PLANT PROTECTION JOURNAL
Year:2011 | Volume:3 | Issue:3 (11)|Papers Count:13

According to this research the population dynamics of cabbage aphid and identification the natural enemies in canola farms in the north of the Fars province that have been done during the years 2009 – 2010. Three species of aphids have been known; Myzus persica Sulzer, Brevicoryne brassicae (L.) and Aphis gossypii Glover. The cabbage aphid was the dominate species with 75.5% abundance. M. persicae and A. gossypii with 16.5% and 8% relative abundance in order were in the second ranges. Also in order to consider the population dynamics of cabbage aphid in the selected farms with 2 hectare spaces for each, gathering 30 leaves regularly by random from canola bushes weekly. So on the basis of these samplings it has been considered that the aphid population began at the middle of March until the middle of May at the time of blossom and sheathes was at the highest point, with the average temperature 7.5ºC daily and 77% R.H. Also regarding the natural enemies, 13 species of predatory and 1 species of parasitoid in the Coccinelledae, Syrphidae, Chrysopidae and Braconidae families have been gathered. This study revealed that in the canola farms the peak of natural enemies density occurred after the aphid's population peak of the late growing season. The most abundant predators were as follow: Coccinella septempunctata (L.), Scaeva albomaculata (Macquart 1842) and Chrysoperla carnea (Stephens 1836). Also a species of parasitoid Diaeretiella rapae (M' Intosh 1855) has been found.

Tribolium confosum is one of the most important pests of stored products that can damage the quality and quantity of flour. Using the plant syntheses is one of the best methods to control of stored products pests especially that insecticides have many dangerous effects in environment and the amount of damage is high. The purpose of this research was to compare the efficiency of hexane extracts of some plants oviposition deterrent rate, larvicidal rate and repellency rate against T.confosum: Calotropis procera, Vinca minor, Zygophylum fabago and Delphinium persicum. The results showed that Z. fabago in 50% pure extract was the most effective extract by 60.69% larvicidal percent and V. minor was the least effective extract by 30.41% larvicidal percent. Z. fabago, D. persicum and C. procera were effective in repelling of pests. This extract reduces to oviposition in comparing to control but there was no significant difference between the extracts oviposition deterrent in adults. As these exctacts have repellency, oviposition deterrent and insecticidal effects, can be used as a source to control this pest.

Pteromalidae (Hym.: Chalcidoidea) is one of the largest families of parasitoid wasps. This family includes some important natural enemies of many harmful insects in orders such as Coleoptera, Diptera, Lepidoptera, Hymenoptera and Hemiptera. This research was conducted in Kurdistan Province (in the West of Iran) in 2010 and 2011. Five species of pteromalid wasps has been collected as new records from Iran: Asaphes vulgaris Walker, 1934, Halticoptera longipetiolus Hedqvist, 1975, Oodera monstrum (Nikol’skaya, 1952), Stenoselma nigrum Delucchi, 1956 and Conomorium amplum Walker, 1935.

In this study variation of Peroxidase activity and phenolic compounds were studied after treating with Pichia guilliermondii (A6) and silicon (Si) and inoculation with Penicillium expansum (F1). The samples were taken in zero, second, fourth, sixth and eighth days after pathogen inoculation. The results showed that Peroxidase activity increased during these days and achieved the highest activity in sixth and eighth days. These results indicated that the phenolic compounds were in maximum amount in the second day after pathogen inoculation. These findings emphasized that increase in peroxidase activity and phenolic compounds could be the reason for induction of resistance in apple fruits.

One of the most important destruction reasons of Juniperus aged and Long Lived trees in Jaysh Abad sits of Tarom township is a semi-parasitic plant from Dwarf Mistletoes group of viscaceae family. Biological study done in Jaysh Abad area of Tarom Township and other Juniperus sits in Zanjan province of Iran revealed that this semi-parasitic plant is Arceuthobium oxycedri. For determining the infection percent, intensity, quality and quantity on the host species half hectare sample pieces were randomly selected in 4 geographical directions. The results of this study showed that Dwarf Mistletoes mostly influences trees with bigger crown size, crown area, height and diameter breast height. Also result showed that Juniperus trees in south directions are more infected in comparison with other directions.

Geographic information system (GIS) as a powerful tool can provide comprehensive information to weed researchers. Based on cultivation area in most cities of Markazi province during 5 years (2000-2004), 70 samples of dryland wheat fields were selected and weed species were counted in each sampling point and population indices were calculated. In each field longitude, latitude and altitude were recorded using GPS. These data were used for producing weed maps using GIS. Results showed that dominate broadleaf species were spurge (Euphorbia sp.), salsify (Tragopogon graminifolius DC.), madwort (Alyssum marginatum Steud. ex Boiss), Goldbachia laevigata (M.B.) DC., and dominante grass weed species were downy brome (Bromus tectorum L.), squarosa couchgrass (Eremopyrum bonaepartis (Spreng) Nevski), common rye (Secale cereal L.), in dryland wheat fields.

In this study, Eurytoma iranicola, 2007 (Hymenoptera: Eurytomidae) was determined as a gregarious larval ectoparasitoid of the Rosaceous branch borer Osphranteria coerulescens (Coleoptera: Cerambycidae) in Iran. This biological data is new for this family of parasitoids.

In this experiment was conducted during growing seasons of 2009-2010, rice fields in different parts of rice growing areas in Fars and Ilam provinces to identify Root and crown rots of rice. Cylindrocarpon hederae was identified as the disease agent, by using Booth identification key. In order to determine the pathogenicity of isolates, Anbarboo rice cultiuar was used. This is the First report of the association of root and crown rots of rice and C. hederae in the world.

Cucumber green mottle mosaic virus (CGMMV) infects many cucurbit species in the world and causing mottle and systemic mosaic symptoms on cucurbitaceous plant leaves. During a survey, Out of 198 samples of cucurbit plants that were collected from the different fields and cucumber greenhouses in khorasan province, 39 samples were infected by CGMMV in DAS-ELISA using specific polyclonal antibody (The rate of infection was 19.7%). Using specific primers which were designed based on the CGMMV coat protein (CP) gene sequence; a fragment with 486bp length was amplified by reverse transcription polymerase chain reaction (RT-PCR). The CP gene was cloned, sequenced and compared with the sequence of homologous gene of other CGMMV isolates recorded in GeneBank. Phylogenetic analysis using 486 nucleotide long sequences of coat protein gene showed that all CGMMV sequences can be placed into two groups: I and II. Members of group I were divided into two subgroups: A, B. Iranian isolate (kalat) was classified in the group IA. The result showed it had high homology with the other isolates (the highest homology could reach 97.9% in nucleic acid level). As well, phylogenetic tree based on CP amino acid sequences was established and the highest amino acid homology was 98.1%. This is the first report of CP sequence of CGMMV Iranian isolate, determination of its phylogenetic relationship and comparison of its nucleotide and amino acid sequences with those of the other isolates of CGMMV obtained from GenBank.

This study was carried out in order to investigate the possibility of controlling seed-born disease of wheat Chamran cultivar by nano silver seed coating and indicate relevant concentration of nano silver on fungal seed-born of wheat at Khouzestan-Ramin Agricultural and Natural Resources University. Experiment was conducted in the form of completely randomized design with four replications and six treatments. Treatments included one level of disinfection by 2.5% sodium hypochlorite and five levels of seed coating by different concentration of silver nano particle (S1=1.30, S2=4, S3=6.70, S4=9.3 and S5=2666 mg of silver nitrate solution). Results showed that there was a significant difference among disinfection levels (P≤0.01) for disease index. In comparison with sodium hypochlorite, the Disease Index was declined about 50% by S1 treatment. The most favorable effect on decreasing Disease Index was observed with S5 treatment where it dropped up to 75%. According to results the mean of mortal concentration of nano silver on dominant species (Aspergillus sp., fusarium graminiarum, Penicilium sp., Torula sp., Alternaria alternaria) was calculated using Fini method in order to approach the finest concentration. The maximum LC50 was obtained for Torula sp.1875.6 ml/lit and the minimum 0.02 ml/lit was for Aspergillus sp. and Alternaria alternaria. Regarding to this point that fungal seed-borne are active on seed bed in the form of a band, for approach to efficient disinfection it is essential to use the maximum needed concentration.