نشریه آفت کش ها در علوم گیاه پزشکی
سال پنجم شماره 1 (بهار و تابستان 1397)

Iran is the in the first rank for pistachio production in the world. Considering the strategic importance and facilitating the export of this product, evaluation and determination of pesticide residues to ensure the safety of the product, based on the optimized and validated methods is very important. Spirotetramate is one of the newest and widely used pesticides in most of the pistachio gardens to control Agonoscena pistaciae. In order to extract this insecticide from the pistachio matrix, the optimized QuEChERS method was used. In order to save costs, all the stages of optimization of the method were performed using high performance liquid chromatography with UV detector (HPLC-UV). The optimization resulted in removal of expensive compounds like C18 and GCB, which in turn resulted in a reduction of at least 60% of the cost of extraction. All validation steps were carried out using blank pistachio samples. The samples were artificially contaminated in the laboratory with different concentrations of the insecticide. In order to confirm the final optimized method to use this method for real samples, HPLC with mass detector (LC- MS / MS) was used. At optimized conditions calibration curve of matrix effect for spirotetramate shows a good linearity in the range of 0.04- 0.10 mg/Kg (r2 of 0.995) and RSD less than 7% with the extraction recovery ranged from 85 to 100.3%. In addition, the matrix matched calibration curve for spirotetramate-enol in the above concentration range was found to have a correlation coefficient of 0.9936. The limit of quantification of the analytes was calculated to be 0.04 mg/Kg according to the SANCO guidelines, which is within the acceptable range with respect to the MRL of pistachio which is 0.05 mg/Kg.

The clearwing moth, Synanthedon caucasica (Gorbunov), is known as an important wood-boring pest of plane trees in Isfahan landscape. It has been reported that more than 50% of the plane trees in the various urban areas of Isfahan have been infested by this species. This research was conducted to evaluate the efficacy of some insecticides on S. caucasica by two application methods namely bark spray and trunk injection of infested plane trees, in two urban areas of Isfahan, in a completely randomized design. Tested insecticides in bark spray were imidacloprid (Confidor® EC 35%), chlorpyrifos (Dorsban® EC 40%) and deltamethrin (Decis ® EC 25%), and in trunk injection the treatments were imidacloprid (Confidor® EC 35%), oxydemeton methyl (Metasystox® EC 25%) and azadirachtin (EC 1%). For both application methods, evaluation was based on the number of active larval holes and pupal exuviae (in summer) or number of live larvae under bark (in October). The results show that bark spray by chlorpyrifos, imidacloprid and deltamethrin significantly reduced S. caucasica larval populations by 92%, 81%, 81% and 81%, respectively. The highest reduction in the larval population by trunk injection of insecticides compared to the water control in October was obtained in azadirachtin treatment (95%), followed by oxydemeton methyl (89%) and imidacloprid (81%). The results of this study show that the effect of insecticide application on the larval population of S. caucasica increased with increasing duration of treatment. Based on the results, application of either bark spray or trunk injection in appropriate period could have suitable effects in the integrated management of S. caucasica.

Elm Leaf Beetle (ELB), Xanthogaleruca luteola (Coleoptera: Chrysomelidae) is one of the important pests of elm trees (Ulmus spp.). This experiment was performed in order to evaluate two chemical control methods of this pest on the elm trees in the 22nd district of Tehran in 2014. The experiment was designed in a randomized complete block with four replications and 13 treatments. Treatments included injection of imidacloprid SC35% (with doses of 6, 12 and 18 g/ tree), oxydemeton-methyl EC 25% (with doses of 6, 12 g formulated/tree), azadirachtin EC 0.03 % (with doses of 6, 12 g formulated/tree), hexaflumuron EC 10% ( with doses of 6, 12 g formulated/tree), fenoxycarb and lufenuron ( Lufox® EC10.5%; with doses of 6, 12 g formulated/tree), control (water injection) and foliage application with diazinon EC60% with concentration of 2ml formulated/L as a conventional control method. Sampling was conducted 14 times until the end of the summer season. Results show that the mean efficacies of imidacloprid (83%) and Lufox® (91%) at high concentrations were the same as diazinon treatment (84.25%) and all of them were ranked in one group. Mean efficacies of azadirachtin (51%), hexaflumuron (33%), and oxydemeton-methyl (23%) injections were significantly less in comparison with the mentioned treatments. Mean damage percentage on sampled leaves and apparent color of the tree crown showed that the trees treated with Lufox® and imidaclopride had the least damage percentage (25.3%), while the control (55%) and azadirachtin (65%) had the highest percentage. Therefore, injection method of imidacloprid and lufox against elm leaf beetle could be applied in the central parts of the cities or places with high risks of contamination and where the tree crown is very high.

The efficacy of Cyazofamid (Ranman SC 10%), was assessed for the control of cucumber downy mildew disease in Yazd, Tehran (Varamin) and south of Kerman (Jiroft) provinces. This fungicide was used at 1, 1.25 and 1.5 ml/L along with some comparative fungicides such as Cyazofamid (Ranman® SC 40%), fluopicolide+hydrochloride (Infinito® SC 75.68%) at 2 ml/L and Copper Oxychloride (Mishocap® WP 35%). The experiment was designed in completely randomized blocks with 4 replications in situ. To assess the efficacy of the fungicides, disease severity was calculated based on a scale described by Thomas et al.. Data were analyzed using SAS software and the means were compared using Duncan's multiple range tests. In all experiments, significance differences were observed in disease severity in plots treated with fungicide compared with control plants. In Yazd, the highest disease control rate was 87.4% in Ranman SC 10% treatment with the dose of 1.5 ml/L compared with the Ranman SC 40% (87.3%), Infinito (88.8%) and Mishocup (62.53%) were observed and in Varamin, Ranman SC 10% fungicide treatment with 1.5 ml/L resulted in control of 82.9% of disease compared with 71.8%, 71.8% and 58% control of disease by Infinito, Ranman SC 40% and Mishocap, respectively. In Jiroft area, there was no significance difference between the fungicides treatments in the disease control and the rate of disease control was 53.04% to 62.64%. The study shows that Ranman 10% SC at the dose of 1.5 ml/L has suitable efficacy for the control of the disease.

The purpose of this study is to investigate the factors affecting the proper selection of pesticides by greenhouse owners. A descriptive-correlation method was used for this study. Target population of this study was 8310 Greenhouse owners in Tehran, Bushehr, Kerman, Isfahan and Yazd (N=8310) provinces, and 368 greenhouse owners (n=368) were selected by stratified random sampling method. Data was collected by a questionnaire as the tool of the study. The instrument was assessed for face and content validities by a panel of experts. The reliability of the questionnaire was between 0.85- 0.91. The results of the research revealed that the main factors influencing the proper selection of pesticides by greenhouse owners were job satisfaction, participation in training courses, interest in the production and export of greenhouse products. The viewpoint of the majority of greenhouse owners (84%) was relatively negative regarding the diversity of agricultural pesticide use. Other results of the research also indicated that there was a positive and significant relationship between education level and the number of hours spent on greenhouse use by the dependent variable of the research (viewpoint on the diversity of agricultural pesticides use).

Aculops lycopersici (TRM) is an important tomato crop pest. Bioassay on registered doses of 0.75, 1.5, 2.5 ppm of GC-mite, Biomite, and Neem EC 1.8% botanical pesticides were conducted in laboratory respectively. One liter stock solution of each pesticide was used to prepare different doses (0.1-0.9 ppm) and bioassay was conducted using tomato infested leaf submerged for 5 seconds with 10 replications. Distilled water was used in control treatment. Mortality of Aculops lycopersici was determined after 24 hours for each dose on TRM and analysis was done by POLO-PC software. According to LC50 determined, minimum dose toxicity recorded was 0.22 ppm for GC-mite which shows 71% reduction compared with the registered dose. Least dose slop recorded was 1.15±0.17 for 1.79 ppm of Neem. Effective dose of each treatment was compared with 20% lower and higher than the dose obtained when 10 TRM were observed in 1cm2 in middle part of lower and upper tomato leaf in the greenhouse. Live TRM population was counted by random collection of 12 leaves from each treatment and moving mites were counted in 1cm2 area on both the sides of leaf one day before and 3,7,14 days after treatment with stereo microscope. Highest mean of mite density recorded was 100.33±17.86 in 1 cm2 on the lower side of the leaf which was two times of the upper side of the leaf. Mean percent mortality on the 3rd day showed significant differences among the treatments although the effect of the treatments at 7th and 14th day caused 83.12% to 99.75% mortality and was not significantly different (p<0.05) except for biomite treatment. The results show that all the doses effectively controlled active TRM and can be substituted with the hazardous acaricides for production of organic tomato under greenhouse conditions.

Weeds are able to reduce bean production up to 75%. Weeding is the traditional method of weed control, which is still the most selective and complete approach. Though herbicides, due to their efficiency and economic benefit play a pivotal role in weed management. In this study the efficacy of herbicides: Imazathapyr, Thrifloralin and their mixture on bean weeds, bean reactions to different doses, application methods as well as its probable residuale effects on the following wheat crop was evaluated. Using RCBD, experiments were carried out with 9 treatments and 4 replications in 2012 and 2013 at Zanjan and Shahr-e-Kord cities. Results show that in zanjan the maximum bean yield was obtained as 4242, 3867, 3815 and 3679 kg/ha in treatments of weeding, Imazathapyr with the doses of 0.75, 0.5, and 1L/ha at pre-emergence stage respectively, whereas at Shahr-e-Kord, treatments of Imazathapyr + Thrifloralin (0.75 & 1L/ha) applied as pre-plant stage, Imazathapyr (0.75 & 0.50 L/ha) as pre-emergence application registered maximum yields of 2874, 2813, and 2694 kg/ha respectively. Pre-plant and pre-emergence applications of Imazathapyr and Thrifloralin had no injury symptoms and negative effects on wheat as the alternative plant.