Iranian Plant Protection Research
Year:2018 | Volume:32 | Issue:2|Papers Count:14

Introduction: The rose family includes many economically important fruit trees known as stone fruits in the genus Prunus, with a basic chromosome number x=8, within the subfamily Pronoidaea. The subfamily is unique among the rosaceous subfamilies, in bearing a fleshy fruit called a drupe with a hard endocarp, often called the stone. Many Prunus species are compatible with the link. This adaptation is very important in the production of commercial fruit. The purpose of using base-link compounds is that plant materials adapt to soil types and climatic conditions. There are different genera of plant parasitic nematodes in rhizosphere such as Amplimerlinius, Basiria, Boleodorus, Coslenchus, Discotylenchus, Filenchus and Psilenchus. Some of them are endoparasites and others ectoparasites. From the economic point of view, fruit-bearing trees are considered to be high-value agricultural products that are cultivated in most parts of the country. Urmia city is one of the major suppliers of fruit in the country. According to Agricultural Statistics in 2013, West Azerbaijan province with 99205. 97 hectares of garden products produces 82. 3 percent of the total land production in the country, which is ranked seventh in the country. Also in the same year, producing 1075465. 73 tons of produce, 74. 6% of the total production of garden products and the third rank of the country. In the year 92, the total amount of the country's garden products (about 227 thousand hectares) is related to the nuclear trees, of which 1. 89 million tons were obtained, accounting for 11. 84 percent of the total production of horticultural products Country is West Azerbaijan province has 2677. 06 hectares of unpolluted levels and 1911. 20 hectares of fertilized surfaces dedicated to nuclear products, of which 105575. 26 tons of nuclear fruit production were produced from these lands. Therefore, due to the importance of nematodes from different aspects such as their high diversity, economic damage to plants in high populations, the intensification of damage to other pathogens in plants, and with regard to the few studies carried out, in particular in the field of plant-parasitic nematodes of the rhizosphere of nucleated fruit trees in West Azerbaijan Province. The aim of this research was to investigate the plant parasitic nematodes associated with stone fruit trees in the Urmia county. Material and Methods: In order to identify plant-parasitic nematodes of stone fruits in Urmia, 85 soil samples were collected during 2013 and 2014. Soil samples were washed and then extracted by centrifugal flotation technique, killed, fixed and transferred to Glycerin by using the method of De Grisse 1969 and Jenkins 1969. The permanent slides were prepared and nematodes were studied by light microscopy, based on morphological and morphometric characters. Result and Discussion: In this research, 11 species of seven different genera of Tylenchidae family were identified as follows: Basiria duplexa, B. macrostriata, Boleodorus thylactus, Coslenchus costatus, C. gracilis, Discotylenchus longicauda, Filenchus cylindricaudus, F. vulgaris, Irantylenchus clavidorus, Psilenchus aestuarius and P. iranicus. In this research, the categorization of the Daily and Blacksters, which is provided up to the family level, is considered, and for lower levels, other sources are used as needed, as stated in the text. Among these identified species, Basiria macrostriata from Nazlou and Coslenchus gracilis and Discotylenchus longicauda from Somaybradoust were reported as a new record for Iran. Basiria macrostriata was identified by these characters: cuticle coarsely striated being 1. 8-2 (µ m) apart on mid-body region. Lateral field with four crenate incisures. Head almost continuous and rounded. A Slender stylet with the flanged knob. Basal bulb more or less pyriform. Excretory pore situated at 89 (µ m) from anterior end. Spermatheca sac-like and elongate. Slender filiform tail with a pointed terminus. Coslenchus gracilis was identified by cuticular annuli flattened indistinct. Stylet knobs small, 7-8(µ m), rounded or slightly elongated. Median bulb spherical, Vagina strongly swollen, slightly anteriorly directed. Spermathecabilobed and containing minute sperm. Annulation on tail indistinct. Discotylenchus longicauda was identified by body straight, maximum width 9-11(µ m). cuticular annuli indistinct. The Lateral field comprising a single ridge formed by two smooth incisures. Stylet thin, cone 1/3 of its length. Median bulb spindle-shaped. Vulva transverse, open. Tail straight, elongated, filiform, gradually tapering to the rounded tip. Conclusion: Among these species in this research, from 11 species of seven different genera of plant parasitic nematodes, Basiria macrostriata, Coslenchus gracilis, and Discotylenchus longicauda were identified for the first time from Iran.

Introduction: Using nematode-resistant cultivars is the most economical and environmentally friendly management strategy for the management of the pathogens like nematodes known for causing great yield losses. Root knot nematode (Meloidogyne javanica) is distributed in all soybeans-producing regions of the world and can result in yield losses in almost all soybean-growing areas. The most important species in Iran is M. javanica, which has the widest host ranges of any of the root-knot nematodes. Control of M. javanica is accomplished through the use of pesticides, crop rotation and resistant cultivars. Resistance to nematodes is usually defined as a plant’s ability to inhibit nematode reproduction. Soybean, Glycine max (L. ) Merrill, which had economic and nutritional significance, is currently the most important oil-seed crop cultivated in the world. The relationship between crop yield response and initial nematode densities is an important property of a crop resistance. The purpose of the current study was to determine damage functions of M. javanica for some soybean cultivars. Materials And Methods: The experiments were conducted under greenhouse conditions and temperature maintained at 25± 3° C. Pots (2500 grams) were fumigated with methyl bromide to eliminate existing biotic factors prior to planting and then were filled with a sterile soil composed of sand 60%, clay 14%, silt 26%, at pH 7. For evaluating the reaction of some soybean cultivars to the target nematode, infected roots collected from Isfahan province, identified using morphological methods, perineal pattern of adult females as well as molecular markers, amplification of 670 bp band of extracted DNA from egg and larvae using single egg mass culture. Then the nematode mass was cultured around the roots of 2-4 leaf stage tomato cultivar Ps using completely randomized design with five replications. Soybean plants inoculated with 8000 eggs of M. javanica per 2. 5 kg of soil. After 80 days, the growth and physiologic factors of host plant such as root length, root fresh and dried weight, shoot length, shoot fresh and dried weight, pod number in plant, seed per pod, 100-seed weight, chlorophyll concentration, leaf area index (LAI) and leaf area ratio (LAR) as well as gall index, egg mass and reproductive factors of nematode was measured. Results And Discussion: The purpose of this study was to determine damage function of M. javanica for some resistant and susceptible soybean cultivars. Similar to M. javanica, the other nematode species was identified using morphological as well as molecular markers as. In greenhouse condition, results showed that the root weight of the infected soybean cultivars increased in comparison to that of healthy roots and the reason is the hormonal imbalance and the gall formation in the roots by the target nematode. The shoot length and shoot fresh weight in infected plants decreased due to the absorption of nutrients and internodes distance reduction. Seed per pod is dependent characteristics on the genotype, and largely is independent of environmental factors and specific environmental stresses may affect grain formation period. The number of seeds per pod was completely genetic trait, indicating significant differences among cultivars, but the cultivars were not affected by nematode infection. The JK cultivar has the most final population of nematodes and Sahar cultivar has the least one. The JK cultivar was sensitive to 2. 65 gall index and Williams and Elit cultivars were tolerant and showed less gall index and Sahar, L-17, 033 along with DPX were recognized as resistant soybean cultivar, among which Sahar cultivar with 0 reproductive factor and 0. 6 gall index was most resistant one. The use of resistant soybean cultivars is the most efficient and control methods for root-knot nematode. Conclusions: The different soybean cultivars have varying degrees of sensitivity, tolerance and resistance to root-knot nematode infection. The present research indicates that using breeding methods as well as biotechnological techniques, tolerant and resistant cultivars can be produced and the farmers can choose the resistant ones to reduce application of hazardous chemicals. On the other hand it is necessary that by a thorough examination of nematode resistant genes in soybean plants and their incorporation in the sensitive plant, the nematode damage would get reduced. The use of resistant soybean cultivars is the most efficient and adequate control measure.

Introduction: Phytoplasmas were first discovered in 1967 and named mycoplasma-like organisms or MLOs. They are wall-less prokaryotes of the class Mollicutes causing diseases in many economically important plant species. Phytoplasmas are transmitted by phloem-feeding leafhoppers and planthoppers. Plants infected by phytoplasmas exhibit a variety of symptoms suggesting profound disturbances to the normal plant physiology. Restriction fragment length polymorphism (RFLP) and sequence analyses of rDNA have been used for the taxonomic characterization and phylogenetic analysis of phytoplasmas. Because of the high economic losses, in particular those of cultivated crops, annuals and high-value vegetables, detection of phytoplasmas is very important. Cowpea (Vigna unguiculata) is an important vegetable crop cultivated in Iran. Progressive growth abnormalities and phyllody symptoms with high economic loss have been observed in cowpea fields of East Azarbaijan province. Causal agent of the disease is, however, unclear. This study was, therefore, carried out to identify pathogen associated with cowpea phyllody in East Azarbaijan province of Iran. Materials And Methods: Infected cowpea plants were collected from fields in East Azarbaijan province of Iran in summer of 2016. The disease agent was transmitted by dodder to periwinkle plants under controlled greenhouse conditions. Leaf midribs from healthy control and naturally-infected hosts were used for DNA extraction. Total DNA was extracted from midrib of six symptomatic cowpeas, inoculated periwinkle plants using CTAB buffer as previously described by Zhang et al., 1998. The universal primer pair P1/P7 was employed in first round PCR to amplify an 1830 bp fragment of 16S rDNA. A 30-fold dilution of the first round PCR product was then used as template for nested PCR using primer pair R16F2n/R16R2 which amplified an internal fragment of 1245 bp from the 16S rDNA. PCR products were ligated into pTZ57R/T using InsT/AcloneTM PCR Product Cloning Kit and transformed to Escherichia coli DH5a cells. The recombinant plasmids were sequenced. The sequences were assembled using DNA baser V. 3 program. About 100 ng of DNA from R16F2n/R16R2 primed PCR product from each province was separately digested with 2. 5 μ L of AluI, HaeIII, HpaII, HinfI, RsaI and TaqI restriction enzymes according to the manufacturer’s instructions. Restricted DNA fragments were analyzed by electrophoresis through a 2% agarose gel. Phylogenetic tree was generated using neighbour-joining method with MEGA7 software. Acholeplasma laidlawii, a culturable mollicute that is phylogenetically related to the phytoplasmas, was designated as the out-group to root the tree. The reliability of the tree was assessed by bootstrap analysis with 1000 times replication. Further, the sequences of the 16S rRNA gene were subjected to virtual restriction fragment length polymorphism (RFLP) using iPhyClassifier software (http: // plantpathology. ba. ars. usda. gov/ cgi-bin/ resource/ iphyclassifier. cgi) to determine ribosomal group affiliation. Results And Discussion: Cowpea plants collected from East Azarbaijan province showed disease symptoms similar to those caused by phytoplasmas. In infected cowpea plants, symptoms of little and thickened leaves, phyllody, proliferation of shoot, wrinkled and malformed leaves, stem fasciation and stunting were observed. Inoculated periwinkles showed little leaf, internode shortening, yellowing, virescence, phyllody, stem and floral proliferation and witches’ broom. Amplification of 1830 and 1245 bp fragments in PCR and nested-PCR, respectively, and Blast analysis of the fragment sequences confirmed phytoplasma infection of cowpea plant associated with phyllody symptoms. No band was found at healthy control. Consensus sequences of 1, 830 bp of three isolates (Tabriz, Nazarlou, Shabestar) were submitted in the NCBI GenBank under accession numbers KC633092 to KC633094. Phylogenetic analyses and restriction fragment length polymorphism (RFLP) of 1245 bp fragment with 17 restriction endonucleases using iPhyClassifier software indicated that phytoplasma associated with cowpea phyllody belong to Clover proliferation group or 16SrVI A subgroup (similarity coefficient 1. 00). Conclusions: Tomato (Solanum lycopersicum), potato (Solanum tuberosum), cucumber (Cucumis sativus), cabbage (Brassica oleracea) and periwinkle (Catharanthus roseous) were reported as hosts for 16SrVI phytoplasma group in Iran. Recently, maize (Zea mays) has also been reported as a natural host of the 16SrVI group. In addition, different phytoplasma groups and subgroups were reported infecting cowpea crops from different countries over the globe. A 16SrXII-B strain of 'Ca. Phytoplasma australiense' associated with witches’ broom and small leaves of V. unguiculata var. sesquipedalis in Australia. A Vigna little leaf phytoplasma belonging to group 16SrV has also been reported from Australia. In India, different phytoplasmas associated with cowpea from 16S rDNA groups 16SrI-B, 16SrXIV-A and 16SrII-D, have been characterized. Identification of the causal agent of phyllody of cowpea in Iran should facilitate studies concerned with epidemic aspects of the disease, and could contribute to knowledge of the genetic diversity of phytoplasmas in Iran. To the best of the present study authors’ knowledge, it is the first report of the Vigna unguiculata infection with phytoplasmas related to the “Clover Proliferation Group” from East Azarbaijan province of Iran.

Introduction: Vascular wilt caused by Fusarium oxysporum is one of the most important problems in producing tomtao. Recently, using the method of biological control by beneficial microorganisms of plant pathogens has an important role in crop management programs. A number of Trichoderma species are now available commercially to be used (discretely or in combination with reduced amount of chemical pesticides) for plant pathogens control. These biocontrol agents include strains belonging to the fungal genera such as Trichoderma and Gliocladium, which these species are the most intensively studied species. They are the most isolated soil-borne fungi commonly found in plant root ecosystem and these opportunistic, a virulent plant symbionts are also antagonistic towards many phytopathogenic fungi. Depending upon the strain, the application of Trichoderma has been proven to improve root and plant growth and induce resistance in plants, as well. In order to utilize the full potential of Trichoderma species in specific applications, precise identification and characterization of these fungi is vital. Trichoderma species are saprophytic fungi with minimal nutritional needs, which secrete a wide range of secondary metabolites conferring major ecological benefits to their host plants. Materials and Methods: In this study, the fungal isolates were cultured using dual culture to assess the nutritional competitiveness, colonization and mean percentage of growth inhibition between Trichoderma isolates and Fusarium oxysporum in three temperature levels (20, 25 and 300C) and pH (4, 5 and 6. 5) in PDA. If one colony has a faster growth rate than the other, a curve in the contact zone would most probably be observed. Then, the effect of growth indices were measured in both methods of cell suspensions injection and mixing the biocontrol agent (Trichoderma species) into the soil in comparison with control in greenhouse condition. In order to evaluate the effect of temperature and pH on the antagonistic activity of native Trichoderma species from kitchen garden crops on the pathogen and greenhouse studies, a factorial experiment was designed in a randomized complete block in vitro and greenhouse. Results and Discussion: The results showed that the biocontrol characteristic of antagonistic species depended on the type of Trichoderma isolate, temperature conditions and pH. This study indicated that all five native species isolates can reduce mycelia growth of F. oxysporum in dual culture in vitro. As for the ability of Trichoderma species in growth inhibition, there was significantly different in the level of %1 for temperature and pH treatments. T. harzianum (Ah90) had the highest antagonistic activity with 58. 33% inhibition of growth at 300C in pH 6. 5. On the other hand, environmental parameters such as temperature and pH were effective on germination and growth of the germ tube in antagonistic species and mycelia growth. As to the contact of Trichoderma isolates and the pathogenic agent, the growth of mycelia was very low and the amount of spore in the pathogen was reduced compared with the control. After 35 days, there were significant differences in the growth indices (average fresh and dry weight and plant height) in both injection of suspension and mixing the biocontrol agent by soil with control in greenhouse condition. Using antagonists in greenhouse conditions caused an increase in plant growth system due to earlier deployment and better absorption of water and nutrients by the plant. According to the statistical analysis, antagonistic activity of T. harzianum (Ah90) plus pathogen were greater than the other two species compared with infected control and increased total dry weight by 2. 14 g and plants height by 2. 32 cm. Adding Trichoderma to soil prior to cultivation had a greater effect on disease control than suspension injection in the soil as the antagonist spores in suspension were not available to the root in long term and removed from the root. While in soil application, soil immersion significantly decreased tomato wilt compared to control treatment. Conclusion: In a temperature range of 33 oC, soil pH of 5. 6 and by application of soil inoculation, T. harzianum (Ah90) isolated from cucurbit fields in Khorasan province was found to be the most suitable species leading to reduced disease and increasing the vegetative parts of the plant under greenhouse conditions.

Introduction: Cucurbit plays an important role in human nutrition because of an ingredient of vitamin and other dietary substances. Cucurbit crops are very sensitive to viral infection. Over 35 viruses from Cucurbitaceae family have been reported. Plant viral diseases are major limiting factors for successful cultivation causing major yield losses in agricultural crops worldwide. Zucchini yellow mosaic virus (ZYMV) is a member of the genus Potyvirus, in the family Potyviridae has flexuous filamentous particles of about 750 nm in length and consists of a single-stranded RNA about 9. 5kb. It was first reported in Italy in 1981. ZYMV is transmitted by certain species of aphids, by plant sap containing the virus and through infected seeds. ZYMV is one of the major pathogens of the family Cucurbitaceae. The common symptoms of ZYMV infection are local lesions, chlorotic mosaic, vein banding, yellowing, and stunting. Thrips-transmitted tospoviruses are economically important viruses affecting a wide range of field and horticultural crops worldwide. Tomato spotted wilt virus (TSWV) is the type member of the Orthospovirus genus in the family Tospoviridae with a broad host range of more than 900 plant species. TSWV has tripartite, ambisense, and single-stranded (ss) RNA genome transmitted by thrips in propagative and persistent manner and is ranked second among the top ten economically important viruses in the world. The aim of this research was to serological and molecular detection of ZYMV and TSWV on cucurbits of Guilan province and Urmia county and concerning their phylogenetic relationship with other isolates of the world. Materials And Methods: In order to detect ZYMV and TSWV during the growing season of 2014, a total of 457 leaf samples of squash, watermelon, cucumber, melon and cantaloupe showing virus symptoms were collected from different fields of Guilan province and Urmia vicinity. DAS-ELISA was carried out on all samples using specific polyclonal antisera and samples with values at least twice the value of the negative control value according to the absorbance at 405 nm was accepted as positive. The samples which showed positive result in ELISA test were inoculated to Chenopodium amaranticolor Coste et Reyn, C. quinoa Wild., Cucumis melo L., Cucurbita pepo L., Lycopersicon esculentum L., Nicotiana rustica, N. tabacum var. Samsun and Gomphrena globosa L. Total RNA were extracted from positive samples in ELISA (for ZYMV) using RNXTM (-Plus) kit and RT-PCR was performed using ZYMV and TSWV specific primers corresponding to the CP and L-gene of these viruses, respectively. PCR positive products were sent for sequencing from both sides. Sequences were compared to data available in GenBank and multiple alignments of the nucleotide sequences and a phylogenetic tree were constructed by MEGA6 using the neighbor-joining method with a 1000 replicate bootstrap search. Results And Discussion: Among 457 symptomatic samples collected from cucurbit fields of Guilan province and Urmia vicinity showing viral symptoms, 39 squash samples were infected by ZYMV but none of them by TSWV in ELISA test. Almost all inoculated plants showed symptoms of infection by ZYMV described in literature them. But this was different symptoms. An amplicon of the expected size (458 bp) was generated from ELISA positive samples during RT-PCR using specific primers but not from the healthy sample and no positive result for TSWV. Two PCR-positive samples of Guilan province and one Urmia isolate were sequenced and submitted to BLASTn. The results revealed that the PCR-amplified fragments of all samples belonged to ZYMV. The Kiashahr and Astaneh isolates showed maximum similarity (98%) with Czech Republic and Iran (Fars) isolates, and Urmia isolates showed the highest homology (99%) with Slovakia isolate in group A. Conclusions: Viruses are known to greatly reduce cucurbitaceous yield. ZYMV is one of the most destructive and widespread plant pathogens. In this study, for the first time, molecular detection of ZYMV in squash fields of Guilan province and Urmia vicinity has been reported concerning its phylogenetic relationship with other isolates of the virus available in the GenBank. Phylogenetic analyses based on CP gene indicated that the Iranian ZYMV isolates are closer to European isolates plus one Iranian isolate and clustered in group a clade. The data obtained in this study will be beneficial to improve control strategies for this virus in Iran and are the base for further work on ecology, epidemiology, and diversity of these viruses in these two regions. Further studies on ZYMV isolates from different geographic regions and hosts of these two regions and genetic diversity evaluation of the virus will be useful for breeders to make more efficient and durable resistant cultivars. TSWV was not detected in cucurbits of these two regions during this study. It has been reported only in Malaysia on cucurbits.

Introduction: The two-spotted spider mite is a cosmopolitan species that exist in wide areas of the world and fed from different varieties of plants. The control of this pest was done by chemical pesticides and acaricides. Due to the high cost of chemical compound and problems such as durability and environmental pollution, alternative control means are necessary. Plants may provide potential alternatives to currently used insect control agents. Plant materials have several advantages over traditional pest control agents; such as specificity, biodegradability and low mammalian toxicity. Sirinol is a natural compound based on garlic extract. Spirodiclofen with a trade name of Envidor® is a broad spectrum acaricide acting via lipid biosynthesis inhibition (LBI) with no cross-resistance to currently available acaricides and with additional insecticidal properties. Envidor is positive IPM listed but in the frame of resistance, management limited to one application per season. In pear growing Envidor constitutes an important tool in pear sucker control in a tandem strategy with abamectin. In this research, the effect of this compound was investigated on the egg and adult of T. uricae under laboratory and field condition. Materials and Methods Rearing of T. urticae: An initial mite colony was collected from infected fields in Sari and was transferred to the laboratory in Sari Agricultural Science and Natural Resource University, plant protection department. The adult mites were released on the bean leaves (3 weeks after leaves germination) and removed 24 h after treatment. Infected plants to mite eggs were placed in a growth incubator at 25± 2˚ C, 65± 5% RH and 16: 8 photoperiods. 12 days after treatment and emerging of adults, they were used for the bioassay. Bioassay: First of all, primary experiments were performed to determine the minimum and maximum concentrations. Then, seven concentrations and also control were considered. The concentrations used for sirinol were 250, 381, 593, 922, 1434, 2230 and 3500 ppm and for spirodiclofen were100, 134, 180, 242, 326, 438 and 600 ppm. The original bean leaf discs (30 mm diameter) were cut and 15 adults of T. urticae were released on each leaf. Then, 500 microliters of each concentration was sprayed on the leaves using spray potter tower and the leaves were put on the petri plates containing moist cotton. The treatments were placed in a growth incubator at 25± 2˚ C, 65± 5% RH and 16: 8 photoperiods. The number of dead mites was counted at 24, 48 and 72 hours post-treatment. To evaluate the effect of three concentrations 1000, 2000 and 4000 ppm of sirinol and 300, 600 and 1200 ppm of spirodiclofen an experiment with seven treatment and four replications was conducted in a randomized complete design under field condition. The numbers of T. urticae and P. persimilis (egg and adult) on leaf samples were counted one day before treatment and 3, 7, 14 and 21 days after treatment. Statistical analyses: The mortality results were analyzed statistically using SPSS data processing software. Significant differences among the groups were determined using the unpaired Duncan-test. A value of P

Introduction: Plant resistance to insect pests as a method of pest control in the context of IPM has a greater potential than any other method of pest suppression. Development of crop varieties resistant to insect pests and diseases has been the major research thrust at ICRISAT (International Crops Research Institute for the Semi-Arid Tropics) for sustainable crop production. The most attractive feature of host plant resistance (HPR) is the simplest seed-based technology for which farmers do not need any extra skills concerning the application, and any additional cash investments. Sugar beet root aphid Pemphigus fuscicornis Koch (Hem.: Aphididae) is one of the most important pests of sugar beet, Beta vulgaris L. in many countries. Variability in response to root aphids by commercial varieties is demonstrated by Campbell and Hutchison (1995). Sugar beet variety trials in the western plains region have shown that sugar beet varieties vary greatly in the level of resistance to sugar beet root aphid feeding. Correlative data from these trials in Nebraska, Wyoming and Colorado indicate that varieties being susceptible to root aphids had the yield reductions as much as 30% compared to those varieties with a high level of resistance. Cultivars resistant to root aphid, Pemphigus spp. have been highly successful and the resistance has been stable for more than 30 years in Texas or other areas. Several seed companies have had trouble developing resistant cultivars and even those companies with resistant parental lines required an evaluation of new hybrids. Materials And Methods: In this research that was carried out during 2010-2011, the responses of Pemphigus fuscicornis to 12 sugar beet genotypes (19610, OtypeA37. 1, Simin2, 19584, Jit13, Polyrave, OtypeA1, Shirin, Zarghan, OtypeC2, Chinock, Branco) were examined under the laboratory conditions. The sugar beet seeds were planted in the field, and plants were grown to 6 true leaf stages, then were transplanted into a peat-vermiculite mix (50: 50) in pots. Four young adult aphids were placed in the root mass before placement into the pot. The plants were irrigated weekly and the incubator was set at 20± 2º C and 16 h in the artificial light. Sixty days after root infestation, the aphid populations were evaluated by floating aphids out of the root mass in 20-cm diameter bowls and they were classified as adults and nymphs based on the presence of the sub-genital plate as an indicator of maturity. Therefore, all count data were transformed by log (x) before the analysis. Statistical analyses were performed using SAS statistical software (SAS Institute Inc, Version 9. 1) and means comparison of treatments were done by Tukey's tests. Results And Discussion: Sugar beet variety trials in the laboratory conditions have shown that sugar beet varieties vary significantly in the level of resistance to P. fuscicornis feeding. There was a significant difference among aphid population densities with regard to different host plant varieties (F=10. 56, df=11, 43., P=0. 0001). Out of 12 genotypes, line 19610 was highly susceptible, OtypeA37. 1 and Simin2 were susceptible, 19584, Jit13, Polyrave and OtypeA1 were moderately susceptible, Zarghan, Shirin and OtypeC2 were moderately resistance and Chincko and Branco were resistance to P. fuscicornis at laboratory condition. Also, the effect of root aphid infestation on the sugar content of plant showed that, P. fuscicornis significantly decreased the sugar content (F=42. 05, df=3, P=0. 0001) in Doreti variety at field conditions. So, more than 15 percent of infestation to root aphid at harvest time significantly decreased the sugar content. Conclusions: Based of the present results, it is concluded that planting of resistant varieties (Chincko and Branco) or moderately resistant varieties (Zarghan, Shirin and OtypeC2) will have a significant effect on reducing the aphid damage in this area. However, it is recommended that these varieties to be examined under greenhouse or field conditions. In this research, screening for resistance has been carried out under laboratory conditions. Laboratory tests are useful to confirm the resistance observed under field conditions. Procedures for infestation and evaluation of resistance under field, greenhouse or laboratory conditions using artificial infestation need to be standardized to breed for plant resistance to this pest. Insecticides have been unsuccessful for controlling root aphid, P. fuscicornis and for chemical control to be effective, a soil drench or systemic action through the sugarbeet plant may be necessary.

Introduction: Poplar trees in Iran are hosts to a number of aphid species, some of which cause excrescences on leaves and other growing parts. These abnormal growths are classified as either galls or pseudogalls but innumerable gradations between the apparently normal and abnormal plant structures have made differentiation difficult. Galls are vegetable excrescences resulting from insect activities and usually sheltering the immature stages of the producers. The aphid genus Pemphigus Hartig, 1839 (Hemiptera: Sternorrhyncha) contains over 70 species widely distributed in the Holarctic, of which, 46 are known to form galls on leaves or twigs of Populus L. Aphids of the genus Pemphigus are usually holocyclic and heteroecious between a primary host, and several herbaceous secondary hosts. The majority of the family representatives are dioecious or heteroecious. Such species migrate from primary hosts (tree species) where they form galls characteristic in their size and shape to roots of secondary hosts (herbs or tree species). Only few species are monoecious, i. e. with life cycle occurring on one host species. Reviewing taxonomic related literature showed that the knowledge of Iranian galling aphids is still limited. So far 7 species e. g. P. borealis Tullgren, 1909, P. bursarius Linnaeus, 1758, P. immunis Buckton, 1896, P. populi Courchet, 1879, P. protospirae Lichtenstein, 1884, P. spyrothecae Passerini, 1856 and P. vesicarius Passerini, 1861 have been reported from Iran. Materials And Methods: This study was conducted during the growing season of 2017. The study area, Razavi Khorasan province (35. 1020° N, 59. 1042° E) is located in the North eastern Iran, where no study has previously been carried out. The galls were collected from the leaves, petioles and branches of poplars, according to their location, and taken from them. Also some galls with aphids were put into vials filled with 75% alcohol for morphological studies. Sampling, preparation and identification of specimens were done according to the Blackman and Eastop (2000)). Specimens was approved by Dr. Roman Hał aj in Entomological Laboratory of the Upper Silesian Nature Society of Poland. Systematic knowledge, host plants, and synonyms of determined species were taken from Blackman and Eastop (2000) and Rezvani (2001). Results And Discussion: Nine gall-inducing aphid species belonging to genus Pemphigus, Tribe Pemphigini and subfamily Eriosomatinae were found on four host plants. The occurrence of Pemphigus passeki (Bö rner), 1952 (Hem.: Aphididae) and Pemphigus populinigrae (Schrank), 1801 (Hem.: Aphididae) on Populus nigra in Iran are reported for the first time. The other recorded gall aphids are: 1-Pemphigus borealis which its galls are more or less oval in shape with a rather smooth surface galls, often merged into groups of 4-6 at the base (even up to 10). 2-Pemphigus bursarius with galls of more or less spherical, pear-shaped or pouch-like, green, yellow-green, sometimes red-brown in color. 3-Pemphigus immunis which its galls are walnut shape (c. a 4 cm in diameter), with think walls and uneven, wrinkled and often cracked surface, usually occurring individually, less often in small groups but always separated from one another. 4-Pemphigus passeki with galls at the base of the lamina, this gall was collected only from Neyshabour city. 5-Pemphigus populi with gall of more or less spherical or oval, more or less irregularly blobbed, almost always narrower at the base than at the top, pear-shaped or even slenderer, placed on the upper side of the lamina on the main nerve usually close to its base, size of a hazelnut, most often green in color. 6-Pemphigus populinigrae Schrank, 1801 with elongated galls and running along the main nerve, rather smooth, in their majority bright reddish and rather without yellowish tint, only partly open from the bottom side of the lamina. 7-Pemphigus protospirae with flattened and strongly spirally twisted galls, the twists are smaller and more numerous (more than 5) than those formed by P. spyrothecae. Galls very often on all the petiole and the base of lamina, shiny, green or green with red spot. 8-Pemphigus spirothecae with galls in the form of flattened and spirally twisted petiole, with the number of twists not exceeding 5 (usually 3-5). Galls are green, yellow-green to red-brown. 9-Pemphigus vesicarius with galls of combe-like, crown like or club-shaped, always with very distinct processes. Conclusions: This preliminary research on gall-inducing aphids and their host plants in NE Iran added two new records of species to Iranian aphid fauna and 5 new records to Razavi Khorasan province. Previously about 485 aphid species were known for Iran. By the present study, the Iranian aphid fauna has at least 487 species. However, the number of insects especially aphids recorded from Iran is far from complete. Most probably due to the fact that the Iranian fauna has been poorly investigated and many areas have been sampled only sporadically

Introduction: Weeds are the major constraint on rice production. It has been reported that weeds cause rice yield losses by 30-40% in Bangladesh, 36 to 56% in the Philippines, 40 to 100% in South Korea and up to 90% in Iran. Extensive application of graminicides, flooding, and continuous hand weeding have increased the population of more problematic weed species like bulrush (Bolboschoenus maritimus (L. ) Palla in rice fields of northern Iran. Bulrush is a perennial weed belongs to cyperaceae family and resistant to most paddy herbicides, flooding and also hand weeding. Yield reduction of rice was estimated up to 100% due to bulrush competition. Despite environmental concerns, theeffect of herbicides on non-target organisms, and the increase of herbicide-resistance weeds, chemical control is still the most commonly used and reliable method for weeds control in paddy rice production in Iran. Materials And Methods: Field experiments were conducted at Rice Research Institute of Iran during 2013 and 2014, Rasht, (36° 54' N, 40° 50' E,-21 masl) to assess the efficacy of paddy herbicides for bulrush control. In the first experiment (2013), commonly used paddy herbicides in Iran including bensulfuron-methyl, butachlor, oxadiargyl, pretilachlor, and thiobencarb were evaluated for bulrush control. Two control treatments (hand weeded and weedy check) were also included for comparison. Based on the result of the first experiment, second experiment (2014) was designed to evaluate the efficacy of some new herbicides including flucetosulfuron, penoxulam, metsulforun-methyl, pyrazolate and also bensulfuron-methyl for bulrush control. Both experiments were conducted as randomized complete block design with three replications. Individual plots were 3m wide by 3m long and rice seedlings (cv. Hashemi) manually were transplanted on 23 May 2013 and 2014, with planting distance of 20cm × 25cm. Visual injury evaluation for rice (chlorosis, and growth stunting) and visual weed control (chlorosis, necrosis, and plant stand reduction) was conducted at 2, 4 and 6-WAT (a week after transplanting) in each plot. Visual ratings of rice toxicity and weed control were based on a scale of 0 to 100%, where 0 means no injury or no weed control and 100 means complete death or complete weed control. Also, bulrush biomass was determined at 2, 4 and 6-WAT in the first experiment and 4 and at 12-WAT in the second experiment from a randomly selected 1m2 quadrate in each plot. Weed samples were oven dried at 70 ° C for 72 h and weighted. At the maturity stage, rice grain yield (based on 14% humidity), and rice biomass was determined from 5 and 1 m2 per plot, respectively. Rice biomass from each plot was dried at 75° C for 96 h and weighted. Harvest index was calculated by dividing the dry weight of the grain by the dry weight of aboveground (biological yield). Data were subjected to analysis of variance (ANOVA), and means were compared using Fisher's protected LSD test at the 0. 05 probability level. All statistical analyses were conducted using SAS (ver. 9. 1) software program. Results And Discussion: Results of the first experiment showed excellent control of bulrush by bensulfuron-methyl (≥ 98) followed by pretilachlor (≥ 85%) at 6-WAT, at the end of critical weed control period in transplanting rice. The efficacy of other herbicides was ≤ 60%. The lowest biomass of bulrush was recorded for plots treated with bensulfuron-methyl (1. 5 g m-2) and pretilachlor (10. 6 g m-2). Results also showed that the highest grain yields were observed in plots treated with bensulfuron-methyl (4000 kg ha-1) or pretilachlor (4231 kg ha-1). This was mainly due to optimum weed control in these plots. Grain yield in weedy plots reduced by 76% compared to hand weeded plots, indicating the severe infestation of the plots to bulrush and the ability of this weed to cause rice yield loss. The reduction in grain yield in weedy plots could be mainly due to severe competition for nutrient, especially nitrogen, and light. Because of adequate moisture in paddy fields, reduction in rice growth due to weed-crop competition for water is negligible. The highest harvest indices were observed in plots treated with pretilachlor (52. 4%) and butachlor (50%) and weed-free plots (48. 8%), while the lowest one was recorded for weedy plots. This result indicates that assimilate partitioning to grain or photosynthesis is reduced under weedy condition. The result of the second experiment also confirmed the result of the first one and indicated that bensulfuron-methyl had good efficacy (≥ 85%) on bulrush control. The result also indicated that bulrush was controlled very well by flucetosulfuron (88%) and pyrazolate (85%). In contrast, penoxulam and metsulforun-methyl had fair efficacy (≤ 49%) on bulrush control. Moreover, flucetosulfuron, and pyrazolate showed good compatibility with rice, and grain yield in these treatments did not statistically differ with gain yield in plots treated with thiobencarb bensulfuron-methyl. Grain yield was significantly lower in weed-free plot compared to plots treated with bensulfuron-methyl, flucetosulfuron, and pyrazolate. This may be due to that manual weeding can be performed only when weeds have reached a sufficient size to be pulled out easily by hand. By that time, yield losses may have already occurred. At the same time, it seems that weed control by 2-or 3-times hand weeding induced severe stress on rice plant, resulted in a decrease in grain yield. Grain yield in a weedy plot was reduced by 51 and 62% compared with weed-free plots and with plots treated with thiobencarb bensulfuron-methyl, respectively. These results indicate the importance of bulrush control in paddy fields. Conclusion: Of the current paddy registered herbicides in Iran, bensulfuron-methyl was the most effective herbicide for bulrush control followed by pretilachlor with partial efficacy on bulrush. Newly investigated herbicides, flucetosulfuron, and pyrazolate, could be registered as good options for bulrush control in paddy rice. In respect to the different mechanism of action of new herbicides and their compatibility with rice, the alternative application of new and current herbicide is recommended for controlling bulrush and delaying weed resistance to the herbicide.

Introduction: Salinity is one of the most important abiotic stresses that cause severe effects on crop production around the world. Estimates indicate that more than 800 million hectares of arable lands in the world are affected by salinity. Salinity impacts on various aspects of growth from germination to seed production in plants. Plants′ responses to salinity, however, are different and depend on the toxicity, osmotic potential, as well as the stress duration. Purple nutsedge (Cyperus rotundus L. ) is one of the noxious weeds. This weed belongs to sedge family, and is a C4 perennial plant which reproduce by sexual (seeds) and asexual (tubers and rhizomes) means. It can cause tremendous damage on summer crop fields such as onion, potato, maize, sunflower, and so on. Evaluation of weed growth responses to saline condition came about by water and soil can provide for us very important information by which we choose appropriate weed control strategies. Since a few experiments have been evaluated growth characteristics of purple nutsedge under salinity stress, this study was conducted to evaluate the salinity effects on growth characteristics of purple nutsedge. Material and Methods: To evaluate the effect of irrigation water and soil salinity on growth characteristics of purple nutsedge, two separate experiments were conducted in a randomized complete block design with three replications in the greenhouse of Faculty of Agriculture at University of Birjand in 2013. The first experiment contained five salinity levels of water including 0, 3, 5, 7 and 9 dS. m-1 and in the second experiment, there were five salinity levels of soil including 1, 3, 5, 7 and 9 dS. m-1. The salinity levels of water were prepared through solving a certain amount of NaCl in water based on this equation: NaCl (mg. L-1) =EC (dS. m-1)×640. . Following determination of soil electrical conductivity, soil salinity levels were prepared by adding NaCl to the soil based on saturation moisture percent and field capacity. A tuber of purple nutsedge was planted at 2. 5 cm depth in each pot. Experiments were terminated at the end of the vegetative growth stage of purple nutsedge (105 days after emergence). Measured traits were plant height, stem number per pot, leaf area, and tuber number per pot, shoot and underground dry weight. After collecting the data, ANOVA was performed using Genstat Ver. 9 and mean comparisons were performed using Fisher's least significant difference test at 5% significant level. In order to evaluate purple nutsedge growth response to salinity stress, an exponential decay model was used; Y=a*exp(-b*x), thta in this model, a and b represents the maximum amount of studied traits and the slope of curve according to the model estimation, respectively. Results And Discussion: The results of both experiments showed that the growth characteristics of purple nutsedge (plant height, stem number per pot, leaf area, tubers number per pot, shoot and underground dry weight) were significantly affected under soil (P

Introduction: Rapeseeds are susceptible to shuttering during harvest increasing soil seed bank. Secondary dormancy is induced in shuttered seeds due to dryness and darkness conditions of soil in summer season and its level is different based on the seed types. Germination may be observed in seeds with low level of secondary dormancy. Before initiation of the next growing season and under undesirable environmental conditions seedlings will die. In contrast, high level of secondary dormancy in the other seeds is not eliminated and then they will emerge in the next growing season along with the crops as rapeseed volunteers. Rapeseed volunteers are considered as weeds in the next growing season and transfer target genes from crops to relative plants and weeds during pollination causing a decrease in quality, yield, and eventually purity of produced seeds. Materials And Methods: Six rapeseeds cultivars and lines were selected with different secondary dormancy levels of low (Gor-o-16 and Gor-H-4), medium (Zarfam and RGS003), and high (Gor-o-4 and Gor-o-6) among 46 lines and/or cultivars of the previous study. Three replications of different seeds were placed in incubator at 20° C in darkness before induction of secondary dormancy (primarily secondary dormancy was determined). In fact, three replications of seeds with different levels of secondary dormancy were first exposed to inducing condition of secondary dormancy (-15 bar potential for 14 days) and then exposed to different treatments of temperature and light i. e. 20° C (darkness), 20° C (light), 25° C (darkness), 25° C (light), 30° C (darkness), 30° C (light), 3-30° C (darkness, 12/12hours), 3-30° C (darkness/light (12/12 hours)), 20-30° C (darkness, 12/12 hours) and 20-30° C (darkness/light (12/12 hours)). Finally, secondary dormancy responses were analyzed. Result and Discussion: Average primary germination in all seeds including cultivars and lines of rapeseeds before secondary dormancy induction was higher than 98% implying the absence of primary dormancy. After secondary dormancy induction, the highest germination was shown in the seeds with low level of seeds secondary dormancy at constant temperature in darkness and light. It was decreased in those with medium level of secondary dormancy by increasing temperature from 20 to 30° C in darkness, even though decreasing process was higher in light treatment. But it was the same in the seeds with secondary dormancy in comparison with medium levels of secondary dormancy in darkness and light. High level of secondary dormancy in G-O-6 and G-O-4 can be attributed to their responses to increased temperature and the light, respectively. Secondary dormancy was eliminated in seeds with high level of secondary dormancy by being exposed to 3-30° C treatment in darkness that implied replacement of alternative temperature with light requirement. Secondary dormancy was not completely eliminated for 20-30° C and 30° C treatments as some parts of seed population need alternative temperature and the others require light for complete elimination. Some studies suggested that light is required for complete elimination of secondary dormancy as it influences hormonal balance indirectly through phytochromic pathways. Moreover, the other studies reported that secondary dormancy can be partially eliminated by impacting heat shock proteins and light requirement. Rapeseeds appear to be photoblastic after inducing secondary dormancy. Further studies are required on the roles of phytochromes and hormonal balance pathways of ABA and GA in eliminating secondary dormancy of rapeseeds. Conclusion: Different rapeseed responses with different levels of secondary dormancy after being placed in soil seed bank were simulated by laboratory conditions with emphasis on two environmental factors of temperature and light. The same response was shown by increasing constant temperature in rapeseed with different levels of secondary dormancy. Decrease in secondary dormancy was obvious in them and a greater increase was found for mentioned treatment in light. Secondary dormancy in all seeds was entirely eliminated after being exposed to alternative temperature and light. Complete elimination of secondary dormancy was observed in response to 3-30° C alternative temperature whether in darkness or darkness/light conditions. It was found that light requirement can be removed after induction of secondary dormancy by 3-30° C alternative temperature in darkness. However, secondary dormancy was only eliminated in some parts of seed population by 20-30° C and 30° C. In addition, light was observed as a critical factor for breaking for the others. It can be thus concluded that light was required for eliminating secondary dormancy in rapeseeds and seeds became photoblastic after the induction. Therefore, secondary dormancy can be removed before next growing season by being exposed to mentioned temperature and light.

Introduction: Maize is among the world's three most important cereal crops. Weeds are one of the most important factors that reduce maize production. They cause important yield losses worldwide with an average of 12. 8% despite weed control applications and 29. 2% in the case of no weed control. Weeds compete with crops when they remove a portion of a resource from a shared resource pool, leaving the crop with less of the resource than is needed for optimum growth. Competition may occur for water, creating or exacerbating water stress. It may occur for nutrients such as nitrogen, leading to chlorosis, leaf senescence and yield loss. Increasing the ability of a crop to compete with weeds has been considered an approach to improving weed management in recent years. The importance of weed competition in maize depends on the maize genotype, weed species, crop growth stage, the weed density, the level of water, and nutrient stress. Some crops can significantly suppress weeds by their ability to grow faster than weeds or to endure greater sowing densities. The plant competitive ability can be expressed in the following two modes: First, the crop weed suppressive ability (WSA) that results in the reduction of weed biomass and second, the crop tolerance ability (CTA) to tolerate weed effects and to have high yields at the same time. Crop tolerance to weed interference aims to improve stability of yield and quality in weedy fields, whereas weed-suppressive ability targets the long-term management of weed populations by reducing seedbank size. Several traits, including the growth intensity in the initial developmental stages, rapid development of a high leaf structure, the plant height, maximum LAI, rate of canopy closure, height of LAI, and leaf architecture, may improve weed-suppressive ability and dent maize tolerance to weed interference. Therefore, the objective of this experiment was to evaluating the competitive ability of maize (Zea mays L. ) genotypes against weeds under different nitrogen rates. Materials And Methods: Experiments were carried out on clay loam soil with low organic matter content (less than 1%) and a pH of 2. 9 at south west Iran in 2011-2012 growing season. The experiment site had a hot climate with a moderate winter and dry and hot summer. Treatments consisted of a split-plot with randomized complete blocks design and three replicates. Nitrogen rates (0, 90, 180 and 260 kgNha-1) were the main plots and four dent maize hybrids Sc. 704, DKC6589, Mobeen and Sc. 640 were planted in sub-plots. DKC6589, Mobeen and Sc. 640 are an early-season hybrids, whereas Sc. 704 is relatively late-season hybrid. Plots consisted of 6 maize rows (distance between and within the rows 75 and 18 cm, respectively) and 6 m long. Maize hybrids were sown on 1st Jun. Fields received 100 kgPha-1 and 150 kg K ha-1. The P and K were supplied in the form of single superphosphate and potassium sulfate, respectively. Nitrogen treatments were applied in two equal splits as urea (46% N) at two and six weeks after planting by side placement. Each plot was divided into two parts hypothetical. One part was maintained weed-free and another weedy for the all maize duration growth stages. In weed-free parts, weed removal was started immediately after crop emergence and the plots were kept weed-free for different growth stage durations until physiological maturity of maize. The experiment was properly monitored and irrigated whenever water was needed. Weed plants were harvested at the R1 (silking) growth stage of maize using 0. 5×0. 5m quadrate, and weed biomass obtained by drying tissues at 68 C to constant mass. Weed density and species also, determined. Interference of maize and weed was quantified by calculating weed index (WI), weed interference tolerance index (WITI) and competition index (CI(. Statistical analysis was made using the SAS statistical software. Differences between traits means were assessed using Duncan's Multiple Range Test. Results And Discussion: The percent loss of grain yield, 100 grain weight, biological yield and grain number per rows under weed interference conditions were 21. 7, 5. 3, 24 and 10%, respectively. Grain yield reduction in weedy plots was resulted from decreasing grain number per rows and biological yield. Negative impact of weeds on maize yield was enhanced under higher rates of nitrogen. When maize competed with weeds, the reduction of grain yield at 260 kg N ha-1 treatment was more compared to 180 kg N ha-1maize. Maize genotypes were different in response to weed competition. The highest weed tolerance interference index was obtained in DKC6589 line due to higher grain yield in both weedy and weed-free plots. Competition index was higher in Sc. 704 and DKC6589 than other genotypes. Although Mobeen and Sc. 640 hybrids had lower grain yield reduction trend under weed competition conditions, but DKC6589 and Sc. 704 showed a high grain yield potential and high ability to withstand weed competition.

Introduction: Weeds are an important challenge to crop production, particularly in sustainable agriculture. Today, identification of highly competitive cultivars is an easy and inexpensive method for weed management in sustainable agriculture systems. Watson et al. in their study of 29 barley varieties found that yield loss due to weed competition varied from 6 to 79 percent, which is related to their ability to compete. In the case of wheat, for more than four decades, the difference of the weed competitive ability between wheat cultivars has been investigated. Two aspects of cultivar competitiveness can be defined, competitive index (CI) and weed interference tolerance index (WITI). CI is the ability of a cultivar to reduce weed growth and WITI is the ability of a cultivar to achieve high yield despite weed competition. These traits differ based on genetical and agronomical aspects. CI is often associated with traits including vigorous growth, allelopathic potential, crop cover, and height and leaf area. Although for environmental stresses high tolerance indexes are important, the competitive index is more important in the long-term management of weed management. Trusting the tolerance index alone can lead to a sharp increase in the weed seed bank, which may not tolerate high-tolerance cultivars. So, the present study was carried out to classify Iranian wheat cultivars based on traits related to competition and tolerance indices and to determine the correlation between indices with yield and yield components. Material and Methods: This experiment was conducted to classify Iranian wheat cultivars based on traits related to competition and tolerance indices and to determine the correlation between indices with yield and yield components in the agricultural research farm of the faculty of agriculture and natural resources, University of Mohaghegh Ardabili at 2015-2016 growing season. For this purpose, 25 wheat cultivars were tilled in November 2015 under with or without weed competition. In each plot, 10 wheat lines were cultivated at a distance of 20 cm and a length of 5 m. The experiment was conducted in a randomized complete block design with three replications. At the beginning of spring, from each plot, a sample of wheat plants was harvested at a surface area of 0. 25 m2, dried at 75 ° C for 48 hours in order to measure the initial dry weight of the cultivars. Sampling from weeds was conducted before the end of growing season. Wheat plants harvested at maturity stage from 1 m2 and seed yield was reordered. To determine the yield loss, CI and WITI was used appropriate formulas. Results And Discussion: The results showed that there was no significant correlation between weed density with growth traits of wheat cultivars, while there was a significant negative correlation between weed dry weight and these traits. The highest correlation was found between the primary cover with dry weeds weight (R2=-0. 70; P

Introduction: Although “the pesticides are a global human rights concern” (24), they can secure global food security provided that the rational herbicide application technique is taken into consideration (7). The principal elements of rational herbicide application technique include the selectivity of herbicide, the application of appropriately timed herbicide and the accuracy of application equipment (4). The hydraulic spray nozzle atomizes the spray solution into droplets (9). Thus, it is a key component to influence on the accuracy of spraying (17). The nozzle technology is always improving, resulting in the introduction of more than 60 nozzle types that all are available to apply in different situations. High nozzle diversity can cause some difficult to select a proper nozzle, particularly when wind speed at time of application is authorized or unauthorized for spraying. The present study aims to compare 14 nozzle types in relation to the efficacy of sethoxydim to control winter wild oat at two wind speeds. Materials And Methods: The seeds of winter wild oat (Avena sterilis ssp. ludoviciana) were treated to germinate (2). Then, the 9 seedlings were planted within each pot and grown in the Research Greenhouse of Bu-Ali Sina University, Hamedan, Iran and thinned to 6 plant pot-1 at the one-leaf stage. At the five-leaf stage, they were treated with 0, 23. 5, 47, 94, 187. 5, and 375 g sethoxydim ha-1 using 14 nozzle types at two wind speeds of 0. 5 and 9. 5 m s-1 in outdoor conditions. A standard 210 L ha-1 carrier volume was sprayed at a pressure of 3 bar with the 11002 yellow nozzles of Twin Fan Standard (TFS), Fan Low Drift (FLD), Standard Flat Fan (SFF), Turbo Wide Angle Flat (TWAF), Low Pressure Air Induction Twin Flat (LPAITF), Low Pressure Air Induction Flat (LPAIF), Compact Fan Air (CFA), Compact Fan Air-Tilt (CFA-T), Turbo Twin Flat (TTF), Air Induction Twin Fan 3070 (AITF3070), Twin Fan Low Drift (TFLD), Air Induction Turbo Twin Flat (AITTF), Twin Fan Air (TFA), Turbo Air Induction Flat (TAIF). Four weeks after spraying, the dry weight of plants were obtained and the date were fitted to analyze using a four-parameter log-logistic model to estimate the Effective Doses (ED) (19). Results And Discussion: The ED10, 50 and 90 values of sethoxydim on the control of winter wild oat were affected significantly by nozzle type or wind speed. When spraying was done at 0. 5 m s-1 wind speed, the lowest and the highest ED50 values were obtained with the TFS and TAIF nozzles, requiring 12. 81 and 62. 72 g sethoxydim ha-1 to give a 50% reduction in dry weight of winter wild oat, respectively. In such a situation of wind speed, the ranking of the nozzle types based on the sethoxydim dose required to give a 50% reduction in dry weight of winter wild oat was TAIF > TFA > LPAIF > TFLD > LPAITF > AITTF > CFA > CFA-T > FLD > TTF > TWAF > AITF3070 > SFF > TFS (Table 1). It can be concluded that the endo-drift by TFS nozzle at low wind speed is lower than other nozzles. When spraying was done at 9. 5 m s-1 wind speed, the lowest and the highest ED50 values were obtained with the AITF3070 and TFS nozzles, requiring 45. 13 and 87. 35 g sethoxydim ha-1 to give a 50% reduction in dry weight of winter wild oat, respectively. In such a situation of wind speed, the ranking of the nozzle types based on the sethoxydim dose required to give a 50% reduction in dry weight of winter wild oat was TFS > FLD > TAIF > TFA > SFF > CFA-T > TWAF > LPAIF > TFLD > AITTF > CFA > TTF > LPAITF > AITF3070. It can be concluded that the exo-drift by TFS nozzle at high wind speed is higher than other nozzles. It seems that a limiting factor for the performance of nozzles categorized as VC to UC at high wind speed can be the spray carrier volume. Conclusions: As a proper nozzle to spray sethoxydim with 210 L carrier volume ha-1 at a pressure of 3 bar to control winter wild oat at low and high wind speed, the TFS and AITF3070 nozzles can be applied to obtain an optimal herbicide efficacy, respectively.