ABSTRACT
Influence of nematicidal activity of either Jatropha curcas or J. gossypiifolia as a intercropping with sunflower cv. Giza 1 (1, 2, 3 and 4 jatropha plants per pot) for control of Rotylenchulus reniformiswas carried out under a greenhouse conditions . The nematode final population and the rate of reproduction were significantly (P≤ 0.01) affected by the number of both Jatropha species when grown with sunflower together. Also, a negative relationship was found with the seedlings number of both jatropha species and both the final nematode population and rate of nematode reproduction. The lowest nematode final population and rate of reproduction were determined at the highest number of both jatropha plants (4 plants per pot). The highest value of nematode reproduction (5.5) was found on sunflower plants grown alone, while, the lowest values (0.5 and 1.6) was found on sunflower plants grown with four plants of J. curcas and J. gossypiifolia; respectively. Eventually, J. curcas plants were more effective against the reniform nematode, R. reniformis than J. gossypiifolia did. Therefore, this type of control is considered easy, pollution-free and inexpensive.
Keywords: Control, Rotylenchulus reniformis, Intercropping, Jatropha curcas, J. gossypiifolia
Introduction
The fast growing population in our country has necessitated increased food production and this in turn has put tremendous pressure on our environment. Nematodes comprise a large phylum of animals that includes plant and animal parasitic nematodes which obtaining nutrition only from the cytoplasm of living plant cells Rotylenchulus reniformis is a major phytonematodes, is extremely polyphagus and attacks many annual and perennial crops affecting quality and quantity of the crop production. Nematodes are difficult control because of their wide host range and high rate of reproduction, with females capable of producing up to thousand eggs. Chemical nematicides which used in reducingR. reniformis are often phytotoxic, cause environmental pollution endangering the life of many animals including fish (Landu and Tucker, 1984) and even contaminate ground water and leave undesirable residues in edible parts of plants (Lue et al., 1984). Because of these inconveniences scientists identified natural products with nematicidal activity such as nematotoxic plants (Yassin and Ismail, 1994, Dhangar et al., 1995, Javed et al., 2008, Claudius- Cole et al., 2010, Abdelnabby and Abdelrahman, 2012 and Onyeke and Akueshi, 2012). Several benefits may result from the identification of the specific antagonistic phytochemicals to plant nematodes, whether they occur in a field or a laboratory. These compounds can be developed for use as nematicides themselves, or they can serve as model compounds for the development of chemically synthesized derivatives with enhanced activity or environmental friendliness (Chitwood, 2002). In this respect, J. curcas and J. gossypiifolia (physic nut or purging nut), perennial plant belonging to Euphorbiaceae family considered economic plants as multipurpose plants, the plant is drought resistant and used as ornamental purpose, as an oil crop, for cosmotic industry, and used as a medicinal plants by using their seeds against constipation, the sap for wound healing and leaves as tea against malaria (Adebowale and Adedire,2006, Hussein et al.,2012 and Taha et al.,2013). Also, the by-products are press cake a good organic fertilizer and oil contains also insecticide (Gubitz et al., 1999 and Hussein et al., 2012). Moreover, Jatropha plants either J.curcas or J. gossypiifolia have been found suppress the population of Meloidogyne incognita by releasing toxins into the soil when used their plant extracts, powdery leaves, adding fresh leaves or grown with susceptible crops as a interculture (Umeh and Ndana, 2010, Ugwouke et al., 2011, Ganai et al., 2013 and Ismail, 2014; respectively). Ugwouke et al. (2011) and Ganai et al. (2013) proved that powdery leaves or fresh leaves of J.curcas to be the best among other different treatments against M. incognita under both laboratory and greenhouse conditions. The aim of this work was to assess the effectiveness of various numbers of each two species of J. curcas and J. gossypiifolia as an intercropping with sunflower plants cv. Giza 1 against R. reniformis under greenhouse conditions.
Materials and Methods
Fifteen days old seedlings of sunflower CV. Giza 1 grown in sterilized soil were transplanted singly in 25 cm clay pots containing 3 kg sterilized sandy loam soil (1:1 w:w). The seedlings were inoculated with about 3000 unswollen females of R. reniformis per pot after four days from planting time. Three days after inoculation, one to four seedlings of each 21 days old physic nut or purging nut, J. curcas and J. gossypiifolia grown in sterilized soil were transplanted into the periphery of each pot with six replicates. Seedlings planted without jatropha plants served as a control. All pots were arranged in a randomized complete block design under a greenhouse conditions at 25 ± 5 ºC. Fifty five days after inoculation, sunflower plants were uprooted, the nematode numbers were determined. Juveniles in soil were extracted by sieving and decanting technique according to Barker (1985). Also, the nematode numbers from roots were extracted by incubation method based on Southey (1970). The rate of reproduction (RR) was determined according to Oostenbrink (1966) as follows: final nematode population (Pf) / initial nematode population (Pi).The obtained data were statistically analyzed by using the Fisher ,s Least Significant Differences (LSD) based on Snedecor and Cochran (1980).
Results and Discussion
The two species of jatropha plants were found to be inhibited reproduction of R. reniformis (tables 1 and 2) as compared with sunflower plants grown alone. The evaluated numbers of jatropha plants significantly (P≤ 0.01) reduced the nematode population on roots, number of juveniles in soil. Accordingly, Pf and RR valueswere greatly suppressed. Also, there was a positive relationship between number of jatropha plants and % reduction in Pf. In this respect, treatment with 4 plants of J. curcas and J. gossypiifolia were achieved the greatest reduction in Pf(91.0 % and 71.1%; respectively). In contrast, there was a negative relation between the number of both jatropha species plants and the RR which attained 5.5 folds with sunflower alone. However these values weredecreased gradually as jatropha plants increased until achieved the lowest folds as 0.5 and 1.6 with sunflower plant growing together four plants of J.curcas or J. gossypiifolia; respectively (Tables 1 and 2).
Table1. Effect of Jatropha curcas as an intercropping with sunflower cv. Giza 1 on development and reproduction of Rotylenchulus reniformis
| Treatments | Nematode numbers * | Rate of
reproduction ** |
|||
| In root | In soil | Total | Reduction (%) | ||
| Sunflower alone (Control)
Sunflower + one plant of J. curcas
Sunflower + two plants of J. curcas
Sunflower + three plants of J. curcas
Sunflower + four plants of J. curcas
LSD 0.05 LSD 0.01 |
1745
800
750
605
134
127.1 152.9 |
14876
6100
4650
2095
1366
596 709 |
16621
6900
5400
2700
1500
951.6 1150.3 |
–
58.5
67.5
83.8
91.0
– – |
5.5
2.3
1.8
0.9
0.5
– – |
*Each value is a mean of six replicates. **Rate of reproduction = Pf / Pi, where Pf = final population, and Pi = initial population.
Table2. Effect of Jatropha gossypiifolia as an intercropping with sunflower cv. Giza 1 on development and reproduction of Rotylenchulus reniformis
| Treatments | Nematode numbers * | Rate of
reproduction ** |
|||
| In root | In soil | Total | Reduction (%) | ||
| Sunflower alone
Sunflower + one plant of J.gossypiifolia
Sunflower + two plants of J.gossypiifolia
Sunflower + three plants of J.gossypiifolia
Sunflower + four plants of J.gossypiifolia
LSD 0.05 LSD 0.01 |
1745
1000
850
810
670
113.5 136.5 |
14876
14090
9350
7890
1130
604.2 770.0 |
16621
15090
10200
8700
4800
921.6 1249.6 |
–
9.2
38.6
47.7
71.1
– – |
5.5
5.03
3.4
2.9
1.6
– – |
*Each value is a mean of six replicates. **Rate of reproduction = Pf / Pi, where Pf = final population, and Pi = initial population.
This study state that there was significant (P≤ 0.01) increase in Pf and its RRaround sunflower grown alone, however, in treatments having different numbers of either J.curcas or J. gossypiifolia (1-4 plants/ pot) with sunflower, the Pf and RR decreased (Tables 1 and 2). Eventually, J. curcas plants were more effective against R. reniformis than J. gossypiifolia did. These data indicate that the decrease in the nematode final population and rate of build-up by growing J.curcas or J. gossypiifolia was mainly attributed to the toxic nature of its root exudates. These findings are in conformity with those of Alam et al.(1977), Korayem and Osman (1992), Claudius- Cole et al.( 2010) and Onyeke and Akueshi (2012). They reported that there are many plants which suppress the population of different plant – parasitic nematodes by releasing nematotoxins into the soil, not phytotoxic to the plants, rather they caused increased plant growth. Also, Debnath and Bisen (2008) found that jatropha plants can be used as a green manure, hence can be used as a soil amendment for improving soil properties. Various parts of J.curcas including seeds hold potential for use as a source of oil, animal feed or medicinal preparations (Openshaw, 2000). Taha et al. (2013) mentioned that peroxidase, polyphenol oxidase and esterase are the main enzymes present in J.curcas. Also, they reported that these compounds play a photoprotective role and are considered as bioactive constituents. Researchers correlated different enzymes with the percentage of oil in seeds of Jatropha and found accessions which have greater laccase enzyme activity showed greater oil percentage (kumar et al., 2006). Selection for peroxidase and polyphenol oxidase enzymes activities will improve the nutritive quality of Jatropha. Also, different enzyme activities and their role in several crops and trees for enhancement of the development process have been reported by Andrews et al. (2000) and Tarkka et al. (2001). Moreover, J.curcas and J. gossypiifolia have been found suppress the population of M. incognita by releasing toxins into the soil when used their plant extracts, powdery leaves , adding fresh leaves or grown with susceptible crops as an interculture (Umeh and Ndana,2010, Ugwouke et al.,2011, Ganai et al.,2013 and Ismail, 2014; respectively). Generally, nematicidal phytochemicals are safe for the environment (Chitwood, 2002).These compounds include repellents, attractants, hatching stimulants or inhibitors and nematotoxicants, either constitutive or formed in response to nematode presence (Chitwood, 2002).
Present findings assume potential importance in developing plant-based natural nematicides for nematode control.
Acknowledgement
The author is grateful to Prof. Dr. Mohamed Morsi Hussein, Water Relations and Field Irrigation Department, National Research Center, Egypt, for providing the seeds of jatropha.
References
