نشریه گیاه پزشکی کاربردی
سال هفتم شماره 2 (پیاپی 24، اسفند 1398)

Barley is one of the world's main sources of nutrients for human and animal, and E. integriceps is one of the most important pests reducing its yield. This study was conducted on different barley genotypes to identify the genotypes that are resistant to Sunn pest. The study was a randomized complete block design with three replications that was conducted in 2016 and 2017 in Neyshabour Agricultural Research Center. The results showed that the highest number of E. integriceps was recorded in genotype 3 and the lowest number of E. integriceps was related to genotypes 2 and 6. Genotype 13, with the important indices of grain yield under non-stress condition (Yp) and genotype 10, with the important indices of grain yield under stress condition (Ys) in the region, were identified to have high yield potential and low sensitivity to E. integriceps. Yp had a positive and significant correlation with the mean of productivity (MP), geometric mean (GMP), and stress tolerance index (STI). YS had a positive and significant correlation with all indices except stress susceptibility index (SSI) and tolerance index (TOL). Therefore, the MP, GMP, and STI were the only indices that showed a positive and significant correlation with Yp and Ys. In conclusion, based on the results of this study, genotype 20 can be nominated as a E. integriceps-resistant genotype in Neishabour region. Genotype 1 can also be reported as a sensitive genotype to E. integriceps with low yield.

Helicoverpa armigera is one of the most important tobacco pests in all over the world. Today, due to the problems of using chemical pesticides such as environmental pollution and endangering the health of humans and other organisms, high costs and the problems of pest resistance, has led to more attention to use of IPM method and important biological control agents such as Bacillus thuringiensis (Bt) and Nuclear Polyhedrosis Virus (NPV). In this research, the interaction effects of combined use of 5 superior Bt isolates and one superior NPV isolate that in previous research of authors, were isolated from different parts of the northern of Iran, the investigation was conducted by combining two concentrations of Bt (2 × 107 – 1 × 107 spore/ml) and two concentrations of NPV (103 – 104 POB/ml). The mortality of 2th larvae of H. armigera was compared among the pathogen treatments on a completely randomized factorial design with 20 treatments and 3 replications under laboratory conditions in plant protection department of Tirtash Research and Education Center through 2016. The results showed that Bt isolates (12, 73, 72, 50) with (2 × 107 spore/ml) concentration in combination with NPV (104 POB/ml) had the most lethal effect, so that on 7 and 14 days after treatment, they had 100% lethal effects. The lowest mortality related to Bt-58 with (1 × 107 spore/ml) in combination with NPV (103 POB/ml), which on the 4Th. day after applying the treatment, it caused only 42/2% mortality. LC50 of superior isolate (Bt-72) was equal to 7 × 106 spore/ml and superior isolate (NPV-10) was equal to 8/1 × 104 POB/ml. The results revealed that 1 × 107 spore/ml concentration of Bt in combination with both two NPV concentrations and also Bt (2 × 107 spore/ml) in combination with 104 POB/ml showed Additive effects. Synergistic interaction effects were observed in combination of the highest concentration of Bt (2 × 107 spore/ml) and the lowest concentration of NPV (103 POB/ml). Generally, the results of this research showed that the combination of (Bt + NPV) leads to increase their pathogenicity and mortality.

The rhinoceros beetles Oryctes elegans Prell and Oryctes agamemnon Burmeister are palms pests. This study was conducted to determine the economic injury level (EIL) of these pests. The statistical design was randomized complete block with 5 treatments and 3 replications. Four concentrations including 0.5, 1, 1.5 and 2 ml/liter DOR 200 SL (Imidacloprid) were injected in palm trunks. Sampling was performed monthly. The date palm yields were recorded at harvest. The relationship between injury and yield reduction was used to estimate damage. The (EIL) was calculated by using Norton method. The regression relation was calculated between the damage and the yield loss rate. The costs of cultural control were calculated based on three different height of trees. Product prices were also subdivided by the prices of first, second and third-degree dates to determine the different economic levels loss for each product quality. Based on the results, the lowest EIL was calculated for the combination of cultural for shorter date palms and chemical control and the first-degree dates that it was 1.5 holes at the base of the petiole per tree. Due to the higher cost of biological control, EIL was higher for the combination of biological and cultural control. This value was 0.5 holes per second in short palm trees. The EIL increased with increasing palm height as well as decreasing crop prices. The highest EIL was calculated for the combination of biological and cultural controls at dates grade 2.

Oxalis corniculata and Artemisia absinthium plants are widely used in Iranian folklore medicine. The aim of this study was to evaluate the antibacterial activity and determination of phytochemical composition of leaves of these two plant species in northern Iran against tomato pathogenic bacteria in vitro. In this study, the antibacterial activity of aquatic and methanolic extracts of leaves of two plants on Xanthomonas, Pseudomonas and Pectobacterium isolates was performed by disk diffusion methods on agar and macrodilution broth to determine MIC and MBC values. The results showed that the herbal extracts used had antibacterial activity in the inhibitory range of 9 to 19 mm relative to the streptomycin antibiotic (25 mm). MIC and MBC values were 32 to 512 mg/ml according to the microdilution method, respectively. The composition of both extracts indicated the presence of saponins, phenolic compounds, anthraquinone, tannins, flavonoids, steroids and terpenoids, alkaloids, phlobatannin and volatile oils. The highest inhibitory effect was seen as a result of the synergistic activity of the aquatic extract of Oxalis corniculata and methanol extract of Artemisia absinthium (11 to 17 mm). Based on the results obtained, the combined effects of the two plants can be useful as a practical component in the preparation of herbal drug formulations.

Edible mushrooms are exposed to various diseases and pests that cause a serious reduction in yield. Dry bubble disease caused by Lecanicillium fungicola (Preuss) Zare and Gams is one of the most important diseases that causes damage to edible fungi. Due to the fact that a small number of fungicides are currently available to fight against fungal diseases, on the other hand, the overall resistance of Gia lavender fungi as an alternative to controlling oral fungal diseases. In this study, the effect of lavender essential oil was tested by two methods of mixing with culture medium and application of paper disc on the fungus causing dry bubble disease and edible fungus. In another part of the study, the effect of this essential oil on pathogenic fungi in storage and on edible mushrooms was investigated. The results of the essential oil mixing test with the culture medium showed that the essential oil of lavender in the concentration of 1000 ppm prevented the growth of pathogenic fungi by 89.25%. In the case of edible fungi, the highest inhibition of growth was related to the concentration of 1000 ppm essential oil of lavender and the control percentage was 65.23%. The results of the paper disk test showed that all the concentrations used in this study were able to reduce the growth rate of the pathogenic fungus. The highest inhibition rate was 1000 ppm and 83.12%. The results of the warehouse test showed that lavender essential oil increased the number of healthy fungi by 67.162% compared to the control by 7.30%. According to the results of laboratory and warehouse tests of lavender essential oil, they showed a high capacity to control diseases of edible fungi, especially dry bubbles.

In order to identify the plant parasitic nematodes in Alborz Province, some soil and root tissues of plants samples were collected from different crops in various regions of the Province during 2017 and 2018. After transferring the samples to the laboratory, soil and root washing operations, nematode extraction, transferring and fixing in pure glycerin were performed. Permanent microscopic slides and incisions were made from different parts of the body of some species. After microscopic observations, the extracted species were identified using different keys. During the survey and morphological studies, 6 nematode species belonging to 5 genera were identified as follows:Ditylenchus triformis, Nothotylenchus affinis, Nothotylenchus medians, Helicotylenchus pseudodigonicus, Rotylenchus agnetis, Pratylenchus mediterraneus Among the identified nematodes, species Helicotylenchus pseudodigonicus, Nothotylenchus affinis, Nothotylenchchus medians and Rotylenchus agnetis were reported for the first time in Alborz province.