کلزا

The rapeseed pollen beetle, Brassicogethes aeneus is one of the key and important pests of rapeseed in the northern provinces of Iran. In this research, the effectiveness of two botanical insecticides, Matrin and azadirachtin, as well as chemical insecticides, Alphacypermetrin and Imidacloprid, were investigated against this pest in laboratory and field conditions. Laboratory bioassay was performed by exposing the insects to different concentrations of the insecticides (five concentrations for each insecticide). In these assays, the highest susceptibility was recorded to Alphacypermetrin (LC50 = 0.1 mg ai/L) and after that, Matrin (1.2), Imidacloprid (60.0), and Azadirachtin (100.7 mg ai/L), respectively. A field experiment, in the form of a randomized complete block design, was implemented in three different creating a barrier (lace fabric) before or after conducting the treatments and plots without any barriers. In the field conditions (common treatment; no barrier), the efficacy of botanicals was slower but after four days, their appropriate effectiveness was observed. However, after one week, the efficiency of all four treatments was more than 90 percent. At the endpoint of the experiment (four weeks), Imidacloprid was the most effective (73.4 %) and after that, there were Alphacypermetrin (59 %), Matrin (51.4 %), and Azadirachtin (47.9 %) treatments. The results of this research showed that Alphacypermetrin can be used as an alternative to Imidacloprid (the prevalent treatment) in pest outbreak conditions. In addition, the data showed the appropriate and competitive efficiency of Matrin, to control rapeseed pollen beetle.

The cabbage aphid, Brevicoryne brassicae L., is one of the major and economic pests of cruciferous plants in the world which has destructive effects on the rapeseed, Brassica napus L. In this research, for accurate estimating of the cabbage aphid population, three sampling methods (photography, measuring the average length of the infected stem and average weight of the aphid) as the main treatments were separately compared to direct count method, as the control treatment during budding, flowering and sheathing stages of rapeseed. For each stage, twenty-two canola plants were chosen and from each chosen plant, top stem covering completely by the aphids was selected as the sampling unit. The results showed that measuring the average length of the infected stem and average weight of aphid methods were significant difference with direct count method during budding, flowering and sheathing stages. However, there was no significant difference between photography and direct count methods during budding stage. Based on this, the photography method with maximum average of correction factor (0.790), coefficient of determination (0.9315) and relative net precision (RNP) (51.56) is the best and most accurate technique for precise estimation of cabbage aphid population during budding period. According to the obtained results of this study, choosing the correct sampling method at the right time can promote the integrated management programs of cabbage aphid.

Low-cost physical methods were evaluated in oilseed rape farms of Golestan and North Khorasan provinces. Experiments were conducted in 400 m2 plots using Completely Randomized Block Design with three replications. Treatments were consisted of: 1. Spanish tape, (EcoBirdNex), 2. Large white plastic bags, 3. white nylon tape, 4. Nylon thread with white yoonolit pieces, 5. Plastic tube, 6. Control (no treatment). In autumn 2019 and 2020, samplings were conducted using ten quadrates of 1×1 m2, 1, 2, 3 and 4 weeks after treatments. Total number of damaged and undamaged plants were registered and the percentage of damaged plants was calculated accordingly. Treatments showed significant difference with control and effects of treatments was significant in North Khorasan and in Golestan (P<0.05). Effects of weeks was significant in Golestan in both years, and in North Khorasan in 2019 (P<0.05). In view of preparation of treatments and economic costs, treatments of plastic bags and Spanish tape were effective and applicable with two functions of physical sight barrier and making nuisance simultaneously, with no harm on the environment.

The false chinch bugs, Nysius cymoides (Spinola) (Hem., Lygaeidae) is a polyphagous and cosmopolitan distributed and it causes damage as the most important pest in canola fields in Kermanshah province in the recent years. In the present study, population fluctuations and spatial distribution of the pest were investigated in canola fields of Kermanshah province during 2020 and 2021 years. The results of this study showed that the first group of the false chinch bugs populations in 2020 and 2021 were observed on the 8 and 11th of April, respectively.The second population peak of the pest in 2020 and 2021 with an average of 372.22 ± 66.31 and 126.45 ± 4.58 was obtained on 22 and 19th June, respectively. The highest population density of nymphs in 2020 and 2021 with an average of 1263.50 ± 125.19 and 206.00 ± 3.91 was obtained on 23th June. The results of spatial distribution showed that in 2020, the spatial distribution of males, females and adults of the N. cymoides was recognized as aggregated based on Taylor’s power law method and as random based on Iwao’s patchiness regression method. In general, the results of this study showed that N. cymoides had two population peaks. Also, based on goodness of fit, the Iwao’s patchiness method was more suitable than the Taylor’s power law method for estimating the spatial distribution of the pest.

Cabbage aphid, Brevicoryne brassicae (L.), is one of the most important pests of the canola in different parts of Iran. This pest causes significant damage on leaves, stems, flowers and pods of canola. In this project, the effect of seven canola cultivars (Okapi, Licord, Talayeh, Modena, Tasilo, Hyola308 and Hyola401) was studied on developmental time and reproductive parameters of B.brassicae under greenhouse conditions (20 ±2 °C, 50 ± 5% RH and 16 light: 8 darkness). Base on the results, Hyola401 and Hyola308 hybrids showed the highest value of intrinsic rate of increase ( ) and shortest duration of immature stage, so they were the most suitable hosts for the pest, whereas Okapi, Talayeh and Tasilo cultivars showed the lowest value of  and the longer duration of immature stage and were unsuitable hosts for development and reproduction of the pest under greenhouse conditions, therefore they are recommended for use in integrated management of the cabbage aphid.

Members of the genus Polerovirus, including Turnip yellows virus (TuYV), are important viruses on field crops. They are being transmitted by aphids in a circulative non-propagative manner. During 2018 and 2019, 32 leaf samples from rapeseed (Brassica napus) and one sample from wild mustard (Sinapis arvensis) were collected in Kermanshah Province, Iran. The samples were tested by a TAS-ELISA kit (DSMZ) that detects four poleroviruses including TuYV, Beet mild yellowing virus (BMYV), Beet western yellows virus (BWYV) and Beet chlorosis virus (BChV). A positive reaction was observed for the wild mustard and seven rapeseed samples. Myzus persicae and Brevicoryne brassicae were used for virus transmission. The virus was successfully transmitted by the aphids to rapeseed and radish but not to sugar beet plants. In IC-RT-PCR using a specific primer pair, a 780 bp fragment was amplified from wild mustard and two rapeseed samples. The two nucleotide sequences from rapeseed and wild mustard had 99.4% identity to each other and showed up to 97.2% similarity to TuYV isolates previously deposited in GenBank from fenugreek, rapeseed, pea and chickpea plants in Australia. In phylogenetic analysis based on the nucleotide sequences of ORF0, two Iranian isolates of TuYV were placed in the same clade with other TuYV isolates and were distinct from other poleroviruses such as BMYV, BWYV and BChV. In this study, for the first time in Kermanshah Province, TuYV was identified in Iranian rapeseed fields based on nucleotide sequencing of the P0 coding region.

Background and Objectives Flea beetles are the main pests of oilseed rape which the adult beetles cause damage via feeding on cotyledons and early leaves of crop. They gnaw small round holes into leaves, decreasing assimilation surface and slowing down plant's growth. Heavy damage at the early stage of cotyledons may destroy the plant. The critical period of damage on the crop is from germination and cotyledon stage until the appearance of 4–6 true leaves, later the damage is less harmful. Control of this pest mostly depends on using chemical pesticides via seed dressing and/or foliar application. This study aimed to estimate the effects of new chemical insecticides to control this pest in Iran. Materials and Methods To chemical control flea beetles, the project was carried out in a Randomized Complete Blocks Design with six treatments and three replications in the provinces of Mazandaran and Golestan in 2018. The treatments were alpha-cypermethrin 15% WDG, with two doses (300 g/ha and 150 g/ha), lambda-cyhalothrin CS10% (75 ml/ha), malathion EC 57% (600 ml/ha), thiacloprid OD24% (300 ml/ha) and control. Sampling and counting of the flea beetles were done 1 day before and 3, 7, and 14 days after treatment via counting the cached beetles on yellow sticky traps (one trap in the center of each plot) as well as the active beetles in a 0.5×0.5m quadrate in each plot center. Fourteen days after treatment, the percentage of infested plants and leaf surface damage were measured. The beetle's mortality was calculated by the Henderson-Tilton formula. Data were analyzed with SAS ver. 9 software, and the means were compared using Duncan.  Results All insecticides showed a significant difference at 1% probability level comparing with control. Alpha-cypermethrin with 300 and 150g/ha and lambda-cyhalothrin in Mazandaran and Golestan provinces with 87.17,84.19, 81.66; 76.66, 86.12, and 76 percentage efficacies had the highest effectiveness in control the pest, respectively. Malathion in Mazandaran and Golestan with 24.59% and 22.66% and thiaclopride 14.01% and 19%, respectively, were less effective in controlling and reducing flea beetles damage on the crop. Moreover, the percentage of infested plants was significantly different among insecticides 14 days after treatment at a probability level of 1%. Discussion Pest management of canola flea beetles faces ecological challenges and severe dependence on synthetic chemical pesticides. Insufficient soil moisture, late planting, unsuitable planting beds, and hot and sunny days with dry winds in the early growing stages of canola in autumn increase the damage and reduce the green area of the field in a short time. Due to the unsatisfactory effect of biological substances and plant compounds on canola flea beetles, chemical insecticides are one of the main options to reduce the population of this distractive pest in rapeseed fields. In various studies, in addition to chemical insecticides, biological compounds and botanical insecticides were tested to manage the control of pest. But in most cases, chemical insecticides were more effective. Therefore, determining the appropriate time for application and using effective insecticides are integral parts of the pest control strategy. This study's result showed that alpha-cypermethrin 15% WDG (150 and 300 g/ha) and lambda-cyhalothrin CS10% (75 ml/ha) could be used as new insecticides to control canola flea beetles.

Canola is an important oilseed crop in the world. Cabbage aphid, Brevicoryne brassicae is one of the most important pests of canola crop in Iran. In this study, the effect of chemical control of cabbage aphid was investigated in autumn and spring on Hyola 401 cultivar. For this purpose, spring and autumn sprayings with imidacloprid and pirimicarb at 1/1000 concentrations and insecticidal soap at 2.5% concentration were assessed using a randomized complete block design. The experiments were conducted during two growing seasons, 2011 and 2012 in Qazvin province. The results showed that, both autumn and spring spraying is necessary for pest control. Autumn and spring sprayings with imidacloprid caused 99.5 ± 0.4%, 94.5 ± 2.4% and 95.4.1 ± 1.0% mortality in 2011 and 99.1 ± 0.5, 86.9 ± 2.7 and 93.1 ± 5.5% mortality in 2012, three, seven and 15 days after treatment, respectively. Highest yield achieved at imidacloprid treatment and was 3533.00 kg/ ha. If not controlled, the damage would be 66.18, 69.35 and 78.0% at spring, autumn and spring-autumn treated plots.

Different species of weevils (Col.: Curculionidae) are found in oilseed rape fields, which some of those are canola stem-borer weevils. They feed inside petioles, crown and/or stems of the crop in larval stages and cause damage. These weevils are mainly belonging to genus Ceutorhynchus, which little information about their taxonomy, distribution and biology is available in Iran.

During 2016-2018, the biological characteristics of canola stem-borer weevils were investigated in canola fields of Mazandaran, Lorestan and Golestan provinces. In each province, three fields were selected for collecting samples. Yellow water traps were used for weekly collecting adult weevils from the fields during crop growing season. For collecting weevil-infested crops and determining infestation rate, 10 quadrates (0.5 × 0.5 m) were used per field. The adult weevils collected by the traps were identified and the pest biology as well as the infestation rates of the crop by the weevils were studied.

In this study, five Ceutorhynchid species were collected and identified: C. picitarsis and C. chalybaeus from Mazandaran, C. erysimi and C. pallidactylus from Golestan and C. sulcicollis from Lorestan, Mazandaran and Golestan. In late November, the adult weevils migrated to canola fields and after feeding and mating, the females deposited their eggs into main veins, petioles of the lower leaves or inside of the collar area of young canola plants and the emerged larvae penetrated into the host plant. The three larval instars of this pest fed inside host plant tissue during autumn and winter till mid spring season. The feeding activity of the first and second instar larvae were observed in late November and late December, respectively. Third instar larvae were found from beginning until mid-spring season. In late April, third instar larvae left the host plant, dropped in the soil for pupation and new generation adults emerged in May. These weevils are univoltine. The results showed that, the maximum infestation rates of oilseed rape by the stem weevils in Mazandaran, Lorestan and Golestan provinces was 20.1±0.89, 14.8±1.29 and 10.2±0.29 percent, respectively.

Determining the time of adult migration activity, oviposiotion and larval development of the weevils is an integral part of pest management strategy in oilseed rape fields. In this study, flight and oviposition activity of adults and also feeding activity of the first instar larvae were mainly observed in late November, which suggests this time as a suitable time for chemical control, if necessary. These weevils are mostly distributed around the Caspian Sea region (Mazandaran and Golestan provinces) however more investigations are required to conclude the existence of those in other parts of country.

The herbicide application has caused some environmental problems. Therefore, optimal application of herbicides was followed in recent years. For this purpose, it is essential to minimize the exo-drift and/or endo-drift of spray droplets. The amount of exo-drift and/or endo-drift is directly related to the size of spray droplets. By decreasing the size of spray droplets, the exo-drift increases and the endo-drift decreases (34). This intricate issue is a stimulus to develop the types of nozzles in different sizes (color) producing different sizes of spray droplets at different spraying pressures. Such a development in the production of nozzles has caused difficulty and confusion in selecting a suitable type of nozzle (2). On the other hand, the agriculture sector is faced with water crisis in recent years. Considering that water is the most important carrier of herbicides, selecting a suitable spray volume is thus necessary. According to previous studies (26), the efficacy of different herbicides can influence spray volume negatively (30), neutrally (29), or positively (12). So far, the effect of spray volume on the efficacy of cycloxydim against any weed has not been investigated. Also, since the types of triplet flat fan nozzles have been recently developed, no investigation has been done on their performance compared to the types of single and twin flat fan nozzles. The current study aimed to fill this knowledge gap.   

The seeds of wild barely (Hordeum spontaneum Koch.) were treated to germinate. Then, 8 seedlings were planted within each 3-L pot and grown in the Research Greenhouse of Bu-Ali Sina University, Hamedan, Iran. At the four-leaf stage, they were treated with 0, 6.25, 12.5, 25, 50, and 100 g cycloxydim ha-1 using 3 nozzle types (i.e. Standard, Anti-Drift, and Air Induction), at 3 orifice numbers (i.e. single, twin, and Triplet) and 3 nozzle sizes (i.e. 11002, 11003, and 11004). The treatments were sprayed at a pressure of 300 kPa when the wind speed was less than 0.4 m s-1. The volume of spray created by 11002, 11003, and 11004 nozzle sizes was 160, 240 and 320 L ha-1, respectively. Three weeks after spraying, the dry weight of plants was determined. The date were fitted using a four-parameter log-logistic model to estimate the dose required to achieve 50% wild barley control (ED50).
 

The ED50 was significantly affected by the type, size, and orifice number of nozzle. In all types of nozzles (Standard, anti-Drift and Air Induction) and sizes (11002, 11003 and 11004), an increase in orifice number significantly reduced the values of ED50 for cycloxydim against wild barely, indicating increased efficiency of herbicide. This can be explained by two reasons. Firstly, with an increase in orifice number in each type of nozzles, the size of spray droplets decreases. Previous studies have proven that there is a negative relationship between the amount of spray droplets deposited on the target surface and the size of spray droplets. Therefore, by decreasing the size of spray droplets, they can be deposited more on the target surface, resulting in an improvement in the foliage-herbicides efficiency. Secondly, increasing the orifice number of nozzle can lead to the penetration of spray droplets into the canopy. Among the nozzles of 11002 in any orifice number, the performance of nozzles was ranked as Standard > Anti-Drift > Air Induction. However, among the nozzles of 11003 or 11004 in any orifice number, the performance of nozzles was as Standard = Anti-Drift > Air Induction. Among all types of nozzles in any orifice number, increasing spray volume from 160 to 240 L ha-1 reduced the ED50. However, only in the types of nozzles of Air Induction in any orifice number, increasing spray volume from 240 to 320 L ha-1 reduced the ED50. 

It can be recommended that the most suitable nozzle for the application of cycloxydim against wild barely at a wind speed of less than 0.4 m s-1 with the aim of optimizing simultaneously both the dose of herbicide and the consumption of water is "Triplet Standard Flat Fan Nozzle 11003 " (spray volume= 240 L ha1).

Canola (Brassica napus</em>) is one of the most important members of Brassicaceae family and Turnip mosaic virus</em> is one of the most widespread viruses in canola fields all around the world. During May and April of 2018, 66 canola samples were collected from different regions of south Khorasan Province. The samples showed symptoms such as yellowing, stunning, mosaic and leaf distortion. Total RNA of samples was extracted by Dena Zist kit (Iran) and then DNA complementary was made by reverse primer. RT-PCR is done using specific primers of TuMV. A fragment with 680 bp length was amplified and sequenced in 12 canola samples that had high similarity to TuMV. Therefore, positive samples used in RT-PCR by specific primers of TuMV related to coat protein coding regions. Finally eight amplified fragments with 980 bp length were sequenced and then analyzed by Blast, MegaX, SDTv and DnaSPs softwares. Results showed that six samples of canola were infected by TuMV. Consequently, phylogenetic analysis of four non- recombinant isolates that are sequenced perfectly used in the phylogeny analysis and results showed that Iranian isolates in this study located in Asian BR phylogeny group included other Asian isolates. Nucleotide similarity between Iranian isolates ranged from 90 to 95%. Recombination analysis using RDP4 showed that two Iranian isolates (CSe55, CSe39) are recombinant and are evolved from minor and major parents. Nucleotide diversity by DnaSP showed that population of TuMV is developing in this part of Iran. This survey is the first report of TuMV in south khorasan and molecular investigation of TuMV in Canola field.

 Crown rot disease caused by Sclerotinia sclerotiorum, is one of the major diseases of canola worldwide. Biological control is a control method in agriculture for living organisms, especially fungi and bacteria, and is used in order to control plant damages caused by harmful factors. In this research, we evaluated the effect of seventy one isolates of Trichoderma spp. against S. sclerotiorum using various in vitro methods including dual culture and slide culture methods. Based on the obtained results of in vitro studies, six Trichoderma isolates and Tebuconazole fungicide were selected in order to study their potentials for controlling the crown rot disease in greenhouse. For this purpose, rapeseed petals were inoculated with S. sclerotiorum and inoculation of suspensions of Trichoderma isolates was done after inoculation of pathogen and also before and after its inoculation and then the severity of the disease was determined in the studied treatments. Based on obtained results, in dual culture, ARCTr281 (T. harzianum) was the most effective isolate for inhibition of mycelial growth. In hyperparasitism test, all isolates of T. harzianum hade successful performance in controlling the pathogenand coiling of Trichoderma was observed around the hyphae of S. sclerotiorum. Lowest disease incidence and severity of disease was observed in the negative control (without Sclerotinia and Trichoderma). Inoculated fungi in two stages, effectively were able to reduce the incidence and severity of disease in leaves and stems that ARCTr281 (T. harzianum) was the most effective fungus under greenhouse conditions. Also, the use of Trichoderma isolates in two stages in presence of pathogen caused an increase in height, fresh and dry weight of the shoot and root under greenhouse conditions. Analysis of variance and comparing the average characters by Least Significant Difference (LSD), Duncan and nonparametric method showed significant difference between used fungi in dual culture and greenhouse studies. According to the results of biocontrol studies under laboratory and greenhouse conditions, ARCTr281 and ARCTr272 fungal isolates belonging to T. harzianum were the most effective antagonists for control of canola's crown rot disease. The results of this study indicated that different isolates of Trichoderma can be considered as potential antagonists for the management of canola's crown rot disease.

Cotton as a second crop is planted at some relatively warm and dry conditions in rotation after wheat, in Iran. In this situation, herbicide residue persistence is a determining factor for cotton production. Seven sulfonylurea herbicides were registered for weed control of wheat in Iran and some of them may have adverse residue effects on growth and yield of cotton. Sulfonylurea herbicides at very low doses, inhibit synthesis of essential amino acid such as leucine, iso-leucine, and valin in the sensitive plants. Many studies demonstrated that there is dangerous residue of sulfonylurea herbicide in a soil with high pH, low moisture and organic matter level, and with the short time between herbicide application and the emergence of the following crop. For example, 135 days after application of metsulfuron, triasulfuron, and chlorosulfuron, cotton biomass was reduced by 23% to 67% in a soil with pH ranged 7.8 to 8.6 (6). In the other studies, sulfosulfuron residue caused damage to barley, lens, sorghum, and sunflower as sensitive crop after one year (16, 20). Residue of triasulfuron (at 22 gr.ha-1) one year after application made injuries to alfalfa, canola, corn, potato and sugar beet (21). This study was conducted during 2013-2014 to evaluate residue effects of some sulfonylurea herbicides of wheat on cotton at Sarakhs region of Iran. The soil textural class was silty clay with EC= 5.62 dS.m-1 and pH= 8.2. The field trial was a randomized complete block design with seven treatments in four replications. The treatments consisted of five sulfonylurea herbicide treatments as follows: 1- sulfosulfuron (26.6 g.ha-1 of Apyros® 75%WG), 2- mesosulfuron + iodosulfuron + mefenpyre (1.5 L.ha-1 of Atlantis® 1.2% OD), 3- triasulfuron + dicamba (165 g.ha-1 of Lenture® 70% WG), 4- triasulfuron + terbutryn (250 g.ha-1 of Logran Extra® 64% WG) and 5- metsulfuron + sulfosulfuron (40 g.ha-1 of Total® 75% WG). All herbicides applied in 3-5 leaf stage of wheat on 23th November, 2013. Furthermore, one herbicide free treatment (all season hand weeding) was considered as the control. Immediately after wheat harvest, cotton (Gossypium hirsutum L. var. Varamin) was planted (June 2, 2014) as the second crop in wheat spaces by a direct seeding machine. Residue effects on cotton plants were measured by plant height, stem length and dry matter (DM). Rankings of visual injury based on EWRC (European Weed Research Council) were recorded at four times starting seven days after cotton emergence. Cotton was harvested on September 26, 2014 and bull number, boll yield, and fiber yield were then determined. At the same time, residual bioassay tests were done in completely randomized design with four replications in the greenhouse using cotton, corn, barley, and canola. Their shoot and root dry matters were measured three weeks after emergence. Analysis of variance and mean comparisons (LSD 5%) was accomplished by SAS® (ver. 9.2) software. The results showed herbicide residue from and sulfosulfuron and metsulfuron+ sulfosulfuron significantly reduced cotton plant height and dry matter in the field at the first time of sampling (30 days after emergence). However, the differences in plant heights were not significant at the second and third sampling time owing to growth compensation after crop fertilization. It seems that metsulfuron is more important than sulfosulfuron in cotton injury as responsible ingredient. According to the previous studies, half-life of metsulfuron was 52 days and for sulfosulfuron was 42 days in average (28). Both of them are more persistent in the soils with high pH and low organic matter like the soils in our experiment. Mesosulfuron + iodosulfuron + mefenpyre residue had somewhat adverse effects on early growth of cotton and reduced shoot dry weight, but after 50 days plants were recovered. According to Tomlin (28), half-life of mesosulfuron and iodosulfuron was reported 38 days and 8.5 days, respectively. No adverse effect was recognized in cotton plants from triasulfuron+ terbutryn and triasulfuron+ dicamba. Half-life is 19 days for triasulfuron and negligible for two other ingredients. The herbicides injures were not as much stable as cotton yields were significantly affected. In greenhouse bioassay experiment, cotton shoot DM was significantly reduced by residues of metsulfuron+ sulfosulfuron, sulfosulfuron and mesosulfuron+ iodosulfuron+ mefenpyre. In addition, residual effects of metsulfuron+ sulfosulfuron and sulfosulfuron were observed on cotton root DM. Adverse effects from metsulfuron+ sulfosulfuron and sulfosulfuron caused a significant reduction in barley. Both of these herbicides were registered for controlling of wild barley (Hordeum spontaneum K. Koch.) in wheat fields. The most residual injuries were observed in canola in which all traits were reduced by residues of herbicides used for wheat. According to the field experiment, we found that the residues of two herbicides Total® 75% and Apyros® 75% lessened cotton height, dry matter of shoot and root at early growth stages. Nevertheless, the plant was recovered with season progress especially after overtop fertilization and consequently cotton yield (boll number, boll yield and fiber yield) was not significantly decreased. The results of pot experiment confirmed the field results and showed that these two herbicides significantly decreased cotton growth. Besides, growth of barley, canola and corn was affected by Total® 75%, Apyros® 75% and Atlantis® 1.2%. Therefore, metsulfuron and sulfosulfuron have the most effective residue among all components investigated. Moreover, canola and corn were, respectively, the most and least sensitive crops in the bioassay experiment.

In this research, the effect of Trichoderma harzianum and T. atroviride against P. lingam was investigated in the laboratory and greenhouse conditions. Laboratory tests were followed as dual cultures and testing of the fungal volatile compounds. In the greenhouse, the antagonistic effects of the isolates were tested through treating rapeseed seeds and rapeseed above-ground parts with the spore suspension of the isolates in 106 spore per ml. The experiments were conducted in complete randomized design with four replications. Percent of plant mortality and disease severity were assessed. Both isolates showed antagonistic activities against the fungal phytopathogen. The two isolates T. harzianum and T. atroviride could inhibit the growth of the pathogen by 58.6 and 71.4 respectively in dual culture. In volatile compound phase, percent of growth inhibition were 15-21% and 31-39% in 120 and 240 hours after culture. In greenhouse experiments, antagonistic species could significantly (P<0.01) reduce disease severity compared to control. The greenhouse results revealed that in the seed treatment experiment, Trichoderma isolates decreased the rapeseed blackleg to 42.5 and 47.5℅, respectively after two weeks. Treating the above-ground parts with isolates T. harzianum and T. atroviride were significantly decreased the disease rate to 63.13 and 78.79℅, respectively. So both Trichoderma species can biologically inhibit canola black leg, but T. atroviride was for the first time more effective than another one.

Stem rot caused by Sclerotinia sclerotiorum, is one of the important diseases of rapeseed, and fungicides are applied for its control. In Iran, carbendazim and tebuconazole are often used for chemical control of the disease. In order to introduce other effective fungicides against the disease, seven fungicides were studied in laboratory conditions and then six of them were applied in the field. In the laboratory conditions, different concentrations of the fungicides showed significant differences (P<0.01) with control (without fungicide) and caused inhibition of pathogen radial growth on potato dextrose agar medium except chlorothalonil (Daconil®). Effective concentration (EC50) and minimum inhibitory concentration (MIC) of the fungicides including iprodione + carbendazim (Rovral TS®), propiconazole (Tilt®), thiophanate methyle (Topsin M®), trifloxystrobin+ tebuconazole (Nativo®), tebuconazole (Folicure®) and spiroxamine+ tebuconazole+ triadimenol (Falcon®) was calculated. The EC50 values of these fungicides were 0.10, 0.11, 0.12, 0.22, 0.36 and 0.60 ppm, and MIC values were 1, 5, 1, 10, 10 and 10 ppm respectively. In the field conditions, all fungicides, had significant difference (P<0.01) with control  and decreased the rate of the disease infection and increased the crop yield about 300 to 700 Kg/ha. Nativo® was the most effective fungicide. The duration of plant protection in Nativo® treatment was longer and occurrence of disease symptoms after spraying was later than other treatments. Therefore, these fungicides can be used in rotation with common fungicides.

The expression of defensive genes from a promoter that is specifically activated in response to pathogen invasion is highly desirable for engineering disease-resistant plants. In this study, chimeric chitinase gene under the control of SP-DDEE pathogen inducible promoter transformed to the canola plants and these plants were evaluated for their in vivo biocontrol potential against fungal pathogens. In this regard, three constructs, pGDEC, pGMPC, pBISM2 containing synthetic promoters, SP-DDEE (two D and two E elements minimal promoter), SP-MP (minimal promoter), and the CaMV35S constitutive promoter, respectively were used. Enzyme activity assay demonstrated that the synthetic pathogen-inducible promoter was responsive to the Methyl jasmonate (MJ) elicitor, but not responsive to the salicylic acid. Moreover, results indicated that leaf total protein from transgenic lines harboring the SP-DDEE promoter treated with MJ, inhibited the growth of the fungal pathogens of Sclerotinia sclerotiorum and Rhizoctonia solani. Overall, data show that not only the SP-DDEE synthetic promoter is highly responsive to MJ, as an important chemical signal in necrotrophic pathogen defense, but the inducible expression of the chimeric chitinase gene, when controlled by the SP-DDEE promoter, is also seems to be appropriate to increased resistance to fungal pathogens.

The diamondback moth, Plutella xylostella (L.), is an important pest of canola in Iran. In this study, the effect of four treatments including strip-intercropping of two, four and six rows of canola with two rows of clover (2Ca: 2Cl, 4Ca: 2Cl, and 6Ca: 2Cl) and canola monoculture were studied on the population density of P. xylostella, species diversity of its predators, parasitism on eggs, larvae and pupae, and associated yield of canola under the field conditions in Ardabil region during 2015 and 2016. The density of eggs, larvae and pupae were significantly higher in monoculture than in intercrops. Moreover, the density of larvae and pupae was lower in 2Ca: 2Cl than in 6Ca: 2Cl. Shannon diversity index (H') for predator's species composition of moth was higher in intercrops than in monoculture. The values of Morisita–Horn index (CMH) for predators species composition of moth between canola monoculture and each of the three intercrops (CMH ≤ 0.897) were lower in comparision with the values of this index among the three intercrops (CMH ≥ 0.957). The percent parasitism for eggs, larvae and pupae was significantly higher in intercrops than in monoculture. Moreover, the percent parasitism for eggs and larvae was higher in 2Ca: 2Cl than in 6Ca: 2Cl. The dry seed weight loss was also lower in 2Ca: 2Cl and 4Ca: 2Cl in comparison with other two treatments. Thsese results indicated that intercropping 2Ca: 2Cl and 4Ca: 2C could be useful in integrated management of P. xylostella in canola fields.

The rapeseed (Brassica napus) is an important oilseed crop throughout the world for oil production. Blackleg disease which caused by Leptosphaeriamaculans is one of the most important disease of rapeseed in Iran. Among pathogenicity groups PG-1 (Leptosphaeria biglobosa) and PG-2, PGT (L. maculans) has been reported on rapeseed from Mazandaran and Golestan provinces of northern Iran (Fernando et al. 2007, Mirabadi et al. 2010). The samples (leaves, stem, flowers and seed) with symptoms of diseases such as discoloration, deformation, wrinkled and presence of pycnidia were collected during 2013-2016 from canola crops in North Iran. In addition, some of the stem debris with stem canker symptoms was examined for the presence and absence of pathogen sexual (perfect) state. Diseased tissues (leaves, stems, flowers and seed) were surface sterilized to obtain pathogen isolates following the procedure described by West et al. (2002) and Chen et al. (2010). Single ascosporic cultures of the fungus were isolated from psedothecia using the method developed by Li et al. (2004). In all 102 isolates when the causal pathogen was isolated from infected tissues, it was identified as L. maculans, by colony morphology/ pigment production on potato dextrose agar (PDA) and potato dextrose broth (PDB) respectively (Boerema et al. 2004), and species specific polymerase chain reaction (PCR) (Liu et al. 2006). The pycnidia of the fungus were black, globose to subglobose in shape, parts of pycnidia have pale pink droplet overflowed from the ostiole and Asci are clavate to cylindrical, bitunicate and 8 spores. Moreover, all isolates were classified as highly virulent using PCR with virulence type specific primers (Kuusk et al. 2002). Thirty-two isolates of L. maculans were used for determining the pathogenicity test using a cotyledon inoculation method. Pathogenicity of the isolates was confirmed by spraying a conidial suspension of the fungus (2×107 conidia mL-1) on cotyledons of Westar, Quinta and Glacier cultivars. All plants were maintained in a growth chamber at 22°C with 16 h light period and relative humidity of 80%. The first review of the plants was performed after 5 days and changes during experimenting plants have been observed after 12 days using the scale of 0–9 developed by Chen & Fernando (2006) which 0 to 3 reaction was considered as resistant (R), 4 to 6 as intermediate (I) and 7 to 9 as susceptible (S) (Fig. 1). Sixteen of isolates were classified as belonging to pathogenicity group PG-4. They were characterized by their ability to sporulate on the three differential hosts (S=7-9). Three isolates were PG-3, they sporulated on Westar and Glacier, and caused brown, non sporulating lesion on Quinta (I=4-6). The remaining isolates belonged to PG-2 and PGT. Moreover, our findings provided evidence that L. maculans (PG-4) is present on oilseed rape seeds in the North Iran. Our results showed that an understanding of possible shift in fungus populations will be of value in developing strategies for successful management of blackleg disease such as longer rotation between canola crops, new resistant cultivars against all PG isolates and strict regulations concerning crop seed trade. In addition, the current study is the first report on the identification of L. maculans (PG-3, PG-4) from oilseed in Northern Iran.

Many species of the family Syrphidae are predators of pests, especially aphids. To study the predacious syrphid species of rapeseed fields of Kermanshah, we assembled a sizable collection of syrphids between 2013-2015. The result showed the existence of 12 species in these fields of which the species Eupeodes corollae F. was found to be the predominant species. The length of growth periods and feeding capability of this species was studied on cabbage aphid (Brevicoryne brassicae) at 3 different temperatures. The growth period means of this fly are 22.45, 18.82 and 15.17 days at 20, 25 and 30oC respectively. The predation rate of E. corollae on third instar nymphs of B. brassicae at 20, 25 and 30°C significantly decreased with increasing temperature with a mean value of 371.07, 283.00 and 253.13, respectively. There were significant differences between daily and total feeding rates of the first, second and third instar larvae of E. corollae at various temperatures. The results suggest that 25ºC was the optimum temperature for both survival and feeding of E. corollae. As the temperature increases of the feeding rate reduces during periods of growth. The lowest mortality rate occurred at 25°C.

Ascospore dimensions of eight populations of Leptosphaeria maculans and L. biglobosa, causal agents of rapeseed blackleg disease, isolated from debris of rapeseed (Brassica napus) and wild mustard (Sinapis arvensis) were evaluated in Mazandaran and Golestan provinces. Results of ANOVA indicated significant differences in the dimensions of ascospores of the different populations. The greatest length and width of sexual spores were 87.5 and 12.5 micrometer, respectively. Variations in the range of Length and width of ascospores in the studied populations was measured, 46.25 and 7.5 micrometer, respectively also these variations were 6.25 and 2.5 micrometers greater than the dimensions of ascospores reported by other studies in the world. The length of sexual spores isolated from stem debris of mustard was much bigger than those of canola. Germination percentage of most studied populations was more than reported in other studies, so likely the most of studied populations of different regions belong to non aggressive group. Sexual spores of aggressive types have greater number of germ tubes, shorter in length, twisted and originate from the middle cells. While in the nonaggressive type the germ tubes grow out of end cells and are not twisted. With regard to morphological characteristics of sexual spore germ tube and also cotyledon test characteristics, field symptoms, pigment production and colony growth rate it was determined that ascospores of the studied populations from Dasht-e-Naz of Sari, Kohikheil and Fazel Abad were of the aggressive type (L. maculans) and most of population in Lala, Mazarustaq and Talookola areas belonged to nonaggressive type (L. biglobosa). There was no correlation between germ tube characteristics of fungus populations on mustard and their pathogenicity.