Effect of Five Organic Soil Amendments on Meloidogyne Incognita Infecting Tomato Plants under Greenhouse Conditions

A pot experiment was conducted in order to study the impact of time application of four animal manures i.e. chicken, horse, farm-yard and pigeon manures and town refuse added separately either pre or post planting treatments comparing to oxamyl on tomato plant cv. Castle Rock infected with M. incognita under greenhouse conditions (25±3C). Results revealed that all tested materials clearly enhanced plant growth characters to great degree and reduce gall and eggmass numbers. Plant receiving pigeon manure as pre-planting or post planting applications at the level of 5g/plant obviously surpassed other tested animal manures and town refuse in the increment values of plant length (85.7 and 71.4%), total plant fresh weight (66.4 and 37.9%) number of flowers (100 and 100%), fruits (300 and 400%), and branches/plant(100 and 300%) and shoot dry weight (42.9 and 38.1%), as well as achieved the highest reduction percentage for number of root galls(89.1 and 81.5 %), eggmasses (90 and 84.2%), for pre or post planting applications, respectively followed by farm-yard manure where as chicken treatment as a pre-planting soil amendments exhibited the lesser values in this respect. All treatments obviously gave sizeable percentage increase values of nitrogen (N), phosphorus(P), potassium(K), organic matter(O.M), and organic carbon(O.C) in leaves of tomato plant. The pigeon or chicken manures showed also very narrow C/N ratio (12.6:1) or (14.3:1), respectively, in this work. Among the tested materials, pigeon manure ranked first in percentage increase values of chemical components of leaves as pre-planting application, whereas chicken manure showed this position as post-planting treatment.


INTRODUCTION
The root-knot nematode, Meloidogyne incognita is the major nematode species that parasitize economic plants in Egypt ( Ibrahim and El-Saedy, 1976). Tomatoes are one of the most common vegetable fruits in Egypt. Phytonemtodes especially the root knot nematode is known to be the most common tomato pests. Moreover, it is well known that nematicides are costly and potentially harmful to the environment. Meanwhile, the improvement in plant growth and yield criteria after the addition of organic matter due to the disinfection of such animal manure as fertilizers were recorded by several investigators (Siddiqui and Alam 1988, El-Sherif et al., 2001, 2004, 2006. Organic soil amendments have been widely used for management of plant-parasitic nematodes. Relatively rapid declines in nematode population levels may occur when decomposing organic materials release toxic compounds, while longer-term effects might include increases in nematode antagonists. Improved crop nutrition and plant growth following organic amendments use may lead to tolerance of plant-parasitic nematodes (McSorley, 2011). Decomposing organic matter is food for many soil microbes i.e. fungi, actinomycetes, and bacteria. Some of those creatures are natural enemies of plant nematodes; increasing their numbers enhances "natural" nematode control (Crow and Dunn, 2013). Therefore, the present investigation was carried out to study the effect of five organic soil amendments i.e. chicken, horse, farm-yard and pigeon manures; and town refuse on M. incognita infecting tomato plants under greenhouse conditions.

MATERIALS AND METHODS 1. Nematode stock culture, propagations and preparing nematode inoculum:
To collect and determine the inocula of Meloidogyne incognita eggs; M. incognita was previously identified according to Taylor et al. (1955). Infected root systems with heavy eggmasses of M. incognita of various growing coleus, Coleus blumei plants, grown in 25 cm-diam plastic pots filled with sterilized clayey soil, at the Nematology Research unit (NERU). Unit, Agricultural Zoology Department, Faculty of Agriculture, Mansoura University, Egypt, were well washed and cleaned by running tap water, then placed in a plastic container with enough solution of 1.0% NaOCl for 60 seconds, shaked vigorously (manually) then quickly passed through nested sieves and thoroughly washed the collected eggs with tap water to remove the bleach (Hussey and Barker, 1973) . Eventually, the number of eggs per unit volume of water was counted and then plants were inoculated directly with eggs according to the design of each experiment of this work which was carried at the greenhouse of Nematological Research Unit (NERU).

3-Preparation of Organic soil mterials:
Four animal manures i.e. chicken, horse, farm-yard and pigeon-dung, ; and town refuse were separately collected, sun-dried on a sheet of paper and kept within a plastic bag until use, where the dose of each was 5g/plant/pot that added according to the design of each experiment.

4-Influence of five Organic Materials on Adjusting Meloidogyne incognita Infecting Tomato plants comparing to Oxamyl under Greenhouse Conditions (25±3 o c).
In order to examine the impact of four organic manures ,i.e. chicken ,farm-yard ,horse ,and pigeondung; and town refuse in comparison with oxamyl at the recommended dose on controlling Meloidogyne incognita infecting tomato plant cv. Castle Rock under greenhouse conditions (25±3 o c),fifty two plastic pots(15cm-diam.)containing 1600g steamsterilized clay sand (1:1,v:v)with one tomato seedling 30 days old each were used in this study. Two trials with twenty pots each ,one as a pre-planting and the other as a post-planting applications were included .Pots of the first trial received the dose of tested organic materials as soil amendments at the level of 5g/pot mixed with soil, irrigated with tap water and left for decomposition one week before tomato seedling transplanting . One week later, the dose of tested materials separately mixed with soil at the level of 5g/pot for four replicates each of the postplanting trial: One week after that ,1000Meloidogyne incognita eggs separately added to forty eight pots (seedlings), where four seedlings with nematode received oxamyl at the rate of 0.3ml per pot (seedling),four seedlings (pots) with nematode only and another four seedlings (pots) without nematode and any treatment. Each treatment was replicated four times. Treatments were as followed: A-Pre-planting trial: 1-N+chicken manure(5g/pot), 2-N+ farm yard manure(5g/pot), 3-N+horse manure (5g/pot), 4-N+ pigeon dung (5g/pot), 5-N +town refuse (5g/pot), B-Post-planting trial: 6-N+chicken manure (5g/pot), 7-N+farmyard manure(5g/pot), 8-N+horse manure (5g/pot), 9-N+pigeon dung (5g/pot), 10-N+town refuse (5g/pot), 11-N+oxamyl (0.3ml/pot), 12-N alone and 13.plant free of Nematode and any treatment.
Plastic pots were then arranged in randomized and complete block design in the greenhouse and treated horticulturally, protected against mites and insects by conventional pesticide, and irrigated with tap water as needed. Plants were harvested after 45 days from nematode inoculation and plant growth parameters i.e. shoot and root length and fresh weights as well as dry weights, number of branches, flowers and fruits/plant were determined and recorded .Infected roots of each plant per treatment were washed with tap water, fixed in 4% formalin for 24h and then examined for the number of galls and eggmasses per root system and recorded. The root gall index (RGI) and egg mass index (EI) were estimated according to the scale given by Taylor and Sasser (1978) as follows: 0= no galls or egg-masses, 1= 1-2 galls or egg-masses, 2= 3-10 galls or egg-masses, 3= 11-30 galls or egg-masses, 4= 31-100 galls or egg-masses and 5= more than 100 galls or egg-masses  Table (  , and shoot dry weight(9.5%), respectively, whereas, chicken manure and town refuse as soil amendments treatments at the level of 5g/plant each (post-planting) achieved the lesser values of the same plant growth characters and were on par in their values comparing to nematode alone, respectively. Oxamyl as a systemic nematicide ranked first in percentage increase values of plant length(86.8%), total plant fresh weight(82.8%), number of flowers(100%), branches(217.5%) and fruits (300%)/plant; and shoot dry weight(85.7%), respectively, comparison to nematode alone( Table 2).

Data in
It is worthy to note that plant receiving none of any treatments and no nematode gave reasonable percentage increase values of plant length(7.1%), total plant fresh weight(8.6%), number of flowers/plant(zero%), number of branches(25%), number of fruits/plant(60%), and shoot dry weight(4.8%) as compared to nematode alone, respectively. (Table  2).  (Table 3).
Oxamyl as a systemic nematicide at the recommended dose significantly ranked first in reduction percentage values of root galls and eggmasses number which were amounted to 90.9 and 99.5%, respectively as compared to nematode alone (Table 3). Likewise, significant results were also observed between eggmasses indices of all tested materials as pre-planting applications and nematode alone, since they ranged from 3 for chicken, farmyard, horse manures and town refuse or 2 for pigeon manure vs 4 for nematode alone .Similar results were recorded in the case of root galls indices that were appointed to 3 for the tested materials vs. 5 for nematode alone, whereas Oxamyl showed root gall and eggmasses indices values of 2 and zero vs 5 or 4 for nematode alone, respectively (Table 3).
Data in Table (4) revealed the reduction percentages of Meloidogyne incognita numbers of root galls and eggmasses on tomato root system as influenced by the addition of soil amendments such as chicken, farm-yard, horse, and pigeon manures; and town refuse at the level of 5g/plant as post-planting applications in comparison with oxamyl at the recommended dose in the greenhouse conditions (25±3 o C). Results obviously indicated that number of root galls and eggmasses of Meloidogyne incognita on tomato plant root system were affected by the organic materials added as post-planting treatments in comparison to nematode alone ( * Each figure is the mean of four replicates. Means in each column followed the same letter(s) did not differ at P<0.05 according to Duncan , s multiple-range test.   (Table 5) or post-planting (Table 6) applications comparing to oxamyl at the recommended dose under the stress of Meloidogyne incognita infection in the greenhouse coditions. In general, all treatments obviously gave considerable percentage increase values of all tested chemical components of tomato leaves (Tables 5&6). It is interesting to observe that pigeon manure as preplanting applications accomplished the highest percentage increase values of N (65.2%), P (44.8%), K (43.1%), O.M (9.8%). O.C (30.0%) with C/N ratio 13.5:1, as compared to nematode alone (Table 5) followed by town refuse and chicken manure treatments, whereas horse manure assigned the intermediate position in percentage increase values of all items tested. In the meantime, farm-yard manure showed the lowest percentage increase values that averaged 33.5, 20.3, 18.1, 5.5 and 5.5% for N, P, K, OM and O.C with C/N ratio of 11.89: 1, respectively comparing to nematode alone (Table 5). It is worthy to note that applying such manures or town refuse as pre-planting treatments for tomato plants gave better results in improving chemical components of leaves than as post-planting applications. Moreover, among the materials tested, pigeon-manure ranked first in percentage increase values of chemical components of leaves when applied as pre-planting , (Table 5) whereas, chicken manure showed this position when applied as post-planting treatment ( Table 6). Oxamyl as a systemic nematicide surpassed all tested treatments in Tables (5 & 6) in increasing percentage values of N (67.4%), P(46.0%), K(40.9%), OM(11.1%), O.C(9.0%) with C/N ratio of 11.42:1 as compared to nematode alone, respectively.   (7) showed the nutrient constituents analysis of the tested organic soil amendments i.e. town refuse; chicken, horse, and farm-yard manure which varied remarkably in amounts of ammonium (in form of nitrogen), phosphorus, potassium, organic matter, organic carbon/nitrogen ratio. Apparently, using animal manures and town refuse added as pre-planting or post planting treatments succeeded to improve tomato plant growth criteria and diminish nematode parameters as well as achieved the high percentage increase values of N, P , K , C , O.M and total phenol comparing to nematode alone. Plant receiving pigeon manure as pre-planting or chicken manure as post-planting application at the level of 5g/plant surpassed other tested animal manures and town refuse in the increment values of plant growth parameters and reduce nematode criteria as well. These findings are in agreement with those of Gad (2008) in respect to effect of organic manure on development of M. javanica infecting peanut plant. Organic amendments enhance soil fertility, improve biological and physical properties of soil, help in controlling root-knot nematodes and increase plant growth, since the majority of nitrogen in pigeon manure is in the form of uric acid and can be rapidly converted to ammonium nitrogen if temperature, pH and moisture are suitable for microbial activity (Sims and Wolf, 1994). The ammonium produced has been shown to kill parasitic nematodes (Eno et al., 1955).
Moreover, plants with fewer root galls would translocate more nutrients to vegetative organs than heavily galled roots (Oteifa and El-Gindi, 1962). The pigeon or chicken manures showed also very narrow C/N ratio (12.6:1) or (14.3:1) in this work, a situation that can be supported by the findings of Miller and Donahue (1990) who reported that organic residues with C: N ratio of 20:1 or narrow have sufficient nitrogen to supply the decomposing microorganisms and also to release for plant use. Improving of plant growth of tomato may be attributed to nematode elimentation and to the improvement of soil nutrients status (Akhtar and Mohamoud, 1996;Firoza and Maqbool, 1996). These result indicated that the tested organic matters showed positive effect on M. incognita development on tomato plant. These findings are in accordance with those reported by Akhtar and Mahmoud (1997) in respect to ammonia. Obviously, the present investigation showed that the nematicidial activity of the tested soil organic amendments against M. incognita on tomato can be varied from component to another. These differences may be due to the variation in the chemical nature composition concentration of both toxin materials present in these tested compounds and methods of adding followed. The safely of such materials and their low cost is on of their advantages. However, additional research work is needed using the integrated of more than one materials of such organic matters both in microplot and field experiments before recommendations can be made for integrated pest management (IPM).