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Infestation assessment of root-knot nematodes (Meloidogyne spp.) associated with cucumber in the Pothowar region of Pakistan
Crop Protection 47 (2013) 49e54
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Infestation assessment of root-knot nematodes (Meloidogyne spp.) associated with cucumber in the Pothowar region of Pakistan Muhammad Zameer Kayani a, Tariq Mukhtar b, Muhammad Arshad Hussain c, *, Muhammad Irfan Ul-Haque a a b c
Green Belt Project, Department of Agriculture, Rawalpindi, Pakistan Department of Plant Pathology, Pir Mehr Ali Shah Arid Agriculture University, Rawalpindi, Pakistan Plant Pathology Section, Regional Agricultural Research Institute, Bahawalpur, Pakistan
a r t i c l e i n f o
a b s t r a c t
Article history: Received 18 May 2012 Received in revised form 6 December 2012 Accepted 4 January 2013
Studies to estimate root-knot nematode infestations on cucumber were conducted during mid- to lateseason at 378 randomly selected sites in 126 villages of the four districts across the Pothowar zone of the country. The overall mean infestation of root-knot nematodes in the region was found to be 15.66%. The studies revealed variations in the incidence and severity of root-knot nematodes in the four districts. The incidence of root-knot nematodes was the highest in Rawalpindi district (21.86%), followed by 13.89% in Attock. Of the four districts, the minimum incidence of 10.97% was recorded in Jhelum district. The maximum mean severity (3.79), measured in terms of the galling index, was found in Rawalpindi district, while the minimum (1.86) was observed in Jhelum district. The mean severities of root-knot nematodes in the districts of Attock and Chakwal were 2.66 and 2.19 respectively. Variations in incidence and severity were also observed among subdivisions of the districts. Of all the associated species of root-knot nematodes, Meloidogyne incognita constituted 78.53%, Meloidogyne javanica 19.03%, Meloidogyne arenaria 1.82% and Meloidogyne hapla 0.62%. M. incognita and M. javanica were recorded in all of the districts, with M. incognita predominating. M. incognita as a pure population was recorded in 29.63% of the villages, while the other three species were found as mixtures. The most common mixed population was M. incognita and M. javanica, observed in 70.37% of villages in the region. M. arenaria and M. hapla were not found together in any of the population mixtures. The results indicate that cucumber is severely attacked by root-knot nematodes, warranting adoption of strict control measures for its management. Ó 2013 Elsevier Ltd. All rights reserved.
Keywords: Meloidogyne Meloidogyne Meloidogyne Meloidogyne Incidence Severity
incognita javanica arenaria Hapla
1. Introduction Pakistan lies between 24e36 North and 61e76 East, with a subtropical climate in the warm temperate zone. This type of climate is suitable for the activity and reproduction of root-knot nematodes throughout the year. Similarly, sandy and warm soils, found in the arid zones, are also favorable for nematode development and infestation. Moreover, in the irrigated areas, monocropping causes considerable amplification of the nematode population by providing a constant host. The Pothowar plateau (latitude 32 10e34 9 N and longitude 71 10e73 55 E) occupies an area of approximately 28,489 sq km and is bounded on the east by the Jhelum River, on the west by the Indus River, on the north by the Kala Chitta Range and the Margalla Hills, and on the south by the Salt Range. The zone consists of Rawalpindi, Chakwal, Attock and * Corresponding author. Tel.: þ92 51 9290239; fax: þ92 51 9290771. E-mail address: [email protected] (M.A. Hussain). 0261-2194/$ e see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.cropro.2013.01.005
Jhelum districts. The terrain is undulating and separated locally by gullies and ranges of low hills. The soils have a pH of 7.5e8.5. Annual precipitation in the area ranges between 500 and 1000 mm and is greatest in the northwest, declining to arid conditions in the southwest. Over 70% of the total rainfall is received during monsoon season (July and August). Due to its being rain-fed, the area makes a significant contribution to the agricultural productivity of the country. Wheat, gram, mungbean, lentil, maize, groundnut and oilseed rape are the major crops of the Pothowar region. In addition to these crops, vegetables also occupy major areas, and cucumber is one of the most widely grown vegetables (Nizami et al., 2004). In many areas of the Pothowar region of Punjab province of the country, the yield obtained is relatively lower owing to a host of constraints including prevalence of diseases caused by different pathogens. Among various pathogens responsible for low yields, root-knot nematodes are of considerable economic importance and cause annual yield losses in the tropics of 22% (Hussain et al., 2011a; Sasser, 1979). In addition, these parasites
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interact with other disease causing organisms to produce disease complexes (Begum et al., 2012) and break down resistance against other pathogens and reduce plant tolerance to environmental stress (Taylor, 1979). To date, more than 100 species of Meloidogyne have been reported from different parts of the world (Karssen and Moens, 2006). Among these, four viz. Meloidogyne incognita, M. javanica, M. arenaria and M. hapla are economically important (Eisenback and Triantaphyllou, 1991) and are responsible for 95% of the infestations in cultivated lands (Sasser and Carter, 1982). These occur in the following order: M. incognita 47%, M. javanica 40%, M. arenaria 7% and M. hapla 6% (Sasser, 1980). The approximate distribution of Meloidogyne spp. in the soils of Pakistan is M. incognita 52%, M. javanica 31%, M. arenaria 8%, M. hapla 7% and other species approximately 2% (Maqbool, 1987). Root-knot nematodes are becoming one of the most serious calamities for the successful cultivation of cucumber in the Pothowar region of the country. The estimated losses in cucumber have been reported to be up to 33% (Sasser, 1979). The infestation of root-knot nematodes on cucumber in Pakistan has been found to be up to 52% (Khan et al., 2005). Increased information on the incidence and severity of root-knot nematodes in cucumber growing areas is important for sustainable production of cucumbers. Plant parasitic nematodes in Pakistan have received little attention, and only a few surveys have been conducted in the past (Brown, 1962; Kafi, 1963; Ahmad and Khan, 1973; Saeed and Ashrafi, 1973; Anwar et al., 1991, 1992; Khan et al., 2006; Zarina and Shahina, 2010; Anwar and McKenry, 2012; Hussain et al., 2012). There is limited information regarding the association of root-knot nematodes with cucumber as a production constraint in the country. The occurrence and distribution spectra and population densities of different Meloidogyne species in a region are important management tools. Therefore, the objective of the present studies was to determine and document the incidence, severity and distribution of root-knot nematodes on cucumber cultivations in the vegetable growing areas of the Pothowar region in Punjab province.
The infected roots along with soil were put into polythene bags, properly labeled and brought to the laboratory of the Plant Pathology Department, Pir Mehr Ali Shah Arid Agriculture University, Rawalpindi. The root systems of individual plants were rated following the galling index developed by Bridge and Page (1980) to determine the severity of the root-knot nematode infestation.
2. Materials and methods
The mean values of incidence and severity for each subdivision and district were calculated. Standard errors of means were calculated in Microsoft Excel 2003. Euclidean distances were used to construct a dendrogram by an unweighted paired group method with arithmetic averages (UPGMA) using Statistica version 6.1.
2.1. Incidence and severity of root-knot nematodes A survey of cucumber fields located in different randomly selected villages of the four districts (Rawalpindi, Jhelum, Chakwal and Attock) of the Pothowar region in the Punjab province of Pakistan was conducted to determine the incidence and severity of root-knot nematodes. Six villages were randomly selected from each subdivision of the four districts, and from each village, three fields of cucumber were randomly selected, thus making a total of 378 fields. From each cucumber field, 20 plants were selected 10 paces apart in succession following a zigzag pattern. The root systems of the selected plants were carefully excavated to a soil depth of 15e30 cm with the help of a trowel. The soil adhering to the root system was gently removed, and the roots were observed for rootknot nematode infection (presence or absence of galls). The incidence of root-knot nematodes in individual cucumber fields was determined as follows.
Total number of infected plants Incidence % ¼ 100 Total number of observed plants The root-knot incidences in all of the fields of each village were averaged to calculate the mean incidence for that village. Similarly, the incidences of all of the villages in each subdivision were averaged to calculate the mean incidence in that subdivision. The mean incidence for each district was calculated in the same way.
2.2. Identification of Meloidogyne species For identification of Meloidogyne species, root-knot nematode infected root samples from all of the fields in each village were pooled and thoroughly mixed to form a composite sample. Rootknot nematodes (Meloidogyne species) were then identified on the basis of female perineal patterns as described by Taylor and Netscher (1974). Mature females of root-knot nematodes were dissected out from the infected cucumber roots and placed in a watch glass containing distilled water. The live mature females were then transferred to a plastic Petri dish containing 45% lactic acid and left for 2 h. The posterior end was then dissected away with a fine needle and the body tissues were removed by lightly brushing the inner surface of the cuticle with a flexible bristle. Once all of the tissues were removed, the cuticle was transferred to a drop of glycerin where it was carefully trimmed. The piece of cuticle containing the vulval portion with the typical perineal pattern was then transferred to a drop of glycerin on a micro slide, a cover slip was applied and sealed with nail polish, and was observed under a microscope. The perineal pattern was compared with standard diagrams, and the species of Meloidogyne was identified (Eisenback et al., 1981). In this way, perineal patterns of 40 randomly selected females from the composite sample for each village were prepared, and the distribution of each Meloidogyne species in each subdivision was calculated. The incidences of pure and/or mixed populations of the four Meloidogyne species were also recorded in the four districts of Pothowar region. 2.3. Statistical analysis
3. Results 3.1. Incidence of root-knot nematodes Varying incidences of root-knot nematodes (Meloidogyne spp.) were recorded for cucumber fields from the districts of Rawalpindi, Attock, Jhelum and Chakwal. The highest root-knot nematode incidence of 21.86% was recorded in Rawalpindi district, followed by 13.89% in Attock. Of the four districts, the minimum incidence of 10.97% was recorded in Jhelum district, as shown in Table 1. Within the districts, variations in incidence among subdivisions were also found. In Rawalpindi district, the maximum incidence (31.11%) was recorded in Taxila, while the minimum (6.94%) was observed in Kotlisattian. In Attock district, the maximum incidence was recorded in Pindi Gheb and the minimum in Fateh Jang. The mean incidences in other subdivisions ranged between 8.06 and 17.50%. Similarly, in Jhelum district, the incidence of root-knot nematodes ranged between 7.78 and 14.44%; Pind Daden Khan showed the maximum incidence of 14.44%. In Chakwal district, the maximum incidence of 15.56% was found in Choa Sayadan Shah subdivision, and minimums of 10 and 10.28% were recorded in Kallar Kahar and Talagang, as shown in Table 1.
M.Z. Kayani et al. / Crop Protection 47 (2013) 49e54 Table 1 Incidence and severity of root-knot nematodes in subdivisions of the districts of Pothowar region. District
Subdivision
Mean incidence
Mean intensity
Rawalpindi
Rawalpindi Gujjar Khan Kallar Syedan Taxila Kahuta Murree Kotlisattian Average Hasan Abdal Hazro Attock Fateh Jang Jand Pindi Gheb Average Jhelum Pind Daden Khan Sohawa Dina Average Chakwal Choa Sayadan Shah Talagang Kallar Kahar Average
17.78 3.16 21.67 3.98 23.33 3.45 31.11 4.34 24.17 4.51 26.11 3.85 6.94 1.62 21.86 1.51 12.50 3.06 15.83 4.70 15.83 3.48 8.06 2.72 13.61 3.52 17.50 2.40 13.89 1.38 10.56 2.86 14.44 3.68 7.78 2.15 11.11 3.04 10.97 1.49 13.06 2.69 15.56 3.02 10.28 2.73 10.00 2.74 12.22 1.39 15.66 0.78
3.33 0.60 3.61 0.76 4.83 0.62 5.39 0.64 3.44 0.67 4.33 0.50 1.53 0.39 3.79 0.25 2.61 0.60 2.78 0.75 3.44 0.72 1.56 0.50 2.56 0.71 3.00 0.38 2.66 0.26 1.78 0.48 2.33 0.60 1.22 0.32 2.17 0.57 1.86 0.25 2.50 0.47 2.72 0.51 1.83 0.47 1.72 0.47 2.19 0.24 2.80 0.13
Attock
Jhelum
Chakwal
Overall mean
51
Rawalpindi district, while the minimum (1.86) was observed in Jhelum district. The mean severity of root-knots in the districts of Attock and Chakwal were 2.66 and 2.19, respectively, as shown in Table 1. Differences in root-knot severity were also observed among subdivisions of each district. In Rawalpindi district, the maximum severity of 5.39 was observed in Taxila, while the minimum was in Kotlisattian. The rest of the subdivisions showed severities above 3. In Attock district, the Attock and Pindi Gheb subdivisions showed severities above 3, while a minimum severity of 1.56 was recorded in Fateh Jang. The mean severities of root-knot nematodes were found to be lower in subdivisions of Jhelum and Chakwal and ranged from 1.22 to 2.72, as given in Table 1. The dendrogram in Fig. 2, constructed on the basis of severity of root-knot nematodes, formed two main clusters at a linkage distance of 2.5. There are three subdivisions in Cluster-1 viz. Taxila, Murree and Kallar Syedan with mean severities of 5.39, 4.33 and 4.83, respectively. All of the subdivisions in this group fall within Rawalpindi district. The second cluster was comprised of the rest of the subdivisions, with mean severities ranging from 1.22 to 3.33. The second cluster is also divided into two sub-clusters. In sub-cluster 2A, the subdivisions of Sohawa, Kallar Kahar, Talagang, Jhelum, Fateh Jang and Kotlisattian showing mean severities of root-knot nematodes from 1.22 to 1.83 are included, while the subdivisions included in sub-cluster 2B ranged in severity from 2.17 to 3.33. 3.3. Occurrence of root-knot nematode species
It is evident from the dendrogram in Fig. 1 that based on incidence, two main clusters were formed. Cluster-1 consisted of five subdivisions viz. Taxila, Murree, Kahuta, Kallar Syedan and Gujjar Khan with a mean incidence above 20%. All of the subdivisions in this group fall in Rawalpindi district. The rest of the subdivisions formed cluster-2, with mean incidences below 18%. Cluster-2, in turn, can be subdivided into two sub-clusters. Sub-cluster 2A includes subdivisions showing mean incidences from 6.94 to 11.11%, while sub-cluster 2B includes the subdivisions of Pind Daden Khan, Choa Sayadan Shah, Attock, Hazro, Pindi Gheb and Rawalpindi with mean root-knot incidences ranging from 14.44 to 17.78%. 3.2. Severity of root-knot nematodes The maximum mean severity (3.79), measured in terms of the galling index as suggested by Bridge and Page (1980), was found in
The different species of Meloidogyne associated with cucumber in different districts are given in Table 2. Of all the associated species of root-knot nematodes, M. incognita constituted 78.53%, M. javanica 19.03%, M. arenaria 1.82% and M. hapla 0.62%. Of the four main Meloidogyne species, three viz. M. incognita, M. javanica and M. arenaria, were found in all districts of the Pothowar region, while M. hapla was recorded only from Rawalpindi and Attock. M. incognita was predominant in all the four districts. The individual percentages of each Meloidogyne species in each district are given in Table 2. In Rawalpindi district, the percentage of M. incognita was the highest in Kahuta and Taxila, 90.00 and 88.33%, respectively, and the lowest (47.5%) in Gujjar Khan. Regarding M. javanica, it was found to the highest degree in Gujjar Khan and the lowest in Kahuta. M. hapla was recorded only from Murree and Kotlisattian, 9.33 and 3.33%, respectively. On the other hand, M. arenaria was recorded from Rawalpindi and Gujjar Khan, as shown in Table 2. In
Tree Diagram for variables Unweighted pair-group average Euclidean distances
5
14
Linkage Distance
12
Linkage Distance
Tree Diagram for Variables Unweighted pair-group average Euclidean distances
10 8 6 4
4 3 2 1
Fig. 1. Dendrogram showing clusters on the basis of incidence of root-knot nematodes in 21 subdivisions of four districts of Pothowar region.
Rawalpindi
Attock
Kahuta
Gujjar Khan
Jand
Hasan Abdal
Hazro
Chakwal
Pindi Gheb
Choa Sayadan Shah
Dina
Pind Daden Khan
Kotlisattian
Jhelum
Fateh Jang
Talagang
Sohawa
Kallar Kahar
Kallar Syedan
Taxila
0
Murree
Rawalpindi
Hazro
Pindi Gheb
Attock
Choa Sayadan Shah
Jand
Hasan Abdal
Chakwal
Pind Daden Khan
Fateh Jang
Kotlisattian
Jhelum
Sohawa
Talagang
Dina
Kallar Kahar
Gujjar Khan
Kahuta
Kallar Saydian
Taxila
0
Murree
2
Fig. 2. Dendrogram showing clusters on the basis of severity of root-knot nematodes in 21 subdivisions of four districts of Pothowar region.
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Table 2 Distribution of Meloidogyne species in subdivisions of the districts of Pothowar region. District
Subdivision
Rawalpindi
Rawalpindi Gujjar Khan Kallar Syedan Taxila Kahuta Murree Kotlisattian Average Hasan Abdal Hazro Attock Fateh Jang Jand Pindi Gheb Average Jhelum Pind Daden Khan Sohawa Dina Average Chakwal Choa Sayadan Shah Talagang Kallar Kahar Average
Attock
Jhelum
Chakwal
Overall Mean
Percentage of Meloidogyne species M. incognita
M. javanica
M. hapla
M. arenaria
58.67 47.50 84.00 88.33 90.00 67.33 83.33 74.17 77.92 86.25 70.83 80.56 85.56 83.33 80.74 85.00 88.33
36.67 40.83 16.00 11.67 10.00 23.33 13.33 21.69 22.08 13.75 17.92 19.44 14.44 16.67 17.38 9.44 8.89
0.00 0.00 0.00 0.00 0.00 9.33 3.33 1.81 0.00 0.00 3.33 0.00 0.00 0.00 0.56 0.00 0.00
4.67 11.67 0.00 0.00 0.00 0.00 0.00 2.33 0.00 0.00 7.92 0.00 0.00 0.00 1.32 5.56 2.78
84.44 86.11 84.93 82.08 70.00
11.67 13.89 12.25 14.17 30.00
0.00 0.00 0.00 0.00 0.00
3.89 0.00 2.82 3.75 0.00
85.56 59.44 74.27 78.53
14.44 40.56 24.79 19.03
0.00 0.00 0.00 0.62
0.00 0.00 0.94 1.82
other districts, M. incognita and M. javanica were recorded with varying degrees, with M. incognita being predominant in all of the subdivisions. M. hapla was recorded in subdivision Attock only and not in any of the subdivisions of Jhelum and Chakwal districts. On the other hand, M. arenaria was recorded only from Attock and Chakwal subdivisions. In Jhelum district, M. arenaria was found in all of the subdivisions except Dina, as shown in Table 2. The incidences of pure and/or mixed populations of the four Meloidogyne species are given in Table 3. M. incognita was recorded as a pure population in 29.63% of the villages, while the remaining three species were not found as pure populations in any village. The occurrence of M. incognita and M. javanica as a mixed population was the most common and was observed in 70.37% of villages in the region. Mixtures of M. incognita, M. javanica and M. arenaria were found in 12.34% of the villages, while mixtures of M. incognita, M. javanica and M. hapla were rare (4.94%). M. arenaria and M. hapla did not occur alone with M. incognita but were found in mixtures of M. incognita and M. javanica. M. arenaria and M. hapla were not found together in any of the population mixtures. The individual incidences of pure and mixed populations of Meloidogyne spp. in the four districts are given in Table 3.
4. Discussion The results of the present studies showed variations in the incidence and severity of root-knot nematodes in different districts and their subdivisions in the Pothowar region of Punjab province. Similar results have also been reported by Lamberti et al. (1975), Khan et al. (2005), Shahid et al. (2007), and Kayani et al. (2012a). The reports of these scientists confirm the present findings regarding the incidence, prevalence and occurrence of Meloidogyne species on vegetables. It is clear from the results of these researchers that the cucumber crop is the most susceptible host of Meloidogyne species in vegetable growing areas. The variations in root-knot infestations in the region are attributable to many environmental and edaphic factors, as differences in various climatic and edaphic factors in these districts have been identified. There are reports confirming that the distribution, prevalence, incidence and severity of root-knot nematodes are affected by varying agroclimatic conditions in the areas, including soil type, moisture, soil pH and particular cropping sequence (Taylor et al., 1982; Davide, 1985; Sasser and Carter, 1985; Van Gundy, 1985). The maximum incidence of root-knot disease was found in Rawalpindi district. This high incidence is due to intensive vegetable cropping pattern and the availability of suitable host throughout the year in the district which allowed rapid multiplication of root-knot nematodes. A number of researchers have previously reported that the abundance of root-knot nematodes is highly dependent upon the presence of suitable host plants (Jacq and Fortuner, 1979; Yeates, 1981; Ferris, 1985; Cuc and Prot, 1992). In the present study, M. incognita and M. javanica were found in all subdivisions of all the districts in varying proportions, and M. incognita was predominant. Trudgill et al. (2000) reported that M. incognita and M. javanica were the most widespread root-knot nematode species in the entire country. Similar results have been reported by many other workers (Khan et al., 1993; Campos, 1994; Das and Das, 2000; Bhosle et al., 2004; Ravichandra and Krishnappa, 2004; Rathour et al., 2006). The reported distribution and infestation of Meloidogyne spp. in Pakistan’s soils was M. incognita 52%, M. javanica 31%, M. arenaria 8%, M. hapla 7% and other species approximately 2% (Maqbool, 1987), which further supports the present findings. The overwhelming dominance of M. incognita in the Pothowar region may be related to the favorable climatic conditions, cropping regime and suitability of the host. The temperature range, precipitation and altitude prevailing in the study area all fall within the optimal range for M. incognita (Whitehead, 1969; Idowu, 1981; Taylor et al., 1982; Ploeg and Maris, 1999). These conditions may differentially enhance the multiplication and/or survival of M. incognita over M. javanica, which was found at low densities in the region, as the climatic conditions operating in this region are sub-optimal for M. javanica (Taylor et al., 1982). The greater density of M. incognita in mixed populations of the two species may reflect the competitive edge of M. incognita over M. javanica (Eisenback and Griffin, 1987),
Table 3 Occurrence of four Meloidogyne species in pure and mixed populations in cucumber growing areas of Pothowar region of Pakistan. District
Rawalpindi Attock Jhelum Chakwal Overall
Total No. of villages infested with Meloidogyne spp. populations
Villages with pure M. incognita populations
Villages with mixed Meloidogyne spp. populations M. incognita and M. javanica
M. incognita, M. javanica and M. arenaria
M. incognita, M. javanica and M. hapla
32 23 12 14 81
9 7 4 4 24
23 16 8 10 57
4 2 3 1 10
3 1 0 0 4
(28.12%) (30.43%) (33.33%) (28.57%) (29.63%)
(71.88%) (69.56%) (66.67%) (71.43%) (70.37%)
(12.5%) (8.7%) (25%) (7.1%) (12.34%)
(9.38%) (4.35%) (0.00%) (0.00%) (4.94%)
M.Z. Kayani et al. / Crop Protection 47 (2013) 49e54
a preference for cucumber and a more suitable cropping system (Wallace, 1973). It has also been shown that M. javanica may be the predominant species in regions with a distinct dry season and less than 5 mm of precipitation per month for three or more successive months (Eisenback et al., 1981). M. hapla was only found in Murree, Kotlisattian and Attock. The climate in these subdivisions is cool, humid and mild. These results are in agreement with the findings of Brown (1962), Lamberti (1979) and Walters and Barker (1994), who considered M. hapla a nematode of cooler climates, although this species can also occur in tropical countries at high elevations (Sasser, 1979). In our study, M. hapla was detected in mixed populations of M. incognita and M. javanica in areas situated at high altitudes. This finding concurs with previous findings and indicates that M. hapla is predominantly distributed at high elevations (Nono-Womdim et al., 2002). M. arenaria was found in those subdivisions where groundnut was widely cultivated. The occurrence of M. arenaria in combined mixtures of M. incognita and M. javanica but never with M. javanica alone shows that M. arenaria is the least adapted of the four species. The fact that the species was found in all of the districts with M. incognita suggests that the species might have the same range of environmental requirements as M. incognita. Taylor et al. (1982) also observed the phenomenon of M. arenaria only occurring in mixtures together with M. incognita and M. javanica in a similar ecological zone as in the present study. It is concluded from the present studies that cucumber is severely attacked by root-knot nematodes, particularly M. incognita, warranting the adoption of strict control measures for its management (Hussain et al., 2011b; Kayani et al., 2012b; Vagelas and Gowen, 2012; Mukhtar et al., 2013a, 2013b). Acknowledgments The assistance and cooperation rendered by the local farmers in the areas visited is gratefully acknowledged. References Ahmad, R., Khan, I.U., 1973. Root-knot of potato in West Pakistan. Plant Dis. Rep. 57, 505e506. Anwar, S.A., Gorsi, S.S., Anwar-ul-Haq, M.M., Rehman, T.T., Yousuf, P.P., 1991. Plant parasitic nematodes of some field, vegetable, fruit and ornamental crops. J. Agric. Res. 29, 233e249. Anwar, S.A., Khan, M.A., Tahir, A.A., 1992. Plant parasitic nematode problems of some field, vegetable, fruit and ornamental crops in the Punjab, Pakistan-II. Proc. Parasitol. 14, 84e98. Anwar, S.A., McKenry, M.V., 2012. Incidence and population density of plantparasitic nematodes infecting vegetable crops and associated yield losses in Punjab, Pakistan. Pak. J. Zool. 44, 327e333. Begum, N., Haque, M.I., Mukhtar, T., Naqvi, S.M., Wang, J.F., 2012. Status of bacterial wilt caused by Ralstonia solanacearum in Pakistan. Pak. J. Phytopathol. 24, 11e20. Bhosle, B.B., Mukesh, S., Puri, S.N., Suvasish, D., 2004. Prevalence of phytophagous nematodes in rhizosphere of okra (Abelmoschus esculentus L. Moench.) in Parbhani District, Maharashtra, India. Ind. J. Nematol. 34, 56e59. Bridge, J., Page, S.L.J., 1980. Estimation of root-knot nematode infestation levels on roots using a rating chart. Trop. Pest Manage. 26, 296e298. Brown, K.F., 1962. A Survey of Some Plant Parasitic Nematodes Problems in Pakistan. Shell International Chemical Company Co. Ltd, 9 pp. Campos, V.P., 1994. Diseases caused by nematodes in artichoke, lettuce, chicory, strawberries and okra. Informe-agropecuario-belo-horizonte 17, 17e22. Cuc, N.T.T., Prot, J.C., 1992. Effect of changing the agricultural environment on ufra occurrence in the Mekong delta. Int. Rice Res. Newsl. 17, 25. Das, J., Das, A.K., 2000. Prevalence of root-knot nematodes on vegetable crops in Assam and Arunachal Pradesh. Ind. J. Nematol. 30, 244e245. Davide, R.G., 1985. Summary report on current status, progress and needs for Meloidogyne research in Region VI. In: Sasser, J.N., Carter, C.C. (Eds.), An Advanced Treatise on Meloidogyne. Biology and Control, vol. 1. North Carolina State University Graphics, Raleigh, North Carolina, pp. 369e372. Eisenback, J.D., Griffin, G.D., 1987. Interactions with other nematodes. In: Veech, J.A., Dickson, G.W. (Eds.), Vistas on Nematology. Society of Nematologists, Inc, Hyattsville, MD, USA, pp. 313e320. Eisenback, J.D., Hirschmann, H., Sasser, J.N., Triantaphyllou, A.C., 1981. A Guide to the Four Most Common Species of Root-knot Nematodes (Meloidogyne Species),
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Infestation assessment of root-knot nematodes (Meloidogyne spp.) associated with cucumber in the Pothowar region of Pakistan Muhammad Zameer Kayani a, Tariq Mukhtar b, Muhammad Arshad Hussain c, *, Muhammad Irfan Ul-Haque a a b c
Green Belt Project, Department of Agriculture, Rawalpindi, Pakistan Department of Plant Pathology, Pir Mehr Ali Shah Arid Agriculture University, Rawalpindi, Pakistan Plant Pathology Section, Regional Agricultural Research Institute, Bahawalpur, Pakistan
a r t i c l e i n f o
a b s t r a c t
Article history: Received 18 May 2012 Received in revised form 6 December 2012 Accepted 4 January 2013
Studies to estimate root-knot nematode infestations on cucumber were conducted during mid- to lateseason at 378 randomly selected sites in 126 villages of the four districts across the Pothowar zone of the country. The overall mean infestation of root-knot nematodes in the region was found to be 15.66%. The studies revealed variations in the incidence and severity of root-knot nematodes in the four districts. The incidence of root-knot nematodes was the highest in Rawalpindi district (21.86%), followed by 13.89% in Attock. Of the four districts, the minimum incidence of 10.97% was recorded in Jhelum district. The maximum mean severity (3.79), measured in terms of the galling index, was found in Rawalpindi district, while the minimum (1.86) was observed in Jhelum district. The mean severities of root-knot nematodes in the districts of Attock and Chakwal were 2.66 and 2.19 respectively. Variations in incidence and severity were also observed among subdivisions of the districts. Of all the associated species of root-knot nematodes, Meloidogyne incognita constituted 78.53%, Meloidogyne javanica 19.03%, Meloidogyne arenaria 1.82% and Meloidogyne hapla 0.62%. M. incognita and M. javanica were recorded in all of the districts, with M. incognita predominating. M. incognita as a pure population was recorded in 29.63% of the villages, while the other three species were found as mixtures. The most common mixed population was M. incognita and M. javanica, observed in 70.37% of villages in the region. M. arenaria and M. hapla were not found together in any of the population mixtures. The results indicate that cucumber is severely attacked by root-knot nematodes, warranting adoption of strict control measures for its management. Ó 2013 Elsevier Ltd. All rights reserved.
Keywords: Meloidogyne Meloidogyne Meloidogyne Meloidogyne Incidence Severity
incognita javanica arenaria Hapla
1. Introduction Pakistan lies between 24e36 North and 61e76 East, with a subtropical climate in the warm temperate zone. This type of climate is suitable for the activity and reproduction of root-knot nematodes throughout the year. Similarly, sandy and warm soils, found in the arid zones, are also favorable for nematode development and infestation. Moreover, in the irrigated areas, monocropping causes considerable amplification of the nematode population by providing a constant host. The Pothowar plateau (latitude 32 10e34 9 N and longitude 71 10e73 55 E) occupies an area of approximately 28,489 sq km and is bounded on the east by the Jhelum River, on the west by the Indus River, on the north by the Kala Chitta Range and the Margalla Hills, and on the south by the Salt Range. The zone consists of Rawalpindi, Chakwal, Attock and * Corresponding author. Tel.: þ92 51 9290239; fax: þ92 51 9290771. E-mail address: [email protected] (M.A. Hussain). 0261-2194/$ e see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.cropro.2013.01.005
Jhelum districts. The terrain is undulating and separated locally by gullies and ranges of low hills. The soils have a pH of 7.5e8.5. Annual precipitation in the area ranges between 500 and 1000 mm and is greatest in the northwest, declining to arid conditions in the southwest. Over 70% of the total rainfall is received during monsoon season (July and August). Due to its being rain-fed, the area makes a significant contribution to the agricultural productivity of the country. Wheat, gram, mungbean, lentil, maize, groundnut and oilseed rape are the major crops of the Pothowar region. In addition to these crops, vegetables also occupy major areas, and cucumber is one of the most widely grown vegetables (Nizami et al., 2004). In many areas of the Pothowar region of Punjab province of the country, the yield obtained is relatively lower owing to a host of constraints including prevalence of diseases caused by different pathogens. Among various pathogens responsible for low yields, root-knot nematodes are of considerable economic importance and cause annual yield losses in the tropics of 22% (Hussain et al., 2011a; Sasser, 1979). In addition, these parasites
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interact with other disease causing organisms to produce disease complexes (Begum et al., 2012) and break down resistance against other pathogens and reduce plant tolerance to environmental stress (Taylor, 1979). To date, more than 100 species of Meloidogyne have been reported from different parts of the world (Karssen and Moens, 2006). Among these, four viz. Meloidogyne incognita, M. javanica, M. arenaria and M. hapla are economically important (Eisenback and Triantaphyllou, 1991) and are responsible for 95% of the infestations in cultivated lands (Sasser and Carter, 1982). These occur in the following order: M. incognita 47%, M. javanica 40%, M. arenaria 7% and M. hapla 6% (Sasser, 1980). The approximate distribution of Meloidogyne spp. in the soils of Pakistan is M. incognita 52%, M. javanica 31%, M. arenaria 8%, M. hapla 7% and other species approximately 2% (Maqbool, 1987). Root-knot nematodes are becoming one of the most serious calamities for the successful cultivation of cucumber in the Pothowar region of the country. The estimated losses in cucumber have been reported to be up to 33% (Sasser, 1979). The infestation of root-knot nematodes on cucumber in Pakistan has been found to be up to 52% (Khan et al., 2005). Increased information on the incidence and severity of root-knot nematodes in cucumber growing areas is important for sustainable production of cucumbers. Plant parasitic nematodes in Pakistan have received little attention, and only a few surveys have been conducted in the past (Brown, 1962; Kafi, 1963; Ahmad and Khan, 1973; Saeed and Ashrafi, 1973; Anwar et al., 1991, 1992; Khan et al., 2006; Zarina and Shahina, 2010; Anwar and McKenry, 2012; Hussain et al., 2012). There is limited information regarding the association of root-knot nematodes with cucumber as a production constraint in the country. The occurrence and distribution spectra and population densities of different Meloidogyne species in a region are important management tools. Therefore, the objective of the present studies was to determine and document the incidence, severity and distribution of root-knot nematodes on cucumber cultivations in the vegetable growing areas of the Pothowar region in Punjab province.
The infected roots along with soil were put into polythene bags, properly labeled and brought to the laboratory of the Plant Pathology Department, Pir Mehr Ali Shah Arid Agriculture University, Rawalpindi. The root systems of individual plants were rated following the galling index developed by Bridge and Page (1980) to determine the severity of the root-knot nematode infestation.
2. Materials and methods
The mean values of incidence and severity for each subdivision and district were calculated. Standard errors of means were calculated in Microsoft Excel 2003. Euclidean distances were used to construct a dendrogram by an unweighted paired group method with arithmetic averages (UPGMA) using Statistica version 6.1.
2.1. Incidence and severity of root-knot nematodes A survey of cucumber fields located in different randomly selected villages of the four districts (Rawalpindi, Jhelum, Chakwal and Attock) of the Pothowar region in the Punjab province of Pakistan was conducted to determine the incidence and severity of root-knot nematodes. Six villages were randomly selected from each subdivision of the four districts, and from each village, three fields of cucumber were randomly selected, thus making a total of 378 fields. From each cucumber field, 20 plants were selected 10 paces apart in succession following a zigzag pattern. The root systems of the selected plants were carefully excavated to a soil depth of 15e30 cm with the help of a trowel. The soil adhering to the root system was gently removed, and the roots were observed for rootknot nematode infection (presence or absence of galls). The incidence of root-knot nematodes in individual cucumber fields was determined as follows.
Total number of infected plants Incidence % ¼ 100 Total number of observed plants The root-knot incidences in all of the fields of each village were averaged to calculate the mean incidence for that village. Similarly, the incidences of all of the villages in each subdivision were averaged to calculate the mean incidence in that subdivision. The mean incidence for each district was calculated in the same way.
2.2. Identification of Meloidogyne species For identification of Meloidogyne species, root-knot nematode infected root samples from all of the fields in each village were pooled and thoroughly mixed to form a composite sample. Rootknot nematodes (Meloidogyne species) were then identified on the basis of female perineal patterns as described by Taylor and Netscher (1974). Mature females of root-knot nematodes were dissected out from the infected cucumber roots and placed in a watch glass containing distilled water. The live mature females were then transferred to a plastic Petri dish containing 45% lactic acid and left for 2 h. The posterior end was then dissected away with a fine needle and the body tissues were removed by lightly brushing the inner surface of the cuticle with a flexible bristle. Once all of the tissues were removed, the cuticle was transferred to a drop of glycerin where it was carefully trimmed. The piece of cuticle containing the vulval portion with the typical perineal pattern was then transferred to a drop of glycerin on a micro slide, a cover slip was applied and sealed with nail polish, and was observed under a microscope. The perineal pattern was compared with standard diagrams, and the species of Meloidogyne was identified (Eisenback et al., 1981). In this way, perineal patterns of 40 randomly selected females from the composite sample for each village were prepared, and the distribution of each Meloidogyne species in each subdivision was calculated. The incidences of pure and/or mixed populations of the four Meloidogyne species were also recorded in the four districts of Pothowar region. 2.3. Statistical analysis
3. Results 3.1. Incidence of root-knot nematodes Varying incidences of root-knot nematodes (Meloidogyne spp.) were recorded for cucumber fields from the districts of Rawalpindi, Attock, Jhelum and Chakwal. The highest root-knot nematode incidence of 21.86% was recorded in Rawalpindi district, followed by 13.89% in Attock. Of the four districts, the minimum incidence of 10.97% was recorded in Jhelum district, as shown in Table 1. Within the districts, variations in incidence among subdivisions were also found. In Rawalpindi district, the maximum incidence (31.11%) was recorded in Taxila, while the minimum (6.94%) was observed in Kotlisattian. In Attock district, the maximum incidence was recorded in Pindi Gheb and the minimum in Fateh Jang. The mean incidences in other subdivisions ranged between 8.06 and 17.50%. Similarly, in Jhelum district, the incidence of root-knot nematodes ranged between 7.78 and 14.44%; Pind Daden Khan showed the maximum incidence of 14.44%. In Chakwal district, the maximum incidence of 15.56% was found in Choa Sayadan Shah subdivision, and minimums of 10 and 10.28% were recorded in Kallar Kahar and Talagang, as shown in Table 1.
M.Z. Kayani et al. / Crop Protection 47 (2013) 49e54 Table 1 Incidence and severity of root-knot nematodes in subdivisions of the districts of Pothowar region. District
Subdivision
Mean incidence
Mean intensity
Rawalpindi
Rawalpindi Gujjar Khan Kallar Syedan Taxila Kahuta Murree Kotlisattian Average Hasan Abdal Hazro Attock Fateh Jang Jand Pindi Gheb Average Jhelum Pind Daden Khan Sohawa Dina Average Chakwal Choa Sayadan Shah Talagang Kallar Kahar Average
17.78 3.16 21.67 3.98 23.33 3.45 31.11 4.34 24.17 4.51 26.11 3.85 6.94 1.62 21.86 1.51 12.50 3.06 15.83 4.70 15.83 3.48 8.06 2.72 13.61 3.52 17.50 2.40 13.89 1.38 10.56 2.86 14.44 3.68 7.78 2.15 11.11 3.04 10.97 1.49 13.06 2.69 15.56 3.02 10.28 2.73 10.00 2.74 12.22 1.39 15.66 0.78
3.33 0.60 3.61 0.76 4.83 0.62 5.39 0.64 3.44 0.67 4.33 0.50 1.53 0.39 3.79 0.25 2.61 0.60 2.78 0.75 3.44 0.72 1.56 0.50 2.56 0.71 3.00 0.38 2.66 0.26 1.78 0.48 2.33 0.60 1.22 0.32 2.17 0.57 1.86 0.25 2.50 0.47 2.72 0.51 1.83 0.47 1.72 0.47 2.19 0.24 2.80 0.13
Attock
Jhelum
Chakwal
Overall mean
51
Rawalpindi district, while the minimum (1.86) was observed in Jhelum district. The mean severity of root-knots in the districts of Attock and Chakwal were 2.66 and 2.19, respectively, as shown in Table 1. Differences in root-knot severity were also observed among subdivisions of each district. In Rawalpindi district, the maximum severity of 5.39 was observed in Taxila, while the minimum was in Kotlisattian. The rest of the subdivisions showed severities above 3. In Attock district, the Attock and Pindi Gheb subdivisions showed severities above 3, while a minimum severity of 1.56 was recorded in Fateh Jang. The mean severities of root-knot nematodes were found to be lower in subdivisions of Jhelum and Chakwal and ranged from 1.22 to 2.72, as given in Table 1. The dendrogram in Fig. 2, constructed on the basis of severity of root-knot nematodes, formed two main clusters at a linkage distance of 2.5. There are three subdivisions in Cluster-1 viz. Taxila, Murree and Kallar Syedan with mean severities of 5.39, 4.33 and 4.83, respectively. All of the subdivisions in this group fall within Rawalpindi district. The second cluster was comprised of the rest of the subdivisions, with mean severities ranging from 1.22 to 3.33. The second cluster is also divided into two sub-clusters. In sub-cluster 2A, the subdivisions of Sohawa, Kallar Kahar, Talagang, Jhelum, Fateh Jang and Kotlisattian showing mean severities of root-knot nematodes from 1.22 to 1.83 are included, while the subdivisions included in sub-cluster 2B ranged in severity from 2.17 to 3.33. 3.3. Occurrence of root-knot nematode species
It is evident from the dendrogram in Fig. 1 that based on incidence, two main clusters were formed. Cluster-1 consisted of five subdivisions viz. Taxila, Murree, Kahuta, Kallar Syedan and Gujjar Khan with a mean incidence above 20%. All of the subdivisions in this group fall in Rawalpindi district. The rest of the subdivisions formed cluster-2, with mean incidences below 18%. Cluster-2, in turn, can be subdivided into two sub-clusters. Sub-cluster 2A includes subdivisions showing mean incidences from 6.94 to 11.11%, while sub-cluster 2B includes the subdivisions of Pind Daden Khan, Choa Sayadan Shah, Attock, Hazro, Pindi Gheb and Rawalpindi with mean root-knot incidences ranging from 14.44 to 17.78%. 3.2. Severity of root-knot nematodes The maximum mean severity (3.79), measured in terms of the galling index as suggested by Bridge and Page (1980), was found in
The different species of Meloidogyne associated with cucumber in different districts are given in Table 2. Of all the associated species of root-knot nematodes, M. incognita constituted 78.53%, M. javanica 19.03%, M. arenaria 1.82% and M. hapla 0.62%. Of the four main Meloidogyne species, three viz. M. incognita, M. javanica and M. arenaria, were found in all districts of the Pothowar region, while M. hapla was recorded only from Rawalpindi and Attock. M. incognita was predominant in all the four districts. The individual percentages of each Meloidogyne species in each district are given in Table 2. In Rawalpindi district, the percentage of M. incognita was the highest in Kahuta and Taxila, 90.00 and 88.33%, respectively, and the lowest (47.5%) in Gujjar Khan. Regarding M. javanica, it was found to the highest degree in Gujjar Khan and the lowest in Kahuta. M. hapla was recorded only from Murree and Kotlisattian, 9.33 and 3.33%, respectively. On the other hand, M. arenaria was recorded from Rawalpindi and Gujjar Khan, as shown in Table 2. In
Tree Diagram for variables Unweighted pair-group average Euclidean distances
5
14
Linkage Distance
12
Linkage Distance
Tree Diagram for Variables Unweighted pair-group average Euclidean distances
10 8 6 4
4 3 2 1
Fig. 1. Dendrogram showing clusters on the basis of incidence of root-knot nematodes in 21 subdivisions of four districts of Pothowar region.
Rawalpindi
Attock
Kahuta
Gujjar Khan
Jand
Hasan Abdal
Hazro
Chakwal
Pindi Gheb
Choa Sayadan Shah
Dina
Pind Daden Khan
Kotlisattian
Jhelum
Fateh Jang
Talagang
Sohawa
Kallar Kahar
Kallar Syedan
Taxila
0
Murree
Rawalpindi
Hazro
Pindi Gheb
Attock
Choa Sayadan Shah
Jand
Hasan Abdal
Chakwal
Pind Daden Khan
Fateh Jang
Kotlisattian
Jhelum
Sohawa
Talagang
Dina
Kallar Kahar
Gujjar Khan
Kahuta
Kallar Saydian
Taxila
0
Murree
2
Fig. 2. Dendrogram showing clusters on the basis of severity of root-knot nematodes in 21 subdivisions of four districts of Pothowar region.
52
M.Z. Kayani et al. / Crop Protection 47 (2013) 49e54
Table 2 Distribution of Meloidogyne species in subdivisions of the districts of Pothowar region. District
Subdivision
Rawalpindi
Rawalpindi Gujjar Khan Kallar Syedan Taxila Kahuta Murree Kotlisattian Average Hasan Abdal Hazro Attock Fateh Jang Jand Pindi Gheb Average Jhelum Pind Daden Khan Sohawa Dina Average Chakwal Choa Sayadan Shah Talagang Kallar Kahar Average
Attock
Jhelum
Chakwal
Overall Mean
Percentage of Meloidogyne species M. incognita
M. javanica
M. hapla
M. arenaria
58.67 47.50 84.00 88.33 90.00 67.33 83.33 74.17 77.92 86.25 70.83 80.56 85.56 83.33 80.74 85.00 88.33
36.67 40.83 16.00 11.67 10.00 23.33 13.33 21.69 22.08 13.75 17.92 19.44 14.44 16.67 17.38 9.44 8.89
0.00 0.00 0.00 0.00 0.00 9.33 3.33 1.81 0.00 0.00 3.33 0.00 0.00 0.00 0.56 0.00 0.00
4.67 11.67 0.00 0.00 0.00 0.00 0.00 2.33 0.00 0.00 7.92 0.00 0.00 0.00 1.32 5.56 2.78
84.44 86.11 84.93 82.08 70.00
11.67 13.89 12.25 14.17 30.00
0.00 0.00 0.00 0.00 0.00
3.89 0.00 2.82 3.75 0.00
85.56 59.44 74.27 78.53
14.44 40.56 24.79 19.03
0.00 0.00 0.00 0.62
0.00 0.00 0.94 1.82
other districts, M. incognita and M. javanica were recorded with varying degrees, with M. incognita being predominant in all of the subdivisions. M. hapla was recorded in subdivision Attock only and not in any of the subdivisions of Jhelum and Chakwal districts. On the other hand, M. arenaria was recorded only from Attock and Chakwal subdivisions. In Jhelum district, M. arenaria was found in all of the subdivisions except Dina, as shown in Table 2. The incidences of pure and/or mixed populations of the four Meloidogyne species are given in Table 3. M. incognita was recorded as a pure population in 29.63% of the villages, while the remaining three species were not found as pure populations in any village. The occurrence of M. incognita and M. javanica as a mixed population was the most common and was observed in 70.37% of villages in the region. Mixtures of M. incognita, M. javanica and M. arenaria were found in 12.34% of the villages, while mixtures of M. incognita, M. javanica and M. hapla were rare (4.94%). M. arenaria and M. hapla did not occur alone with M. incognita but were found in mixtures of M. incognita and M. javanica. M. arenaria and M. hapla were not found together in any of the population mixtures. The individual incidences of pure and mixed populations of Meloidogyne spp. in the four districts are given in Table 3.
4. Discussion The results of the present studies showed variations in the incidence and severity of root-knot nematodes in different districts and their subdivisions in the Pothowar region of Punjab province. Similar results have also been reported by Lamberti et al. (1975), Khan et al. (2005), Shahid et al. (2007), and Kayani et al. (2012a). The reports of these scientists confirm the present findings regarding the incidence, prevalence and occurrence of Meloidogyne species on vegetables. It is clear from the results of these researchers that the cucumber crop is the most susceptible host of Meloidogyne species in vegetable growing areas. The variations in root-knot infestations in the region are attributable to many environmental and edaphic factors, as differences in various climatic and edaphic factors in these districts have been identified. There are reports confirming that the distribution, prevalence, incidence and severity of root-knot nematodes are affected by varying agroclimatic conditions in the areas, including soil type, moisture, soil pH and particular cropping sequence (Taylor et al., 1982; Davide, 1985; Sasser and Carter, 1985; Van Gundy, 1985). The maximum incidence of root-knot disease was found in Rawalpindi district. This high incidence is due to intensive vegetable cropping pattern and the availability of suitable host throughout the year in the district which allowed rapid multiplication of root-knot nematodes. A number of researchers have previously reported that the abundance of root-knot nematodes is highly dependent upon the presence of suitable host plants (Jacq and Fortuner, 1979; Yeates, 1981; Ferris, 1985; Cuc and Prot, 1992). In the present study, M. incognita and M. javanica were found in all subdivisions of all the districts in varying proportions, and M. incognita was predominant. Trudgill et al. (2000) reported that M. incognita and M. javanica were the most widespread root-knot nematode species in the entire country. Similar results have been reported by many other workers (Khan et al., 1993; Campos, 1994; Das and Das, 2000; Bhosle et al., 2004; Ravichandra and Krishnappa, 2004; Rathour et al., 2006). The reported distribution and infestation of Meloidogyne spp. in Pakistan’s soils was M. incognita 52%, M. javanica 31%, M. arenaria 8%, M. hapla 7% and other species approximately 2% (Maqbool, 1987), which further supports the present findings. The overwhelming dominance of M. incognita in the Pothowar region may be related to the favorable climatic conditions, cropping regime and suitability of the host. The temperature range, precipitation and altitude prevailing in the study area all fall within the optimal range for M. incognita (Whitehead, 1969; Idowu, 1981; Taylor et al., 1982; Ploeg and Maris, 1999). These conditions may differentially enhance the multiplication and/or survival of M. incognita over M. javanica, which was found at low densities in the region, as the climatic conditions operating in this region are sub-optimal for M. javanica (Taylor et al., 1982). The greater density of M. incognita in mixed populations of the two species may reflect the competitive edge of M. incognita over M. javanica (Eisenback and Griffin, 1987),
Table 3 Occurrence of four Meloidogyne species in pure and mixed populations in cucumber growing areas of Pothowar region of Pakistan. District
Rawalpindi Attock Jhelum Chakwal Overall
Total No. of villages infested with Meloidogyne spp. populations
Villages with pure M. incognita populations
Villages with mixed Meloidogyne spp. populations M. incognita and M. javanica
M. incognita, M. javanica and M. arenaria
M. incognita, M. javanica and M. hapla
32 23 12 14 81
9 7 4 4 24
23 16 8 10 57
4 2 3 1 10
3 1 0 0 4
(28.12%) (30.43%) (33.33%) (28.57%) (29.63%)
(71.88%) (69.56%) (66.67%) (71.43%) (70.37%)
(12.5%) (8.7%) (25%) (7.1%) (12.34%)
(9.38%) (4.35%) (0.00%) (0.00%) (4.94%)
M.Z. Kayani et al. / Crop Protection 47 (2013) 49e54
a preference for cucumber and a more suitable cropping system (Wallace, 1973). It has also been shown that M. javanica may be the predominant species in regions with a distinct dry season and less than 5 mm of precipitation per month for three or more successive months (Eisenback et al., 1981). M. hapla was only found in Murree, Kotlisattian and Attock. The climate in these subdivisions is cool, humid and mild. These results are in agreement with the findings of Brown (1962), Lamberti (1979) and Walters and Barker (1994), who considered M. hapla a nematode of cooler climates, although this species can also occur in tropical countries at high elevations (Sasser, 1979). In our study, M. hapla was detected in mixed populations of M. incognita and M. javanica in areas situated at high altitudes. This finding concurs with previous findings and indicates that M. hapla is predominantly distributed at high elevations (Nono-Womdim et al., 2002). M. arenaria was found in those subdivisions where groundnut was widely cultivated. The occurrence of M. arenaria in combined mixtures of M. incognita and M. javanica but never with M. javanica alone shows that M. arenaria is the least adapted of the four species. The fact that the species was found in all of the districts with M. incognita suggests that the species might have the same range of environmental requirements as M. incognita. Taylor et al. (1982) also observed the phenomenon of M. arenaria only occurring in mixtures together with M. incognita and M. javanica in a similar ecological zone as in the present study. It is concluded from the present studies that cucumber is severely attacked by root-knot nematodes, particularly M. incognita, warranting the adoption of strict control measures for its management (Hussain et al., 2011b; Kayani et al., 2012b; Vagelas and Gowen, 2012; Mukhtar et al., 2013a, 2013b). Acknowledgments The assistance and cooperation rendered by the local farmers in the areas visited is gratefully acknowledged. References Ahmad, R., Khan, I.U., 1973. Root-knot of potato in West Pakistan. Plant Dis. Rep. 57, 505e506. Anwar, S.A., Gorsi, S.S., Anwar-ul-Haq, M.M., Rehman, T.T., Yousuf, P.P., 1991. Plant parasitic nematodes of some field, vegetable, fruit and ornamental crops. J. Agric. Res. 29, 233e249. Anwar, S.A., Khan, M.A., Tahir, A.A., 1992. Plant parasitic nematode problems of some field, vegetable, fruit and ornamental crops in the Punjab, Pakistan-II. Proc. Parasitol. 14, 84e98. Anwar, S.A., McKenry, M.V., 2012. Incidence and population density of plantparasitic nematodes infecting vegetable crops and associated yield losses in Punjab, Pakistan. Pak. J. Zool. 44, 327e333. Begum, N., Haque, M.I., Mukhtar, T., Naqvi, S.M., Wang, J.F., 2012. Status of bacterial wilt caused by Ralstonia solanacearum in Pakistan. Pak. J. Phytopathol. 24, 11e20. Bhosle, B.B., Mukesh, S., Puri, S.N., Suvasish, D., 2004. Prevalence of phytophagous nematodes in rhizosphere of okra (Abelmoschus esculentus L. Moench.) in Parbhani District, Maharashtra, India. Ind. J. Nematol. 34, 56e59. Bridge, J., Page, S.L.J., 1980. Estimation of root-knot nematode infestation levels on roots using a rating chart. Trop. Pest Manage. 26, 296e298. Brown, K.F., 1962. A Survey of Some Plant Parasitic Nematodes Problems in Pakistan. Shell International Chemical Company Co. Ltd, 9 pp. Campos, V.P., 1994. Diseases caused by nematodes in artichoke, lettuce, chicory, strawberries and okra. Informe-agropecuario-belo-horizonte 17, 17e22. Cuc, N.T.T., Prot, J.C., 1992. Effect of changing the agricultural environment on ufra occurrence in the Mekong delta. Int. Rice Res. Newsl. 17, 25. Das, J., Das, A.K., 2000. Prevalence of root-knot nematodes on vegetable crops in Assam and Arunachal Pradesh. Ind. J. Nematol. 30, 244e245. Davide, R.G., 1985. Summary report on current status, progress and needs for Meloidogyne research in Region VI. In: Sasser, J.N., Carter, C.C. (Eds.), An Advanced Treatise on Meloidogyne. Biology and Control, vol. 1. North Carolina State University Graphics, Raleigh, North Carolina, pp. 369e372. Eisenback, J.D., Griffin, G.D., 1987. Interactions with other nematodes. In: Veech, J.A., Dickson, G.W. (Eds.), Vistas on Nematology. Society of Nematologists, Inc, Hyattsville, MD, USA, pp. 313e320. Eisenback, J.D., Hirschmann, H., Sasser, J.N., Triantaphyllou, A.C., 1981. A Guide to the Four Most Common Species of Root-knot Nematodes (Meloidogyne Species),
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