فصلنامه مطالعات حفاظت گیاهان
سال سی و ششم شماره 1 (بهار 1401)

Dwarfing, yellowing and yellow mosaic are the most common symptoms observed in cereal fields. Various pathogens such as viruses are involved in development of these symptoms. Over 30 different plant viruses are known to infect wheat. Among them, Wheat dwarf virus (WDV), Barley yellow dwarf virus (BYDV) and Wheat streak mosaic virus (WSMV) are important viral diseases around the world. Little comprehensive information on the distribution of these viruses is available in Khuzestan Province, Iran. This study aimed to determine the occurrence of WDV, BYDV-MAV and WSMV in the major wheat-producing regions in Khuzestan province.

 A survey of wheat fields showing yellowing, dwarfing and mosaic symptoms was conducted during 2020-21 crop season. The six counties in Khuzestan province were covered in the survey include Elhai, Mollasani, Shadegan, Ramhormoz, Shush, and Andimeshk. Plant leaves exhibiting viral disease symptoms were placed separately in plastic bags and quickly transported to the laboratory. Five hundred seventy (570) wheat samples were collected. These samples were tested by Enzyme-linked immune sorbent assay (ELISA) using specific antibodies of WSMV (from Shiraz Virology Research Center), BYDV-MAV (Bioreba, Switzerland) and WDV (DSMZ, Germany).

 The results showed that three tested viruses were present in Khuzestan province. Among the tested viruses, WDV was the most commonly detected (30% of the 570 wheat samples), followed by BYDV-MAV (29%) and WSMV (5%). WDV was found in all counties except Ramhormoz (Table 1). In Elhai county, 28 of the 53 tested samples were infected with WDV, which was the highest infection ratio (52.8%). Symptoms caused by BYDV-MAV are severe dwarfism and yellowing (Figure 1), and it is impossible to distinguish between WDV and BYDV-MAV viruses. The virus was the most widespread and was found in all counties (Table 1). The infection ratio in the six counties were 35% in Elhai, 27% in Mollasani, 10% in Ramhormoz, 25% in Shush, 11% in Andimeshk and 28% in Shadegan. In Ramhormoz, BYDV-MAV existed only in 8 out of 78 tested samples. Selected plants may be shortened due to lack of physiological factors or maybe infected by other strains of the virus. It is recommended that the occurrence of other virus species, including the dominant BYDV-PAV species, be investigated. The mixed infection with WDV+BYDV-MAV was detected in 9% of tested plants. However, the severity of the plant infection was similar to that of plants infected with any of the viruses. WDV was introduced as the predominant virus in wheat fields infected with yellowing and dwarfism in Khuzestan in 2020-2021. Of course, this does not mean that most of the symptoms dwarfing and yellowing in wheat are related to this virus. Studies in Germany also show that grain infection ratio with WDV and BYDV has been different between different years, so that in 1998-1998 WDV was predominant, while in 2005-2001 BYDV was predominant. WSMV is less common than other viruses. It was not found in Shadegan, Ramhormoz, and Mollasani counties. The highest incidence of the virus was observed in Andimeshk county. 13 of the 111 tested samples were infected with the virus (Table 1). Considering that in recent years corn cultivation has been developed as summer crops in Andimeshk and Dezful counties, the corn plant probably provides suitable conditions for strengthening the source of virus and its vector. As a result, crop damage caused by the virus will increase in these farms. In Khuzestan, wheat is cultivated in December, when the temperature is colder than other seasons, and the conditions for mite activity are not completely favorable, and as a result, the incidence of WSMV is lower. It is possible that cultivated wheat cultivars are resistant to mites. Since a positive correlation has been reported between mite resistance and virus resistance, this may play a role in reducing the incidence of the virus.

In this study, the distribution of major wheat viruses in six counties of the province was first investigated. The results showed that wheat dwarf virus and barley yellow dwarf viruses infect high percentages of wheat fields. Considering the important of Khuzestan province in the country’s self-sufficiency in wheat production, the available information about these viruses will cause extensive research in the field of virus damage assessment and additional molecular studies to be on the agenda.

Beet curly top disease is one of the most important sugar beet viral diseases. Numbers of viruses in the family Geminiviridae, including Beet Curly Top Iran Virus (BCTIrV), Beet Curly Top Virus (BCTV), and Turnip Curly Top Virus (TCTV) have generated curly top symptoms in sugar beet. BCTIrV belongs to the genus Becurtovirus, but BCTV and TCTV put in Curtovirus and Turncurtovirus genera, respectively. BCTIrV is known as the most prevalent causal agent of curly top disease in Iran. It has circular single-stranded DNA genomes with 2.8–3.2 kb nucleotides length. The genome encapsidate in quasiicosahedral twinned particle with 22 nm diameters. BCTIrV is transmitted by Circulifer Haematoceps leafhopper naturally. Non-uniform transmission and time-consuming process of reproduction of a virus-free population of the leafhopper make experimental transmission of BCTIrV troublous. Generation of an infectious clone is another strategy for efficient inoculation of BCTIrV to host without dependency on its natural insect vector. The aim of this study is comparison of pathogenicity of two infectious clones of BCTIrV (1.1 and 1.4 mer constructs) in several hosts and optimization of criteria for efficient reproduction of the vector for transmission of the virus.

The complete genome of BCTIrV was cloned in pBlueScript II SK (+) previously. Plasmid extraction from the bacterial cells was carried out using plasmid extraction procedure described by Kotchoni et. al. (24). The 1.4 and 1.1 BCTIrV infectious clones were made by joining 1029 and 308 kb fragments respectively to a unit length of BCTIrV genome. The infectious clones were agroinoculated to seedling s of sugar beet. DNA extraction from newly grown leaves of agroinoculated plants was performed using CTAB. Polymerase chain reaction (PCR) using specific primer pair for BCTIrV coat protein gene (CP) was carried out to identify infectivity of the constructs. To optimize the reproduction of Circulifer hematoceps in greenhouse conditions, Beta vulgaris, Solanum lycopersicum, Capsicum annuum, Nicotiana glutinosa, Sesamum indicum and Amaranthus retroflexus plants were used as hosts. To determine rate of reproduction of C. Hematoceps in greenhouse conditions, firstly optimum temperature for the leafhopper reproduction was determined, then C. Hematoceps population was counted at optimum temperature in 21, 45, and 60 days after release. In transmission test, an adult C. Hematoceps was used to transmit BCTIrV to sugar beet seedling.ResultSequencing data and RFLP pattern using EcoRI/XhoI restriction endonuclease were confirmed integrity of the 1.4 and 1.1 constructs. Four weeks after inoculation, BCTIrV was identified in newly grown leaves of sugar beet seedlings using PCR. Eight weeks after inoculation yellowing and leaf curling symptoms were generated on infected plants. Circulifer hematoceps was successfully reproduced on B. vulgaris, S. indicum and A. retroflexus in greenhouse. Moreover, S. lycopersicum, C. annuum, N. glutinosa were not suitable hosts for the leafhopper reproduction. The maximum, minimum, and optimum of daily temperature required for C. hematoceps reproduction was 34°C, 18°C and 29°C, respectively in a period of 45 days after the leafhopper release. Also, the best fitted host for C. hematoceps multiplication was A. retroflexus, however, BCTIrV was not infective in this plant. BCTIrV was successfully transmitted from pG-BCTIrV 1.4 and pG-BCTIrV 1.1 agroinoculated B. vulgaris plants to healthy sugar beet using C. hematoceps. Fifth weeks after the leafhopper feeding systemic symptoms of the virus were developed.

The curly top is a destructive disease of sugar beet which is a threat to sugar beet production. Previously, several BCTIrV infectious clones with different lengths were made by other researchers. The pG-BCTIrV 1.4 is similar to constructs of previous studies. In this study, pG-BCTIrV 1.1 that is the smallest infectious construct of BCTIrV with a length of 3153 nucleotides, is successfully constructed for the first time. The 1.1 mer infectious clone will provide a facility for induction of point mutation in the BCTIrV genome to identify the role of genetic elements in virus pathogenicity via reverse genetic approach. The results indicated no significant difference in infection efficiency, symptoms severity, and vector transmission rate between pG-BCTIrV 1.4 and pG-BCTIrV 1.1 constructs. Forth weeks after inoculation symptoms were observed in B. vulgaris plants that vector transmission by pG-BCTIrV 1.4 and pG-BCTIrV 1.1, but Taheri et. al. (2012) represented symptoms appearance at two weeks post inoculation. This discrepancy may cause by differences in host susceptibility, virulence of the virus, or environmental conditions. The results revealed that, the preferential host for C. haematoceps multiplication was A. retroflexus in greenhouse conditions. The population of C. haematoceps increased up to 11.1-fold on this plant in 45 days. In the current study, infectivity of BCTIrV in A. retroflexus not identified either using agroinoculation or vector transmission, but Jahanbin et. al. (2015) represented BCTIrV infection in 20 % of agroinoculated A. retroflexus plants.

Black dot disease triggered by Dilophospora alopecuri causes considerable damage in some fields in Golestan province, North of Iran. D. alopecuri is its causal agent and carried in to wheat by wheat gall nematode. Extracellular appendages on the conidia adhere to the cuticule of the nematode juveniles. The disease was reported in united state of America, Canada, Germany, Ugoslavia, India and Pakistan.The fungi is classDothideomycetes and order Dothideales. The geographical distribution of disease was studied in South-Eastern Australia in the summer 1995.The disease in Iran has been reported by Bamdadian since 1973 from Baluchistan, Isfahan, Golestan, Khorasan, Kerman and Khuzestan. The disease agent causes considerable damage in some fields in Golestan province, North of Iran. Symptoms have been found during a survey of foliar disease of wheat in Golestan province. The disease incidence was very low but fungus interaction with seed gall nematode causes considerable damage. The symptoms start with yellow spindle-shaped flecks which develop and become tan brown with black border. This spots may occur on peduncle and heads. The pathogen survives as mycelium in host debris or as conidia on seeds. The purpose of this study was determining the geographical distribution, disease incidence (DI) and disease severity (DS). Then molecular identification of isolates with ITS rDNA in North of Iran, Golestan province.

 Wheat fields infected with the disease in the cities of Golestan province were visited and subjected to sampling during spring 2017-2018. 42 samples suspected to infection with the twist disease were gathered from seven cities of Golestan province. The rate of disease distribution from seven cities farms with disease symptoms, three farms were selected in each crop year and their geographical coordinates were recorded. In this research mapping the geographical distribution of disease was prepared by ArcGIS10.2 software. During 2018 and 2019, a survey was conducted to characterize the disease incidence (DI) and disease severity (DS). The D. alpoecuri leaf spot reading scales rate carried out in this study. No visible symptoms are observed and the leaf remain a health 0; A few chlorotic lesions are present and the infection site is a tan-spot colored 1: Necrosis and chlorosis both exist on the leaf 2: A few pycnidia are visible on the infected site and less than 30% of the leaf is occupied by pycnidia 3: The entire leaf is covered by pycnidial lesions scored 4. A significant difference was observed between the disease rates in the two cropping years. Seven D. alopecuri isolates were identified on the based on morphological and molecular parameters. After purification of fungal isolates, 50 conidia and pycnidia were selected in each isolate and the length and width of pycnidia, conidia cell number, conidia size (length and width), colony shape on the culture medium were also measured in the laboratory. After that identifying of the fungus isolates pathogenicity test was performed in the greenhouse. The D. alopecuri spore suspension with 1.75× 106 CFU concentration and for nematode population with 25000 larvae (L2) were used for inoculation to plants. After three months symptoms of leaf spot (twist) disease was appeared in tillering stage. Fungal DNA extraction from mycelium mass of selected isolates was performed by Murray and Thompson (1980) method and part of ITS region was amplified using ITS4 and ITS5 primers by polymerase chain reaction (PCR). The amplified PCR products of fragments were purified and sequenced at sequencing Microsense Company in Switzerland.

  Comparing of harvested fungal isolates which have been grown on PDA medium showed some variation in different characteristics such as the number of conidia walls, conidia appendages and pycnidia size. In both subsequent years, maximum disease incidence (DI) and disease severity (DS) was measured in Kalaleh by 3.6% to 3.9%, while for Bandar-Torkaman, the city with the lowest DS, were1.3% to 1.65%. The average size of conidia length was 4-8×1 μm in diameters.The pathogenicity test showed that the D.alopecuri is capable to produce twist  disease symptoms only  in the presence with seed gall nematode in the host. The nucleic acid sequences of Internal Spacer Transcribed (ITS) regions for Golestan isolates showed 100% similarity and had small genetic similarity with D. alopecuri MH859142.1 deposited in NCBI Genbank. The sequences belong to D.alopecuri from Gonbad, Aqala, Azadshahr, Maravehtapeh, Kalaleh, Minodasht cities were registered in NCBI Genbank with MW302360, MW291507, MW291561, MW303438, MW303517, MW303518 accession number, respectively.

This is the first study carried out on the morphological and molecular characteristics of twist disease agent isolates, disease severity and its distribution in Golestan province as a major wheat production area of Iran. Many of results especially molecular data and submitted sequences form Iranian isolates of D.alopecuri to databanks are new for Iran.

 The two-spotted spider mite, Tetranychus urticae Koch is one of the most important pests of soybean fields. This mite is one of the most important and harmful pests of soybeans in hot and dry summers, which often begins to cause damage at the end of the growing stage and the beginning of the reproductive stage of plants. Damaged leaves turn yellow and brown and fall off prematurely. The severity of the damage of this pest is greater when the distance between the plants is short and irrigation is not enough. This mite feed on soybean leaves and cause injury by sucking contents out of leaf cells. In severe infestations, infested leaves will turn yellow to tan, or sometimes bronze-colored, and may drop off plants. Infestations can reduce yield. In most cases, the use of acaricides is the only way to control this pest. The use of new acaricides while avoiding their resistance is important for plant mites control.

The present study was conducted in soybean fields of Golestan and Ardabil provinces (Moghan) with 6 treatments and 4 replicates. Treatments were, including clorfenapyr (Payton®) 36% SC  0.5 ml/L (recommended dose), clorfenapyr (Payton®) 36% SC  0.4 ml/L, propargite (Omite®) 57% EC 1 ml/L (recommended dose), bromopropylate (Neuron®) 25% EC 1 ml/L (recommended dose), hexythiazox (Nissorun®) 10%EC 0.75 ml/L (recommended dose) and a control treatment by spraying water. Mean number of mites per leaf was counted one day before and 3, 7, 14, 21 and 28 days after spraying in three floors of plant (bottom, middle and top of plant).The percentage of efficiency was calculated by the Henderson-Tilton method. Statistical analyses were done using SAS software with randomized complete block design in multiple spaces. Data analysis and comparison of means were performed using Tukey test.

The efficacy of studied acaricides was acceptable in all three floors. In Moghan and Glostan province, before spraying on the lower, middle and upper leaves of soybean plants, the number of T. urticae mites counted per leaf in different treatments did not differ significantly. Clorfenapyr (Payton®) was effective after 3 days. The percent mortality of mites when were treated with clorfenapyr (0.5 ml/L) in the upper, lower and middle floors was 83-86% in Ardabil province, although has been reported 72-84% for Payton (0.4 ml/L). While in Golestan province, it has been 100%. The efficacy of the compound was 68-72% (0.4 ml/L) and 78-94% (0.5 ml/L) in Ardabil province (Moghan) and was 100% in Golestan province after 7 days. The knock down effect of this acaricide compared the others was significant. The efficacy of the compound was up to 99% (Ardabil province) and 96% Golestan province after 28 days that indicated the persistence of these acaricides. The results showed that two-spotted spider mite on the lower leaves in both provinces showed more infection. However when used pesticides, it did not show any significant differences. The percentage mortality of mites in Moghan were reported for Payton (0.4 ml/L) (86.32 ± 2.75%, 83.61 ±7.21%), (78.49 ± 4.01%, 82.87 ± 4.58%), (93.52 ± 1.47%, 74.80 ± 9.91%), (95.12 ± 3.90%, 80.39 ± 3.54%) and (99.33 ± 0.67%, 84.82 ± 8.29%) respectively after 3, 7, 14, 21 and 28 days in lower leaves, while the percentage mortality of the spider mites when treated with Payton (0.5 ml/L) after  3, 7, 14, 21 and 28 days  were 100 ± 0%, 100 ± 0 %, 94.94 ± 5.05%, 100 ± 0% and 93.95 ± 4.72% and for Payton (0.5 ml/L) were 100 ± 0%, 100 ± 0%, 88.80 ± 8.57%, 95.02 ± 2.87% and 85.51± 4.92% in lower leaves in Glostan province.

 It is recommended to use chlorfenapyr acaricide with Payton brand due to high short-term effect (three days after spraying) and duration of action up to 28 days after spraying to control two-spotted spider mite in soybean fields. These compounds showed acceptable efficacy in controlling two-spotted sider mites on soybean fields. In most cases, the application of the two concentrations of the clorfenapyr was not significantly different, but the percent mortality was more when it treated with 0.4 ml/L. The number mites in lower floors of soybean was more than the upper and middle floors, but after the application of this pesticides was not significantly different. Based on these results, we recommend the 0.4 ml/L dose of clorfenapyr (Payton®) for the control of two-spotted spider mite in soybean fields.

The ornamental plants are sold according their beauty. Different mite species imposing damages on various ornamental plant parts. At the moment total mite pest species in greenhouse commercial ornamental plant productions in the world exceed to 31 species from 15 genera and 6 mite families (Tetranychidae, 7 species, Tenuipalpidae, 4 species, Eriophyoidea, 13 species, Tarsonemidae, 2 species, Acaridae, 5 species) respectively. Among Acarina mites and other arthropods pest species, Tetranychus urticae Koch (Two spotted spider mite) is the most economical pest in the greenhouses in Iran and in the world. This mite pest due to possess shorter time of generation, number of generations through host plant existed, higher daily and total fecundity, higher adaptation range of temperature and humidity during roses plant cultivation time, enhanced this mite to become the first arthropods receiving higher resistance to different pesticides group under greenhouse conditions. Biological control achievement of this mite pest by rotational natural enemies like Phytoseiulus persimilis A. H. received for few percent only under special circumstances in developing countries. But control major of this mite still depended to pesticides effects and how and when to apply. Economical rose plants generally harvested for two or three years in greenhouse condition while enhancing longer period activities for two spotted spider mite population with constant noticeable damages. Substitution new chemical group of acaricide at short period of time against this mite pest under greenhouses reported effective by concerned researchers under greenhouse conditions. Most pesticides effects in agricultural crops can enter and kill the mite as stomach or contact poisons and can classified them into organic and inorganic pesticides. Inorganic pesticides do not contain the element of carbon but include arsenic, mercury, zinc, sulfured, boron or fluorine. While botanical pesticides, positives relatively with high LD50 values to mammals, they usually are considered safe to human. Dependency to pesticides application against spider mite population although will not eliminated them in agricultural crop productions, they should not automatically be given the higher priority especially under greenhouses. Tetranychus urticae causes longer period damages and faster resistance to various group of pesticides among cut rose’s pests in the greenhouses in Iran and elsewhere in the world. Spray new acaricidal compounds in rotation, is one of the control measures which to keep out further mite resistance to the acaricidal application.

 In this concerned, an investigation carried out to evaluate effects of  different doses of flufenzin 20% SC (0.4 and 0.5 ml/lit) and Dayabon-3 (8 and 10 ml/lit doses) a botanical pesticide manufactured in Iran in comparison with effects of 0.75 ml/lit of abamectin, 0.5 ml/lit of hexythiazox 10% EC and etoxazole 10% EC of registered acaricides against T. urticae mobile stages on cut roses in greenhouses of Tehran, Mahalat and Esfahan regions during period of 2014-2015 respectively. The completely randomized design method with three replications were used. In each replicated, 10 meters roses plants cultivated in the plastic pots were used. Time of treatment’s done at weekly sampling from all roses’ plants in different treatments including controlled treatment and total 200 leaves randomly sampled from various rose plant parts and carried out into polyethylene bag into laboratory to examine mobile stages of spider mite under stereomicroscope. Alive mite stages counted under rose leaf side and when at least 3 active spider mite stages observed with 30% rose leaves infested by mite, different treatments applied at early morning hours. Water spray also used in controlled treatment. Effects of each treatment determined through random 30 leaves collected from bent and vertical shoots and number alive mites were counted under rose leaf side and registered for each treatment. Sampling period followed at one day before treatment and 3, 7, 14 days after treatments sprayed respectively. Raw collected data for each treatment through Aboutte formula converted into mortality%. Analysis of variance on mean of mortality% done with the help of SAS software and those treatment grouped according Duncan multiple range test method.

Mite mortality% caused by 0.5ml/l of flufenzin and 10 ml/l of Dayabon-3 found varied from 3rd to 14th days after treatment in Tehran with decreasing effects from 82.89% to 56.35%, 82.64% to 49.65% for both treatments respectively. While effects of these two treatments in Esfahan recorded from 78.61% to 82.93%, and 71.04% to 74.27% with increasing effects against rose spider mite population. Comparing effects of these two treatments in Mahalat however remained almost at constant and mite mortality% fluctuated from 68.8% to 70%, 62.97% to 66% during sampling period respectively.

 Spraying higher doses of these two pesticides at lower mean of population and % of mite infested rose leaves and implementing different acaricidal compounds in rotation, will provide higher mite control as well as protect further risk of spider mite resistance to the pesticides in rose greenhouses.

Grape, Vitis vinifera L. is one the most important economic and major global crop. Grape production is aimed at various markets, namely, table grapes for fresh consumption and processed grapes that are dried into raisins or pressed for grape juice. The European grapevine moth, Lobesia botrana Denis and Schiffermuller, (Lepidoptera: Tortricidae) is one of the major pest of grape in Iran and worldwide. Larvae of the first generation feed on bud clusters and flowers, whereas larvae of the subsequent generations feed exclusively on ripening and ripe berries and causes considerable yield losses. One L. botrana larva is capable of damaging between 2 and 10 berries, depending on the cultivar and the grape phenology. L. botrana is a multivoltine species with three to four generations per year. The focus of the control methods against this pest in our country is the use of insecticides. In Iran, three insecticides azinphos-methyl, diazinon and phosalone (all registered in 1968) were previously registered to control this pest. However, azinphos-methyl and diazinon have been now phased out from the list of authorized pesticides. Therefore, registration of the new active ingredient of insecticides with novel mode of action is very important. Methoxyfenozide is one of the most effective of the non-steroidal ecdysteroid agonist insecticides that has been commercialized and used against Lepidoptera species globally. Its mode of action is based on their capacity to induce a premature and incomplete moulting and susceptible insects die from desiccation and starvation. In addition, methoxyfenozide have a high safety profile against natural enemies of pests. Accordingly, methoxyfenozide is compatible in integrated pest management (IPM) programs. In directions to register new pesticides and diversify the pesticide basket in our country, the current research was done to evaluate the field efficacy of methoxyfenozide (SC24%), in comparison with spinosad (SC24%), Bacillus thuringiensis (Bt) and Lufox® (Lufenuron+Fenoxycarb, EC10.5%).

 The project was performed against the second and third generations, based on a completely randomized design with three replicates in Dizaj Dol (Urmia West Azarbaijan), Khalil Abad (Kashmar, Khorasan Razavi) and Dehnok (Takestan, Qazvin). The efficacy of the treatments was done based on the damaged bunches. To do this, at 3, 7, 14 and 21 days after treatment, the total bunches of each treatments firstly were counted and then the rate of damaged bunches were evaluated. The experimental treatments were: 1) methoxyfenozide (0.5 ml/L); 2) methoxyfenozide (0.75 ml/L); 3) spinosad 4) Lufox; 5) Bt and 6) control. The control treatment was sprayed by water only. Applications were made according to pheromone trap captures of males. In each treatment, 50-90 randomly selected bunches (from five treated plant) were collected and carefully examined for damage caused by L. botrana. Statistical analysis was performed using the SAS software (ver. 9.1). One row was considered as the distance between the experimental units.

The combine analysis of variance showed that interaction of treatment×location was significant, meaning that the experimental treatments had different responds in different locations. Accordingly, the data were statistically analyzed based on this. Moreover, the results of the factorial statistical analysis indicated that the effect of generation and the interaction between generation and location were not significant. Thus, in this article only the results of the second generation are provided. The results showed that in all cases, methoxyfenozide has acceptable efficacy at 14 and 21 days of post treatment. Therefore, no notable expectation of methoxyfenozide, in term of efficacy, should be expected until one week after spraying. The observed delayed toxicity of methoxyfenozide is consistence with previous reports and it is due to unique mode of action being moulting hormone agonist which induce premature moulting leading to death. It is necessary to note that there was no statistically significant difference in the efficacy of methoxyfenozide with Spinozad and Lufox during the mentioned period. For example, in Urmia methoxyfenozide (0.75 ml/L) exhibited 78.72% efficacy (at 14 days of post treatment, which was not statistically significant with spinosad (80.63%) and Lufox (81.04%). In conclusion, our results showed that methoxyfenozide exhibited acceptable efficacy against Lobesia botrana, required for registration in Iran. However, since the both methoxyfenozide concentrations (0.75 and 0.5 ml/L) had the same efficiency and considering the low-input of pesticides to the environment, it is recommended to use the application rate of 0.5 ml/L against this pest.

One of the most important pests of the tomato plant, which belongs to the order lepidoptera and the family Gelechiidae, is the tomato leaf miner. The tomato leaf miner, scientifically named Tuta absoluta (Meyrick), was first described and reported in Peru in 1917 (EPPO, 2005). After reaching Spain in 2002, the pest spread rapidly to other European and North African countries, and eventually to Middle Eastern countries, including Iran.

This study was conducted in a randomized complete block design with 6 treatments (5 insecticide treatments and one control treatment) and with three replications in tomato fields (private farm) of Kermanshah, Markazi and Hormozgan provinces. Each experimental plot consisted of 5 planting rows, each of which was 10 meters long and 5 meters wide (plot dimensions were 50 square meters). The distance between the plots was at least 5 meters. Fertilization and weed control operations were performed according to local customs. Plants were inspected daily and as soon as the economic loss threshold (4 to 5 larvae per plant) was reached, foliar application was performed. For spraying, a back sprayer with a conical nozzle was used after calibration. Sampling was performed one day before spraying and 3, 7, 10 and 14 days after spraying. For this purpose, 10 plants were randomly selected from each plot and two leaflets were taken from each plant from the semi-terminal leaves of the plant, which were transferred to separate nylon bags by mentioning the name of the treatment and repeated.. The percentage of insecticide effect was calculated using Henderson-Tilton formula. The means were compared by Tukey test using Ver 9.1 software (SAS Institute, 2001).

 In order to introduce new and effective insecticides to control this pest, the present study was conducted in a randomized complete block design with 6 treatments and 3 replications in tomato fields of three provinces of Hormozgan, Kermanshah and Markazi and the effect of, Tetraniliprole (Vayego SC200) insecticides with two concentrations of 250 and 350 ml / ha Indoxacarb EC 15% at a rate of 250 ml / ha, Flubendiamide WG20% at a rate of 250 gr/ ha Lufenuron + Emamectin benzoateWG 50% 100 gr/ ha on mortality This pest was examined. The results of this study showed that on the 14 days after spraying, Tetraniliprol 350 ml / ha with 73.02 percent efficiency, in Markazi province, with 82.74 percent efficiency, in Kermanshah province, and with 82.17 percent efficiency in Hormozgan province had higher efficiency than other treatments. Therefore, a concentration of 350 ml/ha of the insecticide Tetraniliprol is effective and can be recommended for the control of tomato leaf miner in fields.

 In a study of the effects of eight insecticides, chloropyrifosmethyl, lambdacy halothrin, imidaclopride, abamectin, chlorfenapyr, emamectinbenzoate and chlorantraniliprole on tomato leaf miner in field conditions were investigated. The results showed that all the insecticides tested had a significant effect on the average insect population and the reduction of the percentage of infection in the tomato field. However, the greatest effect in controlling this insect was obtained with the use of abamectin, chlorfenapyr and chlorantraniliprole (Sallam, 2015). Another study looked at the effects of a number of biocides on the pest. All of the studied toxins caused mortality of T. absoluta larvae, but the effect of Azadirachta indica and Allium sativum extracts as well as Beauveria bassiana was reported to be more than 70%. However, these treatments were statistically significantly different from conventional insecticides and the highest product with marketable value was obtained in Tetraniliprole (Wiego) and Coragen treatments (Shiberu and Getu, 2018). Evaluated the efficacy of 7 insecticides on tomato leaf miner in vitro and showed that the insecticides Spinosad, chlorantraniliprole + Abamectin and Indoxacarb resulted in 100% mortality in all populations. These results were similar to the present study.

Saffron is a vulnerable crop to weed competition because of its short canopy and narrow leaves. So weeds are the major problem in saffron production. Weeds are mainly controlled by hand or mechanically in saffron fields, these traditional methods are effective and environmental friendly but they are expensive and time consuming.These traditional methods are effective and environmental friendly, however they are expensive and time consuming. The number of suitable herbicide for weed control in saffron fields are limited. The importance of herbicide as alternatives method for weed control was recognized long ago. Herbicide treated mulch (HTM) is the combination of physical (mulch) and chemical (herbicide) weed control methods. This experiment was conducted to investigate the possibility of using mulch and herbicide treated mulch (HTM) to increase the efficiency of herbicides in saffron weeds management. The objectives of this study were to compare the effect of herbicides alone and in combination with mulch on weed control and also determine the influence of herbicide placement (on soil surface, under mulch or herbicide-treated mulch) on weed control and phytotoxicity of saffron.

 Field experiments were conducted during the growing seasons of 2016 and 2017 in Khorasan Razavi, Iran. Two field of 4-year-old saffron that had not received herbicide applications for at least two years in two different climates were chosen. The treatments consist of trifluralin (EC48%) at 1200 g i.a.ha-1, pendimethalin (EC33%) at 1485 g i.a.ha-1 and metribuzin (WP70%) at 525 g i.a.ha-1 were applied in three method 1) Directly to soil: herbicides were applied before crust crushing directly in soil. 2) Under the mulch: herbicides were sprayed with an electric knapsack sprayer after crust crushing directly in soil, then the soil surface was covered with a layer of wood chips mulch with a depth of 3 cm. 3) Herbicide treated mulch: mulch of wood chips were pretreated with herbicides by placing the mulch on a plastic sheet at the depth of 3 cm above and herbicide was sprayed on top of the mulch and evenly mixed and allowed to dry for 48 hours before applying them to field. The non-treated control with and without mulch and also treatment of hand weeding was included for comparison.

 There was no severe phytotoxicity to saffron after treatments application according to EWRC, slight injuries observed in all plots ranging from 1 (No damage) to 2 (Very little damage including slightly yellowing). Metribuzin herbicide induced more phytotoxicity symptoms on saffron compared to two other herbicides, but it was better to weeds control and increasing saffron yield. Treatment of metribuzin mixed with mulch in both fields after hand weeding were the best treatment to decreasing of weeds dry weight and improvement of yield components of saffron. Treatment of metribuzin mixed with mulch compared with control caused 85% and 87% reduction of weed dry weight in both fields, also this treatment compared with control increased dry weight stigma to 2.5 times and 2 times. It seems that after metribuzin, pendimethalin herbicide has better efficiency for use in saffron fields. Although, treatment of mulch without herbicide, is not prevented weed growth, but had more effective on increasing of saffron yield compared to weedy check, especially in field 1(region of Kashmar). Therefore, the use of mulch in warm and dry areas has better effect on saffron yield improvement. Considering that the cultivation of saffron is carried in semi-arid regions of Iran such as Khorasan, the correct application of plant residues in semi-arid regions can have a direct effect on the amount of organic matter in the soil, which leads to an increase in flower yield. Generally the pre-mixed mulch with herbicide, in addition to improving the herbicide efficiency, increased saffron yield. This results indicate that the proper combination of herbicides with mulch layer as thin as 3 cm can provide acceptable weed control. According to the result, one suggested way to weed management in saffron could be the combination of herbicide (Metribuzin) with mulch.

Widespread application of herbicides to control weeds during the past few decades has resulted in serious ecological and environmental problems, such as resistance and shifts in weed populations. Sulfonylurea herbicides are acetoacetate synthase inhibitors. These herbicides will be used effectively to control a wide range of grassy and broad leaf weeds. Nicosulfuron is one of the main ALS inhibitors that was registered for corn in Iran. Under certain conditions some sulfonylurea herbicides can persist at phytotoxic concentrations in soils long enough to affect sensitive crops in the following season. There are many factors affecting persistence of herbicides, included soil type, soil organic matter, soil pH, soil temperature and moisture. Bioassay and HPLC methods are the most common methods for determining herbicide residues in soil. HPLC methods is a time-consuming, costly, and expensive. But bioassay method is a simple, fast, and inexpensive that uses sensitive plants to detect low concentrations of residual in the soil. Several bioassay methods for sulfonylurea herbicides have been reported using lentil (Lens culinaris L.), lettuce (Lactuca sativa L.), sunflower (Helianthus annuus L.), corn (Zea mays L.) pea (pisum sativum L.), and lupin (Lupinus angustifolius L.). This study was aimed to understanding the nicosulfuron persistence in soil using HPLC and bioassay methods.

In order to study the soil persistence of nicosulfuron using bioassay and HPLC, an experiment was carried out as a factorial arrangement based on completely randomized block design with three replications in Research Field of Ferdowsi University of Mashhad during 2014-2015. Treatments included of the application of organic and bio-fertilizers in four different levels of cow manure (40 t ha-1), vermicompost (10 t ha-1), mycorrhiza (2.5 t ha-1) fertilizers and control as first factor. The second factor was nicosulfuron doses (40 and 80 g a.i ha-1), and the third factor was the application of nicosulfuron with and without of Hydromax adjuvant. The herbicide was applied at four leaf stages using an overhead trolley sprayer equipped with an 8002 flat fan nozzle tip delivering 200 L ha-1 at 2 bar spray pressure. To determine nicosulfuron residue in soil sampling was performed at different periods of 0, 2, 5, 8, 16, 30, 60, 90 days after spraying from 0-15 cm depth of soil. The herbicide residue was determined using HPLC and bioassay methods. Garden cress (Lepidium sativum L.) was the bio-indicator in bioassay method.

 Results showed by increasing of nicosulfuron dose, it’s soil residue increased, however; nicosulfuron half time (DT50) was not affected. Application of Hydromax decreased nicosulfuron degradation rate (K) and increased its half-life of nicosulfuron. However, the application of organic and biological fertilizers increased degradation rate and decreased its half-life of nicosulfuron. So that the highest nicosulfuron degradation rate was indicated (0.066 and 0.073 μg kg-1 soil) and the lowest DT50 (10.5 and 9.50 days) were indicated in HPLC and bioassay methods respectively, when nicosulfuron applied in the dose of 40 g a.i ha-   + cow manure mixed in soil. Based on the results, significant positive correlation (r2 = 0.97) was observed between HPLC and bioassay methods in degradation rates and half-life of nicosulfuron herbicide. According to bioassay method, garden cress is high sensitive to nicosulfuron residue in soil. Therefore, garden cress especially it’s root bioassay is recommended as an acceptable method for nicosulfuron soil residue detection and can be used as desirable bio-indicator for tracing of nicosulfuron persistence and soil residue. 

The application Hydromax decreased nicosulfuron degradation rate and increased DT50 of nicosulfuron. But organic fertilizers increased nicosulfuron degradation rate and decreased DT50. Based on this sudy results garden cress is desirable bio-indicator for tracing of nicosulfuron persistence in soil.

Water is the primary carrier for herbicide applications (it usually makes up about 99% of the spray solution) and deliver them to the target weeds that they are intended to control. The quality of water available for spraying will depend on the source of the water on the vineyard, eg. dam or channel. Many chemical elements can be dissolved in water but six major ions make up the dissolved material in most water: Calcium (Ca++), Magnesium (Mg++), Sodium (Na+), Sulfate (SO4-), Chloride (Cl-), and Bicarbonate (HCO3-). Hard water becomes “hard” because of the presence of carbonates, sulfates, and chlorides of calcium, magnesium, and iron. Water containing calcium and magnesium can reduce the effectiveness of post-emergence herbicides that are weak acids include glyphosate (Roundup), paraquat (Gramaxone), bentazon (Basagran), clethodim (Envoy), sethoxydim (Poast), nicosulforun (Cruise) and 2,4-D (many products).Nicosulfuron is a post-emergence sulfonylurea herbicide that act through inhibition of acetolactate synthase (ALS) and controls many difficult-to-manage monocotyledonous weeds at low rates in corn. Also, 2,4-D is a selective herbicide from the group of auxin-like herbicides that act systematically to control broadleaf weeds in cereals. "Mixing herbicides" can be used to reduce the effect of hardness factors in the water carrying herbicides. The purpose of a good mix is to increase the effect of the compound on weeds without damaging the crop. The primary reasons that herbicides are mixed are to improve bioactivity and reduce costs. Therefore, the application of mixing reduces labor costs, the number of crossings across the farm, equipment depreciation, and mechanical damage to the crop and soil. Interactions of two herbicides can occur in three ways: each herbicide has an independent mode of action (additive effect); one herbicide reduces the action of another herbicide (antagonism), and one herbicide increases the presence of another herbicide (synergism). The question is whether the synergistic effects that occur in some conditions in the mixing of two herbicides can be used to reduce the negative effects of hard water on the performance of hard water sensitive herbicides? Therefore, this study was conducted to evaluate the effect of water hardness on the efficacy of nicosulfuron and 2,4-D tank mixing on the control of velvetleaf (Abutilon theophrastis Medicus.).

 The effect of mixing nicosulfuron (Cruse- OD4%) and 2,4-D amine (U46- SL72%) herbicides on velvetleaf (Abutilon theophrastis Medicus.) weed control in the presence of hard agents carried out as factorial arrangement based on randomized complete block design with three replications at the Research Greenhouse of Ferdowsi University of Mashhad in 2019. The first factor of water hardness applied in four levels including deionized water (non-hard), 0.1 M concentrations of CaCl2, MgCl2, FeCl3 salts (Merck, Darmstadt, Germany). The second factor was mixing nicosulfuron and 2,4-D amine herbicides as 6.25, 12.5, 25, 50 and 100% of the recommended dose. The mixing ratios were (0:100), (25:75), (50:50), (75:25) and (100: 0). In addition, 10 pots were considered as control without spraying.Velvetleaf seeds were collected from a heavily infested corn fields in Mashhad, Khorasan Razavi province in northeastern part of Iran. To obtain uniform seedlings, seeds were treated by sulfuric acid 98% during 1 min. Seven seeds pre-germinated in petri dishes were transplanted at 1 cm deep in 1 L plastic pots in a mixture of soil, sand and cocopeat (1 : 1 : 1 wt ⁄ wt ⁄ wt) containing all necessary macro- and micronutrients. The pots were kept in a greenhouse at natural daylength and a temperature around 25°C during the day. The pots were sub-irrigated daily. Prior to herbicide application, plants were thinned to five uniformly sized plants per pot.The herbicide solutions were applied at the 3-4 leaf stage of the weed using a cabinet sprayer equipped with a flat fan nozzle (No.11004) delivering a spray volume of 390 Lha-1. A four-parameter log-logistic model (equation 1) was fitted to the data using the open-source statistical software R 2.6.2 and the drc statistical addition package.   Y=c+[d-c ⁄ 1+exp[b(log x-log e)]]   (1)where Y is the response expressed as percentage of the untreated control, c and d are the responses at very high and very low herbicide rates, respectively, b is the slope of the curve around the point of inflection, and e  is the herbicide rate giving response halfway between d and c (=ED50). If c = 0, then the four-parameter model reduces to the three-parameter model (equation 2), with the lower limit being zero.   Y=d ⁄ 1+exp[b(log x - log e)] .

The results showed that the net effects of herbicides were affected by hard water factors such as calcium, magnesium and iron III chloride. Besides, their efficiency in controlling biomass, survival percentage and height of velvetleaf were decreased. The inhibitory effect of hardness factors on herbicide performance was different. Calcium chloride and magnesium chloride had the highest reduction effect on nicosulfuron and 2,4-D amine, respectively. Therefore, to reduce the effect of water hardness factors, two herbicides were evaluated by mixing. The results indicated that the type of effect on herbicide mixing in biomass control of velvetleaf was synergistic, and reduced antagonistic effect of water hardness factors. Equal proportions of both herbicides in reducing the effect of calcium chloride and iron III chlorides, high ratio of nicosulfuron in reducing the effect of magnesium chloride, had the best performance in controlling the biomass of velvetleaf. Therefore, depending on the salts involved in the water hardness of the sprayer tank, changing the mixing ratio of the two herbicides nicosulfuron and 2,4-D amine can be achieved the best performance control of velvetleaf.

Weeds are among the worst limiting factors of the crop yield potential. I. purpurea belongs to Convolvulaceae family and is an annual broadleaf vine and a problem weed in many annual and perennial crops. This weed is becoming an increasing problem in soybean fields of Mazandaran province, Iran. Seed germination is one of the most important processes for weed success in agricultural ecosystems; because the first step is for a weed to compete in an ecological nich. Understanding the biology and germination pattern and emergence of common weeds in crops is an undeniable necessity in effective weed management systems. This process is regulated by several environmental factors such as light, salinity, pH and soil moisture. Among the factors affecting germination, temperature and light are the most important regulatory environmental factors. Temperature has significant effects on germination characteristics such as onset, rate and rate of germination, therefore it is the most critical factor that determines the success and failure of plant establishment. Salinity and drought are one of the most important environmental stresses that affect germination. Weed phenology is determined by the interaction between plant internal factors and external environmental signals such as temperature, day length and drought; phenological stages and their characteristics are very important for the design and implementation of weed management methods. A better understanding of the germination biology of I. purpurea would facilitate the development of better control strategies for this weed. Also, predict the weed phenological developments are useful research tools for advancing our knowledge of population dynamics or crop and weed competition; in this way, the study of phenology allows accurate estimation of weed competition time and its effect on crop yield. The aim of this study was to investigate the effect of temperature, salinity, and drought and to investigate the phenology of this weed based on the growing degree-day.

 These experiments were conducted in the weed science laboratory of Sari Agricultural Sciences and Natural Resources University. The treatments were carried out in a completely randomized design with four replications. The treatments including constant temperature with 8 levels: 5, 10, 15, 20, 25, 30, 35, and 40 °C; salinity stress in 9 levels of control, 0.92, 1.84, 3.68, 7.36, 14.75, 29.5, 35 and 40 (dS m-1 chloride sodium), drought stress in 6 levels of control, -0.2, -0.4, -0.6, -0.8 and -1 MPa. To study the phenology of I. purpurea, a field experiment was accomplished in a randomized complete block design.

The results showed that I. purpurea seeds started to germinate at 10 °C and the germination percentage increased with increasing temperature. No germination occurred at 40 oC. To determine the cardinal temperatures beta, segmented and dent-like models were used. The dent-like model was the best model to predict the germination rate. Based on the dent-like model outputs, base, lower limit optimum, upper limit optimum and maximum temperatures of I. purpurea seed germination were 7.39, 23.54, 29.54, and 39.54 °C, respectively. Also, the salinity level of 31.33 dS m-1 causes a 50% reduction in germination percentage. In drought stress, the highest germination percentage (100%) was observed in the control treatment and the lowest germination percentage (97.5%) was observed in -0.4 MPa. In general, six phenological stages were recorded, including emergence, stem elongation, budding, flowering, fruiting, and seed maturation. The results showed that the shortest and longest growth stages of this weed in terms of time are emergence and stem elongation, respectively. It was observed that the I. purpurea is a weed that completes its phenological stages in 168 days by achieving 2378.01 growing degree-day. These results revealed that the best time to control of this weed is before the flowering stage.

Seed germination of this weed is in the temperature range of 10 to 35 °C and it seems that this weed germinates better at warmer temperatures. Chemical methods are among the most common methods in controlling weeds and other invasive species in the country, so the spread of these species in addition to direct effects can increase the use of chemical pesticides on farms and double the negative consequences of these species. Therefore, with full knowledge of the different stages of I. purpurea phenology, it is possible to plan for proper management. From a managerial point of view, the best time to use the herbicide is in the 3-4 leaf stage; however, in case of negligence at this stage, they should be checked before bud production so that its seeds do not enter the seed bank; because the seeds of this plant are considered as causes of pollution in the field.