plot in 2009 and 2010. Multivariate analysis, regression and analysis of variance were used to analyze the responses of these parameters to the different fertilization treatments. Important Findings Four dominant weeds (Galium aparine L., Veronica persica Poir., Vicia sativa L. and Geranium carolinianum L.) accounted for similar to 90% of the total weed density in the 2 years of experimental duration. The residual weed community assembly was influenced primarily by topsoil available nutrients in the order P > N > K. Competition for nutrients and solar radiation between crops and weeds was the main indirect effect of fertilization on the changes in weed community composition and species diversity. The indices of species diversity (species richness, Shannon-Wiener, Pielou and Simpson indices) showed significant linear relationships with wheat yield. The balanced fertilization treatment was more efficient at inhibiting the potential growth of weeds because of solar radiation being intercepted by wheat. These results support the conclusion that wheat yield is favored by balanced fertilization, whereas the weed community is favored by PK fertilization in terms of density and diversity. However, the negative effects on wheat yield may be compromised by simultaneous positive effects of weed communities in the fertilization treatments, for instance, the NP and NK treatments, which are intermediate in terms of increasing wheat production and to a level maintaining a diverse community.

The stubble-field plant communities in South-Eastern Poland. P. III. Plant communities of mountain agricultural utility complexes

In the Part I and II the stubble-field plant communities of lowlands agricultural utility complexes in South-Eastern Poland were introduced. The Part III contains a description of such communities occurring in mountain complexes. In the years 1972-1975, since August till September, 95 phytosociological records were taken on the area elevated from 300 to 650 m over the sea level, embracing the Carpathian Foreland and the Low Carpathian region. The research was conducted upon the typical, acid and leached brown soils, as well as on clay, dusty clay and silt alluvial soils belonging to three mountain complexes: wheat, cereal and oat-potatoes. The following communities were specified: I. <i>Setaria glauca</i> community, divided into two variants: 1) typical; 2) with <i>Aphanes arvensis</i>; II. <i>Veronica persica</i> community, divided into four variants: 1) with <i>Aphanes arvensis</i>, 2) typical, 3) with <i>Geranium dissectum</i>, 4) with <i>Aethusa cynapium</i>. The variant with <i>Geranium dissectum</i>, belonging to the community with <i>Veronica persica</i>, was considered as having the most mountain character.

The stuble-field plant communities in South-East Poland. Part V. The comparative characteristics of stuble-fleld plant communities

In this of the presented paper results of the studies conducted in preceding four parts (I-IV) were synthetically assumed. On that background a comparative characteristics of specified stuble-field plant communities was conducted. It contains the most important features of communities and seats, in which they appear. In climatically, geomorphologically, hydrologically and with respect to soils differentiated conditions of South-East Poland, especially in former Rzeszów region, there were described stubble-field plant communities occurring as well on lowland, as on highland agricultural utility complexes. There were analysed 359 phytosociological records, in which 232 ones came from lowland, while 127 from highland complexes. The specified communities were included to two orders: <i>Secali-Violetalia arvensis</i> (suborder <i>Polygono-Chenopodienalia</i> : alliances <i>Eu-Polygono-Chenopodion</i> and <i>Panico-Setarion</i>) and <i>Cyperetalia fusci</i> (alliance <i>Nanocyperion flavescentis</i>). On the lowland agricultural utility complexes specified were seven types of communities: 3 belonged to <i>Panico-Setarion</i> alliance (association <i>Digitarietum ischaemi</i>; community with <i>Setaria glauca</i> and association <i>Echinochloo-Setarietum</i>), 2 to <i>Eu-Polygono-Chenopodion</i> alliance (the community with <i>Euphorbia esula</i> and <i>Oxalis stricta</i> as well the community with <i>Veronica persica</i>), while 2 associations from the <i>Nanocyperion flavescentis</i> (<i>Hyperico-Spergularietum</i> and <i>Centunculo-Anthocerotetum</i>) alliance. On the other hand, on the highland complexes of South-East Poland only 3 communities were found: 1) with <i>Setaria glauca</i> included to <i>Panico-Setarion</i> alliance, 2) with <i>Veronica persica</i> from <i>Eu-Polygono-Chenopodion</i> alliance and 3) <i>Centunculo-Anthocerotetum</i> association from <i>Nanocyperion flavescentis</i> alliance. The specified floral types, as well as lower units (variants and sub variants), reflected the mechanical structure, hydrological conditions and pH soils in their seats, what confrumed a great differentiation of soil conditions on the tested area.

Weed infestation of field crops in different soils in the protective zone of Roztocze National Park. Part II. Root crops

The study on weed infestation of root crops in different soils in the protective zone of Roztocze National Park was conducted in the years 1991-1995. As many as 240 phytosociological records, made with the use of Braun-Blanquet method, were taken in potato and sugar beet fields. The number of weed species in sugar beet and potato in the area depended on the soil and type of root crop. In the same environment conditions. the iiuinber of weed species was higher in potato than in sugar beet. The most difficult weed species iii all types of soil were: <i>Chenopodium album, Stellaria media</i> and <i>Convolvulus arvensis</i>. Podsolic soils were highly infested by two acidophylic species: <i>Spergula arvensis</i> and <i>Raphanus raphanistum</i>. Potato in loess soil and brown soil made of loamy sands were highly infested by <i>Echinochloa crus-galli, Equisetum arvense</i> and <i>Galinsoga parviflora</i>. Root crop plantations in brown soils formed from gaizes of granulometric loam texture and limestone soils were infested by: <i>Galium aparine, Sonchus arvensis, Sinapis arvensis</i> and <i>Veronica persica</i>.

Weed infestation of winter wheat (Triticum aestivum L.) under the conditions of application of some retardants

<p>A field study was conducted in the period 2004–2007 on grey-brown podzolic soil (sandy). This study analysed the relationship between the use of stem shortening in cereals by means of retardants with the following active substances: chlormequat chloride (Antywylegacz Płynny 675 SL), trinexapac-ethyl (Moddus 250 EC), chlormequat chloride + ethephon (Cecefon 465 SL), and weed infestation. The retardants were applied at the 1st node stage (BBCH 31 – Antywylegacz Płynny 675 SL) and the 2nd node stage of winter wheat (BBCH 32 – Moddus 250 EC and Cecefon 465 SL), together with the adjuvant Atpolan 80 EC (75% of SN 200 mineral oil) or without the adjuvant. Winter wheat, cv. 'Muza', was grown after vetch grown for seed. The whole experiment was sprayed with the herbicides Apyros 75 WG and Starane 250 EC at the full tillering stage (BBCH 29–30). Plots where no growth regulators were used were the control treatment.</p><p>Weed density and biomass showed great variation between years. In the winter wheat crop, <em>Veronica persica, Viola arvensis, Veronica arvensis, Capsella bursa-pastoris</em>,and<em> Chenopodium album </em>dominated in the dicotyledonous class, whereas <em>Apera spica-venti</em>, <em>Echinochloa crus-galli</em>,and<em> Elymus repens </em>were predominant among monocotyledonous plants<em>. </em>The level of weed infestation of the winter wheat crop, as measured by the number and air-dry weight of weeds, was significantly differentiated by years and retardants used as well as by interactions of these factors. The adjuvant Atpolan 80 EC did not have a significant effect on the above-mentioned weed infestation parameters.</p>.

Present and potential weed infestation of spring cereals in different cropping system

This paper presents the results of investigations on the weed infestation and vertical distribution of weed seed bank in rendzina under spring cereals cultivation in crop rotations and monoculture. Used herbicides (MCPA and <i>fenoxaprop-P-etylu</i>) decreased the number of weeds and species composition in comparison with harrowing. In the soil layer of 0-25 cm used in the monoculture there was found about 22,9% weed seeds more than in crop rotation. In the canopy of spring cereals the following weeds dominated: in crop rotation - <i>Chenopodium album, Echinochloa crus-galli and Veronica persica; and in monoculture - Stellaria media, Galium aparine</i> and <i>Chenopodium album</i>. In the soil layer of 0-25 cm used in crop rotation and monoculture the following weed seeds dominated : <i>Amaranthus retroflexus, Chenopodium album</i> and <i>Stellaria media</i>.