Pak. J. Weed Sci. Res. 18(2): 149-156, 212 L. - A PREDOMINANT WEED FLORA AMONG PHYTOSOCIOLOGY OF ISLAMABAD, PAKISTAN Gul Hassan 1, Khan Bahadar Marwat 1, Sadiq Ali 1, Mohammad Munir 2 and Pervaiz Khaliq 2 ABSTRACT belonging to family Asteraceae is a fast maturing invasive weed native to the subtropics of North and South America and now a cumbersome weed in Pakistan. Its invasion in Pakistan is of recent era and spreading like wild fire. Hence documentation of its infestation in various areas of the country is immensely important. A survey was conducted in five randomly selected residential sectors of Islamabad Pakistan selected randomly viz. F-8, G-8, I-1, G-9 and H-9. The data were recorded on absolute density, relative density, frequency and relative frequency. The data reveal the highest relative density percentage (23.41%, 11.36%, 19.11%, 3.65%, and 28.88%) for top ranking weed. was recorded for at sectors F-8, G-8, I-1, G-9 and H-9 respectively. Parthenium emerged as the next predominant species across the various Sectors. The data exhibit that it even surpassed the C. dactylon at I-1 (2.42%) and H-9 (15.55). While the minimum relative density (7.29 %) of Parthenium occurred in sector G-9 along the roadsides Mean data across all 5 locations further exhibit that C. dactylon was the predominant Species with relative density of 22.68% followed by Parthenium (13.42%) and A. viridis (1.33%). C. sativa prevailed at a mean density of only 7.9%. It is speculated that C. sativa; one of the predominant natives species in the past has been replaced with Parthenium at many a locations studied. The dominance of C. sativa followed by Parthenium, across all sectors was depicted. However, the highest relative frequency (66.84%) of C. sativa was recorded in Sector I-1. The computation of Importance value further exhibit that Cynodon-Parthenium-Euphorbia community dominated at F-8. While at G-8, Parthenium- Euphorbia-Cynodon was prevalent. In I-1. Cannabis- Parthenium-Boerhavia community dominated, whereas at G-9 Boerhavia-Cynodon-Cannabis Parthenium-Cannabis community was evidenced, looking at the overall distribution of flora in Islamabad Capital Territory the Cynodon-Parthenium-Cannabis 1 Department of Weed Science, Khyber Pakhtunkhwa Agricultural University, Peshawar 2513, Pakistan. E-mail:hassanpk_2pk@yahoo.com 2 Pakistan Agricultural Research Council, Islamabad.
15 Gul Hassan et al., L. community predominates. All the parameters examined suggest that Parthenium has spread in the area and keeping in view its nature as a successful weed it is quite inevitable to check its further spread into other areas and into the crops of the adjoining Pothohar tract and safeguard the human and animal populations from the allergy hazard of parthenium. Key words: Parthenium, phytosociology, importance value, relative density. INTRODUCTION L. is an upright annual herb of 3-15 cm of family Asteraceae. It is native to subtropics of North and South America (Adkins et al., 1996) and was accidentally introduced in subcontinent in 1955 through imported food grains. The weed has rapidly spread in last twenty years and now it occurs widely along the roadsides, wastelands and sometimes in crop fields. The predominance of Parthenium is attributed to its fast growth rate, higher reproductive potential, adaptability and interference with its neighbours by allelopathy (Kohli and Rani, 1994). P. hysterophorus establishes only from seeds, which can germinate anytime of year given suitablemoisture levels. Plants flower when they are 4-8 weeks old and may flower for several months (Dhawan and Dhawan, 1996). However, in Pakistan we confirmed its perennial nature resprouting in Spring from the above ground parts (Hassan and Amin, 29). An individual plant may produce 15,-25, seeds (Navie et al., 1996). The weed lacks natural enemies in Pakistan, consequently rapidly spreading along the road sides and now entering the crops. The infestation of the Peshawar city is witnessed during summer 29 while the weed was not observed previously even during last year. Is has been further observed that weed is entered into the agriculture of Dera Ismail Khan, Lakki Marwat, Bannu, Kohat, Peshawar, Mardan, Charsada and Swabi. The other areas in KPK could not be surveyed due to security reasons (Personal observations). Keeping in view the importance of Parthenium its distribution was monitored in the different sectors of Islamabad in wastelands and along the roadsides. MATERIALS AND METHODS A study was carried out to evaluate the distribution of Parthenium weed in capital city of Pakistan, Islamabad during August 28. Five residential sectors were randomly selected viz. F-8, G-8, I- 1, G-9 and H-9. In the surveyed areas, P. hysterophorus distribution was studied in the flora of wastelands and along the roadsides, In order to study the impact of P. hysterophorus on the distribution of native weeds, data were collected from undisturbed localities along the
Pak. J. Weed Sci. Res. 18(2): 149-156, 212 151 road sides and vacant plots. Frequency and density of P. hysterophorus and other weed species was estimated by applying the following formulae as outlined by Hussain (1989) and Hussain et al. (). Absolute density (AD) (%) = Relative density (RD) (%) = Absolute frequency (AF) (%) = Relative frequency (RF) (%) = Total number of individuals of a species in all quadrates Total number of quadrates Absolute density for a species x 1 Total absolute density for all species Number of quadrates in which species occurs x 1 Total number of quadrates Absolute frequency value for a species x 1 Total absolute frequency values for all species Importance value (IV) (%) = Relative frequency +Relative density 2 At each of the selected sectors, five locations along the road sides were selected randomly and were surveyed. At each location five 1x1m 2 quadrates were randomly placed along an inverted horizontal pattern. The distance between each quadrate depended upon the area available along the road side and any obstructions that may have been present. The collected weed samples were identified from the Department of Weed Science, KPK Agricultural University, Peshawar. RESULTS AND DISCUSSION Density m -2 Variability was observed in weed dynamics across the 5 sites studied (Table-1). Higher infestation of P. hysterophorus 4.96 m -2 was recorded at Sector I-1 location as compared to the lowest infested site possessing mean Parthenium plants m -2 in sector G-9. Whereas the Sectors F8, G8 and H9 were infested with Parthenium to the extent of 2.72, 3.52 and 2. m -2, respectively. For C. dactylon, the most infested site was Sector G-9 roadside having 6.72 plants m -2 sectors studied (Table-1). Computing the means for each species across all the sectors, C. dactylon (4.86 m -2 ) was deciphered to be the most predominant species followed by P. hysterophorus (3.8 m -2 ) and Dactyloctenium aegypticum (Egyptian grass) infesting to the extent of 2.97 m -2. Except Sector H9 having the least number of total flora, all other sectors possessed equal number of total weeds (Table-1). Parthenium causes health hazards. A lot of available data also highlights its impact on agriculture as well as natural ecosystems (Batish et al., 22; Singh et al., 22). There are reports of total
152 Gul Hassan et al., L. habitat change in native Australian grasslands, open woodlands, river banks and floodplains due to Parthenium invasion (McFadyen, 1992; Chippendale and Panetta, 1994) Table-1. Density m -2 of various weed species across different sectors of Islamabad during 28. Weed Species F -8 G- 8 I- 1 G- 9 H-9 Mean Malvastrum coromendelianum 2.72.96 1.92 2.4 5.6.96 1.92 3.6 3.52 3.2 3.2 4.8 3.2 1.92 3.52 4.96 3.64 4.64 2.4 3.2 2. 3.84 6.72.8 2.56 2.56 2. 2.8.48 4. 2.8 1.28.8 1.28 3.8 2.97 1.88 1.97 4.86 2.33 1.72 1.76 2.64 Total 23.92 28..28 21.92 14.4 Relative Density (%) Analysis of the data depicted that the highest percentage (23.41%, 11.36%, 19.11%, 3.65%, and 28.88%) of flora comprised of C. dactylon at sectors F-8, G-8, I-1, G-9 and H-9, respectively (Table-2). Parthenium emerged as the next predominant species across the various Sectors. The data exhibit that it even surpassed the C. dactylon at I-1 (2.42%) and H-9 (15.55). While the minimum relative density (7.29 %) of Parthenium occurred in sector G-9 along the roadsides (Table-2). Mean data presented in Table-2 further exhibit that C. dactylon was the predominant Species with relative density of 22.68% followed by Parthenium (13.42%) and A. viridis (1.33%). C. sativa prevailed at a mean density of only 7.9%. It is speculated C. sativa; one of the predominant native species in the past has been replaced with Parthenium at many a locations studied. The dominance and rapid spread of P. hysterophorus in wastelands with gradual reduction of local flora could be attributed to its invasive capability, allelopathic properties, high growth rate, short growth cycle and large number of seed production (Srivastava et al., 1985; Evans, 1997; Oudhia, 1998). A similar invasion of Parthenium in National Wildlife Park in Southern India has also been reported (Evans, 1997). It has been reported as causing a total habitat change in native Australian grasslands, open woodlands, riverbanks and flood plains in Australia (McFadyen, 1992; Chippendale and Panetta, 1994).
Pak. J. Weed Sci. Res. 18(2): 149-156, 212 153 Table-2. Relative density (%) of various weed Species across various Sectors of Islamabad during 28. Weed Species F -8 G- 8 I- 1 G -9 H -9 Mean Malvastrum coromendelianum 11.37 4.1 8.2 1.3 23.41 6.68 4.1 8.2 15.5 12.5 5.68 11.36 11.36 17.4 11.36 6.81 12.5 2.42 6.58 14.99 19.11 9.88 13.17 6.58 7.29 1.21 17.51 3.65 3.64 17 17 15.55 14.44 3.33 28.88 14.44 8.88 5.55 8.88 13.42 4.82 7.9 8.5 22.68 1.33 7.48 7.72 9.62 Frequency (%) The data (Table-3) evidence the composition of flora in the studied sites at Islamabad. Highest frequency of 84% of P. hysterophours observed at Sector I-1, followed by 56% at F-8 and the minimum frequency of 4 % each of P. hysterophours was observed at Sectors G-8, G-9 and H-9, which clearly depicts the even distribution of the weed at all locations surveyed. C. dactylon, C. sativa and A. viridis emerged as the next evenly distributed species in the target area. The mean Frequency data occurred reveals the Parthenium and C. dactylon as the most frequent weeds followed by, and A.viridis (Table-3). C. sativa with a mean frequency of % emerged the next prevalent plant across the various Sectors of Islamabad. Table-3. Frequency (%) of various weed species across various Sectors of Islamabad during 28. Weed Species F -8 G- 8 I- 1 G -9 H -9 Mean Malvastrum coromendelianum 56 4 56 12 36 4 12 84 2 68 2 8 12 4 44 48 12 2 4 2 8 44 44 28 28 Total 272 212 748 22 212 52 9.6 28 42.4.8 14.4 25.6 Relative frequency (%) The relative frequency of weeds is a good statistic that shows the distribution of weeds in the study area. A reference to the mean data in Table-4 depicts the dominance of C. sativa followed by Parthenium, across all sectors. However, the highest relative
154 Gul Hassan et al., L. frequency (66.84%) of C. sativa was recorded in Sector I-1. Data in Table-4 further shows that Parthenium infestation was almost uniform in all the Sectors along the roadsides, however its minimum relative frequency (11.22%) was recorded at Sector I-1 where there was no niche for Parthenium to replace C. sativa infestation. Malvestrum coromendelianum was found with very low relative frequency of only 5.5 % while there was no presence of this species at H-9 Sector in the study sites. Table-4. Relative frequency (%) of various weed species across various Sectors of Islamabad during 28. Weed Species F -8 G- 8 I- 1 G -9 H -9 Mean Malvastrum sp 2.58 5.88 8.82 14.7 2.58 5.88 4.41 5.88 13.23 18.86 5.66 11. 15.9 5.9 11. 7.54 15.9 11.22 66.84 9.9 4. 2.67 3.2 18.18 2 6 21.8 5.45 1.9 9.9 18.86 9.43 3.77 2.75 2.75 13.2 13.2 17.54 4.19 22.15.75.49 9.96 5.99 5.5 1.44 Importance Value (%) The Importance Value determination is a prime indicator for the flora distribution in an area. Among the locations studied, the highest importance value of 38.76% for C. dactylon was recorded at G9 closely followed by 36.71% recorded for C. sativai in I-1 6.6%. C. dactylon ranked as top most species in F-8 and H-9 as well as in the mean values for all 5 locations (Table-5). The perusal of data further exhibit that Cynodon-Parthenium- Euphorbia community dominated at F-8. While at G-8, Parthenium- Euphorbia-Cynodon was prevalent. In I-1. Cannabis-Parthenium- Boerhavia community dominated, whereas at G-9 Boerhavia-Cynodon- Cannabis Parthenium-Cannabis community was evidenced. Looking at the overall distribution of flora in Islamabad Capital Territory, it is obvious that the Cynodon-Parthenium-Cannabis community predominates (Table-5). The data exhibit that Parthenium has spread in the area and keeping in view its nature as a successful weed it is quite inevitable to check its further spread into other areas and into the crops of the adjoining Pothohar tract and safeguard the human and animal populations from the allergy hazard of parthenium.
Pak. J. Weed Sci. Res. 18(2): 149-156, 212 155 Table-5. Importance value (%) of various weed species across various Sectors of Islamabad during 28. Weed Species F -8 G- 8 I- 1 G -9 H -9 Mean Malvastrum sp 15.98 4.95 8.42 12.37 27. 6.28 4.21 6.95 14.14 15.28 5.67 11.34. 13.23 11.7 11.34 7.18 13.8 15.82. 36.71 12.4 18 6.28 7.12 4.89.8 12.74. 15.11 38.76 26.23 4.55. 11.29 1.38 17.21 11.94 3.55.6.82 17.6 11.4 2.74 11.4 15.33 4.51 15.3 12.63 19.59 1.15 6.74 6.61 1.3 ACKNOWLEDGEMENT The present research was undertaken under the International Linkage Program of the Higher Education Commission, Islamabad, which is highly acknowledged. REFERENCES CITED Adkins, S.W., S.C. Navie and R.E. McFadyen. 1996. Control of Parthenium weed ( L.): A centre for tropical pest management team effort pp. 573-578. In R.C.H. Shepherd (ed.). Proc. 11 th Aust. Weeds Conf., Weed Sci. Soc. Victoria, Frankston. Batish D.R, H.P. Singh, R.K. Kohli, D.B.Saxena and S.Kaur. 22. Allelopathic effects of parthenin against two weedy species, Avena fatua and Bidens pilosa. Envir. Exp. Bot. 47: 149-155 Chippendale, J.F. and F.D. Panetta. 1994. The cost of Parthenium weed to the Queensland cattle industry. Plant Prot. Quart. 9: 73-76. Dhawan, S.R. and P. Dhawan. 1996. Regeneration in Parthenium hysterophorus L. World Weeds 3:181-182. Evans, H.C. 1997. : a review of its weed status and the possibilities for biological control. Biocontrol/News and Information, 18: 89-98. Hassan, G. and A. Amin. Annual Report, International Linkages Project on Parthenium Weed. Pp. 1- Hussain, F. 1989. Field and Laboratory Manual of Plant Ecology. University Grants Commission, Islamabad, pp. 155-156. Hussain, F. A, Murad and M.J.Durrani.. Weed communities in wheat fields of Mastuj, district Chitral, Pakistan. Pak. J. Weed Sci. Res. 1(3-4): 11-18. Kohli, R.K. and D. Rani, 1994. a review. Res. Bull. Sci. Punjab University. 44: 15-149.
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