Journal of Applied Research in Plant Protection
Year:2018 | Volume:6 | Issue:4 |Papers Count:12

In this study, direct application effects of antagonistic bacteria Bacillus subtilis and Salicylic acid on Fusarium growth Fusarium oxysporoum f. sp. lycopersici examined in vitro, in two formats, contrast test and volatile materials test. Effect of different concentrations of salicylic acid (2-8 mM) on Fusarium growth has tested as a manner mixing with medium. In greenhouse tests induction effects was resuled from application of Salicylic acid and Bacillus subtilison on activity of PAL as one of the most important enzymes in plant defense tomato which infected with Fusarium wilt and Meloidogyne javanica also it was investigated when the two diseases interact with each other. According to the results all Salicylic acid concentrations completely prevented growth of the fungui. In contrast tests and volatile, antagonist bacteria significantly controlled Fusarium that respectively was 34. 8 and 35 %. Evaluation the activity PAL indicated that all treatments including bacteria and Salicylic acid effectively increased level of enzyme activity compared with control and infected plants with fungi and nematodes and highest enzyme activity was in plant treated with pathogens and B. subtilis and salicylic acid on fifth days after inoculation.

Puccinia graminis f. sp. tritici is the causal agent of wheat stem rust disease. This fungus is heteroecious with complete life cycle that its intermediate host plant is barberry (Berberis spp. ) In some areas that urediniospores cannot survive in winter conditions, basidiospores produced from teliospores in feat barberry which result in the survival of the fungus and its transmission to the next season. In this research, samples of barberry leaves showing symptoms of rust disease were collected from North Khorasan, Mazandaran, Golestan, Semnan, Fars, Lorestan and South Khorasan provinces. Host plant species and infecting fungal species were determined based on their morphological characteristics. In addition, the relationship of these fungal species to stem rust of wheat was investigated by inoculating them on two susceptible wheat cultivars Moroco and Local Red. A total of five hybrids and species of barbery as Berberis vulgaris, B. integerrima × vulgaris, B. integerrima × cartingia, B. orthobotrys and B. integerrima were identified as the host. According to morphological characteristics, three fungal species were identified as: Puccinia magelhaenica, P. brachypodii s. lat. And Aecidium berberidis, where none of these species are known as wheat stem rust disease agent. Inoculation of aecidiospores obtained from Barberry species on the susceptible wheat cultivars showed that only two samples produced stem rust symptoms indicating most barberry shrubs in Iran are the host for rust species that are not pathogenic on wheat and may not have significant impact on epidemic of stem rust in the region.

Infections with predominant viruses including Cucumber mosaic virus (CMV), Tomato mosaic virus (ToMV), Tomato spotted wilt virus (TSWV) and Tobacco mosaic virus (TMV) in tomato fields of Azarbaijan-e-Sharqi Province were surveyed. 205 samples showing symptoms such as mosaic, dwarfing, necrosis, leaf narrowing, leaf and fruit deformation were collected from … . and subjected to glasshouse inoculations. Samples suspected to be infected by CMV were first screened against the virus by ELISA, and then RNA were extracted. RT-PCR reactions were performed by the use of CMV-, Tospovirus or Tobamovirus specific primers depending on virus symptoms. Upon optimization of the annealing temperature in the PCR the anticipated bands were amplified corresponding to Tospovirus, Tobamovirus or CMV in 6, 37 and 23 samples, respectively. Restriction analyses with HindIII, EcoRI and XbaI of the fragments which were amplified with Tospovirus-specific primers showed, TSWV wasin all the six samples. In addition, cloning and sequencing of the amplified fragments proved the TSWV identity of the isolates. When the fragments amplified with the Tobamovirus primers were restricted by TaqI the resultant restriction profile revealed ToMV identitiy of the virus in 37 samples, but no TMV was present in the samples. Also, MspI restriction digestion of the fragments amplified with the CMV primers showed that the CMV isolates were placed in Subgroup I. In addition, the resultant data were indicative of high frequency of infection with CMV and ToMV in the collected samples.

Wheat as the most strategic agricultural crop has an important role in food security, and so the most cultivation area among the agronomic crops, belongs to wheat. Fungi associated with root and crown of wheat, are effective on crop production and yield. Therefore, in order to identify mycobiota of wheat root and crown in Zanjan province, sampling was carried out from 58 rainfed and irrigated wheat fields during cultivation season of 2011. Out of 286 fungal isolates obtained, 248 isolates belonged to hyphomycetes as identified morphologically. Sequence data of ITSrDNA region was used to confirm the identify of the isolates. Accoreding 10 genera and 23 species of Alternaria alternata, A. atrum, A. chlamydospora A. tenuissima, Aspergillus auricomus, A. niger, Bipolaris sorokiniana, Botrytis cinerea., Curvularia australiensis, C. inaequalis, Fusarium acuminatum, F. avenaceum, F. chlamydosporum, F. equiseti, F. redolens, F. sambucium, F. scirpi, F. solani, F. tricinctum, Microdochium nivale, Periconia circinata, Penicillium chrysogenum, Trichoderma atroviride were identified. Pathogenicity test of some fungal isolates were conducted based on completely randomized design with three replications under greenhouse condition. According to the results B. cinerea, B. sorokiniana, F. avenaceum, F. acuminatum, P. circinata, C. australiensis, F. equiseti, F. solani and A. chlamydospora caused disease with different severity on their host. Among the species, B. cinerea, B. sorokiniana, F. avenaceum and F. acuminatum caused visible root necrosis. A. auricomus was isolated for the first time from wheat rhizosphere in Iran. This study is the first report of A. tenuissima, B. cinerea, C. inaequalis, E. chlamydospora, F. avenaceum, F. chlamydosporum, F. scirpi, F. tricinctum, M. nivale (= F. nivale), P. circinata, P. chrysogenum and T. atroviride from Zanjan province. Also this is the first report of the pathogenicity of B. cinerea on wheat in Iran.

Fusarium head blight (FHB), caused by various species of Fusarium particularly Fusarium graminearum, is one of the destructive diseases of wheat in Iran especially in northern parts of the country. In addition to reducing wheat yield and quality, the disease is important due to potent mycotoxin production by the pathogens. The present study was carried out to evaluate the responses of 117 accessions of wheat landraces from the collection of Cereal Research Department (CRD), Seed & Plant Improvement Institute (SPII), Karaj, Iran to FHB under field and greenhouse conditions. Based on the results of spray-inoculated field experiments, 31 out of 117 genotypes were detected to be resistant to FHB with mean disease index ≤ 10%. It seems that at least 21 genotypes have a genetic basis, possessing Type I resistance. Results of greenhouse experiments using point inoculations showed that all genotypes were susceptible which may refer to lack of Type II resistance among the genotypes tested. Considering the presence of Type I resistance among the considerable number of accessions tested, which can largely keep the product clean of the disease under field conditions, these genotypes may be used as FHB-resistant parents in wheat breeding programs in order to transfer disease resistance into commercial cultivars.

In this research, the biochemical properties of galactosidase enzymes in the gut, salivary glands and hemolymph of the fall web worm, Hyphantria cunea Drury (Lepidoptera: Arctiidae) larvae were studied. The results revealed that with the measuring of the enzyme activity in different larval instar, the maximum activity was observed in 5th instar larvae. The optimal pH for α-galactosidase in the gut of H. cunea was 7 and for β-galactosidase in the gut, salivary glands and hemolymph were 7, 7 and 6 respectively. The optimal temprature for α – galactosidase activity in the gut of H. cunea was 45° C and for β-galactosidase in the gut, salivary glands and hemolymph were 45, 45 and 55° C, respectively. The activity of α-galactosidase was significantly increased by adding K+ ion (10 mM) compared with the control. Urea (4 mM) and SDS (8 mM) showed the greatest inhibition of α-and β-galactosidase activities, respectively.

Tuta absoluta (Meyrick) is one of the most important pests of tomato crops in Iran. In this study, the pathogenecity of the entomopathogenic fungi, Beauveria bassiana isolate Iran 1395C and Metarhizium asisopliae isolate Iran 1018C and a commercial formulation of Bacillus thuringiensis was evaluated against 2nd instar larvae of this pest. The experiments were performed by leaf dipping bioassay method at 25 ± 1° C and 70 ± 5% R. H. under laboratory conditions. The results showed that B. bassiana alone and in combination with M. anisopliae, caused more than 80% mortality in T. absoluta larvae seven days after treatment. The lowest LT50, 35. 84 and 28. 25 h, was observed in these two treatments, respectively. The mortality rate for B. thuringiensis was about 65%, seven days after treatment. There was no significant difference between mortality caused by B. tharingiensis and B. bassiana. However, M. asisopliae isolate Iran 1018C showed significantly lower effect than B. bassiana Iran 1395C and B. thuringiensis against T. absoluta larvae.

Egg parasitoids have important role in reducing pest populations. Trissolcus vassilievi (Mayr) is one of the most important biological control agents of the sunn pest. In this study, two populations of both the parasitoid and the host, one from Tabriz and the other from Varamin were used. The functional response experiments were carried out for both populations as well as progeny obtained by reciprocal crosses between them (Tabriz females×Varamin males vs. Varamin females×Tabriz males). The total time of experiment considered to be either 6 or 24 h. Logistic regression analysis revealed that the functional response of T. vassilievi was from type III in all treatments. Parameter estimation also revealed that searching rate (b) and handling time (Th) was close to each other in all treatments. Experiment time had no considerable effect on parasitism rate and only unrealistically increased the handling time and decreased the line slope of the attack rate. Maximum attack rate varied between 42 and 45 in original populations while it reached to a maximum of 47. 5 in crossed populations. Handling time was longer and, parameter b was smaller in Tabriz wasps. This may suggest that attack rate increases more rapidly in Varamin wasps. In other words, they have stronger density dependent response. Host effect was not significant among treatments. This study showed that Varamin wasps have a minor superiority in terms of attack rate and handling time.

The effect of mineral spray oil (MSO) and imidacloprid were compared to control Phyllocnistis citrella Stainton (Lep: Gracillariidae) and Panonychus citri and Phytoseiid predatory mites populations. The first experiment, the average number of mines per leaf by citrus leaf miner larvae in MSO treatment with 700 ml per 100 litres of water, imidacloprid (4 cc/2litres of water) and control were 0. 27, 0. 37 and 2. 95, respectively. Percent larval mortality were 51. 85, 37. 83 and 26. 10%, respectively and Percent pupae were 47. 09, 59. 4 and 73. 8, respectively. The average number of mines per citrus leaf miner larvae in MSO treatments with 900 ml per 100 litres of water, imidacloprid (4 cc/2litres of water) and control were obtained 0. 09, 0. 3 and 2. 9, respectively. Percent larvae mortality were 77. 57, 60. 06 and 26. 1%, respectively and Percent pupae were 11. 01, 36. 23 and 75. 32%, respectively. The second experiment, average number of eggs and developmental stages of Panonychus citri in control using imidacloprid at all sampling dates was significantly higher than the MSO spraying. On the other hand, the number of eggs and developmental stages of Phytoseiid predatory mites in MSO spraying were significantly higher than control using imidacloprid. The results showed that mineral oil was able to control citrus leafminer sufficiently and could be replaced the imidaclopridic pesticide in citrus orchards of Mazandaran province.

Ommatissus lybicus (Hemiptera: Tropiduchidae), is a key pest of date palm in Iran. It causes heavy damages to date palm trees through sucking sap from tender leaves and fruit bunches and secretion high amounts of honeydew which result in trees weakens and lowering the quality and quantity of fruits. The main goal of this study was to compare the insecticidal efficacy of kaolin powder (3%, 5% and 7%) and three formulation of mineral oil (at 1. 5% concentration) with Diazinon insecticide (2 L/1000L) against the first generation of Dubas Bug nymphs in Fars and Kerman provinces during 2013 and 2014 in Iran. In both regions, significant differences were observed between treatments in case of the nymphs' percentage mortality (P≤ 0. 01). Application of Kaolin at 3%, 5%, and 7% concentrations caused 35. 2± 11. 7, 58. 2± 9. 4 and 61. 5± 5. 4% mortality in nymphs on Fars and 49. 5± 6. 3, 70. 5± 2. 3 and 80± 2. 9% mortality in Kerman province respectively. Also, nymphs’ mortality by volk mineral oil in Kerman was 26. 4± 4. 7% while nymphs’ mortality by Partonar and Aria-Shimi mineral oils in Fars province were 41. 7± 12 and 39. 4± 12. 43%, respectively. In conclusion, all three used mineral oil were not effective against nymphs of Dubus bug, but kaolin (7 percent) as a biorational compound, would be a feasible alternatives for Diazinon insecticide in Dubus bug IPM program in studied areas.

Amongst the temperate fruits, the strawberry is an unparalleled crop, and suitable climatic conditions and organic production would make it possible that Iran could be rise as an important producer and exporter. In this study, possibility of using insect-proof screen was evaluated against the two-spotted spider mite (Tetranychus urticae), the western flower thrips (Frankliniella occidentalis), and the strawberry aphid (Chaetosiphon fragaefolii). Infestation of both organic and control greenhouses to the pests, as well as Plant measures (yield and quality average weight per fruit) were compared in organic, control, and commercial greenhouses as CRD. Effects of biorational compounds on the spider mite were evaluated as CRD by the Taguchi’ s method. In the organic greenhouse, infestation levels of the leaves to the spider mite and population abundance of the thrips during one-month sampling interval were always below the economic injury level (EIL) (25% of leaflets infested by mite and 5 thrips/flower, respectively), whereas in the control greenhouse they were always above the EIL. In addition, population abundance of the aphid in control greenhouse was always greater than that of the organic greenhouse (0), but in both greenhouses, population abundance was below EIL (30 aphids/bush). Crop yield in commercial greenhouse (317. 4 g/bush) was higher than that of the organic one (216. 9 g/bush), No significant difference was preset the fruit weight the in between two greenhouses (12. 10 and 11. 91 g, respectively). Twice application of at a two-day interval NeemAzal® (12000 ppm) 40 ml/pot controlled the mite properly. Results suggest that, insect-proof screens of appropriate mesh may prevent entrance of these pests into greenhouses. Futher more the azadirachtin-containing biorational formulations are recommended for use in organic production of strawberry.

Cotton bollworm, Helicoverpa armigera Hü bner (Lepidoptera: Noctuidae) is one of the important pests of agricultural products in the world, including Iran. In this study, the sublethal effects of Bacillus thuringiensis Berliner subsp. kurstaki (Bacillales: Bacillaceae) were evaluated on third instar larva of H. armigera under laboratory conditions 26± 1 ° C, 65± 10% RH and 16: 8 (L: D) photoperiod. The LC20 value of B. thuringiensis on 3rd instar larva of H. armigera was 9. 8 × 105 IU/L. The mean female longevity and fecundity in control and Bt-treatment were 16. 63 ± 1. 05 and 13. 88 ± 1. 05 days and 1336. 83 ± 147. 68 and 1029 ± 147. 68 eggs respectively that in both cases, there was a significant difference. In control and Bt-treatment, the net reproductive rate (R0) were 582. 22 ± 51. 89 and 126. 38 ± 27. 78 f/f/g, the intrinsic rate of natural increase (rm) were 0. 1442 ± 0. 002 and 0. 1082 ± 0. 004 f/f/d, the finite rate of increase (λ ) were 1. 155 ± 0. 003 and 1. 114 ± 0. 004 f/f/d, the mean generation time (T) were 44. 16 ± 0. 62 and 44. 73 ± 0. 62 d and the doubling time (DT) were 4. 80 ± 0. 08 and 6. 41 ± 021 d respectively. Except the mean generation time (T), other population parameters of H. armigera showed a significant difference between control and Bt-treatment. The results indicated that the B. thuringiensis have high potential to reduce the cotton bollworm population and can be recommended for reducing the use of pesticides in the areas where the pest is present.