نشریه تحقیقات نوین در گیاه پزشکی
سال نهم شماره 1 (پیاپی 22، بهار 1397)

The Sunn pest, Eurygaster integriceps Put. is the most important pest of wheat and barley in Iran. Many studies have shown that various biotic and abiotic environmental factors affect the population of this pest. In this study, the relationship between population density of the Sunn pest adult insect with different environmental factors including sampling date, average daily temperature, average relative humidity, wind speed, wind direction, height from sea level and degree-day was investigated. Field data were collected from two wheat farm of one-hectare in the city of Chadegan, Isfahan province. The used network type was multilayer perceptron with back propagation algorithm and the learning algorithm was Levenberg-Markvart. After sensitivity analysis due to the ease of the model and extraction of effectiveness of factors including four factors of sampling date, temperature, humidity and wind speed were selected. The results showed that a neural network with two hidden layer, 7 neuron in the first hidden layer and three neuron in the second hidden layer, as a sigmoid activation function, and a data percentage of 60, 30, 10 for training, testing and validation for prediction of population fluctuation of the Sunn pest adult insect is used (R2= 0.94).

For fruit set in edible figs, Blastophaga psenes wasp inside caprifig syconium has important role. To synchronize of wasp exit from caprifig syconium and flower reception inside fig syconium, effect of cold storage was evaluated on wasp. In order to determine the effect of cold storage with 4 oC on wasps inside syconia of four caprifig cultivars of Gohari, Shanehi, Kouhi and Poozdombali, this experiment was carried out in a randomized complete design at laboratory conditions in Estahban figs research station in 2017. The results showed that caprifigs syconia of Gohari, Kouhi and Poozdombali cultivars had the highest number of living female B. psenes wasps after two days storage in cold, and the number of survived wasps gradually decreased until the 10th day of cold storage. Kouhi and Gohari caprifigs syconia had the largest and lowest living male B. psenes wasps from the beginning to 10th storage day, respectively and their number decreased gradually with an increase in storage time. The ability to withstand in cold storage condition for female B. psenes wasps inside syconia of Gohari, Shanehi, Kouhi and Poozdombali cultivars  was extended until 18, 14, 22 and 32 days of cold storage, respectively. Caprifig syconium of Gohari cultivar was more effective in figs caprification with the highest of living female wasp and the highest ratio of wasp number to syconium weight. Caprifig syconium of Poozdombali cultivar showed a good storage tolerance without any adverse effect of cold storage on syconium and with the lowest mortality of pollinator wasps.

In order to find a suitable alternative to conventional pesticides, fumigant toxicity of essential oils from Mentha longifolia, Tagetes minuta and Salvia macrosiphon were tested against adult of Tribolium castaneum (Herbst, 1797) (Coleoptera: Tenebrionidae) on laboratory condition. The experiment was conducted using a completely randomized design of factorial experiment with five concentrations and three replications at 25±10C, 60±5% R.H in darkness. The results showed that the percentage of mortality was increased with increase in concentration and exposure of time. The results also showed the effect of fumigant toxicity of Mentha longifolia was weaker than Salvia macrosiphon on the studied insects. The LC50 values were evaluated by M. longifoli, T. minuta and S. macrosiphon were 9.595, 12.434 and16.649 μl/l after 12h as well as 7.422, 9.128 and 13.071 μl/l after 24h for T. castaneum, respectively. Mean adult mortalities of Tribolium castaneum, at the highest concentration of essential oils (25μl/l), by M. longifolia, T. minuta and S. macrosiphon as 76.6%, 73.3% and 63.3% after 12h as well as 90%, 76.6%, and 70% after 24h, were recorded, respectively. It was found that plant essential oils could be used as a safe pesticide or model for new synthetic pesticides to control of insect pests

Using medicinal plants essential oils to control or suppress plant diseases causing reduce of undesirable chemical pesticides. In order to study the effect of essential oils on control of two plant pathogens, an experiment was conducted as a three factorial experiment based on randomized complete block design with four replications carried out In-Vitro condition. The factors were including four essential oils of medicinal plants (Lavender, Rosemary, Cinnamon and Eucalyptus) in five concentration (0, 500, 1000, 1500 and 2000 µL/ L) on control of Fusarium oxysporum and Fusarium solani fungi. The results showed that essential oil of Cinnamon can wholly control (100 %) mycelium growth of F. solani fungi in all concentrations, but in F. oxysporum fungi, only in 1500 and 2000 µL/ L of essential oil can control growth of fungus.The least and most of essential oil of lavender (88/5 and 100 %) observed in F. oxysporum and F. solani respectively. The highest of control in F. solani and F. oxysporum by Rosemary was 100 and 46/6 % respectively. The eucalyptus essential oil was the lowest effect on control of fungi. The highest of eucalyptus concentration can with 48 and 49 % inhibitor growth mycelium of F. solani and F. oxysporum respectively. On average, the maximum and minimum control of F. solani fungus observed respectively in cinnamon and eucalyptus essential oils, and in F. oxysporum was in cinnamon and rosemary essential oils. Cinnamaldehyde in cinnamon essential oil is a very strong inhibitor and can be used to control plant fungi.

Zeuzera pyrina (Linnaeus, 1761) (Lepidoptera: Coccidae) is a polyphagous pest that feeds more than 100 plant species. Entomophagous fungi are one of the limiting factors to control the population of this pest in nature. In this study, the lethal effect of two fungi Metarhizium anisopliae and Beauveria bassiana on the first and second larval instars of Zeuzera pyrina was investigated in laboratory conditions. The first and second instar larvae of Z. pyrinia were collected from the branches of walnut trees in Baft, Kerman province, Iran. The larvae were transferred to sterile Petri dishes after sterilization with Mercury chloride and distilled water. Spore suspension at concentrations of 1.5 ×10 6, 1.5×10 7, 1.5×10 8 conidia/ml was prepared, and then mortality rate of adults was examined after 5, 6, 9, 12, 14, 16 days. The lowest value LC50 in presence of B. bassiana (16 day), M. anisoplaie (12day) and two combined fungi (50:50), M. anisoplaie and B. bassiana (9 day) was 1/5×104.5, 1/5×103.9 and 1/5×102.2 conidia/ml respectively. Therefore, the combination of two B. bassiana and M. anisoplaie fungi had the best effect in the shortest time and M. anisoplaie had better effect than B. bassiana. Nowadays, biological control is one of the best and most practical control programs to protect of environment; biological control of pests, chemical pesticides that have harmful effects on humans and other organisms. In this study, the simultaneous use of two fungi B. bassiana and M. anisoplaie caused to 100% mortality of woodworker worm larvae during 16 days in concentration of1/5 ×10 8 conidia/ml.

Mugwort, (Artemisia vulgaris L.,) is a rhizomatous perennial weed common in field grown nursery crops, landscape plantings, and turf grass. Greenhouse experiment was conducted based on a factorial in randomized completely block design in 2014. Mugwort rhizomes were collected around Karaj and were trimmed into 3 cm-long segments. Three of these Mugwort rhizome segments were planted in 20-cm-diameter pots containing sandy loam soil, with pH 7.5 and 0.9 % organic matter content. Experimental factors included type of herbicide at six levels (2,4-D, glufosinate, picloram, dicamba, glyphosate and clopyralid) and herbicide concentration at six level (0, 0.28, 0.56, 1.1, 2.2 and 1.1+1.1 ai ha-1). Results showed that shoot dry weight of Mugwort was 2.52, 1.57, 2.17, 2.22, 3.25 and 0.63 g at 4 weeks after treatment and 0.28, 0.2, 0.25, 0.25, 0.35 and 0.1 g  at 9 weeks after treatment with application of 2,4-D, clopyralid, dicamba, glyphosate, glufosinate and picloram, respectively. So long-term control of mugwort plants and rhizomes can be achieved with picloram at lower concentrations. This level of mugwort control is more than likely because of the greater persistence of picloram in the soil compared with other growth regulator–type herbicides. 2,4-D and glufosinate could not control this weed in long-term and extensive regrowth from underground rhizomes was observed 9 weeks after spraying. This suggests that inadequate concentrations of glufosinate reach the underground rhizomes of mugwort, resulting in immediate regrowth and unacceptable long-term mugwort control. Clopyralid, dicamba and glyphosate were moderately effective in controlling mugwort under greenhouse conditions, but re-growth occurred after all herbicide concentrations, but higher rates were needed for complete control.

Integrated pest management (IPM) is an ecosystem approach to crop production and protection that combines different management strategies and practices to grow healthy crops and minimize the use of pesticides. Essential oils and extracts are used in the developing world for many purposes including management of agricultural insect pests. This study evaluated the individual and synergistic effects of essential oil and methanolic extract of Mentha pulegium against Ommatissus lybicus adults. The LC50 andLD50 of M. pulegium values are 9.68 μL/L air and 36.97 mg/mL, respectively. To assess the sublethal effects, adult bugs were exposed to the essential oil (LC25), methanolic extract (LD25) and their combination, and mortality of immature stages and life table parameters of the surviving O. lybicus were studied. The highest percent of egg and nymphal mortality were observed, 27.33% and 37.60% respectively, after exposure to LC25 ofM. pulegium oil. Exposure to sublethal LC25 and/or LD25 of M. pulegium negatively affected the life table of O. lybicus. All treatments significantly reduced the R0, rm, λ, and GRR while that increased T of O. lybicus and prolonged the developmental time from egg to adult. In comparison to extract treatment, R0 and rm parameters were reduced to a greater extent in insects exposed to both M. pulegium oil and extract, however, a statistically significant difference was not found when compared with essential oil treatment. According to these results, both tested essential oil and methanolic extract has potential applications for the integrated management of O. lybicus.