Iranian Plant Protection Research
Year:2018 | Volume:32 | Issue:3|Papers Count:13

Introduction: Venturia species include many important plant pathogenic species such as Venturiainaequalis and V. pyrina causing scab or black spot on apple and pear. The Venturia teleomorph is the overwintering structure developing in leaf and fruit litters. The immersed teleomorphicpseudothecia are produced in the host tissues. This Ascomycetous genus is characterized by small, solitary, scattered or gregarious, globose, sub-globose, papillateascomata with setae around the ostiole. Asci are bitunicate, oblong to obclavate with a short pedicel or not. Ascospores ellipsoidal with broadly rounded ends, pale brown, one septate with two unequal size cells. Venturia has some species like V. inopina as homothallic and some like V. populina as heterothallic species. Sexual reproduction with producing sexual air-born spores plays an important role in distribution of disease in early spring. Therefore, awareness of sexual cycle in plant pathogenic fungi is very important due to management and forecasting probability of incidence of new genotypes (races). Materials and Methods: Venturia and related anamorphic species were collected from different places of Iran (18 provinces including Alborz, Ardabil, Eastern Azarbaijan, Golestan, Guilan, Hamadan, Isfahan, Kermanshah, Kurdistan, Lorestan, Markazi, Mazandaran, North Khorasan, Qazvin, Razavi Khorasan, Tehran, Western Azarbaijan, and Zanjan) during years 2013 and 2014. The collected specimens (800 specimens) were identified based onmorphological features. Isolation of the fungi from the infected samples was conducted using single spore method by streaking out spores on 2% water agar (WA) and culturing of single germinated conidium on potato dextrose agar (PDA). V. inaequalis was determined as a dominant species in Iran. Ten isolates from each of V. inaequalis and V. pyrina were crossed together under in vitro condition. Some isolates were cultured as single isolate in the petri dishes for investigation of homothallism and heterothallism. Several isolates from two species were crossed together to survey the biological species definition. Mature leaves of Golab apple cultivar (Malusdomestica) (for V. inaequalis isolates) and pear (for V. pyrina isolates) were washed under running tap water to remove dust and debris, and cut into 2×2 cm squares avoiding the midrib of the leaf. The leaf pieces were autoclaved and placed in petri dishes with 2% water agar. A plug of mycelium of each isolate was scraped from the edge of three weeks old colonies on PDA and mixed onto the leaf pieces with a scalpel. The plates were sealed with parafilm and placed in a sealed plastic bag. The cultures were incubated at room temperature under 12 hours light / 12 hours dark condition for 2 weeks, after which they were maintained, inverted in the dark at 8° C. The cultures were checked for the production of pseudothecia for the first time after six months. Results and Discussion: Among crossed isolates, seven and five fertile crosses were obtained from V. inaequalis and V. pyrina isolates, respectively, after six to eight months. In single isolate cultures, no sexual fertility was observed which confirm the heterothallic nature of both species. Moreover, between isolates from two species, no fertile crosswasobtained, which is the evidence of two distinct biological species. This is the first study on sexual reproduction of thesetwo species under in vitro condition in Iran. Morphological features of obtained sexual organs in vitro were the same as pseudothecia, asci and ascospores features in vivo. All ascospores in an ascus were fertile and they germinated on water agar after 24 hours. Based on this study, isolates with two different mating types are available as tester isolates. These isolates will be useful to design the primers to detect MAT alleles. PCR based methods can be used to study population genetic diversity, phylogeny, disease epidemiology and population biology (fungal species overwintering in a region based on mating types frequencies and their proportion). Development of reliable methods of sexual reproduction in vitroseems to be a valuable toolfor studies e. g. classic genetic analysis, strains modification and a supplement for modern genetic manipulations and evolutionary analysis. Conclusions: Our results verified heterothallism in both of V. inaequalis and V. pyrinaspecies. There was nofertile cross between isolates from two species that is the evidence of two distinct biological species. In this study, some tester isolates for mating typewere obtained which appear to be useful for the next PCR-based molecular studies on MAT alleles.

Introduction: Potato virus Y (PVY) is the type member of the genus Potyvirus, which is responsible for serious diseases in a wide range of plant species, mostly from the family Solanaceaesuch as potato, tomato, tobacco and pepper worldwide. The virus is transmitted by at least 40 aphid species (family Aphididae) in a nonpersistent manner. The level of damage to crop is determined by the strain of PVY infecting the plants, the viral load, the time at which infection occurs as well as the tolerance the host possesses toward the virus. Infection of a potato field with PVY may ultimately result in 10-100% loss in yield. Several distinct strains of PVY have been identified according to their biological and serological properties and their genome sequences. These include the ordinary strain (PVYO), the tobacco veinal necrosis strain (PVYN), the stipple streak strain (PVYC). In addition, two most prominent recombinant strains, PVYNTN and PVYN-Wi (PVYN: O) have been generated by recombination between PVYO and PVYN. Like other potyviruses, PVY has non-enveloped flexuous filamentous virions of 730-740 nm long and 11– 12 nm wide, which encapsidate a single-stranded, positive-sense RNA molecule of approximately 10, 000 nt long. PVY causes severe crop losses and consequently economic damage in the world as well as in Iran. Hence, identification of the virus in different regions of the country is a concern. The aim of this research was to study the existence of PVY in tomato fields of Mazandaran province and determining the type of the strain and finally finding their phylogenetic relationship. Polymerase chain reaction (PCR) with degenerate primers for conserved sequences of the viral genomes has facilitated the rapid detection of many potyviruses and enabled partial genomic sequencing. According to previous studies comparisons using the CI-coding region most accurately reflected those for the complete genome, and this region was deemed to be the most suitable for diagnostic and taxonomy purposes if the complete sequence could not be obtained. Materials and Methods: From July to September 2013, a total of 38 leaf samples of tomato showing virus symptoms were collected from different tomato fields in Mazandaran province. Total RNA was extracted from all samples. RT-PCR assay was performed using potyvirus degenerate primers corresponding to the virus CI gene. Expected PCR products were purified from 1% agarose gels, cloned into the pTZ57R/T vector and then sequenced. Sequences were compared to data available in GenBank. Multiple alignments of the nucleotide (nt) and amino acid (aa) sequences were performed with Clustal W implemented in MEGA6 or in BioEdit v. 7. 2. 5. Phylogenetic tree for grouping was constructed by MEGA6 using neighbor-joining method. Results and Discussion: An amplicon of the expected size (680 bp) was generated from 9 out of 38 plant samples. Specific amplification using the potyvirus degenerate primers in infected samples, but not from healthy sample, confirmed the presence of a potyvirus. All PCR-positive samples were cloned, sequenced and submitted to BLASTn to identify the best matching sequences recorded in GenBank. BLASTn analysis showed that the PCR-amplified fragments of four samples belonged to Potato virus Y strainC. The most typical symptoms in PVY-positive leaf samples were mosaic, mottling, distortion and rugosity. Among them two isolates namely GB and GRA were selected for further analyses. Phylogenetic tree based on multiple sequence alignment of 680 nt of CI gene divided 117 PVY isolates into three main groups: I, II and III. Group I included a wide range of isolates from Europe, Asia, Australia, America and Africa. Members of group I were divided into six subgroups. Iranian isolates (GB and GRA) were classified in the group IF with isolates nnp (Italy), Foggia (Italy), CN1 (Australia), PRI-509 (Netherland), LYE84. 2 (Spain) and Tannat (Uruguay), which all were belonging to strain C. Isolate of GB showed the highest (96. 5%) nt sequence identity with isolate LYE84. 2 and the lowest (81. 3%) with isolates T13 (Japan), Tu_660 (Canada), ME162 (China) and ID20 (USA). Also, GRA displayed the highest (95. 7%) nt sequence identity with LYE84. 2 and the lowest (80. 9%) withT13 and Tu_660 isolates. The two Iranian isolates had the highest (99. 1%) aa sequence identity with isolates LYE84. 2, Foggia and Tannat and the lowest (93. 4%) with T13. The identities between isolates GB and GRA were 98. 4% and 100% at nt and aa levels, respectively. Conclusions: PVY is one of the most destructive and widespread plant pathogen. In this study, for the first time we reported the occurrence of PVY in tomato fields in Mazandaran province and determining its phylogenetic relationship with other isolates of the virus available in the GenBank. Also, to our knowledge this is the first report of PVY strain C in tomato in Iran. Because the use of CI is more accurate in defining orders in potyvirus taxonomy and in evolutionary relationships, detection of the virus was performed by RT-PCR using potyvirus degenerate primers based on CI coding region. Phylogenetic analyses based on CI gene indicates that the Iranian PVYC isolates are much close to European isolates plus one Australian (CN1) and one Uruguayan (Tannat) isolates. One possible explanation for such sequence similarities is that most of seed potatoes in Iran originated from seed tubers imported from Europe, and not directly from its original habitat, South America. So, it is possible that the Iranian C strain originated potentially from an ancestral European PVY strains and then spread in the country via aphid vectors from infected to healthy plants. Resistance to PVY infection by hosts is low in many cases. On the other hand, PVV is transmitted by aphids in a non-persistent manner, which makes the control of the virus vectors inefficient. Therefore, cultivation of resistant varieties is the most suitable approach for control of the virus. The data obtained in this study will be beneficial to improve control strategies for this virus in Iran. Further studies on PVY isolates from different geographic regions and hosts of Iran and genetic diversity evaluation of the virus will be useful for breeders to make more efficient and durable resistant cultivars.

Introduction: Wheat Triticum aestivum L., is one of the most important and strategic crops in the world. Bread wheat (2n = 6x = 42), belonging to the family Poaceae, which is considered the most diverse and important family of the plant kingdom, produces large edible grains and provides about one-half of humans’ food calories(Wang et al., 2017). A number of pests and diseases attack wheat, out of which nematodes have been considered universally as one of the important microscopic organisms (ref). The Cereal Cyst Nematodes (CCN: Heterodera spp. ) have a global distribution and cause significant economic yield losses in many countries of the world (Pariyar et al., 2016). It is known as the first and most important cereal crop in the world and widely consumed by 75 % of world populations (Drikvand et al., 2013). Cereal cyst nematode Heterodera filipjevi has wider distribution, than other species in cereal fields in Iran. Materials and Methods: In this study, the reaction of 30 wheat cultivars against cyst nematode were evaluated in statistical design in greenhouse and the field. These cultivars planted in growing seasons (2015/2016) in a H. filipjevi-infested field in Agricultural Research Station, Central Kabotrabad area of Isfahan (30° 42′ and 34° 30′ N latitude and 49° 36′ and 55° 32′ E longitude), in a completely randomized block design, with three replications, each of which in a four rows of three meter length and 20cm distance. The cereal cyst species were identified based on morphological, morphometric features and molecular characters. The number of cysts, second stage juveniles and eggs were analyzed. Also, reproductive factor and percentage reduction and or increase in cereal cyst nematode population in each treatment were calculated into its initial population. Statistical and clustered analysis data were carried out on by Duncan's multiple range test (DMRT), SAS and SPSS statistical softwares, respectively. Results and Discussion: The results showed that, in the greenhouse, the lowest brown cyst was in Behrang cultivar with an average of 15 cysts and then Bam cultivar with an average of 15. 25 in 200 cc of soil. The lowest number of CCN eggs and second stage juveniles and reproductive factor were of Pyshtaz cultivar with the average of 0. 49 per gram of soil. The, cultivars were classified into three ranges of resistant, tolerant and susceptible. In field conditions, the lowest brown cyst was of Bam cultivar with 113. 33 per 200 cc of soil. Whereas the lowest numbers of CCN eggs and second stage juveniles and reproductive factors were in Parsi cultivar with 0. 69 per gram of soil, fallowed by Aflak cultivar with 1. 69 in two different statistically groups. Also, cluster analysis classified the cultivars into three different categories, which also showed remarkable similarities to Duncan's test results. Currently, the resistant and tolerant wheat cultivars to cyst nematode is widely used in many European countries such as the UK, Denmark, France, Sweden and Australia. Row. Therefore, identifying and recognizing resistant genes in the cultivars under study provides a way for the production of resistant transgenic commercial wheat varieties. From our results, we confirmed that wheat accessions Behrang and Bam possess resistance and can subsequently be crossed with high yielding cultivars improving their genetic resistance to CCNs. Conclusions: There is a deal of potential for this study to develop new resistant varieties to H. filipjevi which will have a great value to the agriculture sector in Iran. These resistant cultivars can be used in crop nematode management program and tracking and transferring resistance genes to desirable crop cultivars. Also, in addition to number of cysts, the number of larvae took into screening programs for better susceptibility assessment justifications. It is suggested that Marker-assisted selection will further improve the development of resistant cultivars. Isolation of candidate genes associated with specific markers will greatly facilitate this process. Finding new sources of resistance would be very much demanded to control the different populations especially in areas, where a mixture of Heterodera species occurs. Therefore, wheat origin countries including Iran, Iraq, Syrian and Turkey obtained wild wheat relatives, which is to be screened to the main Heterodera species. Taking advantage of these sources of resistance is necessary to know the reaction of genotypes against CCN species for new resistant gene/s in Iran.

Introduction: Legumes may be considered as the second most important source of high-quality protein after cereals. According to available reports, more than 35 species of nematodes belonging to 20 different genera of plant parasitic or fungal nematodes including Aphelenchoides, Basiria, Boleodorus, Criconemoides, Helicotylenchus, Hemicriconemoides, Heterodera, Hoplolaimus, Malenchus, Meloidogyne, Merlinius, Paratylenchus, Pratylenchoides, Pratylenchus, Rotylenchulus, Trophorus, Tylenchorhynchus, Tylenchus, Xiphinema and Zygotylenchus are reported from the legume fields worldwide. Kermanshah province with a cultivated area of 135060 hectares is the second legume producer in Iran. Plant parasitic nematodes associated with legumes have been identified in some provinces of Iran including Markazi (Khomein county), Lorestan and North Khorasan. Despite the fact that the province has been cultivated in such large area and the amount of legume production has been high in the country, so far no comprehensive study has been done on the identification of plant parasitic nematodes in Kermanshah province. In a few surveys, only three species of plant parasitic nematodes namely Pratylenchus thornei, Pratylenchoides ritteri and Paratylenchus elachistus have been recovered from chickpea fields in this province. Therefore, the aim of this research was to identify and determine the dominant species of important plant parasitic nematodes in the legume fields and determine their distribution in Kermanshah province. Materials and Methods: In order to identify and determine distribution of the most common plant parasitic nematodes, 173 root and soil samples were collected from legume fields (chickpea, lentil and faba bean) in several localities of Kermanshah province, during years 2016-2017. After extraction, fixation and transferring to anhydrous glycerol, the nematodes were mounted on microscopic slides and studied by using a light microscope, equipped with digital camera. Finally, they were identified using available identification keys. Results and Discussion: Based on morphometric and morphological characteristics, in this study, 19 species of the infraorder Tylenchomorpha viz. Aphelenchoides graminis, A. obtusus, Aphelenchus avenae, Ditylenchus adasi, D. equalis, D. medicaginis, D. myceliophagus, D. parvus, Filenchus vulgaris, Helicotylenchus scoticus, Merlinius brevidens, Nagelus obscurus, Neopsilenchus magnidens, Pratylenchus thornei, Pratylenchoides ritteri, Scutylenchus rugosus, S. tartuensis, Trophorus ussuriensis and Tylenchorhynchus parvus were identified. The species F. vulgaris, D. medicaginis, P. ritteri, H. scoticus, M. brevidens and T. parvus were the most common species in the legume fields of Kermanshah province with 33. 8, 29. 4, 27. 9, 26. 5, 13. 2 and 13. 2 percent frequency rates, respectively. Among 12 cities under legumes cultivation in the province, Kermanshah with 16 species, Ravansar and Gilan gharb each with nine species, Eslam Abad and Kerend Gharb each with seven species, had highest number of the nematode species. In chickpea fields, F. vulgaris, P. ritteri, H. scoticus and D. medicaginis were the most prevalent species, in lentil fields D. medicaginis, H. scoticus, T. parvus, F. vulgaris and S. tartuensis had higher frequency rates, and in faba bean fields D. medicaginis, M. brevidens and A. avenae were highly distributed species. The species Aphelenchoides obtusus, which has not been previously described in Iran, is described in full, and the males of A. obtusus is reported for the first time from Iran. Also A. graminis, D. medicaginis and P. ritteri which are more common or have morphological or morphometric diversity were described briefly. Seven species namely Aphelenchoides graminis, A. obtusus, Ditylenchus equalis, Nagelus obscurus, Scutylenchus tartuensis, Trophurus usuriensis and Tylenchorhynchus parvus are reported for the first time from legume fields in Iran. These seven species with together six other species namely D. adasi, D. parvus, Helicotylenchus scoticus, Merlinius brevidens, S. rugosus and Neopsilenchus magnidens are reported for the first time from Kermanshah province. Conclusions: In the present paper, description of four species with together their morphometric data and illustrations (line drawings or photomicrographs) are provided. Also discussions were made on the diagnosis and relationships of these four species either with other populations or closely related species. Among the 19 identified species, it seems that Pratylenchoides ritteri (with potential damaging effects on legumes), and Ditylenchus medicaginis and Helicotylenchus scoticus (with high frequency and distribution in the studied regions) should be considered as important species for conducting further supplemental surveys in Kermanshah province. A very damaging species of nematodes to legumes, Pratylenchus thornei, was found only in 4. 4 % of the studied fields, and the other important group of nematodes, root-knot nematodes (Meloidogyne spp. ) were not recovered from the legume fields of Kermanshah province.

Introduction: Small black and yellow wasp, AllantusviennensisSchr. (Hym.: Tenthredinidae) is a serious pest of rose plants. Larvae feed on the leaves of rose bushes initially, the parenchyma of leaves and eventually the entire leaf except main rib. Carbohydrases such as amylases and galactosidases have main role in digestion and metabolism of carbohydrates in insects. The nutrients were used for growth, development, survival and reproduction of insects. Therefore, any interruption in enzymatic carbohydrate digestion and blocking of carbohydrases by inhibitors can deprive herbivorefrom utilizing the sources of carbohydrate energy efficiently. Transgenic plants expressing carbohydrase inhibitors have been considered as safe alternatives to chemical pesticides against herbivorous pests. Knowledge on digestive enzymes of insects is the first step to use plant origin inhibitors in pest control programs. In the present study, identification and characterization of α-amylase and α-β galactosidases in gut extract of A. viennensiswerestudied. Materials and Methods: The α-amylase activity was measured in the different larval stages (2-5 L) and three parts of gut including foregut, midgutand hindgut of fifth larval instar ofA. viennensis. 10 μ l of the enzyme was added to a tube containing 40 μ l of universal buffer (50 mMsodium acetate-phosphate-glycine) and 50 μ l of 1% (w/v) starch as substrate. The reaction was incubated at 30° C for 30 min and then was stopped by adding100 μ l of dinitrosalycylic acid. Absorbance of product was measured at 540 nm with a Microplate Reader Model Stat Fax® 3200. One unit α-amylase was defined as the amount of the enzyme that liberated one micro mole of maltose from starch (as substrate) per minute. The activities of α and β-galactosidase were measured with pNα Ga (p-nitrophenyl-α-D-galactopyranoside) and pNβ Ga (p-nitrophenyl-β-D-galactopyranoside) as substrates, respectively. 10 μ l of the enzyme, 45 μ L of substrate and 115 μ L of universal buffer were incubated for 20 min at 35 ° C. After incubation time, 600 μ L of NaOH (0. 25 M) was added to stop the reaction. P-nitrophenol absorbance was measured at 405 nm using a microplate reader. One unit enzyme is defined as the amount of the enzyme that liberates one micro mole of p-nitrophenol per minute. To obtain the optimal pH and temperature for the enzyme activity, various pHfrom 3. 0 to 12. 0 and different temperatures ranging from 10 to 70º C were examined. To determine the kinetic valuesfor α-amylase, different concentrations of starch (0. 05, 0. 1, 0. 25, 0. 5 and 0. 75) and for galactosidases different concentrations (2. 5, 5, 10, 20, 40 and 80mM) of pNα Ga and pNβ Ga were prepared. The Michaelis-Menten constant (Km) and maximal velocity (Vmax) of the enzymes were estimated from the Lineweaver-Burk plots. Electrophoresis was performed and appeared bands in the native gel were observed. Results and Discussion: The highest enzymes activity was obtainedin 5thinstarandas food absorption increased the enzyme activityenhanced. Also, the specific activity of enzyme in midgut was higher than that of foregut and hindgut. Midgut is the most important source of digestive enzymes as one of the main sites for the absorption of digested material. The greatestactivity of α-amylase in gut of A. viennensis was at alkaline pH (8). The high gut pH in A. viennensisis largely due to adaptation for feeding on rosecontaining tannins. Because tannin can bind with proteins in insect’ s midgut at acidic pH values and then decrease the efficiency of food digestion. The highestactivities of α / β galactosidases in gut of A. viennensis were at pH 6. Optimal temperature for α-amylase, α and β galactosidases activity was obtained 50, 60 and 30° C, respectively. As calculated from Lineweaver-Burk plots, the Kmand Vmaxvalues for α-amylase were 1. 478 mg/ml and 0. 14 μ mol min-1 mg-1 protein. The Km and Vmaxvalues for α and β galactosidase were 0. 69 Mm, 0. 41 Mm, 0. 84 and 1. 76 Mm min-1 ml-1, respectively. Zymogram pattern in the native gel revealed three, one and one bands for α-amylase, α and β galactosidases, respectively. Conclusions: According to the results, α-amylase, α and β galactosidasesexistedin gut of larvae of A. viennensis. These findings showed potential of digestive enzymes inhibitors for management of A. viennensispopulation and more research is needed.

Introduction: Alfalfa (Medicagosativa L. ) is a high-quality forage crop widely grown throughout the world. This plant is attacked by a wide range of pests. Alfalfa weevil, Hyperapostica(Gyllenhal) (Coleoptera: Curculionidae), is a pest of concern in alfalfa on the globe. This introduced pest is most problematic in the early season, causing defoliation and reduced yield and quality. Both adults and larvae feed on alfalfa, but the larvae cause the majority of the damage to terminals, foliage, and new crown shoots. This pest has many natural enemies. Among the beneficial insects, the green lacewing, Chrysoperlacarnea (Stephens) (Neuroptera: Chrysopidae), has received special attention since its larvae are important natural enemies of alfalfa weevil. The control of H. postica was done by chemical pesticides. There is now overwhelming evidence that some of these chemicals do pose a potential risk to humans and other life forms and unwanted side effects to the environment. Palizin (Coconut soap) is a natural compound based coconut extract. In the current research work, the effect of this compound on the adult of H. postica and egg and 1st instars larvae of C. carnea was investigated under laboratory and field conditions. Rearing of insects: postica: H. postica larvae were collected from alfalfa fields in Miandoab using sweep nets in July 2016 and taken to the laboratory. Larvae were placed in plastic dishes (5 × 10 × 20 cm), fed by alfalfa foliage, and held at 25 ± 2 ° C, 75± 5% RH to complete their growth and convert to adults. The adults were used for all tests. Carnea: C. carnea adults were collected from alfalfa field at the Miandoab region, taken to the laboratory for identification of species and reared in the laboratory. Clear plastic cylinder containers (with 15 cm diameter × 25 cm height), which were covered with a mesh cloth were used for rearing. A thin layer of food source (mixture of yeast 50%, water 25% and honey 25%) was smeared to a plastic tape which was inserted into the plastic container. Water was provided for the adults through a wet sponge placed on the mesh cloth. To harvest the eggs, the adults were transferred to fresh containers every day. The eggs were laid on a colored paper which was attached to the interior wall of the cage. The eggs hatched after 3 days and the first larvae were used for bioassay. Bioassay: First, primary experiments were performed to determine the minimum and maximum concentrations. Afterward, seven concentrations and also control were considered. Concentrations used for Palizin were 400, 543, 737, 1000, 1357, 1842 and 2500 ppm and for Fenvalerate were 200, 265, 353, 468, 622, 827 and 1200 ppm. Adult were kept at 4 ° C to be inactive. Then, 15 adults were release on the petri plate (with 9cm diameter and 1. 5 cm height). Using spray potter tower, 500 microliter of each concentration was sprayed on the petri and the dishes were placed in a growth incubator at 25± 2˚ C, 65± 5% RH. To evaluate the recommended concentrations (2500 ppm Palizin and 1000 ppm Fenvalerate), an experiment was conducted in a randomized complete block with three treatments and five replications under field conditions. The number of H. postica (adults and larvae) and C. carnea (larvae) was counted day before and 3, 7, 14 and 21 days after treatment. Statistical analyses: The mortality results were analyzed using SPSS data processing software. Significant differences among the groups were determined using the unpaired Duncan-test in 5 % level of significance. The percentage of population reduction in the treatments was corrected in relation to the control (water) by Henderson and Tilton’ s formula under field condition. Results and Discussion: Insecticides may be a good option if other options have not sufficiently controlled alfalfa weevil. Several com mercially available products are labeled for control of alfalfa weevil. Although effective, their repeated usagehas disrupted natural biological control systems and led to resurgence of this pest, resulted in the development of resistance and had undesirable effects on no target organisms. In order to prevent resistance, effective chemical control of the pest requires new insecticides with novel modes of action. In laboratory condition, the LC50 values of Palizin and Fenvalerate on H. postica were 601. 72 and 321. 87 ppm 24 h after treatment, respectively. Toxicity of Fenvalerate for egg and 1st instars larvae of C. carnea was higher than Palizin. The LC50 values of this insecticide were 563. 02 and 178. 46 ppm and the LC50 values of Palizin were 1664 and 1663 ppm. The results of field trial showed that Palizinhas a longer persistency effect. According to IOBC standards, Palizin and Fenvalerate were categorized as slightly toxic and very toxic to C. carnea, respectively. Conclusions: The plant pesticide used in this research caused the high mortality on the adults of H. posticawith proper persistency. In addition, its toxicity is less than Fenvalerate to C. Carnea and can be applied as an effective alternative to chemical insecticides in alfalfa fields.

Introduction: Spontaneous barley is a category of cereal, annual plant, winter, self-pollinated, and diploid (2n=14). It has very close genetic relationship with barley. Very long awn, resistant to drought and salinity, seed dormancy and allelopathic potential are the features of this plant. The average 1000-seed weight without awn is 45grams and with awn is 47grams. Apart of the five provinces (Semnan, Golestan, Mazandaran, Guilan, Sistan and Baluchestan), the existence of this species was reported in Iran. The highest prevalence belongs to Fars province with an average density of 34 plants per square meter. Due to genetic and morphological similarities of spontaneous barley with wheat and barley, none of selective herbicide for wheat are able to control spontaneous barley. This study aimed to investigate the effects of the herbicide metsulfuron methyl + Sulfosulfuron (TOTAL) on morphological and reproductive characteristics of different ecotypes spontaneous barley and determine the best of use time these herbicides in the various growth stages of spontaneous barley. Materials and Methods: This experiment performed in Varamin region during 2013 and 2014 in form of Factorial randomized complete block design with four replications. The first factor included two levels of MetsulfuronMetyl+ Sulfosulfuron herbicide application at two leaf (GS =12) and second node (GS = 32) stages of growth spontaneous barley, and control without herbicide. The second factor was 20 ecotypes, which collected from across the country. At thirty days after the treatment which was equivalent to the heading stage of spontaneous barley, a box (0. 5 × 0. 5) was dropped on each line and then the morphology and reproductive traits of spontaneous barley were recorded. Results and Discussion: The greatest effect of TOTAL herbicide was at the time of the second node, but in two leaf also had a significant effect on reducing the density of spontaneous barley. Ecotypes Shush, Marvdasht, Urima, Shahreza, Islamabad, Isfahan, Golpayegan and Varamin after herbicide application at two stages were significantly more than control in term of plant density reduction. The use of herbicide reduced the number of stems per plant. Differences between treatments indicate that the effect of herbicides on stem growth has been positive. Totally, stems per plant reduction caused to reduction of the fruiting stems. This causes to reduce reproductive efficiency in spontaneous barley. In Ecotypes of Shush, Darab, Mahabad, and Biseton areas, effective of herbicides on leaf area index was higher at the two-leaf stage. Reduction of leaf area reduced the size and plant dry weight. TOTAL herbicide caused to weaken plants and plant density reduction by reducing the leaf area growth, and the growth of young stems. In Mahidasht, Fasa and Zarghan ecotypes, herbicide application at two leaves stage reduced the plant height more than second node stage. Using herbicides at second node stage, significantly changed the height of Salmas, Miandoab, Darab, Biseton, Shahryar, Golpayegan and shahreza ecotypes compared to control. Final height is one of the most important and effective indicator, in terms of weed-crop competition, which by light advantage, resulted to increasing the canopy, leaf area, dry weight and better competitive conditions. The use of herbicides at the two-leaf and the second node stages resulted incontrolling the final height of spontaneous barley compared to control. The plant fresh weight and dry weight of ecotypes showed a significant decrease as compared to the control. By reduction of spontaneous barley fresh weight, the reproductive ability reduced and also the canopy was decreased, which both have an important role on control of spontaneous barley. Moreover, according to another study among several tested herbicides in wheat, spontaneous barley did not lead to optimal control and only TOTAL decreased the dry weight by 67 percent. Using herbicides at second node stage resulted to reduction of spike weight in Shush, Fasa, Shiraz, Kerend and Varamin ecotypes than control. After herbicide application, due to unfavorable growing conditions and stress, the plant with minimal resources went to reproductive stage. Consequentlythe plants were weaker as compared to the control. Finally, the fertility rate reduced and spike length was shorter under the influence of herbicides. Using of herbicides at second node, most of the ecotypes showed seed weight reduction. Conclusion: The results showed that the use of TOTAL herbicide at the two-leaf stage and the second node decreased morphological and reproductive characteristics of this weed. The biggest influence on morphological characteristics of the Bistoon ecotype (density), Shiraz ecotype (plant density, leaf area, fresh weight, Dry weight, spike length), Rā mhormoz ecotype (number of stems, plant fresh weight, Dry weight), Mahidasht ecotype (LAI), Fasa ecotype (height, leaf area index, fresh weight, dry weight, grain weight, spike weight), Golpayegan ecotype (final height), Branch ecotype (final height), Shush ecotype (number of stems, number of grains per spike), Marvdasht ecotypes (seed weight, weight spike), Zarghan ecotype (spike length). Ecotypes reactions to the herbicide suggested that potential genetic differences among ecotypes creates different conditions of increasing or decreasing of the studied traits. Knowing these differences guide us to control this weed at different stages of plant growth by suitable approaches.

Introduction: Emergence is one of the most important events in the life cycle of annual species, because of its role in survival of the plant. Weed emergence timing has an important effect on the competition outcome of weeds with crops. Knowledge of weed emergence in the field could help reduce the loss from weeds. Many studies aim to develop prediction models that can provide information to farmers about methods and timing for weed management. Prediction of weed emergence could enhance crop management, facilitating implementation of effective strategies by optimizing the timing of weed control; this is becoming relevant for farmers because of current pressure to reduce herbicides and adopting nonchemical weed control methods. Materials and Methods: Seed dormancy state, after-ripening, and emergence pattern of wild wheat (Triticum boeoticum Boiss) and wild barley (Hordeum spontaneum C. Koch), the most important grass weeds were studied underLorestan dry conditions. Wild wheat and wild barley weed emergence pattern in three stages during the fall, winter and spring were studied by split plot arrangement in a randomized complete block design with four replications. Furthermore, wild wheat and wild barley seed emergence trends was investigated in 12 stages with intervals of about two weeks from late November to mid-May. Results and Discussion: Results showed that the presence of seed coat (Lemma and palea) acted as a serious obstacle for germination in both weeds. Regardless of treatment conditions, seed germination of wild wheat did not happen in intact seeds, up to 130 days after harvest. For wild barley, seed coat was also a serious obstacle for germination up to 130 days after harvest. Intact seeds of wild barley, generally did not germinate until two months after harvest, on the other hand, after about three months germination was less than 10%, while the germination of the seeds after 140 days under both conditions, including exposure to sun and stored at room were promoted to 87 and 37%, respectively. Both wild wheat and wild barley weeds, emergence rate during autumn dramatically exceeds the emergence rate during winter and spring. Spike number of grasses were significantly affected by planting season. Underthe spring sowing, wild wheat and wild barley as well as wheat crop, generally did not produce grain. The number of spike per area for autumn sowing was significantly more than the winter sowing up to 64. 6 percent. Based on the equations fitted to the emergence of wild wheat and wild barley intact seeds planted over 12 stages from late November to mid-May of the growing season of 2013-2014, the minimum emergence in both grass weeds were estimated 75% and 56 %, respectively. Average emergence of before winter, during winter and in the spring for the wild wheat was estimated to 90, 86 and 89 percent and for wild barley 62, 77 and 69 percent, respectively. With the onset of the cold season in the late of autumn, the emergence rate of this grass weeds were reduced, but subsequently, with elimination of cold condition in late of winter emergence rate became more prominent, until deal with high temperatures in late spring that emergence declined. Considering the temperature changes during the growing season indicates that the correlation of emergence rate with the fluctuations in temperature. Emergence rate of wild wheat grass weed in autumn and spring seasons were 2. 8 and 3. 5 times more than the emergence rate in spring season, respectively. In the case of wild barley, grass weed emergence rate in autumn and spring seasons were 1. 3 and 2. 1 times more than that of winter. After four months of harvesting wild wheat seeds, the germination of seeds exposed to sunlight and stored under room temperature, on average, was 8. 4 times more than the germination ability of seeds stored in the freezing condition. Germination rate of wild barley weed seeds exposed to sunlight and stored at room conditions during after-ripening period rose sharply. The germination rate for seeds placed in the sun and stored at room conditions, were 56 and 61 times more than seeds stored in freezing condition, respectively, after about five months of harvesting seeds. Conclusions: The results of this study suggest that physiological dormancy, physical dormancy (seed coat), and after-ripening during the summer season play an important role as an obstacle in germination of both wild wheat and wild barley in rain-fed conditions. In case of soil moisture availability, the required time window to achieve 50% of achievable germination of wild wheat and wild barley in autumn, winter and spring seasons were estimated 9, 18 and 3 days, respectively.

Introduction: Sesame (Sesamum indicum L. ) is an annual and thermophilic plant, drought resistant, and short day crop. Sesame has great importance forproviding the needed oil in Iran. In the agro-ecosystems, weeds are considered as unwanted plantsneeding to be controlled. The competition between weeds and sesame for moisture, light and nutrients over the growing season reducesthe quality and quantity of crop grain yield. Although the sesame is a tall and powerful crop, it is a sensitive crop to weed competition. Since the weeds are well adapted to environmental conditions, they are successful in competitionwith crops. Chemical control seems not to be the unique and best way to manage the weeds and it reduces the sustainability of agro-ecosystems. The main approach for sustainable weed management in an integrated weed management program is to decreaseherbicides usage through increasing crop competitiveness with weeds. In this regard, fertilizer management is one of the most important crop management strategies. Among the nutrients necessary for plants, nitrogen is the most crucial nutrient required forplant growth and competition. Therefore, its application management plays a key role in decliningweed interference with crops thereby reducing the herbicide utilization. Hence, the objective of this study was to determine the effects of nitrogen levels and control methods on competition between weeds and sesame. Materials and Methods: In order to evaluate the effect of different levels of nitrogen fertilizer and controlmethods on density and dry weight of weeds and grain yield of sesame (Sesamum indicum L. ), a two-year field study was conducted as a factorial experiment in randomized complete block design with four replications during 2012 and 2013 growing seasons in Agriculture Research Center of Jiroft. The treatments included controlmethods at five levels (pendimethalin herbicide application at 0, 2, 3, and 4 lit ha-1 and weeding) as the first factor and nitrogen fertilizer rates at three levels (56, 80 and 104 kg ha-1), as the second factor. The nitrogen fertilizer rates (urea N, 46%) corresponded to 70, 100 and 130% of the optimum nitrogen requirement. 80 kg ha-1 net nitrogen was considered as the optimum rate needed for sesame production. Fertilizerwas placedbeside the plants and banded beneath the surface in three stages (pre-planting, pre-flowering and pre-capsule forming). The herbicide was applied using a back pack sprayer equipped with a flood jet nozzle with 2 bar pressure and 350 lit ha-1 output volume of the sprayer. Weed species each were oven-dried at 75° C for 48 h and weighed for measuring dry weight. Also, the grain yield of sesame was measured at the end of the growing season. The data were statistically analyzed using combined variance of analysis and the differences among mean values of the treatments were compared by LSD test (p≤ 0. 05) using SAS 9. 4 software. Results and Discussion: Evaluation of weed flora indicated that 5 weed species including Egyptian crowfoot grass (Dactyloctenium aegyptiumL. ), prostrate pigweed (Amaranthus blitoides S. Wats), digera (Digera muricata (L. ) Mart. ), purple nutsedge (Cyperus rotundus L. ), and barnyard grass (Echinochloa colonum L. ) were dominant species, with high evenness in the experimental plots. The results showed that the weed control method and nitrogen levels had a significant effect (p≤ 0. 01) on density and dry weight of all weeds. Further, the weed control method had a significant effect (p≤ 0. 01) on grain yield of sesame in the first and second year. The influences of nitrogen levels and interaction effects were, however, not statistically significant on grain yield, whereas the effect of nitrogen levels on density and dry weight of weeds was different. Under non-weed control conditions, nitrogen fertilizer increased the density and dry matter of weeds, and under weed control conditions, nitrogen fertilizer decreased the density and dry matter of weeds. After hand weeding, the application of pendimethalin at 4 lit ha-1 in addition tousing104 and 80 kg ha-1 of nitrogen was the best treatment for reducing the density and biomass of weeds. Furthermore, the application of pendimethalin at 4 lit ha-1 resulted in the greatest seed yield. Conclusions: Using agronomic methods to improve crop competitiveness against weeds can be effective in reducing the contribution of herbicides into weed management programs. Moreover, these approaches would be considered as effective step towards sustainable weed management. It seems that combining nitrogen application with weed control improves the efficacy of weed control through improving competitive ability of crops. Therefore, it is necessary to consider the application of nitrogen fertilizer as an effective component in the integrated weeds control management in sesame production system.

Introduction: Weeds control has been recognized as an essential action in crop production systems. Weeds, in addition to crop quantity, are effective on crop quality, harvest costs and pest abundance diversity. Onion (Allium cepa L. ) cannot tolerate prolonged competition withweeds because of its initial slow growth rate after planting, shallow fibrous roots, and small above-ground canopy for effective soil shading (7, 8). Weed infestation in garlic is one of the major factors for loss in yield and bulb loss to the tune of 40-80% (2, 5, 25). Regarding the increase and development of onion cultivation in recent years, effective control of weeds in all stages of growth stages is necessary in order to increase bulb yield. In all researches, hand weeding has the highest onion yield, but due to increased production costs, it may not be economies. The use of herbicides can be an alternative to lowering costs, lack of labor and increasing onion gain. Herbicides such as Oxyflourfen, Oxadiazone, Linerone and Pendimethalin are used to control onion weeds (11, 15). With evaluation the effect of Oxyflourfen and Oxadiazonon onion weed in the early growth stage, it was demonstrated that the Oxyflourfen after hand weeding had the best weed control and onion bulb yield (7). In general, very limited research on chemical control of onion weeds in Iran and in the world has been carried out. Therefore, this research was carried out to evaluate the effect of three post-emergence herbicides in two application timing on weed control and onion bulb yield in Ramhormoz region. Materials and Methods: In order to evaluate the effect of application time of some post-emergence herbicides on onion (Allium cepa L. ) weeds control, a factorial experiment was conducted in complete randomized blocks design with 3 replications in Ramhormoz region. Experimental factors included post emergence herbicides (Clethodim 1. 5 Lit. ha-1, Oxadiazon 2 Lit. ha-1, Oxyflourfen 1. 5 Lit. ha-1 and Clethodim+Oxadiazon 1. 5 and 2 Lit. ha-1, respectively) and two different times of herbicide application (1-2 and 3-4 true-leaves stage of onion). Onion seeds were planted directly on Oct. 4th and the onion planting density was 25 plants per m-2. Fields received 100 kg P ha-1 and 150 kg N ha-1. The P was supplied in the form of single superphosphate. Nitrogen treatments were applied as urea (46% N). Dominant weeds in time of herbicides application were Echinocloacrusgalli, Malvaspp, Convolvulus arvensisand in time of bulb formation were Malvaspp, Melilotusofficinalis and ScorpiurusmuricatusL. . Living weed plants were calculated before and after herbicide application using 0. 5×0. 5m quadrate, and weed biomass obtained by harvesting and drying tissues at 75 ˚ C to constant mass using 0. 5×0. 5m quadrate at bulb formation stage. In order to evaluatethe efficiency of weed control, below equation was used: WCE=[(A-B)/A]×100 In this equation, WCE is the weed control efficiency (reduction of weed number in percent), A is weed density before and B is the number of weeds after herbicides application. The evaluated onion traits included: bulb fresh weight, bulb number, bulb diameter, bulb dry weight. Statistical analysis was made using the SAS statistical program. Differences between traits means were assessed using Duncan's Multiple Range Test. Results and Discussion: The major weeds flora in the field experiment were Echinochloa crus-galli., MalvarotundifoliaL. and Convolvulus arvensisL. Results showed that the effect of time of herbicides application on evaluated traits was not significant but the effect of herbicides treatments on the decrease of weed density and biomass was significant. The lowest Echinocloacrusgalli abundance and the highest control of this narrow weed was obtained from Clethodimherbicide treatment. Clethodimdid not control broadleaf weeds. Regarding the growth and coincidence of broadleaf weed growth such as Scorpiurusmuricatus L, Malvaspp and Melilotusofficinalis with onion growth, Clethodimhad no effect on these weeds and had the lowest onion yield. Oxyflourfen was the most effective herbicide onthe decrease of weed density and dry biomass (including Malvaspp and Melilotusofficinalis)and resulted in the highest bulb fresh yield, the bulb number, the bulb diameter and the bulb dry weight. It has been reported that the use of Oxyflourfen during post-harvest resulted in the highest number of onion bulbs per unit area, and then Oxadiazone and Fluozifop were arranged in subsequent positions (13). Although the difference of dry weight of bulb was not significant between different application timing, post-emergence application of oxyfluorfen at 3– 4 leaf stage resulted in onion. Thus, itwas recommended for effective onion weed control and high economic yield.

Introduction: The use of allelopathic materials has been a favorite natural herbicide for plant scientists. The effect of these natural compounds is more than artificial compoundsdue to its water-soluble and halogen-free characteristics. Regarding the increasing resistance of weeds to herbicides, application ofallelopathic method can reduce the use of artificial herbicides and prevent environmental degradation. The purpose of this study was investigation of using Euphorbia heterophylla metabolites in growth and germination control of weed Avena Ludoviciana in farms Materials and Methods: In order to investigate the allelopathy effects of aqueous and alcohol extracts of (heterophylla Euphorbia), an experiment was conducted at Agricultural Research Center of Golestan (Gorgan city) Province during 2014 and 2015 with a completely randomized design under greenhouse condition on Avena ludoviciana with three replications. The treatments in this experiments were the plant species organs at 2 levels (dry powdered of leaf and stem), solvent type for preparing extracts at 2 levels (water and alcohol(methanol)) and the extract concentrations at 5 levels (0, 25, 50, 75 and 100 percentage). The measured traits included height, leaf wet weight, leaf dry weight, stem wet weight, stem dry weight and leaf area. The aqueous and alcoholic extract of Euphorbiaheterophylla were obtained by dipping of dried material in the special solvents in dark place at room temprature for three days and finally, filtration with muslin cloths. The prepared extracts was stored in 4 degree centigrad refrigerator. This extrat was considered as stock solution and the rest concentrations were preapared from this solution. The extracts sprayed on the target plant (Avenaludoviciana) as post-emergence at 3-4 leaved stages. Total phenolic content was measured using the Folin-Ciocalteu reagent method and the total flavonoid content of the extracts was surveyed by a colorometric method based on aluminum chloride. Finally, the relative recognition of the nature of plant compounds was done by chemical methods and colorimetry. The data were analyzed with SAS, 9. 9 software and the means were compared to eache other using LSD (least significant difference) at (p < 0. 05) and the graphes was drawn with Excel software. Results and Discussion: Based on the results of the analysis of variance, except for leaf area of Avena ludoviciana which was affected by the treatments at 95% confidence level (p < 0. 05), all the measured traits were significantly affected by the treatments at 99% confidence level (p < 0. 01). In general, the results of this study showed that the aqueous extracts of Euphorbia heterophylla stem and leaves had no inhibitory effects on the measured traits at zero levels (control treatment), but the growth and germination of Avena ludoviciana was inhibited by the leaf alcoholic extract and stem aqueous extract at 50 and 100% concentration. These extracts significantly decreased plant height, stem fresh weight, leaf fresh weight and leaf dry weight of Avena ludoviciana. The highest effect was observed on Avena ludoviciana leaf area at 100% concentration of leaf extract and the lowest effect was observed at 75% concentration of stem extract. The results of phytochemical experiments of the aqueous and alcoholic extract of the leaves indicated that the aqueous extract of leaves and stems followed by alcoholic extract of leaves had the highest phenolic compounds and also highest antioxidant properties, respectively. According to the results of this study, it is suggested that, further research must be carried out on the identification and mechanism of action of Euphorbia heterophylla allelopathic compound and their effects on Avena ludoviciana seedlings growth. Thus, it can be used as an alternative source of antioxidant compounds in the organic fertilizer industry. Conclusions: Based on the phytochemical experiments conducted in this study, the existence of secondary metabolites in the Euphorbiaheterophylla extracts was proved. The obtained results from the different extracts (aqueous extract of stem, aqueous extract of leaf, alcoholic extract of stem and alcoholic extract of leaf) showed thatthe alcoholic extracts of leaves significantly affected the growth traits of Avenaludovicianamore than the rest of extracts. It seems that attempting to accurately identify the chemical nature of the allelopathic compounds present in different organs of Euphorbiaheterophyllaand the factors that affecting these compounds can lead to the other studies based on biological weed management.

Introduction: Wild melon (Cucumismelo) is a monoecious, annual, trailing-vine plant of the Cucurbitaceae family. The reproduction of wild melon is only by seeds. Wild melon is native to Africa but is aggressively invading crop lands in the northern Iran. Because of rapid growth and limited control measures of wild melon, it is fast becoming a dominant weed in soybean fields. As wild melon and soybean share similar ecological niches, information pertaining to wild melon germination, and emergence would be beneficial. The ability to predict the time of seedling emergence is an important step towards increasing the timeliness and efficiency of chemical and cultural weed control measures. Controlling weed seedlings that emerge early may help to reduce competition during the critical phase of crop seedling establishment, but later emerging cohorts may escape control and contribute to the soil seed bank. Therefore, understanding the factors that regulate the time of weed emergence is crucial for both short-and long-term crop production goals. The time of weed germination and emergence in the field is influenced by environmental factors such as light, and soil moistureand temperature. Soil temperature is often considered as the primary environmental factor regulating emergence. The cumulative effect of temperature, expressed as thermal time, is correlated with the processes of after-ripening and seedling elongation. The aim of this study was to determine the effects of different management operations on the seedlings emergence of wild melon and to develop a soil thermal time (STT) model to predict the emergence of this species in soybeans. Material and Methods: Experiment was arranged as split-split plot in a completely randomized block design with three replications. Conventional tillage (CT) and no-till (NT) systems were main plots, three seed rates of soybean (200, 000; 300, 000 and 400, 000 seed ha-1) were sub-plots and sub-sub plots comprised five different doses of imazethapyear (0, 50, 75 100 and 125 g ai ha-1). The soybean cultivar used in the experiment was Telar (BP). Before performing the experiment, field had also been in a continuous soybean production and contained natural infestations of annual weed, especially wild melon. The experimental design was then carried out during the growing seasons in 2016 and 2017. The experimental farm was divided into two uniform areas each year to adopt the CT and NT treatments. After seedbed preparation, planting in the first year was carried out on 17/6/2016 and in the second year on 25/6/2017 in both tillage systems. The spacing of the planting rows was 19 cm and the dimensions of each plot were 6×6 m. Each year after planting until flowering, irrigation was held once by week starting at 20 days after planting in each year, the indoxacarb (Avaunt) was used to control of heliotis. To evaluate the effect of different doses of imazethapyear (Pursuit) on the emergence pattern of wild melon during each year, spraying was carried out as PRI based on the mentioned treatments by using Marina-type 20 liter sprayer equipped with a flood jet nozzle and 2. 5 bar pressure (calibrated based on applying 200 to 300 lit ha-1 water). To predict the wild melon emergence pattern in each plot, a fixed 50×50 cm quadrate was placed at the center of each plot, and from the beginning of the season after the first irrigation, the newly emerged seedling was counted. The counts were repeated every week, and then the seedlings counted at each stage were removed until new emerged seedling was not observed. Statistical Analysis: Thermal time models were developed and evaluated, to describe observed wild melon seedling emergence pattern. Therefore, to estimate the cumulative seedlings emergence during the growing season, number of purslane seedlings was calculated based on the number of seedlings m-2. STT was obtained with the soil temperature by the following: whereSTmean is the mean daily soil temperature, Tbase is the minimum temperature at which purslane seed germinates, and n is the number of days after sowing. Base temperature used in the calculations of STT for wild melon was 10 ° C (Baker and Reddy 2001). Temperature Model software (STM2) (Spokas and Forcella 2009) was used to predict daily soil temperature at the 3cm depth. Daily precipitation, minimum and maximum air temperature were taken from the nearest meteorological station located near Sari, Mazandaran province. Soil texture properties and organic matter (%), along with the latitude, longitude, and elevation (1 m) of the research site were also used to predict daily soil temperature. To describe the pattern of seedling emergence, cumulative emergence data were fitted using a three-parameters logistic model (Equation 2) (Brown and Mayer 1988; Eizenberg et al. 2005): where a represents the upper asymptote (final CE), T50 represents the STT when the CE is 50% of the final CE (median), and b represents the slope of the curve at approximately T50. The parameter estimates were compared by using a two-tailed t-test (p < 0. 05). The goodness of model fit was evaluated with root mean square error (RMSE) and adjusted coefficient of determination (R2adj) (Izquierdo et al. 2009). RMSE was calculated as follows: wherePi and Oi are the predicted and observed emergence values, respectively, andn is the number of observations. Preliminary analysis of variance was conducted using PROC GLM in SAS to determine treatment effects and their interactions. Nonlinear regression analyses were applied using Sigma Plot ver. 12. 5. Results: The statistical measures of the model's performance showed that STT model is a good predictor for wild melon emergence, with adjusted coefficient of determination (R2adj) values ranging from 0. 92 to 0. 99 and root-mean-square error (RMSE) values ranging from 2. 59 to 12. 69. The time of wild melon emergence was significantly affected by management practices such as tillage systems, soybean seeding rates, and imazethapyr doses. In the CT system, a seeding density of 400, 000 seeds ha-1 and a 125 g ai ha-1imazethapyr dose showed a reduced wild melon emergence rate and had the highest T50, thus resulting in a long lag phase of wild melon emergence at the beginning of season. This provides more time for crops to establish and improves soybean competitive ability. The current study provides valuable information on prediction of the time of wild melon emergence to develop effective management strategies for this species. The proposed emergence models precisely predict the emergence pattern of wild melon seedlings as a function of STT, and STT models developed on the basis of field observations offer relatively strong predictions. With the continued development of such models, IWM will be more practical, enabling us to predict how farm management changes affect weed populations, the biological outcomes of the various management options, and the economic and environmental impact of crop-weed competition.

Introduction: Pistachio is one of the most important horticultural products in Iran, especially in Kerman province. Other areas that pistachios are grown include Yazd, Khorasan, Fars, Semnan, SistanandBaluchestan, Qazvin, Isfahan and Qom. Pistachio is being attacked by several pests. One of these pests is pistachio mealybug, Anapulvinariapistaciae (Bodenheimer) (Hem.: Coccidae) which however, is not a major, , in unmanaged gardensof some parts of Iran, becomes to a damaging agent. Scale insects are highly specialized herbivores. This group widely distributed from the Siberian tundra to the tropical areasareserious crop pests. The superfamily Coccoideacontains nearly 8000 species in 48 families in the World (5). In Iran, 13 families of the superfamilyhave been identified (8). Mealybugs of family Coccidae are important agricultural pests whichinfect leaves, branches and shootsof many fruit trees and ornamental plants. Biological control of some species of this family is successful and is carried out at relatively low cost and least harmful effects on the environment (12). The subfamily Coccophaginae has a host relationships that are different for males and females, and are defined as heteronomous. In this groups some males are hyperparasitoid of female larvae (11). Pistachio mealybug, A. pistaciae) is the only species of Anapulvinaria genus in the world (9)andfor the first time, was reported from Iran in 1937 (2). Pistachio have been recorded from the provinces of Hormozgan, Kerman, Sistan and Baluchestan, South Khorasan and Yazd, on the host plants from the families Anacardiaceae (Pistaciakhinjuk and Rhuscoriaria), Juglandaceae (Juglansregia) and Tamaricaceae (Tamarix sp. ) (8). So far it has been reported from Georgia, Syria, Tajikistan, Turkey, Ukraine, Uzbekistan, Kyrgyzstan, Azerbaijan, Turkmenistan, Iraq, Greece, Cyprus, Armenia, Afghanistan (5). The superfamily Chalcidoidea-as main biocontrolagant of these pests-contains 22, 500 known species, and an estimated total diversity of more than 500, 000 species (7). Parasitoids of the families Aphelinidae and Encyrtidae (Hym.: Chalcidoidea) are the most important natural enemies of the mealybugswidely distributed in the World (1, 13). Aphelinidae are a moderate-sized family of tiny parasitic wasps. Most species are parasitoids of mealybugs, scale insects, whiteflies and aphids. Some other are hyperparasitic (10). More than 1300 species of the Aphelinidae family have been reported in the world (7, 10) and about 60 species of different species of this family did from Iran (7, 10). Materials and Methods: During sampling from Pistachio Garden of Birjand Agricultural Research Station (32° 53'N 59° 13'E and elevation 1491m) in May 2016, some pistachio mealybugs were collected and transferred to the laboratory for rearing possible parasitoids. A handmade rearing plastic bag was used for rearing and collecting parasitoids (Fig. 1B). The collectedparasitic wasps on this pest were transferred to alcohol 75% and identified by second author, using available keys (13 and 14) and morphological characteristics in different parts of the body, especially the head, thorax and wings. The samples weredeposited in the insect collection, department of Plant Protection Research, East-Azarbaijan Agricultural and Natural Resources Research Center, Tabriz. Results and Discussion: Reared wasps were identified as CoccophaguspiceaeErdö s, 1956 (Hym.: Chalcidoidea, Aphelinidae). This is first report of C. piceae on the pistachio mealybug. Important morphological features of C. piceaeare as follow: body length 1-1. 3 mm, body generally dark (Fig. 1A), thorax dark, abdomen dark brown, antennae (Fig. 1B) and legs yellow, trochanter of mid and hind legs, hind femur medially and last tarsomers of all tarsi are dark; scutellum with only 2 to 3 pairs of long hairs. This parasitoid has previously been reported from East-Azarbaijan province as parasitoid of Eulecaniumcoryli (L. ), Eulecaniumtiliae (L. ) and Didesmococcusunifasciatus (Archangelskaya) (Hem.: Coccidae) (4). Generally, it is known as the parasitoid of different species of Pulvinaria(9). This wasp has been reported from the Eastern European countries (Czech Republic, Hungary, Slovakia, Sweden, Poland and North Russia) and the Middle East (Asia, Turkey, Caucasus, Russia, Georgia, Armenia, Azerbaijan, Lebanon, Syria, Jordan, Egypt, Saudi Arabia, Iran and Iraq (9, 5). The pistachio mealybugis attacked by another wasp parasitoid, Blastothrixsericea (Dalman, 1820) (Hym.: Chalcidoidea, Encyrtidae) in Tehran, Isfahan, Markazi, Gilan and Mazandaran provinces (3).