نشریه گیاه پزشکی کاربردی
سال ششم شماره 2 (پیاپی 22، مهر 1396)

One of the most important pests in the Alshtar region is the sunn pest, Eurygaster integriceps Puton (Hemipterta: Scutelleridae). This pest infests a large part of the wheat fields each year, and more specifically its damage during the years when the drought occurs. The population of the sunn pest, like other insects, is affected by biotic factors or natural enemies, including predators, parasitoids, and pathogens. In this research, adult parasitic flies of the nymph and adult stages of E. integriceps in wheat fields of Alshtar region were collected and identified. In total, three species of parasitoid flies of the family Tachinidae and subfamily Phasiinae were identified including Elomya lateralis (Meigen, 1824), Phasia subcoleopterata (Linné, 1767) and Eliozeta helluo (Fabricius, 1805). The results of parasitism in adult stage of the sunn pest by parasitoid flies showed adult flies were emerged from their hosts from the first decade of May to the second decade of June. So that the highest rate of percentage of parasitism in both years (2015-17) was observed in the second and third decades of May. In these dates, the population of E. helluo species was higher than the other two species. The total parasitism by these tree species was estimated to be about 60%. Due to the fact that a wide range of cultivated lands of this region is dedicated to wheat cultivation, the results can be considered as a small step in the management of the sunn pest.

The disorder causes die back of the twigs, the leaves take silver color appearance and the tree declined. In the summer of 2014-2016 during visits to the eastern regions of the province, the trees affected by the disease and dying were determined from 8 to 10 %. Sampling was done from nectarine and peach trees with the symptoms and contamination with pathogens capable of causing such symptoms were examined. The samples were tested by RT-PCR using specific primers for European stone fruit yellows(‘Candidatus Phytoplasma prunorum’) and almond witches’ broom (‘Candidatus Phytoplasma phoenicium’) Phytoplasmas, Prunus necrotic ringspot ilarvirus (PNRSV), Tomato ringspot nepovirus (ToRSV) and Plum pox potyvirus (PPV). Segments of necrotic tissue margin under the bark of each sample were plated onto NA and PDA media after surface disinfection. Study results did not show any contamination to the mentioned viral and Phytoplasmas agents. Bacterial colonies did not seen on the culture media. The fungal isolates were purified and identified as Trametes versicolor, based on the morphological characteristics. Pathogenicity test was done and proved by inoculation of 3-4mm cut pellets of PDA media containing fungal mycelia of the isolates on the peach and nectarines seedlings. Genomic DNA extraction was done from the fungal isolates and amplification was done with ITS1, ITS4 and LAC regions primers. The amplicons were sequenced and compared with the available sequences in GenBank (NCBI). BLAST analysis showed 95 to 100 % nucleotide similarity between the isolates and Trametes versicolor.

Potato is one of the most important food and economic crops in all over the world, Rhizoctonia solani, the causal agent of stem canker causes high loss of the product quality and quantity annually. In this study, the effects of two essential oils of Thyme and Carum, were investigated on the colony growth rate and inhibitory growth in concentrations of 100, 200, 300, 400 and 500 ppm on PDA medium. In vitro tests, essential oils of thyme and Carum in two concentrations of 0.5 and 0.75, the combination of thyme 0.25+ Carum 0.25 and Rovral-Ts fungicide at 1.5 at 1000 were evaluated in a completely randomized block design in four replications. The tubers substratum cultivated in soil contaminated by R. solani that planted in pots were inoculated by essential oils and fungicides. The disease severity data were recorded and scored six weeks after inoculation using Das scale. The results demonstrated that fungal growth rate under treatment by Thyme at 500 ppm (21.63 mm /day) and Carum (17.7 mm/day) and thyme + Carum (67.85) essences were more than 50 percent growth inhibitory. The results of disease severity index in greenhouse revealed that Thyme and Carum essences and Rovral-Ts fungicide respectively by 28.1, 35.92 and 17.17 percent were successful in disease control as well as the mean of fresh and dry weight of shoot area under Thyme treatment increased relatively.

Tomato Fusarium wilt caused by Fusarium oxysporum fsp lycopersici is an important disease to tropical regions and sandy soils of Iran. In this study, the effect of essential oils of thyme, zynan, fennel and antagonist fungus of Tricoderma harzianum (Th-va-104) evaluated on the colony growth rate and growth inhibition in seven concentrations of 100-1000 ppm on PDA medium in vitro. The minimum percentage of inhibitory growth (Ec50) determined in essences of thyme, zynan and fennel with 83.95, 62/685, and 59.97% respectively. Tricoderma showed the maximum inhibition of fungal mycelial growth of F. oxysporum fsp lycopersici as 78.53% followed by thyme. The effect of thyme, Fennel and zynan essential oils at the concentration of 0.5 and 1, Fungicide (Iprodione+Carbendazim 52.5% WP) by concentrations of 1.5 and Tricoderma were evaluated in a completely randomized block design in greenhouse experiments. The essential oils were incorporated with potting soil with planting seedlings and Trichoderma fungus simultaneously in three days before transplanting. The percentage of disease severity index was assessed four weeks after inoculation. The results demonstrated that the disease index severity of thyme and Trichoderma by 2.6 and 2.06 respectively were placed in the closest disease index to check. The root area fresh and dry of thyme treatment (1.53, 2 gr), shoot area weight mean (13.19, 1.82) and the root area fresh and dry of Trichoderma (1.79, 0.27 gr) and shoot area weight mean (12.77, 1.63 gr), respectively were classified in the similar statistical groups with check.

Ants (Hymenoptera: Formicidae) are social insects with more than 12,000 species, 365 genera and 27 subfamilies. As the most successful living organisms on Earth, have a very positive impact on soil ecosystem. Identification of ant species was performed in Kadkan and Jolge Rokh, Torbat Heydarieh, by sampling from June - September 2016. The samples were first identified in the laboratory using available identification keys and morphological characteristics such as oral fragments, tentacles, seams and body hairs. Then they were sent to Nihat Aktac, Turkey for confirmation of identification. In this study, 12 species belonging to 7 genera in 3 subfamilies were collected and identified. The scientific names of the species and their subfamily and genera are as followed: Subfamily Myrmicinae: Messor structor (Latreille, 1798); Messor ebeninus Santschi, 1927; Messor caducus (Victor, 1839); Monomorium kusnezowi Santsci, 1928; Crematogaster sordidula Nylander, 1849; Crematogaster subdentata Mayr, 1877 Subfamily Dolichoderinae: Tapinoma karavaievi Emery, 1925 Subfamily Formicinae: Lasius neglectus Van Loon; Boomsma and Andrasfalvy, 1990; Formica cunicularia Latreille, 1798; Cataglyphis aenescens (Nylander, 1849); Cataglyphis nodus (Brulle, 1833); Cataglyphis niger (Andree, 1881).

In this research, the inhibitory effect of aqueous, ethanolic and methanolic extracts of three medicinal plants including Mentha piperita L., Eucalyptus camaldulensis and Allium sativum on the mortality rate of juveniles and adults of Pratylenchus loosi were studied at the Tea Research Center (HSRI, AREEO) of the country. The experiment was carried out as a two level factorial experiments in a completely randomized design with three replications. The first factor was the different concentrations of mint, Eucalyptusand garlic extracts in 5 levels (0, 500, 1000, 1500 and 2000 ppm for mint; 0, 500, 1100, 2300 and 4000 ppm for Eucalyptus and 0, 50, 125, 250 and 500 ppm for garlic) and the second factor included four intervals of 24, 48, 72 and 96 hours. The results analysis of variance showed that there were significant differences between concentrations and time intervals at 1% probability level. Based on the results, the mean comparison of the interactions of concentration × time interval, each of the aqueous, ethanolic and methanolic extracts of mint, Eucalyptusand garlic showed a significant effect on the mortality of larvae and adults, and the results indicated the efficacy of the secondary metabolites in the extracts of these plants on the control of tea root-lesion nematode. The highest mortality rate of juveniles and adults was observed using 500 ppm garlic extract after 96 hours with 93.9 and 90.92%, respectively.