PLANT PROTECTION JOURNAL
Year:2010 | Volume:2 | Issue:2 (6)|Papers Count:10

Field studies were performed to identify larval and pupal parasitoids of diamondback moth, Plutella xylostella (Lepidoptera, Plutellidae), in Isfahan province during summer and autumn of 2009. In each main cabbage growing areas (Flavarjan and Mobarakeh counties), two fields of common cabbage (Brassica oleracea var. capitata) and two fields of cauliflower (Brassica oleracea var. botrytis) were chosen. Sampling was then carried out on ten randomly selected plants within each field, where all P. xylostella larvae and pupae were collected and reared under laboratory conditions. In present study, seven species of parasitoid wasps (five larval and two pupal parasitoids) and two species of hyperparasitoid wasps were determined:1- Larval Parasitoeids:Cotesia plutellae (Braconidae)Apanteles sp. (Braconidae)Bracon hebetor (Braconidae)Diadegma semiclausum (Ichneumonidae)Diadromus collaris (Ichneumonidae)2- Pupal Parasitoeids:Diadromus subtilicornis (Ichneumonidae)Oomyzus sokolowskii (Eulophidae)3- Hyperparasitoeids:Mokrzeckia obscura (Pteromalidae)Pteromalus sp. (Pteromalidae)The proportional abundance and some biological characteristics of parasitoid species were investigated. This is the first record of M. obscura on P. xylostella in Iran.

Chick pod borer Heliothis viriplaca Hufn. is an important pest of chickpea in East Azarbaijan provience. In recent years, pesticides harmful effects has became a problem for the life.This matter, also is right about chemical control of chickpea pod borer.Therefore, the efficacy of some insecticides such as Indoxacarb Sc15%, Indoxacarb Ec15%, Pyridalyl Ec 50%, Carbaryl Wp 85% with a control (only water) against chickpea pod borer, was evaluated in Maragheh, East Azarbaijan during 2007-2008. The experiment was carried out with ILC 482 variety in RCBD design with three replication. Sampling and counting of live larvae was done 1 day before and 1, 3, 7 and 12 days after treatment by randomly selected 20 plants from four middle rows in each plot and at the end of experiment, the number of total pods and damaged pods in 20 plants of each plot was determined. The results of 7th and 12th days after insecticides application showed a significant difference among treatments at level of 5%. Indoxacarb Ec 15% (200 ml/ha) and Indoxacarb Sc15% (200 ml/ha) were both the most effective treatments followed by Piridalyl EC 50% (150 and 200 ml/ha) and Carbaryl wp 85%.

In order to evaluate the resistance mechanism of Navy Bean (Phaseolus vulgaris L.) to two-spotted spider mite (Tetranychus urticae Koch), an experiment was conducted in greenhouse conditions during 2009-2010. Efficient mechanism of resistance including antibiosis, antixenosis and tolerance of 50 genotypes of navy bean was evaluated using standard greenhouse tests. All experiments followed a complete randomized design (CRD) with 3 replications and 50 treatments (Genotypes). Analysis of variance and mean values comparison using the Duncan procedure showed that there was significant difference between three mechanisms of resistance in 50 genotypes at 5 % level. The most response of antibiosis was seen in genotype numbers 41188, 41103, 41117, 41190, 41109, 41111, 41161, 41178, 41106, 41127, 41133 and 41151. Genotype numbers 41188, 41121, 41158, 41113, 11867 and 41101 were the most tolerate genotypes. 16 genotypes showed the most response of antixenosis. To appraise the Plant Resistance Index (PRI) used the reverse product of values of resistance mechanisms and genotype numbers 41151 and 41134 showed the highest and lowest values, respectively. Our results show that genotype numbers 41151, 41121 and 41188 have the most potential of resistance to this pest with antibiosis and antixenosis as the principal mechanisms of resistance.

Lentil Fusarium wilt, caused by Fusarium oxysporum f. sp. lentis (Vasd. and Srin.) Gordon is one of the most important factors of reduce lentil yield in the world. Effect of four soil borne fungi Piriformospora indica, Sebacina vermifera, Trichoderma harzianum and Trichoderma viride on Fusarium wilt of lentil were evaluated in a completely randomized design under greenhouse condition. Pathogen inoculated to soil pots in three times (10 days before sowing, concordant sowing and 10 days after sowing). Seventeen treatments include two controls (plant without pathogen and plant with pathogen) and fifteen combination of above antagonistic fungi inoculated concordant sowing. Different growth factors namely: plant heights, root length, dry weight of shoot and root and disease severity were assessed in flowering stage. Resulted revealed that the most effect of combination of antagonistic fungi with considering three times were observed in pots inoculated with treatment (S. vermifera + T. harzianum).

During 2000-2002, A faunistic study was carried out on mites associated with pine bark beetles in various parks of Tehran. A new species of the genus Cercoleipus Kinn, 1970 belonginig to family Cercomegistidae (Acari: Mesostigmata) was collected and identified. Record of this family and genus is new to the mites' fauna of Iran. Presence of Cercoleipus in Iran, the first record of this mite in Asia, is reported from Orthotomicus erosus (Wollaston) and Ips mannsfeldi (Wachtl) (Coleoptera: Scolytidae) in parks of Tehran on Pinus eldarica Medw.

During the investigation of fauna of edaphic mites in the areas of Fars Science and Research Branch (Marvdasht, Fars province ), some species belonging to the family Laelapidae were collected and identified, among them the species Androlaelaps aegypticus Hafez, Elbadry & Naser is considered as a new record for acarofauna of Iran.

Fire blight of pome friuts trees caused by Erwinia amylovora (Burrill) Winslow et al., 1920 has become one of the most important disease of pome fruits in Iran. Ninty five strains of bacteria were isolated from affected tissuse (leaves, branches, flowers and fruits) all isolates were compared according to the standard physiological, biochemical and pathogenicity tests. Sensitivity of strains against some antibiotics such as streptomycin, oxytetracyclin and copper were determined. All strains produced hypersensitive reaction in tobacco and geranium. All of strains were the same in phenotypic characteristics moreover there was not any difference in disease severity between different strains. None of strains tested were resistant to streptomycin, oxytetracyclin and copper. All strians were homogenous phenotypic characteristics and anyibiotics resistance, regardless of their original hosts or geographical areas. There is no chance of finding new species of E. pyrifoliae.

In this study, the mycoparasitism inhibitory effects of five Trichoderma species (T. harzianum, T. koningi, T. longiconis, T. hamatum and T. viride) on the growth of the causal agent of tomato Fusarium wilt (Fusarium oxysporum f.sp. lycopersici) were investigated by dual culture in laboratory condition. In this step, the maximum and minimum inhibitory effect caused by T. harzianum and T. viride. In the greenhouse, the comparison of the efficacy of disease decrease was carried out between soil and seed treatments affected by T. harzianum spores. Results showed that seed treatment did not cause disease decrease but soil treatment caused disease decrease as 92%.