نشریه آفات و بیماریهای گیاهی
سال هشتاد و نهم شماره 2 (پیاپی 113، اسفند 1400)

This study was carried out to investigate oribatid mite species diversity of two agricultural ecosystems in Khorasan-e-Razavi Province. Samplings have been done monthly in a three-year old alfalfa field with an area of two hectares, and a fruit orchard with an area of 0.6 hectare from April to October 2014. In each month, 10 soil samples were randomly taken with equal volumes from depth of 0-20 cm, totally 60 samples. Berlese funnel was used to extract the oribatid mites and collected individuals were then cleared, mounted on microscope slides and identified based on external morphological characters and supposed as morphological species. Community structure, Alfa diversity indices and nonparametric estimation of maximum species richness in both ecosystems with five relevant methods were determined. From the total 1425 collected individuals, 1097 individuals including 40 species and 328 individuals including 25 species were belonged to the orchard and alfalfa ecosystems, respectively. The orchard ecosystem has a higher species richness as well as species diversity compared to that of the alfalfa one. The relative abundance of oribatid species in the orchard was also more equitable than that of alfalfa field. Estimation of the maximum species richness (Smax) in these two ecosystems with the five relevant methods showed that the number of detectable species in alfalfa and orchard ecosystems will increase to 54 and 185 species, respectively. The probable indications on the change in the oribatid mite species diversity in these two ecosystems are discussed.

Biology and natural parasitism of Copidosoma subalbicornis parasitoid wasp of A. lineatella was evaluated in almond and peach orchards of Chahar Mahal va Bakhtiari province in 2016-2017. Parasitism and the presence of parasitoid wasp in nature, host preference and life span of parasitoid wasp and the pest were evaluated at laboratory conditions. Results showed that maximum parasitism percentage of third generation larvae was 26.5±2.22 and 27.1±3.11 in Emamieh and minimum was 18±1.18 and 17.9±2.37% in Saman and Cham Ali almond Mamaei cultivar orchards in 2016 and 2017, respectively. The rate of parasitism of peach twig borer larvae in the first and second generation was 13.3 and 16% in Saman city in 2016, respectively, and in 2017 was 13.9 and 15.5%. C. subalbicornis could parasitize the all larval instars of the pest during three generations, however, last instar larvae were preferred.

In order to study the effects of sowing date and damage of two insect pest, Empoasca decipiens Paoli (Hemiptera.:Cicadellidae) and Thrips tabaci Lindeman (Thysanoptera: Thripidae) on seed yield and yield components of pinto bean, line COS16, an experiment was conducted at Boroujerd Agricultural Research and Education Campus, in  2008 and 2009. The experiment design was a split plot arranged in RCBD with 4 replications. Two pest managements (spraying with pesticide and no spraying) were assigned to main plots and three sowing date (early May, late May and mid June) were randomized to subplots. The results showed that except of seed yield, more of yield components were not significantly decreased by these pests. Results of combined analysis of variance, showed that, seed number per plant, weight of seeds per plant, 100-seed weight, seed yields and pest damage index were significantly affected by sowing dates. Based on this study, the highest yield components (pod number/plant, seed number/plant and seed weight/plant) were obtained in the first sowing date. The lowest pest damage indices was in the third sowing date, which was significantly different with the first and second sowing dates.

Xylophagous moth, Euzopherodes vapidella vapidella Mann (Lep.: Pyralidae), as a new pest in Iran, causes damage in olive orchards of Fars province specially at Fasa, Kazeron, Darab and Shiraz area in recent years. Its biological characteristics was studies using light trap and field sampling during 2007-2008 at Fasa olive orchards. Female moths lay their eggs at the wounded sites, which cause by pruning, grafting and broken branches. Neonate larvae penetrate under the bark and fed on cambium layers. The larval and pupal development occurred under the barks. The pest overwintered in different larval stages, mostly in final instars.The first adult moths appeared gradually from mid-March, and based on light traps observations, its four generations were observed in mid-April, the second half of July, late-September and mid-December, respectively.The mean length of embryonic, larval and pupal stage development lasted 5.25 ± 0.18, 21.8 ±0.19 and 7.4 ± 0.24 days, respectively. Sex ratio of the male: female in laboratory and field study were same and estimated 1: 1.4.  The longevity of male and female moths was 7.45 ±0.25 and 5.15±0.17 days, respectively.

Fungal species Fusarium pseudograminearum, F. culmorum and Bipolaris sorokiniana are the most economically important pathogens causing crown and root rot of cereals. The use of resistant cultivars can be the most efficient measure to reduce the effect of this disease. As an alternative strategy, screening of resistant wheat genotypes has been emphasized in the recent studies. This research was conducted to evaluate level of resistance of 66 genotypes of bread wheat and durum wheat to B. sorokiniana, F. pseudograminearum and F. culmorum isolates in greenhouse condition. These experiments were conducted based on completely randomized design with seven replications in greenhouse condition. The results showed that, 11 genotypes including C-87-11, C-87-18, BACANORA /3/MASON/JGR//PECOS, 05899G01-2, F06580G2-1, F06659G6-1, McCormick/Trego, VA01W-205/TX99D4628, GA951079-3-5/Neuse, Owl,85224*-3H-*o-HOH/7/T.SPH/2*H567.71//4/CMH79.959/6/Gaspard and AWD99*5725/FL9547 were moderately resistant to diseases caused by B. sorokiniana isolates and its combination with F. pseudograminearum and F. culmorum. Among these genotypes, three genotypes C-87-11, GA951079-3-5 / Neuse and 05899G01-2 were resistant to the combination of all diseases caused by these three fungal species. These genotypes have potential to be incorporated into wheat breeding programs. Cluster analysis of reaction of wheat genotypes to all diseases caused by these three fungal species, as well as to different combination of them were able to separate susceptibe and relatively resistant genotypes from each other. In both dendrograms, genotypes that were relatively resistant to disease caused byB. sorokiniana and its combination with other diseases caused by fungal species were grouped into cluster 3.

Diplodia seriata is the causal agent of apple limb and trunk cankers as well as fruit black rot. Disease was detected in the Iranian apple collection located at horticultural research station of Kamal-shahr, Karaj. Fourteen apple promising genotypes and two commercial cultivars (Golden Delicious and Fuji) were tested in the field and laboratory for their relative susceptibility to the pathogen, during 2016-2017. The fruits were inoculated in the field at 2 to 3 weeks before harvest with fungal mycelia from 11-day-old cultures of PDA medium. In the laboratory, detached fruits were inoculated similarly. Genotypes were classified for susceptibility to the fungus by determining disease severity of attached fruits in the field based on lesion expansion (mm/degree-day), and on detached inoculated fruits in laboratory according to the mean lesion diameter, both 5 days after inoculation. Based on the laboratory and field data, Iranian genotypes were classified into three relative susceptibility groups: most susceptible: TR-1, SSB, and H1-SH; moderately susceptible: MD-N2, GO-N3, B-K-KH, DO-P-SH, MN8, T5 and Golden Delicious; least susceptible: SBA, MN10, S-O-G, KH2, ME6 and Fuji. There was a negative correlation between disease severity and flesh firmness, but total solid soluble (TSS) and les

Most EC formulations contain toxic solvents such as xylene that have environmental and carcinogenic risks, using more effective nanoformulations can be effective in developing healthy and safe methods in managing pests.The nanoformulation of 2.5% deltamethrin was prepared and the size, shape, and amount of active ingredient were investigated using SEM, AFM, DLS, and TGA methods. This nanoformulation was compared with commercial pesticides to control Sunn-pest in the stages of overwintered adults, 4th instar nymphs, and new generation adults. The treatments included nanoformulation, nanocarrier, commercial EC2.5%, and water as control. The results showed that this nanoformulation has improved ingredient efficiency. The insecticidal effect was well preserved in 45 days after spraying (73%), but the effect of commercial EC formulation was reduced and the mortality rate was very low (13%). Evaluation of treatments in greenhouse conditions showed that both formulations at a concentration of 125 mg.L had a percentage of mortality above 90% compared to the overwintering adults and in 45 days after spraying the percentage of 4th instar nymphs mortality was reduced to 40%.

Breeding and use of resistant tomato varieties agaist  two-spotted spider mite, which is one of its critical pests in farms and greenhouses, require adequate knowledge of the effective factors of the crop in reducing the fitness of the pest as well as realizing the plant’s ability to mitigate the herbivore injury. Therefore, the host recognition and host acceptance of the mite and the host suitability of the plant and its responses to mite injury were assessed in laboratory by evaluating the behavioral and physiological responses of the mite and by measuring the physical and chemical characteristics of ten tomato varieties. Results showed that the mite colonization by using a free-choice test and the oviposition rate and  the population growth of the mite by using a no-choice test were significantly different on tomato varieties, indicating some degrees of antixenosis and antibiosis resistance mechanisms especially in Super-Luna and Super-Urbana varieties which also had higher densities of type IV and VI glandular trichomes. Phenol concentration were increased significantly after being injured by the mites in Cal-JN3, and Super-Urbana varieties and it showed significant negative correlations with mite densities. Varieties Cal-JN3, Super-Luna, Super-Urbana and Comodoro were placed in the resistant group, Super-Chief, Mobil-Royal, Queen-2274, and Primo-Early inside the intermediate group and Chef-Falat and Firenze in the sensitive group.

Using biocontrol agents is one of the methods to reduce mortality of Phytophthora root rot in pistachio orchards. In the present study, the effect of arbuscular mycorrhizal fungi (AM) (mixture of three species), Trichoderma harzianum (Th) and their combination (AM+Th) were evaluated on Phytophthora root rot caused by Phytophthora drechsleri (Pd) in pistachio seedlings cv. Momtaz. Arbuscular mycorrhizal fungi, Th and their combination were inoculated at the time of sowing pistachio seeds, but the pathogen was inoculated two months later. The results showed that AM, Th and AM+Th treatments and their interaction with Pd significantly increased growth, nutritional and biochemical characteristics of seedlings compared to the control and Pd treatment. The highest increase was observed in AM+Th and AM+Th+Pd treatments. At the end of the experiment, the mortality of pistachio seedlings was significantly reduced from 92% in Pd treatment and reached to 67, 67 and 50% in AM+Pd, Th+Pd and AM+Th+Pd treatments, respectively. It is concluded that inoculation of AM, Th and especially their combination improved the growth, nutritional and biochemical characteristics which can lead to biological control of Phytophthora root rot of pistachio seedlings.

In the framework of study on Septoria and Septoria-like species in Iran, a new species Sphaerulina osypianiae sp. nov. on Populus sp. is described using morphological and rDNA ITS sequencing data. DNA extraction, amplification and sequencing were performed using methods and protocols mentioned by Azimi (2011). The resulting 511-bp sequence obtained from isolate 52935 was deposited in GenBank. The sequence shared 99% identity with Mycosphaerella populi (=Sphaerulina frondicola) sequences available in GenBank (see table 1 for identities). NJ tree generated using TreeView Display Option in NCBI BLAST, supported Sphaerulina species on Populus from Iran as a distinct species from all other Sphaerulina species sequences on Populus. In the framework of study on Septoria and Septoria-like species in Iran, a new species Sphaerulina osypianiae sp. nov. on Populus sp. is described using morphological and rDNA ITS sequencing data. DNA extraction, amplification and sequencing were performed using methods and protocols mentioned by Azimi (2011). The resulting 511-bp sequence obtained from isolate 52935 was deposited in GenBank. The sequence shared 99% identity with Mycosphaerella populi (=Sphaerulina frondicola) sequences available in GenBank (see table 1 for identities). NJ tree generated using TreeView Display Option in NCBI BLAST, supported Sphaerulina species on Populus from Iran as a distinct species from all other Sphaerulina species sequences on Populus.

In order to be used in studies related to the production of a kit for detection of the causal agent of bacterial leaf streak of cereals, in contaminated wheat and barley seeds, a hybridoma cell line (named L-B7) secreting monoclonal antibody to Xanthomonas translucens pv. translucens by fusing SP2/0 myeloma cells with splenocytes from immunized BALB/c mice with one strain of this bacteria (UPB684 isolated from barley in Iran), were produced. The monoclonal antibody produced, reacted positively with X. c. pv. undulosa (15 strains) and pv. translucens (15 strains). Strains from other pathovars (X. c. pv. graminis and pv. poae) gave a negative reaction. Antibody potency was assessed by testing in ELISA. Whole cells were used both as immunogen and as antigen in ELISA tests. This antibody could be used to differentiate Xanthomonas translucens pathovars, causing bacterial leaf streak of cereals, from other pathovars, as well as in the process of producing a detection kit.

Despite the availability of nozzle types, the role of nozzle on the performance of unmanned aerial sprayer has received less attention. The study was performed in factorial as a completely randomized design to investigate the effect of factors of nozzle type (standard, anti-drift, and air induction) and nozzle orifice number (single, twin, and triplet flat fans) on the deposition of spray droplets at the target site and their drift up to a distance of 5 m from the target site and the efficacy of herbicide haloxyfop-R-methyl against volunteer barley. In all types of nozzles, with increasing the nozzle orifice number, drift increased. Except for the standard nozzle, in other nozzles types, with increasing the nozzle orifice number, the deposition of spray droplets at the target site and herbicide efficacy increased. The lowest (2.7%) and highest (22.5%) drift was observed with the air induction single flat fan nozzle and the standard triplet flat fan nozzle, respectively. The highest (35.2%) and the lowest (8.3%) deposition at the target site was observed with the air induction triplet flat fan nozzle and the standard triplet flat fan nozzle, respectively. The lowest control was observed using the standard triplet flat fan nozzle (38.3%). The highest control of barley with haloxyfop-R-methyl was observed when the air induction twin flat fan (94.3%) and air induction triplet flat fan (91.7%) nozzles have been used; therefore, the selection and installation of these two nozzles on UAV, not only better weed control is achieved, but also an effective step is taken to prevent environmental pollution.