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Abstract Results obtained in the present investigation can be summarized as follows: The nematological survey conducted in leguminous fields at El-Nubaria region, El- Beheira governorate revealed the presence of eleven genera of plant parasitic nematodes associated with soil and root samples of leguminous plants. The most prevalent genus was Meloidogyne spp. occurred in 57.0 % of the surveyed samples. The genera Aphelenchus, Aphelenchoides, Tylenchus and Tylenchorhynchus were less frequent, occurring in 11.7-28.0 % of the tested samples. On the other hand, Trichodorus, Hoplolaimus, Heterodera, Paratrichodorus and Ditylenchus were scarce and occurred in 2.2 to 8.6 % of the tested samples. While, the genera Pratylenchus and Helicotylenchus were the least occurrence with 0.9 and 1.6 % FO, respectively. The Tylenchorhynchus, Tylenchus, Meloidogyne, Aphelenchoides, Aphelenchus and Ditylenchus were recorded in samples of three surveyed crops. Nematode genera Paratrichodorus, Hoplolaimus and Heterodera were recovered from bean and faba bean soil samples. But, Helicotylenchus was recovered from bean and peanut soil samples. While, the genus Pratylenchus was found only in soil samples of faba bean. Population as high as 8437.4 juveniles (J2) of Meloidogyne spp. (per 250g soil extract) were recorded. In this respect, the genera Aphelenchus, Aphelenchoides, Tylenchus, Tylenchorhynchus and Helicotylenchus showed counts ranged between 447.1 and 2210.9 juveniles/250g. Pratylenchus, Heterodera, Hoplolaimus, Trichodorus, Paratylenchus and Ditylenchus had an average populations ranged from 30.6 to 310.2 juveniles/250g soil. Results of the present work clarify the presence of M.javanica at El-Nubaria region in El-Beheira governorate was found in galled roots of peanut and M. incognita on galled roots of bean and faba bean. Pathogenicity of five common bean cultivars (Bronco-Contender-Giza3-Nebraska- Paulista) to M.incognita, M.javanica and M.arenaria was investigated. All the tested common bean cultivars were susceptible to M.incognita, M.javanica and M.arenaria. The obtained data showed that bean cv. Giza3, cv. Nebraska and cv. Contender were less susceptible to M. incognita than bean cv. Paulista and cv. Bronco. Also, it was found that bean cvs. (Giza3, Nebraska) were less susceptible to M.javanica than bean cvs. (Paulista, Bronco and Contender). The results showed bean cv. Contender and bean cv. Paulista were susceptible to M. arenaria than bean cv. Bronco, cv. Giza3 and bean cv. Nebraska. Also, results showed that tested root-knot nematodes caused reduction in root and shoot growth compared with uninoculated control. Effect of essential oils Garlic, Thymus, Myrtle and Rosemary on M. javanica spp. Eggs hatching percentage after 7 days from treatment was recorded. The obtained results showed that the concentration of 1.000 μl of the tested above oils significantly reduced egg hatching of M. javanica compared with untreated control. Myrtle oil was the best oil followed by Garlic and Rosemary to reduce M.javanica eggs hatching. While, Thymus oil cause the lowest effect in reducing eggs hatching compared with the other tested oils. In vitro the results indicated that abamectin was the most effective compared with the other tested substances to M. javanica second stage juveniles (J2) with the LC50 values of 2.94, 1.68 mg L-1, followed by fenitrothion with the LC50 values 147.44 and 34.69 mg L-1 and rugby with the LC50 values 976.77 and 163.13 mg L-1. Whereas biofly was the least toxic with the LC50 values 3190.18 and 877.98 mg L-1, respectively after 24 and 48 hrs from exposure to these compounds, . While, abamectin was the highest effective with the LC50 58 value 1.07 mgL-1, followed by rugby (LC50 = 4.76 mgL-1) and fenitrothion (LC50 = 20.64 mgL-1) and biofly was the least toxic (LC50 = 386.48 mgL-1), respectively. after 72 hrs from exposure against J2. Also, results indicated that abamectin was the most effective one in reducing hatching eggs of Meloidogyne javanica after 7 days followed by rugby, fenitrothion, biofly with the LC50 values 1.10, 308.04, 577.69 and 620.62 mg L-1, respectively in reducing hatching eggs of Meloidogyne javanica. Significant differences in inhibition of ACHE and ATPase were observed between second stage juveniles (J2) and eggs applications of abamectin, biofly, fenitrothion and rugby. The organophosphate pesticide rugby has the most inhibitory effects on ACHE of both J2 and eggs of M.javanica at all the concentrations tested. The biopesticide abamectin had the second most inhibitory effect on ACHE enzyme activity in J2 but ranked third in toxicity against the eggs. The organophosphate pesticide fenitrothion had the lowest effect on ACHE regardless of the stage of growth of M.javanica. The inhibitory effects of the organophosphate pesticides Rugby and fenitrothion were much more pronounced on the J2 stage of M.javanica when compared with that of the biopesticides tested. biofly was the least effective biopesticides against the second stage juveniles (J2), while abamectin showed an inhibitory effect on ATPase of J2 only at higher concentrations (4.5 mgL-1). Contrarily, the two biopesticides and the organophosphate pesticide fentro were equally effective against the eggs of M.javanica. The nematicide rugby exerted the least inhibitory effect against eggs ATPase. Effect of the nematicide Vydate (oxymyl 24 % liquid), Citral 95 %, Cumin 98 %, Carvone 98 %, Menthol 98 % and Thymol 99 % on common bean cv. Paulista infected with M. javanca under greenhouse conditions was investigated. The results showed that Vydate ( 96 μl plant-1) ) and Cuminaldehyde ( 250 μl plant-1) gave the highly significant reduction in number of root galls (92.88 and 94.66 %, respectively) and egg-masses (94.89% for them) M.javanca on common bean cv. Paulista. compared with the untreated control followed by Thymol, Carvone, Citral and Menthol (250 μl plant-1) in reducing nematode galls and eggmasses per root system compred with untreated control, respectively. The effect of some biopesticides at a recommended doses on common bean cv. Paulista infected with M.javanica under greenhouse conditions was investigated. Results showed that all the tested doses of biopesticides caused significant decrease in number of galls and egg-masses per root system compared with untreated control. Rugby (20 % L) compound was the highest reduction in root galls and egg-masses. Also, Di-Tera at 0.3 g per plant gave the highly reduction in root galls and egg-masses per roots. followed by B.subtilis, Pseudomonas fluorescens, Paecilomyces lilacinus (wp), Paecilomyces lilacinus(l) and Trichoderma viride in reducing nematode galls and Trichoderma viride, Paecilomyces lilacinus (wp), Pseudomonas fluorescens, Paecilomyces lilacinus(l) and Bacillus subtilis in reducing of egg-masses, respectively. |