Electronic Journal of Polish Agricultural Universities (EJPAU) founded by all Polish Agriculture Universities presents original papers and review articles relevant to all aspects of agricultural sciences. It is target for persons working both in science and industry,regulatory agencies or teaching in agricultural sector. Covered by IFIS Publishing (Food Science and Technology Abstracts), ELSEVIER Science - Food Science and Technology Program, CAS USA (Chemical Abstracts), CABI Publishing UK and ALPSP (Association of Learned and Professional Society Publisher - full membership). Presented in the Master List of Thomson ISI.
2017
Volume 20
Issue 4
Topic:
Agronomy
ELECTRONIC
JOURNAL OF
POLISH
AGRICULTURAL
UNIVERSITIES
Gołębiowska H. , Kieloch R. , Topolski J. 2017. INHIBITORY EFFECT OF AQUEOUS EXTRACTS FROM REED CANARY GRASS (PHALARIS ARUNDINACEA L.) ON THE DEVELOPMENT OF SELECTED WEED SPECIES, EJPAU 20(4), #06.
Available Online: http://www.ejpau.media.pl/volume20/issue4/art-06.html

INHIBITORY EFFECT OF AQUEOUS EXTRACTS FROM REED CANARY GRASS (PHALARIS ARUNDINACEA L.) ON THE DEVELOPMENT OF SELECTED WEED SPECIES

Hanna Gołębiowska, Renata Kieloch, Jakub Topolski
Institute of Soil Science and Plant Cultivation, National Research Institute in Puławy, Department of Weed Science and Tillage Systems, Poland

 

ABSTRACT

The reed canary grass (Phalaris arundinacea L.) features high content of bioactive compounds from the group of alkaloids with allelopathic activity. Habitat factors and the harvest time determine the synthesis of chemical compounds required for plant survival in adverse conditions. The aim of the research was to reveal the inhibitory effect of extracts from the reed canary grass on some weed species. The biotypes of the reed canary grass originated from two floristically different habitats. The material was collected in two periods: in spring and in late autumn before the winter dormancy. In each period, aboveground parts and runners of each biotype were collected as raw material for preparation of the extracts. Several series of the tests showed strong inhibitory activity towards Amaranthus retroflexus L., Papaver rhoeas L.,and Stellaria media (L.) Vill of the extract prepared from the runners collected on the bank of a midfield watercourse in Pisarzowice. The strongest inhibitory effect was exhibited by the extracts from runners collected before the winter dormancy period. Extracts derived from both aboveground parts and runners collected from the habitat in Jarnołtów had a considerably weaker phytotoxic and inhibitory effect regardless of the harvest date.

Key words: Phalaris arundinacea L., biotype, bioactive extracts, fresh weight reduction.

INTRODUCTION

The reed canary grass (Phalaris arundinacea L.) is a perennial grass with high allelopathic potential ensured by bioactive chemical compounds accumulated primarily in mature organs – leaves or runners at varied levels associated with the growing habitat [1, 2, 8].

As indicated in numerous literature reports, wild-growing plants in natural habitats are capable of synthesis of bioactive compounds in amounts that are only necessary for plant survival; these include phenolic compounds, flavonoids, alkaloids, or glycosides, which are mainly stimulated by light intensity, temperature, and hydration [4, 21]. In turn, in synanthropic habitats affected by human activity, they are additionally exposed to accumulation of heavy metals derived from fertilisers and plant protection agents, and their metabolism changes towards intensive production of nitrogen compounds, e.g. free amino acids, proteins, or alkaloids [21]. The level of secondary metabolites in plant material may also contribute to their increasing expansiveness towards other plant species and an effect on their germination performance, morphology, or quality [33].

The previous studies indicate that habitat conditions exert strong influence on life cycles, the terms of germination, growth stages duration and also nutrients accumulation. The authors of these researches point out greater concentration of bioactive substances and enzymatic activity of plant materials collected from natural environments [10, 18, 22]. The knowledge of these processes is useful in phytoterapy and ecological agriculture to obtain the most valuable product [6].

The reed canary grass is a typical hydrophyte, which easily tolerates long-term waterlogging but is also resistant to drought, frost, and shading. In general, Phalaris arundinacea L. occurs on humus soils with neutral pH, but it also appears on acidic soils, in the neighbourhood of cereal crops, close to watercourses. Under such conditions, in upper layer of the soil, there is a large number of crop residues and uptake and accumulations of heavy metals from fertilizers and pesticides is easier that affects bioactivity and allelopathic activity of this species  [5, 17, 24, 25]. In such conditions, this species but Phalaris arundinacea L. are highly competitive to plants or microorganisms living in the community, which may pose a considerable threat to the ecological balance [18, 20].

It has not yet been determined whether the expansiveness of the species depends on the living habitat or is related to the inhibitory effect of specific metabolic substances modified by weather conditions on other species present in the community.

It is assumed that the reed canary grass plants may contain chemical compounds that exert an inhibitory effect on some species accompanying this grass in the community. They content of the chemical substances may vary depending on the habitat, which may indicate its expansive nature.

The aim of the study was to demonstrate the different effects of aqueous extracts from aboveground parts and runners of the reed canary grass (Phalaris arundinacea L.) on selected  species of weeds depending on the locality and the time of harvest.

MATERIAL AND METHODS

The investigations were conducted in 2010–2012 in the Department of Weed Science and Tillage Systems in Wrocław, a branch of the Institute of Soil Science and Plant Cultivation, National Research Institute in Puławy. The plant material was collected in two localities with different habitat conditions. One of them – Jarnołtów is a natural habitat of the reed canary grass on a wet meadow near the Bystrzyca River. The other locality in Pisarzowice located on muddy banks of a midfield watercourse comprised mainly a Phalaris arundinacea rush community in a synanthropic habitat subjected to periodic cleaning and management. Dominance of the reed canary grass in the sward was observed on muddy soils in the former locality and on alluvial soils distributed in parallel to the riverbed or the watercourse in the latter locality.

In both localities, the plant material was collected by hand in two terms: in spring – at the beginning of the vegetation season and in late autumn before the winter dormancy period. Aboveground parts and runners of each biotype were collected as raw material for preparation of aqueous extracts. The inhibitory activity of the aqueous extracts was shown based on three series of biological assays performed in a vegetation room using several weed species: Geranium pusillum L., Amaranthus retroflexus L., Papaver rhoeas L., Viola arvensis Murray,and Stellaria media (L.) Vill. The selection of weed species for this study was due to their high harmfulness for cereal crops.

The pH of the soil was determined with the potentiometric method. Nitrogen in the plant material was assessed with a modified Kjeldahl method. Available phosphorus and potassium in the soils were determined with the Egner Riehm method; the level of phosphorus was measured with the spectrophotometric method, potassium with atomic emission spectrometry, and magnesium with atomic spectrometry. The granulometric composition of the soil was determined using a laser method and the content of C org. with the Tiurin method.

The experiments based on the aqueous extracts were carried out in the conditions of a controlled level of soil moisture, air, and temperature. The seeds of the weeds were sown in pots with a volume of 5 dcm3 and a size of 4 cm × 4 cm. The pots were filled with a mixture of peat and sand in the volume ratio 2:1. The experiments were conducted in three replicates in the following conditions: day length – 14 h, night length – 10 h, temperature 21°C, and light radiation 250 µmol·m-2s-1. Seeds of weeds were sown in the number of 20 pcs. per pot. After seed germination, the plants were thinned to leave 9 plants per pot. Aqueous extracts were prepared from dried and milled plant material and runners (Phalaris arundinacea L.) at a ratio of 1:10, i.e. 1000 ml of distilled water were added to 100 g of dry weight. After 24 h, the solution was filtered to obtain a clear extract, which was used for spraying 7–8 leaved weeds in the “Aporo” greenhouse spray chamber equipped with a mobile head with a TeeJet XR 11003 – VS nozzle, ensuring constant working pressure of 0,25 MPa  and spraying fluid consumption at the level of 250 l·ha-1. 

The evaluation of the phytotoxicity of the analysed extracts were carried out six times at 4-day intervals with the use of a 9-degree scale to assess the plants in terms of ig – growth inhibition, ch – leaf chlorosis, de – deformation. After that period, the fresh weigh of the aboveground parts of the weeds was determined for each pot. The weeds were cut directly above the soil surface and weighed. The response of the weeds to the action of the analysed agents was determined on the basis of differences in the fresh weigh of weeds from the treated pots and the untreated control. Statistical analysis was carried out with the method of analysis of variance in a completely randomised design for the pot experiments by comparison of the impact of the aqueous extracts from the runners and plant material on reduction of the fresh weight of the selected weeds. The significance of differences was tested with the Tukey confidence interval at a significance level α = 0.05.

RESULTS

The analysis of the soil in the sward layer revealed a neutral pH 6.87 in Pisarzowice and a slightly acidic pH 5.1 in Jarnołtów. The content of organic substances differed between the localities and reached 1.52% in Pisarzowice and 2.06% in Jarnołtów. Both soils were characterised by a moderate and low level of potassium – 18.3 and 7.9 mg K2O·100 g-1, a very high and moderate content of phosphorus – 14.64 and 26.69 mg P2O5·100 g-1, and a moderate and high level of magnesium 7.3 and 4.1 mg Mg·100 g-1 (Tab. 1). In turn, the plant material exhibited a similar level of microelements.

Table 1. Soil conditions in the examined Phalaris arundinacea L. habitats
Soil properties
Jarnołtów
Pisarzowice
fraction >0.02 mm
26.67%
34.61%
pH 1M KCl
5.10
6.87
organic matter content [%]
1.52 (humus-poor soil)
2.06 (humus-rich soil)
nutrient content [mg/100 g soil]
P2O5
14.64 (a)
26.69 (vh)
K2O
7.9 (l)
18.3 (a)
Mg
4.1 (a)
7.3 (h)
Macroelement content:
vh – very high, h – high, a – average, l – low according to IUNG recommendations [11]

The weather conditions prevailing during the investigations were similar to the multiyear average. It was found that the annual precipitation sum was 489 mm, the average air temperature was 8.3ºC, the number of days with snow cover was 38.9, and there were periodic water deficits in summer. Only in July 2012, there were torrential rainfalls, which lead to flooding in both villages. In the phytocoenosis on the muddy soils, the reed canary grass was accompanied by a small admixture of stinging nettle (Urtica dioica L.), spotted deadnettle (Lamium maculatum L.), cocksfoot (Dactylis glomerata L.), and sporadically Geranium pusillum Burm. f. ex L., Amaranthus retroflexus L., Papaver rhoeas L., Viola arvensis Murray, and Stellaria media (L.) Vill. In the other locality P. arundinacea was much more abundant and it was accompanied by Bromus hordeaceous L., Lolium perenne L., Urtica dioica L., Dactylis glomerata  L.

The investigations showed that the aqueous extracts from the Phalaris arundinacea L. plant material and runners originating from Pisarzowice exerted a stronger inhibitory effect on the selected weed species than that noted for the plant material from the other locality. Severe signs of growth inhibition and plant deformation as well as a high degree of statistically significant reduction of dry weight were induced in Amaranthus retroflexus L. by both extracts obtained in this locality, particularly in the autumn period. In the case of Stellaria media L., potent inhibitory activity, leading to plant growth inhibition, leaf chlorosis, and statistically significant loss of fresh weight, was reported after the application of the runner extract; it was higher in the autumn period (Tab. 2, 3).

Table 2. Response of Amaranthus retroflexus L. on aqueous extracts of Pharlaris arundinacea L. depending on the time and place of gathering, and part of this grass species
Treatment
Time of gathering
Spring
Autumn
Susceptibility#
Fresh weight
[g]*
Difference
[%]
Susceptibility#
Fresh weight
[g]*
Difference
[%]
Control
1
12.02
100
1
10.30
100
Shoot extract
Pisarzowice
5 ig, de
7.40
-38.4
7 ig, ch, de
6.15
-40.3
Jarnołtów
1
12.43
+3.4
1
10.66
+3.5
Runners extract
Pisarzowice
7 ig, ch, de
5.90
-50.9
8 ig, ch, de
2.89
-71.9
Jarnołtów
1
12.11
+0.8
1
10.89
+5.7
Mean for extracts
9.46
-21.3
Means for extracts
8.18
-25.7
LSD(0.05)
2.55
2.58
# in 1:9 scale 1 – no symptoms, 9 – total plant damage; * per pot
ch – chlorosis and leaf decoloration, de – deformation, ig – inhibition of growth

Table 3. Influence of aqueous extractsof Pharlaris arundinacea L. on reducing fresh weight of Stelaria media (L.) Vill depending on the time of harvest
Treatment
The time of harvest
Spring
Autumn
Susceptibility#
Fresh weight
[g]*
Difference
[%]
Susceptibility#
Fresh weight
[g]*
Difference
[%]
Untreated
1
12.80
100
1
11.20
100
Shoot extract
Pisarzowice
2 ig
9.30
-27.4
4 ig
7.30
-34.9
Jarnołtów
1–2 ig
11.00
-14.1
1-2 ig
10.70
-4.5
Runners extract
Pisarzowice
4 ig, de
5.90
-53.9
6 ig, ch, de
4.20
-62.5
Jarnołtów
1–2 ig
10.90
-14.9
2 ig
10.20
-8.9
Means for extract
9.98
-22.1
Means for extracts
8.72
-22.2
LSD (0.05)
3.42
3.06
# in 1:9 scale 1 – no symptoms, 9 – total plant damage; * per pot
ch – chlorosis and leaf decoloration, de – deformation, ig – inhibition of growth

Papaver rhoeas L. exhibited growth inhibition and reduction of fresh weight after application of both extracts prepared from plants harvested in autumn. Additionally, leaf decoloration and slight plant deformations were recorded for plants treated with extracts obtained from runners. The application of the aqueous extract from the plant material sampled in autumn resulted in reduction of fresh weight of the weeds by 40.3% in Amaranthus retroflexus L.,34.9% in Stelaria media L., and 21.8% in Papaver rhoeas L. In turn, the use of the aqueous extract prepared from the runners collected in the same period led to reduction of fresh plant weight by 71.05% in Amaranthus retroflexus L.,62.5% in Stellaria media (L.) Vill, and 41.8% in Papaver rhoeas L, compared with the control. Geranium pusillum L.and Viola arvensis Murray tolerated spraying with the extracts and did not exhibit permanent damage or fresh weight loss, regardless of the origin of the plant material (Tab. 2–6).

Table 4. Influence of aqueous extracts of Pharlaris arundinacea L. on reducing fresh weight of Viola arvensis Murray depending on the time of harvest
Treatment
The time of harvest
Spring
Autumn
Susceptibility#
Fresh weight
[g]*
Difference
[%]
Susceptibility#
Fresh weight
[g]*
Difference
[%]
Untreated
1
13.40
100
1
14.02
100
Shoot extract
Pisarzowice
1
13.32
-0.6
2 ig
13.89
-0.9
Jarnołtów
1
13.35
-0.4
1-2 ig
13.95
-0.5
Runners extract
Pisarzowice
2 ig
13.15
-1.9
2 ig
13.67
-2.5
Jarnołtów
1–2 ig
13.28
-0.9
1-2 ig
13.89
-0.9
Means for extract
13.28
-0.9
Means for extracts
13.85
-1.3
LSD (0.05)
ns
ns
ns – not significant differences; *per pot
# in 1:9 scale 1 – no symptoms, 9 – total plant damage
ch – chlorosis and leaf decoloration, de – deformation, ig – inhibition of growth

Table 5. Influence of aqueous extractsof Pharlaris arundinacea L. on reducing fresh weight of Papaver rhoeas L. depending on the time of harvest
Treatment
The time of harvest
Spring
Autumn
Susceptibility#
Fresh weight
[g]*
Difference
[%]
Susceptibility#
Fresh weight
[g]*
Difference
[%]
Untreated
1
12.70
100
1
11.90
100
Shoot extract
Pisarzowice
1
12.66
-0.3
4 ig
9.30
-21.8
Jarnołtów
1
12.69
-0.1
1-2 ig
10.70
-10.1
Runners extract
Pisarzowice
2 ig
12.56
-1.1
6 ig, ch, de
6.20
-41.8
Jarnołtów
1–2 ig
12.65
-0.4
2 ig
10.20
-14.3
Means for extract
12.64
-0.5
Means for extracts
9.10
-25.6
LSD (0.05)
ns
2.77
ns – not significant differences; * per pot
# in 1:9 scale 1 – no symptoms, 9 – total plant damage
ch – chlorosis and leaf decoloration, de – deformation, ig – inhibition of growth

Table 6. Influence of aqueous extractsof Pharlaris arundinacea L. on reducing fresh weight of Geranium pusillum L. depending on the time of harvest
Treatment
The time of harvest
Spring
Autumn
Susceptibility#
Fresh
weight
[g]*
Difference
[%]
Susceptibility#
Fresh
weight
[g]*
Difference
[%]
Untreated
1
13.90
100
1
14.33
100
Shoot extract
Pisarzowice
2 ig
13.80
-0.7
2 ig
14.17
-1.1
Jarnołtów
1
13.95
+0.4
1-2 ig
14.28
-0.3
Runners extract
Pisarzowice
2 ig
13.69
-1.5
2 ig
14.11
-1.5
Jarnołtów
1
13.80
-0.7
1-2 ig
14.27
-0.4
Means for extract
13.81
-0.7
Means for extracts
14.21
-0.8
LSD (0.05)
ns
ns
ns – not significant differences; * per pot
# in 1:9 scale 1 – no symptoms, 9 – total plant damage
ch – chlorosis and leaf decoloration, de – deformation, ig – inhibition of growth

DISCUSSION

Interspecific interactions in biocoenosis can have both an inhibitory and stimulating impact among not only plants but also other microorganisms [16]. Numerous literature reports show that the adverse influence of wild-growing invasive plants not only may be associated with competition for light, water, and minerals but also may result from secretion of chemical compounds with high phytotoxic potential into the soil environment, which cause growth inhibition or delay the development of other species [14]. Active secondary metabolites in plants and microorganisms are the prime source of natural chemical substances with toxic properties [15, 26, 31].

The reed canary grass is a highly competitive grass, which easily adapts to various soil conditions thanks to the deep, well-developed root system producing many long underground runners [30]. This allows it to tolerate periodic waterlogging, droughts, and slightly acidic to alkaline pH [17]. The plant material analysed in the presented investigations originated from localities that differed in terms of soil conditions. Stronger inhibitory effect on the development of Amaranthus retroflexus L. and Stellaria media (L.) Vill was exerted by the aqueous extract from runners obtained from the locality with a neutral reaction dominated by the reed canary grass rush. Literature data reveal that most wild-growing plants prefer soils with neutral or alkaline pH. An acidic environment has an indirect negative impact on soil structure and water absorption resulting in underdevelopment of root systems and lack of soil organisms, which may lead to differences in the contents of active substances in plants [22]. Golińska and Kozłowski report that the harvest time has an effect on the presence of nutrients in Phalaris arundinacea L., as lower contents thereof were detected in plant material collected in spring [17]. In the presented investigations, the aqueous extracts from the plant material and runners collected in autumn had a stronger inhibitory effect on the selected weed species, which may suggest a higher concentration of the specific chemical substances (tryptamine alkaloids, indole alkaloids, phalarine, gramine, cyanogenic glycosides) in the Phalaris arundinacea L. [3, 7, 8].

The greatest inhibitory effect on the growth of segetal weeds was observed for the extracts obtained from underground parts of plants localized in the neighbourhood of arable field (Pisarzowice). The extract obtained from plant material collected in the autumn showed stronger activity in biomass reduction of A. retroflexus and S. media than the extract gained from plants harvested in the spring. It derived from greater concentration of specific chemical compounds, i.e. tryptamine alcaloids, indolo alcaloids, phalarines, gramine, cyanogenic glycosides that were recorded in P. arundinacea [1, 3, 6–8, 25, 26]. Two studies concerning the direct use of plants with allelopathic potential were focused on the possibility of deriving alleloherbicides, natural biological agents with potential phytotoxic activity provided by chemical substances isolated from plants [13, 31]. 

Given the resistance of some agrophages to chemical plant protection agents, there is a need to search for new bioactive compounds that could improve their herbicidal activity as an alternative or complement to synthetic pesticides [11, 12]. Bioactive compounds can be used as components of bioherbicides where herbicides should not be applied, e.g. in parks, on lawns, in gardens, or where they are ineffective, i.e. in the case of resistant and invasive weeds as well as weeds that are closely related with crops or those that require high doses of  herbicides [26, 28, 31, 32].

The use of bioactive chemical compounds derived from wild-growing species can also meet the requirements of the law of integrated production based on sustainable technical and biological progress. The consequence of this law is the Regulation of the European Parliament (Directive 2009/128/EC and Regulation No. 1107/2009) for Community action to achieve a sustainable use of pesticides [9, 29].

CONCLUSION

In the investigations, the aqueous extracts derived from the Phalaris arundinacea L. plant material and runners collected in Pisarzowice exerted a stronger inhibitory effect on the selected weed species than the effect of the extracts from plants growing in Jarnołtów. In response to the application of the aqueous extracts from both the plant material and runners, Amaranthus retroflexus L. exhibited severe damage, including growth inhibition, plant deformations, and chlorosis. The same symptoms were also observed for Papaver rhoeas L. and Stelaria media (L.) Vill treated with the extract obtained for runners only. Stronger inhibitory activity was shown by the extract of runners collected in autumn, which reduced fresh weight by 71.05% in Amaranthus retroflexus L.,62.5% in Stelaria media (L.) Vill, and 41.8% in Papaver rhoeas L., compared with the untreated control. Geranium pusillum L.and Viola arvensis Murray tolerated treatment with the extracts and did not exhibit permanent damage or fresh weight loss, regardless of the origin of the plant material.

REFERENCES

  1. Adams A.A., Raman A., Nicol H.I., 2010. Assessment of allelophatic effects of Phalaris aquatica on Chloris truncate, Trifolium subterraneum, Medicago trunculata, and P. aquatica. J. Appl. Bot. Food Qual., 83, 163–169.
  2. Anderton N., Cockrum P. A., Colegate S. M., Edgar J. A., Flower K., Gardner D., Willing  R. I., 1999. (-)-Phalarine, a furanobisindole alkaloid from Phalaris coerulescens. Phytochemistry, 51, 153–157.
  3. Anderton N., Cockrum P.A., Walker D.W., Edgar J.A., 1994. In S. M. Colegate, & P. R. Dorling (EDS.), Plant-associated toxins: agricultural, phytochemical and ecological aspects (p. 269). Wall-ingrofd: CAB International.
  4. Asami D.K., Hong Y.J., Barrett D.M., Mitchell A.E., 2003. Comparison of the total phenolic and ascorbic acid content of freeze-dried and air-dried marionberry, strawberry, and corn grown using conventional, organic, and sustainable agricultural practices. J. Agric. Food Chem., 51, 1237–1241.
  5. Bhowmik P.C., Inderjit, 2003. Challenges and opportunities in implementing allelopathy for natural weed management. Crop Prot., 22, 661–671.
  6. Brandt K., Mølgaard J.P., 2001. Organic agriculture: does it enhance or reduce the nutritional value of plants foods? J. Sci. Food Agr., 18, 924–931.
  7. Corcuera L.J., 1989. Indole alkaloids from Phalaris and other Gramineae [in:] Cheeke, P.R. (ed.),Toxicants of plant origin, the alkaloids, Vol. L,: 169–177.
  8. Culvenor C.C.J., Dal Bon R., Smith W.L., 1964. The occurrence of indolealkiloamine alkaloids in Phalaris tuberosa L. and P. arundinacea L. Austr. J. Chem., 17, 1301–1304. 
  9. Directive 2009/128/EC of The European Parliament and of The Council of 21 October 2009 establishing a framework for Community action to achieve the sustainable use of pesticides. http://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32009L0128&rid=1
  10. Duer I., Feledyn-Szewczyk B., 2003. Skład gatunkowy i biomasa chwastów występujących w pszenicy ozimej uprawianej w różnych systemach produkcji oraz ich udział w pobieraniu składników mineralnych z gleby. Pam. Puł.,  134, 65–77 [in Polish].
  11. Duke S.O., Baerson S.R., Dayan F.E., Rimando A.M., Scheffler B.E., Tellez M.R., Wedge D.E., Schrader K.K, Akey D.H, Arthur F.H, De Lucca A.J., Gibson D.M, Harrison Jr H.F., Peterson J.K., Gealy D.R., Tworkoski T., Wilson C.L., Morris J.B., 2003. United States Department of Agriculture-Agricultural Research Service research on natural products for pest management. Pest. Manag. Sci., 59, 708–717.
  12. Duke S.O., Dayan F.E, Rimando A.M., Schrader K.K., Aliotta G., Oliva A., 2002. Chemicals from nature for weed management. Weed Sci., 50, 138–151.
  13. Duke, S.O., Copping L.G., 2007. Review natural products that have been used commercially as crop protection agents. Pest. Manag. Sci., 63, 524–654.
  14. Gniazdowska A., 2005. Oddziaływania allelopatyczne – “nowa broń” roślin inwazyjnych [Allelopathic interaction – a “Novel Weapon” of alien invasive plant species]. Problemy Nauk Biologicznych. Kosmos, t. 54, nr 2–3 (267–268), 221–226 [in Polish].
  15. Gniazdowska A., 2007. Biotechnology – a chance for using allelopathy as alternative weed management strategy. Biotechnologia,  2(77), 42–53.
  16. Gniazdowska A., Oracz K., Bogatek R., 2004. Allelopatia – nowe interpretacje oddziaływań pomiędzy roślinami [Allelopathy – new interpretations of plant – plant interactions]. Kosmos, 53, 2, 207–217 [in Polish].
  17. Golińska B., Kozłowski S., 2006. Variation in the occurrence of organic and mineral compounds in Phalaris arundinacea. Annales UMCS, Sec. E, 61, 353–360 [in Polish].
  18. Hochół T. 2003. Chwasty czy rośliny towarzyszące uprawom? Pam. Puł.,  134, 89–95.
  19. Holst N., Rasmussen I.A., Bastiaans L., 2007. Field weed population dynamics: a review of model approaches and applications. Weed Res., 47, 1–14.
  20. Janzen D.H., 1978. The ecology and evolutionary biology of seed chemistry as relates to seed predation. Biochemical aspects of plant and animal coevolution [in:] Harborne, J. B. (ed.), 163–206.
  21. Kaczmarek S., 2009. Wykorzystanie potencjału allelopatycznego roślin w wybranych uprawach rolniczych [Using of the allelochemical potential in selected agricultural crops]. Prog. Plant Prot./Post. Ochr. Roślin, 49, 1502–1511 [in Polish].
  22. Kazimierczak R., Hallmann E., Ardasińska B., Łoś B., Rembiałkowska E., 2012. Wpływ ekologicznego i konwencjonalnego systemu uprawy na zawartość związków fenolowych w roślinach zielarskich [The impact of organic and conventional crop production systems on phenolic compounds content in medicinal plants]. J. Res. Appl. Agric. Eng., 57(3), 198–203 [in Polish].
  23. Kazimierczak R., Hallmann E., Zduńska U., Rembiałkowska E., 2011c. Zawartość wybranych związków bioaktywnych w ziołach przyprawowych pochodzących z produkcji ekologicznej i konwencjonalnej. Zeszyty Naukowe UEP w Poznaniu, 90–99.
  24. Łuczka-Bakuła W., 2007. Rynek żywności ekologicznej. PWE, Warszawa.
  25. Marten G.C. 1985. Reed canarygrass [in:] Heath M.E., Barnes R.F., Metcalfe D.S. (Eds.), Forages. Iowa State University Press, Ames, 207–216.
  26. Müller-Schärer H., Scheepens P.C., Greaves M.P., 2000. Biological control of weeds in European crops: recent achievements and future work. Weed Res., 40, 83–98.
  27. Piskorz B., 2000. Allelopatyczne oddziaływanie wyciągów wodnych z rozłogów perzu właściwego (Agropyron repens L.) na kiełkowanie i początkowy wzrost wybranych roślin uprawnych. Mat. Konf. nt. "Biochemiczne interakcje w oddziaływaniach środowiskowych”. IUNG Puławy, 89–90.
  28. Praczyk T., Skrzypczak G., 2001. Stan aktualny i kierunki rozwoju herbologii [The current state and directions of weed science development]. Prog. Plant Prot./Post. Ochr. Roślin, 51, 354–363 [in Polish].
  29. Regulation (EC) No. 1107/2009. Report from the commission to The European Parliament and The Council on the establishment of a European fund for minor uses in the field of plant protection products. http://eur-lex.europa.eu/legal-content/EN/TXT/?qid=1467625528743&uri=CELEX:52014DC0082
  30. Sekutowski T., Bortniak M., 2009. Wykorzystanie mikrobiotestu Phytotoxkit™ w wykrywaniu potencjału allelopatycznego mozgi trzcinowatej (Phalaris arundinacea) [Usage of microbiotest phytotoxkit in detecting of allelopathic pothential of phalaris arundinacea]. J. Res. Appl. Agric. Eng., 54(4), 88–93 [in Polish].
  31. Stokłosa A., 2006. Bioherbicydy i alleloherbicydy w walce z chwastami [Bioherbicides and alleloherbicides as weed control methods]. Post. Nauk Rol., 6, 41–52 [in Polish].
  32. Yang X., Scheffer B.E., Weston L.A., 2004. SOR1, a gene assocciated with bioherbicide production in sorghum root hairs. J. Exp. Bot., 55(406), 2251–2259.
  33. Young J.E., Zhao X., Carey E.E., Welti R., Yang S-S., Wang W., 2005. Phytochemical phenolics in organically grown vegetables. Mol. Nutr. Food Res., 49, 1136–1142.

Accepted for print: 23.11.2017


Hanna Gołębiowska
Institute of Soil Science and Plant Cultivation, National Research Institute in Puławy, Department of Weed Science and Tillage Systems, Poland
phone: +48 71 363 8707
Orzechowa 61
50-540 Wrocław
Poland
email: h.golebiowska@iung.wroclaw.pl

Renata Kieloch
Institute of Soil Science and Plant Cultivation, National Research Institute in Puławy, Department of Weed Science and Tillage Systems, Poland
phone: +48 71 363 8707
Orzechowa 61
50-540 Wrocław
Poland
email: r.kieloch@iung.wroclaw.pl

Jakub Topolski
Institute of Soil Science and Plant Cultivation, National Research Institute in Puławy, Department of Weed Science and Tillage Systems, Poland
phone: +48 71 363 8707
Orzechowa 61
50-540 Wrocław
Poland
email: j.topolski@iung.wroclaw.pl

Responses to this article, comments are invited and should be submitted within three months of the publication of the article. If accepted for publication, they will be published in the chapter headed 'Discussions' and hyperlinked to the article.