nobilis L.) and Its Main Components on the Germination of Some Weed and Crop Species

Transcription

1 Inhibitory Effects of Laurel (Laurus nobilis L.) and Its Main Components on the Germination of Some Weed and Crop Species R. CETINTS, N. TURSUN,.. ISIKER,. KRCİ M. H. LM, and M. SEYİTHNO THNOĞLU Faculty of griculture, Department of Plant Protection, Kahramanmaraş Sütçü Imam University, Kahramanmaraş TURKEY

2 Outline: Introduction Objectives Materials and methods Results Conclusion

3 PROLEMS IN CONVENTIONL Consumer safety HERICIDES Spectrum of activity (non-target effects) Induction of secondary weeds Resistance

4 IO-HERICIDE S POSSILE LTERNTIVE CONVENTIONL HERICIDES Recently, there has been growing interest in research concerning the possible use of plant extracts as an alternative to synthetic herbicides (Dudai et al., 1993; Dudai et al., 1999; Singh et al., 2002a). Plant extracts, volatile oils, oleoresins are the among semichemicals that has been used for weed control. These chemicals show fumigant and contact effects on weeds. Since weeds develop the resistance against herbicides, there has been growing needs for new herbicides with different way of efficacy (Woodward and Lampkin,, 1990; ond and Grudy, 2001; Singh et al., 2002).

5 WHY ESSENTIL OILS CONSIDERED S IO-HERICIDE? Essential oils, among the constituents of aromatic plants, are being explored for the discovery of new herbicides since they do not persist in soil or contaminate ground water and cause almost no mammalian toxicity (Isman, 2000; Singh et al., 2005). Furthermore, essential oils are also responsible for imparting allelopathic properties to the donor plant (Fischer et al., 1994; Vokou, 1999). There has been studies indicating that essential oils can be used as viable weed control technology under organic farming systems (Tworkoski, 2002).

6 EFFECTS OF ESSENTIL OILS ND THEIR COMPONENTS ON WEEDS Terpenoids, particularly monoterpenes and sesquiterpenes, are the main components of essential oils and are often responsible for their inhibitory activity. mong the Lamiaceae family many species release phytotoxic monoterpenes that hinder the development of herbaceous species (Muller, 1966; lsaadawi et al., 1985) among which the common ones are α- and β-pinene, camphene, limonene, α-phellandrene, ρ-cymene, 1,8- cineole, borneol, pulegone and camphor (Fisher, 1986).

7 OJECTIVES OF THE STUDY: to identify chemical compositions of laurel essential oil, to evaluate in vitro the allelopathic activity of laurel essential oil and some of its main compounds in vapor phase on the germination of some weed and crop species, to discuss their possible use as bio-herbicide for future weed management.

8 MTERILS ND METHODS The treatments were used for four weeds and three crop species: Mature seeds of the weeds maranth (maranthus retroflexus), wild licorice (Glycyrrhiza glabra L.), curled dock (Rumex crispus L.) and cutleaf ground-cherry (Physalis angulata L.) were collected from parent plants in Karamanmaras region in Turkey. Certified seeds with recommended germination and purity caracteristics of cotton (Gossypium hirsitum L.), wheat (Triticum aestivum L.), and corn (Zea mays L. ) were used kindly provided by eyaz ltin Seed Co. fter 4 weeks, the seeds were evaluated for their germinations.

9 Weed Seeds Used for Germination Test maranthus retroflexus L. Rumex crispus Physalis angulata

10 MTERILS ND METHODS Cont. Plant materials and distillation procedure: The plant materials of L. nobilis were collected in highlands of Kahramanmaraş Province of Turkey during the spring of The essential oils from the fresh leaves of L. nobilis were extracted by steam distillation by using a modified Clevengertype apparatus and were refrigerated in the dark at 4 ºC until their use.

11 MTERILS ND METHODS Cont. Weed and crop germination bioassay procedure: Seeds of the weeds were then equidistantly placed in 9 cm diameter Petri dishes (10 seeds per Petri dishes, six replicates per treatment) lined with two layers of moistened Whatman no. 1 filter paper wetted with 7 ml of distilled water. piece of filter paper (3 cm diameter) stuck on the inner side of cover of Petri dishes was treated with 0, 5, 10, 15, and 20 µl/petri dish of Laurel.

12 Weed and crop germination bioassay procedure (cont.) fter closing the covers treated Petri dishes were sealed with paraffin film and placed in an illuminated growth chamber at 25±1 ºC temperature and 65±5% r.h. in the darkness. fter four weeks, the number of seeds that germinated (0.5 cm radicule length) was counted in each Petri dish and then germination percentages of each treatment were calculated. Control treatment were kept without loading any essential oils.

13 PPLICTION METHOD

14 RESULTS

15 Chemical Composition of Essential Oils From Laurel (Laurus nobilis L.) Components of L. nobilis Content in vol.-% of components ± SD α-terpineol 1.90±0.03 α-terpinyl acetate 6.95±0.01 γ-terpinene 2,29±0,07 orneol 1,75±0,04 Sabinene 9.19±0.09 ρ-cymene 3.04 ±0.02 α-pinene 5.34±0.12 1,8 Cineole 54.71±0.13 β-pinene 4.28 ±0.005 Terpinen-4-ol 2.60±0.02

16 Treatment Treatment GERMINTION (%) FOR WEED SPECIES maranthus rate (µl/petri)( retroflexus Glycyrrhiza glabra Rumex crispus Physalis angulata Laurel 5 16,67±6 6 c 53,33±6,66 a 31,66±1,66 bc 36,66±3,33 3,33 ab 10 8,33±6 6 C b 31,33±5,92 C a 13,33±3,33 C b 10±0 0 C b 15 0 C b 0 D b 13,33 ±3,33 C a 0 D b 20 0 C b 0 D b 10±0 0 C a 3,33±3,33 D b Control 0 78,3 ±3,3 3,3 ab 73,33±6,66 ab 63,33 ±3,33 b 80 ±5,77 a 1,8-Cineole 5 73,33±3,33 a 0 d 33,33±3,33 3,33 c 56,66±3,33 b 10 23,33±1,66 b 0 d 13,33±3,33 C c 53,33±3,33 a 15 10±5 5 C b 0 c 13,33±3,33 C b 50±0 0 a 20 0 D b 0 b 10±5,77 C a 13,33±3,33 C a Control 0 78,3 ±3,3 ab 73,33±6,66 ab 63,33 ±3,33 b 80 ±5,77 a α-pinnen 5 61,66±4,40 a 60±0 0 a 26,66±6,66 b 76,66±6,66 a 10 33,33±7,26 bc 46,66±6,66 C ab 26,66±3,33 c 56,66±3,33 a 15 23,33±6 6 ab 33,33±6,66 C a 16,66±3,33 C b 10±0 0 C b 20 21,66±4,40 a 31,33±5,92 C a 6,67±3,33 C b 0 D b Control 0 78,3 ±3,3 ab 73,33±6,66 ab 63,33 ±3,33 b 80±5,77 a

17 GERMINTION (%) FOR CROP SPECIES Treatment Treatment rate (µl/petri) Wheat Corn Cotton Laurel 5 90±0 0 b 100±0 0 a 26,57±0 0 c 10 60±10 C b 100±0 0 a 26,57±0 0 c 15 0 D b 46,67±6,66 6,66 a 0 C b 20 0 D b 23,33±8,8 C a 0 C b Control ±0 a 100±0 a 100±0 a 1,8-Cineole 5 63,33±6,66 6,66 b 100±0 0 a 26,67±6,66 6,66 c 10 10±0 0 C b 80±11,54 a 13,33±6,66 b 15 0 D b 46,66±6,66 C a 0 C b 20 0 D b 23,33±8,8 C a 0 C b Control ±0 a 100±0 a 100±0 a α-pinene 5 100±0 0 a 100±0 0 a 66,67±6,66 6,66 b ±0 0 a 100±0 0 a 40±11,54 C b ±0 0 a 100±0 0 a 33,33±6,66 6,66 CD b 20 80±20 a 86,67±13,33 a 13,33±6,66 D b Control 0 100±0 a 100±0 a 100±0 a

18 Germination Rate of Some Weed and Crop Species at 5 µl/petri 120 Laurel Cineol 100 α-pinene Control Germination (%) C 20 C C 0 maranth (maranthus retroflexus) Wild licorice (Glcycrrhiza glabra) Curled dock (Rumex crispus) Cutleaf ground-cherry (Physalis angulata) Wheat Corn Cotton Seeds

19 120 Germination Rate of Some Weed and Crop Species at 10 µl/petri Germination (%) C C C C C C C C Laurel Cineol α-pinene Control 0 maranth (maranthus retroflexus) Wild licorice (Glcycrrhiza glabra) Curled dock (Rumex crispus) Cutleaf groundcherry (Physalis angulata) Wheat Corn Cotton Seeds

20 120 Germination Rate of Some Weed and Crop Speies at 15 µl/petr 100 Germination (%) Laurel Cineol α-pinene Control 20 I C C D C CC 0 maranth (maranthus retroflexus) Wild licorice (Glcycrrhiza glabra) Curled dock (Rumex crispus) Cutleaf ground-cherry (Physalis angulata) Wheat Corn Cotton Seeds

21 Germination Rate of Some Weed and Crop Speies at 20 ul/petri Laurel Cineol α-pinene Control Germination(%) C C maranth (maranthus retroflexus) C C Wild licorice (Glcycrrhiza glabra) Curled dock (Rumex crispus) C C Cutleaf ground-cherry (Physalis angulata) Seeds CC Wheat Corn Cotton

22 CONCLUSIONS Our study showed that laurel essential oil and two of its components (1,8-cineole and α-pinene) were effective inhibiting germination of certain weeds. When they were used for the agronomic crops, two of three compounds (laurel essential oil and cineol) showed increasing inhibitory effect with the increasing concentrations. Whereas, there was no effect of α-pinene in all four concentrations in corn and wheat.

23 CONCLUSIONS Cont. These results indicate that using essentials oils could be a great promise for weed control in agro-agriculture system. However, more studies needed for laurel essential oil and its monoterponoid compounds to be used as a part of the weed management. Future experiments would focus on the possible effects of the length of time during which such compounds are present in soil, possible structural modifications with consequent loss or acquisition of activity and, allelopathic action on weed seeds in field conditions.

24 THNK YOU FOR YOUR PTIENCE