نشریه آفت کش ها در علوم گیاه پزشکی
سال هفتم شماره 2 (پاییز و زمستان 1399)

The Melon Aphid, Aphis gossypii, is a key pest of greenhouse cultivated cucumber which is economically important due to its wide host-range and cosmopolitan status. Due to its high potential for evolving resistant biotypes against insecticides, it is necessary to test and present new insecticides against it. This research was conducted in the greenhouses of Tehran and Yazd provinces, based on a completely randomized design with 6 treatments and 4 replications. Treatments  included pirimicarb (WP 50%)  at the rate of 1/1000 L, flonicamide (Teppeki ® WG 50%)  at the rate of 0.2/1000 L and 0.25/1000 L, pymetrozine (Chess ® WG 50%)  at the rate of 0.5/1000 L, palizin insecticide soap  at the rate of 2.5/1000 L and control (water spray). The sampling was done one day before the treatment and 3, 7 and 14 days after the treatment. Analysis of variance of data was performed by SAS software and means were compared using Duncan multiple range Test. On the third day after treatment, the mean efficacy of Teppeki (0.2/1000 L), pirimicarb, pymetrozine, Teppeki (0.25/1000 L) and palizin was 97.83%, 87.7%, 82.43%, 90.53% and 76.94%, respectively. On the seventh day after treatment, the highest and the lowest efficacies were observed in Teppeki (0.25/1000 L) and palizin treatments, which were 92.27% and 38.7%, respectively.   The mean efficacy in Yazd province, on the third day after treatment was 90.25%, 79.66%, 86.28%, 88.74% and 75.25% for Teppeki (0.2/1000 L), Teppeki (0.25/1000 L), pirimicarb, pymetrozine, palizin, respectively. In general, the new insecticide, Teppeki, has an acceptable efficacy against this pest in the greenhouse.

The white peach scale, Pseudaulacaspis pentagona, is one of the most important pests of stone fruit trees in the northern provinces of Iran. The efficacy of several synthetic and biorational insecticides was investigated on white peach scale in a peach orchard in Shirang-E-Olya village of Kamalan district in Aliabad-E-Katoul city. The study was conducted in a randomized complete block design with 9 treatments and four replications in the peach orchard. Treatments in this experiment include: Pyriproxyfen (EC10%) at the rate of 1 and 2 ml/L, Chlorpyrifos (EC 40.8%) at the rate of 4 and 8 ml/L, Thiacloprid (OD 24%) at the rate of 0.6 and 1.2 ml/L, Spirotetramate (SC 100) at the rate of 1 and 2 ml/L, Flupyradifurone (SL 20%) at the rate of 1 and 2 ml/L, Palizin (SL) at the rate of 3 and 1.5 ml/L, Tondexir (EC) at the rate of 4 and 8 ml/L, Citral (EC) at the rate of 1 and 2 ml/L and control. Sampling was performed 1 day before spraying, and then the first and second generation of this pest after spraying. Data were analyzed by Glm method and means were compared by Duncan multiple range test using SAS software. Spirotetramate (1 ml/L) had the highest efficacy percentage among the insecticides used on the first generation of this pest. For the second generation also, the highest efficacy was observed by Spirotetramate (1ml/L) and Chlorpyrifos (4 ml/L). Among the bio-insecticides, 1.5 ml/L of Palizin and 8 ml/L of Tondexir were highly effective, too. Although chemical insecticide such as Chlorpyrifos showed good results, the new insecticide Spirotetramate had the same or better efficacy than Chlorpyrifos. Therefore this insecticide can be a suitable substituted for chlorpyrifos. Biorational insecticides also had good effect in eliminating white peach scale and can be used as biocompatible insecticide.

Over the last two decades in response to rising production costs in many Asian countries the method of establishing rice by manual seedling transplantation has changed to direct cultivation. Changing the method of rice establishment and the resulting stresses has led to pay more attention to management methods in direct rice cultivation. Rice stem borer (Chilo suppressalis) is one of the most destructive pests of this product. In this study, the efficacy of Hexaflumuron (Consult®) and Kitoagrosens inhibitor fertilizer with the recommended concentrations  was evaluated to control this pest at intervals of 3, 7, 14 and 21 days after spraying using Henderson-Tilton method. Their effects on rice yield components were investigated, too. The results showed that in terms of insecticidal efficacy on rice stem borer, both the compounds were most effective after 7 days, while Hexaflumuron ( >90%) was more effective than Kitoagrosens (~70%). On the other hand, the results related to crop yield components showed that Kitoagrosens had better effects on all parameters, especially on 100-seed weight, which is significantly higher than other treatments. Based on the results of this study, it can be concluded that Kitoagrosens has e less insecticidal ability than Hexaflumuron but have a greater strengthening effect on the quantitative and qualitative indicators of rice crop.

The lateral bud death disorder in almond (cv. Shahroud 12) is observed in some replanted orchards in Chaharmahal and Bakhtiary province. The abundance of plant parasitic nematodes, phytophthora species and zinc deficiency were more in trees with symptoms than the asymptomatic trees. Experiment was performed in a randomized complete block design with seven treatments including pesticides like fluopyram (Velum Prime®; EC, 41.5%), Abamectin (Vertimec®; EC, 1.8%), Fosetyl-Al + Propamocarb (Previcur Energy®; SL, 840), Fosetyl-Al (Elite®; WDG, 80%), Diazinon (Bazodin®; EC, 60%) , Zinc sulfate (ZnSO4H2O, 33%) and control with five replications on Shahroud 12 cultivar almond trees along Zayandehrood during 2018-2020. A week before the application of chemical treatment and three months later, soil and root samples were collected for the measurement of plant-parasitic nematode population and isolation of Phytophthora species and the zinc content. Four branches per tree were selected from different directions, a week before the chemical treatment and five months later, and  healthy (containing leaf and fruit) and dead buds were counted. The results show the treatments of Velum Prime, Abamectin, Diazinon, Zinc sulfate, Previcor and Elite reduced the bud death and improved the disorder of the almond trees by 66.1%, 53.2%, 36.3%, 33%, 19.3% and 16.9%, compared with the control, respectively. Although compounds with nematicidal properties were more effective in improving this disorder; other treatments were also significantly different compared with control in terms of reducing the symptoms of bud death. The role of other factors in causing this disorder can not be ignored; therefore, the interactional effects of these factors in causing or exacerbating  the symptoms of  bud death of almond (Shahroud 12 cv.) may be more effective than a single cause alone.

Powdery mildew is one of the most important diseases of apple globally and is caused by the fungus Podosphaera leucotricha. The aim of this study was to determine the efficacy of the fungicides Boscalid + Pyraclovastrobin (Bellis®; WG, 38%) with the doses of 0.4, 0.7 and 1 ml L-1 compared with the fungicides Tri-floxystrobin + Fluopyram (Luna Sensation®; SC, 500) with the dose of 0.2 ml L-1, Tri-floxystrobin (Flint®; WG, 50%) with the dose of 0.2 ml L-1 and Tri-floxystrobin + Teboconazol (Nativo®; WG, 50%) with  the dose of 0.2 ml L-1 to control the apple powdery mildew disease. The experiment was carried out in Ardabil province in a randomized complete block design (RCBD) with 8 treatments and 4 replications in 2019-2020. Control treatments were with water spraying and without any spraying Treatments were applied in the spring in three stages (full green bud stage, pink flower stage and 10 days after the 2nd spraying). Ten days after the first symptoms of the disease were observed in the control treatments, samples were taken from the sheets and the disease incidence and disease severity percentages were calculated. The results showed that the highest rate of control (80%) of apple powdery mildew disease was related to Luna Sensation® (0.2 ml L-1). Then   the fungicide treatment of Bellis® (1 ml L-1) had the highest rate of control of the disease (76%) and the treatments of Flint® (0.2 ml L-1), Bellis® (0.7 and 0.4 ml L-1) and Nativo® (0.2 ml L-1) were ranked next in this regard. The efficacy of the new fungicide Bellis® at the rates of 1 and 0.7 ml L-1 was 76 and 60%, respectively. Since both the doses of Bellis® are effective in controlling the disease, therefore, to protect the health of the fungicide users, the consumers  of the products and the environment as well as reduction in costs, the preferred dose was chosen as 0.7 ml L-1.

Powdery mildew of wheat caused by Blumeria graminis f.sp. tritici, is one of the most important and common wheat disease in humid, semi-humid and semi-arid regions of the world, including Iran. At present, one of the important aspects of the management of this disease is its chemical control. In this study, the efficacy of the Pilartep (Tebuconazole +Pyraclostrobin) SC 30% was evaluated in controlling the powdery mildew of wheat in three regions of Qarakheil and Bayekola (Mazandaran) and Kohnekand (North Khorasan province) regions based on randomized complete block design with six treatments and four replications. Experimental treatments included Pilartep (SC 30%) 0.4, 0.5, 0.6 and 0.7 l/h, Tilt (EC 25%) 1 l/h, Folicur (EW 25%) 1 l/h and control. Spraying operation was performed in the growing stage of stem emergence with the emergence of flag leaves. The plots were evaluated for disease incidence and severity percentage using double digit scale and at the end of the season, wheat yields were recorded for each plot. In evaluating the effect of fungicides on incidence, disease severity percentage and crop yield, Pilartep fungicide at the rate of 0.6 and 0.7 l/h was placed in the first statistical group (the highest group). In general, according to the results obtained in order to use the fungicide optimally, Pilartep (SC 30%) at the rate of 0.6 l/h is recommended in the control of powdery mildew of wheat.

One of the main problems in the production of chickpeas in most of the provinces where chickpea is cultivated including west and north-west provinces is the general and specific pests, including chickpea pod borer, Helicoverpa armigera. This project was conducted in a randomized complete block design in Kermanshah and Lorestan provinces with seven treatments in three replications. Treatments included, Lofenuron 2 l/1000 l , Roy Agro 1 l/1000 l , Biolep P 1 l/1000 l , insecticide Bacillus thuringiensis Ber, (Biotech Indian)  with three doses of 1000, 600 and 400 grams per hectare. The efficacy of the insecticides was investigated 3 and 7 days after the treatment, and the number of damaged pods was recorded at the mentioned time intervals, and the percentage of damage of the pods was calculated. The results showed that the treatments were significantly different in efficacy and the percentage of damage and B. thuringiensis-based insecticides were statistically effective (75 to 81%) in controlling chickpea pod borer after seven days.  Biolep P biological pesticide showed 68.79 and 81.27% and Bt (Biotech India) 74.59 and 79.99% efficacy in Lorestan and Kermanshah provinces respectively. There was no significant difference in efficacy percentage between the biological pesticides and Roy Agro pesticide. The biopesticide Biolep showed no significant difference in terms of efficacy and damage percentage in comparison with the Biotech India biopesticide. The results show that if the pest is not controlled (control), the percentage of damage on chickpea pods is about 40%, but with the use of biological pesticides, this damage could be reduced to less than 10%.