فصلنامه مطالعات حفاظت گیاهان
سال سی‌ام شماره 2 (تابستان 1395)

This study was conducted to investigate the effect of organic and bio-fertilizers on trifluralin durability.Herbicide persistence is an important consideration in crop production since residue levels of trifluralin herbicides can persist to the next growing season and may injure sensitive crops in the rotation. Residues of trifluralin persist in the soil for long periods. Extremely small amounts of resides can be devastating to some crops that are planted in the following year. Bioassay experirent is a common and cheaper experiment for herbicide residue detection in soil.In order to estimation of trifluraline halfe life in soila field experiment conducted as a factorial arrangement in completely randomized block designwith 3 replications. Experimental factor included two levels of trifluraline (EC %48) application rate480 and 960 g.Ha-1 a.i.). For determination of trifluralin residue, soil sampling was taken from 0 to 10 cm soil dept at 0, 3, 7, 15, 30, 60, 90 and 120 days after spraying. soil sampling and soil treatments were transferred to the greenhouse. The results of Bioassay experiment with sorghum plants showed decreasing trifluralin durability with the application of organic and biological fertilizer. The highest half life were observed (144 and 130 days), by using 480 g. a.i/ha related to shoot and root biomass and no fertilizer application respectively and the Least a half-life was in shoot biomass related to organic fertilizer treatment (18 and 19 days) and 480 and 960 g trifluralin active ingredient.

There are many reasons for no effectiveness of herbicides on weeds, including the incorrect herbicide, the insufficient use of herbicide, the unprincipled sprayer, spraying at the wrong time especially adverse weather conditions, and a factor that often overlooked is the "water quality in herbicide spray tank". Most of the herbicides are mixed with water and applied as a spray. Obviously water quality is an extremely important issue. Water quality factors in this regard that effect on uptake and translocation of herbicides included as water hardness, pH, bicarbonate ion concentration, turbidity, organic matter and other substances. Hardness is determined by the amount of calcium and magnesium present and is expressed as calcium carbonate (CaCO3) equivalent in parts per million. Petroff (27) classified water based on hardness: water with a hardness 0-75 ppm is considered “soft” water, 75-150 ppm is “medium hard”, 150-300 ppm is considered “hard”, and more than 300 ppm is “very hard”. Hard water is a problem in over 85% of the United States according to the US Geological Survey. The contrast between the herbicides and dissolved ions depend on amount and type of minerals in the spray tank. So that different herbicide may show different responses to the same action. If soft water is not available, surfactant and chemicals additives such as ammonium sulfate (AMS), ammonium nitrate (AMN) and urea- ammonium nitrate can be added to the spray tank to increase herbicide efficacy (7). These compounds prevent from the adverse effects of the ions in water. Glyphosate and nicosulfuron belong to two different chemical families of herbicides and are soluble in water. Therefore, water quality such as the presence of calcium carbonate may have a significant effect on these herbicide performances, while removing the inhibitory effect of water hardness by adding nitrogen compounds such as ammonium sulfate need to experiment. According to the above, basic experiments carried out as the influence of adding ammonium sulphate to spray solution of calcium carbonate-containing glyphosate and nicosulfuron on barnyardgrass and velvetleaf control.
Four experiments were performed as factorial arrangement of treatments 6×2 based on completely randomized design with six replications (눬 control pots for each weed species) at Research Greenhouse of the Ferdowsi University of Mashhad in 2010. Factors were included different concentrations of calcium carbonate (CaCO3; Merck, Germany) of water in spray tank at six levels 0, 100, 200, 300, 400 and 500 ppm in deionized water (w/v) in combination with 0 (-AMS) or 3 kg/ha (Ä) ammonium sulphate (Merck, Germany) as adjuster the hardness. Glyphosate (Roundup®) and nicosulfuron (Cruse®) herbicides were applied post emergent at 385 and 550 mL ha-1 as commercial products (158 and 22 g ai ha-1; based on ED50 outcome preliminary test (12), recpectively) at the 3-4 leaf stage of the weeds (barnyardgrass and velvetleaf) in a spray volume of 250 L ha-1. Four weeks after treatment, survival, plant height, leaf area, and shoot dry weight of weeds (% control) were calculated. The data of experiment were subjected to ANOVA using MSTATC software. Means of the treatments were separated using Duncan’s Multiple Range Test at α = 0.05. Also, based on the distribution of data, regression analysis was used as linear, two, and third-degree polynomial by EXCEL 2007.
The results showed a significant reduction (p≤0.01) for survival, plant height, leaf area, and shoot dry weight of weeds (% control) with addition of calcium carbonate in spray tank of glyphosate and nicosulfuron herbicides, but this effect was not similar. So that, 500 ppm Ca2 to the nicosulfuron spray solution compared with its absence increased barnyardgrass and velvetleaf biomass (% control) 16 and 50%, respectively. The corresponding values for glyphosate were 78 and 51%. Accordingly, Nalewaja et al. (24) reviewed the effect of different calcium compounds such as calcium carbonate (0.02 mol) in water as a solvent nicosulfuron herbicide (15 g ai ha-1; 160 L ha-1) interaction to seven surfactants on finger grass (Digitaria sanguinalis L.) at greenhouse conditions found that CaCO3 across seven surfactants reduced about 8% nicosulfuron performance. In research conducted by Buhler and Burnside (5) concluded that an increase in calcium ion (prepared from CaCl2) to 2 mmol in spray tank was not affected on glyphosate (400 g ai ha-1; 190 L ha-1) performance. With the increasing of Ca to 8 mmol, was reduced significantly (P≤0.05) toxicity herbicide on oat (Avena sativa L.) from 80 to less than 20%, 14 days after spray at the greenhouse experiment. Adding ammonium sulphate (Ä) decreased the antagonistic effects of water hardness, and increased herbicides efficacy on barnyardgrass and velvetleaf. However, the synergistic effect of Ä on velvetleaf control by glyphosate was higher. Green and Cahill (10) concluded adding 2% AMS to spray tank increased the pH of nicosulfuron solution from 4.6 to 4.7 and finger grass was well controlled by this herbicide because of increasing nicosulfuron solubility from 12 to 16%. In research conducted by Mueller et al. (22), the presence of calcium (Ca) and magnesium (Mg) ions concentration of 250 ppm reduced the effectiveness of three types of glyphosate salt, but adding 2% by weight of ammonium sulfate (AMS) to the spray tank overcame to the ions antagonistic effect.
Results of current experiment emphasized the role of water hardness (CaCO3) in spray tank of glyphosate and nicosulfuron on barnyardgrass and velvetleaf control.

Herbicides, despite of their control of weeds, have the potential to affect sensitive crops in rotation and also beneficial non-targeted soil microbes including vesicular arbuscular mycorrhiza (VAM) fungi (6). AM fungi can increase the growth of crops through increasing uptake of phosphorus and insoluble micronutrients, and indirectly by improving soil quality parameters (30). However, several authors have reported different effects of herbicides on VAM symbiosis, which ranges from no adverse effects to slightly or highly toxic effects (6). Pesticides have also been reported to stimulate colonization of plant roots by AM fungi (27). Therefore, the objective of this study was to investigate the interaction effects of mycorrhizal fungi and Trifluralin herbicide on the growth and root colonization of clover.
A factorial experiment was arranged in randomized complete block design with three replicates at the College of Agricultural, University of Shahrood during 2012. Treatments were included three levels of mycorrhiza inoculation, M1: non mycorrhiza (control), M2: Glommus mosseae and M3: Glommus intraradices and herbicide treatments were included four levels of Trifluralin(T1: 0, T2: 1000, T3: 1500 and T4: 2000 ml ha-1). In mycorrhizal treatments, 20 g inoculums were thoroughly mixed with soil. Seeds of clover (Trifolium repens L.) were sown in the pots maintained near the field in order to provide normal environmental conditions. Seedlings were thinned to two plants per pot at three leaf stages. At the time of harvesting, the emergence and growth characteristics of clover and root colonization was also registered. Statistical analyses of data were performed with statistical software MSTATC. Significant differences between means refer to the probability level of 0.05 calculated by LSD test.
The results showed that emergence, uniformity (EU) values decreased and time to 10% (D10) and 90% (D90) of emergence increased significantly with increasing herbicide dose. The maximum emergence (Emax) value and clover shoot dry matter was obtained with inoculation by mycorrhiza species in all levels of herbicide doses than non-inoculation treatments (figures 1 and 3). Inoculation of clover with G. intraradices increased root length by 34 and 57% at the herbicide doses of 1000 and 1500 ml ha-1 than non-inoculation treatments, respectively (figure 2). Results showed that, the root colonization percentage improved in low rate of Treflan by inoculation of mycorrhizal than non-inoculation treatment significantly (figure 4). These results are in agreement with the results reported by Garcia-Romeria et al. (14). They reported that shoot dry weights of AM fungi infected pea plants, were higher when the cyanazine was applied at the rate of 0.05mg ml -1 than applied at the rate of 0.1 ml per pot (14). Busse et al. (6), reported that triclorpyr, imazapyr and sulfometuron methyl herbicides did not alter the capability of mycorrhizal fungi to infect roots, even at concentrations detrimental to seedling growth. Makarian et al., (21) reported that herbicide application significantly decreased the growth (dry matter, chlorophyll content and height) of maize and barley plants but mycorrhizal colonization increased plant growth at low levels of herbicide concentration. It seems that, one of the main reasons that enable the mycorrhizal plant to partially or completely overcome the stress of herbicides as compared with non-mycorrhizal plant is the enhanced nutrient uptake (6). Enhanced nutrients uptake is due, in part, to the hyphal extension into the soil and subsequent transfer of them back to the root (30). Recent researches have established that AM fungi are able to absorb organic compounds, macro and micro nutrients from the soil and transfer them to plants (29). Pesticides have also been reported to stimulate colonization of plant roots by AM fungi. This may be due to a reduction or elimination of competing microorganisms or to a pesticide mediated change in plant metabolism resulting in increased production of materials stimulatory to AM fungi in the rhizosphere (27).
In conclusion, the results of this study indicated that with increasing Treflan doses the clover seed emergence, root colonization, dry matter production and root length of clover significantly decreased than non-herbicide application treatment. But inoculation of clover seeds with mycorrhizal fungi increased seed emergence and shoot dry matter at the all doses and root length and colonization percentage of the low rates of herbicide. Based on our results, mycorrhiza fungi can alleviate crop stress due to low doses of Treflan injury through increasing of plant growth.

Garlic (Allium sativum) (family Amaryllidaceae) are one of important crops in Hamedan province. There are several insects and mites that by feeding on this plant cause to damage garlic yield. Among the insect pests, the most dangerous pests of garlic are thrips species (Insecta: Thysanoptera). In this group, onion thrips, Thrips tabaci Lindeman is widely distributed and is a dominant species. Its sap sucking causes tiny and silvery spots on the leaves that may spread all over the leaf surface with an unfavorable effect on yield production. In addition, imagoes and larvae living and feeding on this plant cause more serious damages. Due to serious damage of thrips in garlic fields of Hamedan province, it is necessary to identify thripsspecies for pest control programs.
Thrips specimens were collected on leaves of garlic in Hamedan province (Maryanaj and Heydareh) situated in the west of Iran, during 2012–2013. Herein, specimens were collected by shaking plants to white dish and specimens were kept in 70 % ethanol and transferred to the laboratory. All collected material was macerated in 5% KOH and subjected to dehydration in an ethanol series before being mounted onto glass slides. Subsequently, thrips specimens mounted onto slides in Hoyer’s medium form of the protocol given in Mirab-balou and Chen (2010). All descriptions, measurements and photos were made with a Leica DM IRB microscope, with a Leica Image 1000 system. Thrips specimens were identified by author in species level. Specimens are deposited in the collection of Department of Plant Protection, College of Agriculture, Ilam University, Iran (ILAMU). In addition, dominant thrips species were also determined. For this purpose, regular samplings were done in fields of two regions of Hamedan province every two weeks, and totally, 2040 specimens (adult) were collected.
The world fauna of Thysanoptera, are presently known to be consisted of about 6000 species placed in two suborders and nine families. A large number of thrips species are considered pests, because they feed on economical crops. In this study, a total of eight species in seven genera and three families were collected and identified, including Aeolothrips intermedius Bagnall and Rhipidothrips gratiosus Uzel from family Aeolothripidae, Aptinothrips rufus (Haliday), Frankliniella intonsa (Trybom), Scolothrips longicornis Priesner, Thrips alliorum (Priesner) and Thrips tabaci Lindeman from family Thripidae, and Haplothrips reuteri (Karny) from family Phlaeothripidae. All of the species existed in two years in both two regions. Thrips tabaci was the dominant species (64.89%) in garlic fields. Among the predatory thrips, Aeolothrips intermedius and Scolothrips longicornis were present in greater numbers. However, their number was not enough to reduce the number of phytophagous thrips. The predatory species feeds mainly on the larvae and imagoes of onion thrips but they feed on mites as well. An identification key for thrips species associated with garlic is also given.
In this study, eight species of thrips were collected on garlic fields of Hamedan province which Thrips tabaci was dominant species (64.89%); and three of which were identified as predatory species. Up to the present, several thrips were collected and recorded from Hamedan province by the author, but there is no study on thrips associated to garlic; therefore, this study was firstly carried out in Hamedan province. There are several insect pests on garlic, and T. tabaci was also reported as important pest on garlic fileds in this province. Onion thrips, T. tabaci is one of the important pests in the world, and it has more than 300 host plants. At present, it is widely distributed in Iran and is a key insect pest in most onion and cotton cultivation areas as well as ornamental plants. In addition, thrips species in the genera Thrips and Frankliniella spread plant diseases through the transmission of viruses, such as Tospoviruses, Tomato Spotted Wilt Virus, and the Impatiens Necrotic Spot Viruses; So, it is necessary to pay more attention to the management of T. tabaci . In garlic crops of Hamedan province, T. tabaci was established on the plant from earlier time to near harvest; and because of high damaging, the farmers used several insecticides within one year.

Land use change, deforestation, grazing, intentional and unintentional fire and invasive pests and diseases are all the major cause of damage to the Zagros forest ecosystem. The green oak leaf roller (Tortrix viridana L.) is one of the important pests of Zagros forests. Larvae of the pest significantly damage the oak forests with feeding on leaves and buds of different species of oaks each year. Larvae enter 2'd instar after eating the internal contents of oak buds, then the third and 4th instars larvae consume whole buds and even oak leaves. After development to the 5th larval instar, they roll the leaves and enter the pupal stage. The attacked trees revitalize by creating new leaves from early May onwards. New leaves, pale green and are smaller than normal leaves. Continuation of the pest activity on Quercus species causes gradual weakness the trees and readiness to accept a variety of secondary pests and diseases in later years. Based on the status of Zagros forests and their importance in the conservation of soil and water sources, the nutritional indices of Tortrix viridana larvae of two species of Oak i.e. Quercus infectoria and Q. libani were determined to get a better understanding of this pest.
Since early April, with regular visits, last instar larvae (5th instar) of T. viridana in oak forests in Perdanan areas (around the village Ghabr Hossein) were collected and transferred to the laboratory chamber. The larvae were fed on the two oak species. The leaves of these species were collected and transported to the laboratory in a room at a temperature of 25°C and suitable photoperiod conditions. The larvae were fed individually or in a group. In a grouping method, 10 larvae in two replicates and in individually method 40 larvae (one larva per replicate) for each host were considered. Larval weight, amount of consumed food and weight of feces were estimated by using a sensitive digital Carriage scale (0.001 gr). Relative consumption rate (RCR), relative growth rate (RGR), the efficiency of conversion of ingested food (ECI), the efficiency of conversion of digested food (ECD) and approximate digestibility (AD) were also calculated. For statistical analysis t-test and SPSS17 software were used to compare the mean of the data.
Results of t-test (α=5%) indicated that the larval biomass, RGR, ECI, and AD were significantly different among the hosts in both methods of grouping and individually rearing of the larvae. In this study, Q. libani showed the lowest rate of digestibility. The larvae fed on Q. infectoria have the higher rate of AD than Q. libani because of high RCR, RGR, ECD and ECI. Also, the results related to the comparison of two methods (grouping and individually rearing of the larvae), on nutritional indices were significantly different and in both host trees, the rate of RGR, ECI and ECD in grouping method was more than individually rearing method. RCR is the indication of the insect's exploitation speed of food. In the other words, it shows feeding rate regarding insect's weight at the specific point of time depending on the amount of water and other nutrition physicochemical characteristics in insects. The result showed that this index rate in group rearing method on two host species is equal, but in individual rearing method on Q. infectoria, it is more than Q. libani. The possible reasons are more feeding of larvae in individual rearing method due to the lack of competition stress, the more likelihood of the desirability of Q. infectoria compared to Q. libani, the probability of the existence of antixenosis in Q. libani. The similar study investigating individual and group rearing methods in one insect species is not available. This result confirms that T. viridana larvae’s has a tendency toward social life and in the group situation, they eat effectively. In fact, although larvae in individual form feed more because of lack of competition stress, but in the group they make use of that little food in the best way.
In this study, Q. libani had low food quality. As a result, its relative consumption rate, relative growth rate, the efficiency of conversion of ingested food and efficiency of conversion of digested food was less than Q. infectoria. According to the results, Q. infectoria is an appropriate host for this pest. Also, it shows that the larvae were more considering the rate of larval biomass, RCR, RGR, ECI and ECD in grouping method than the single method.

Considering the importance of healthy and inexpensive agricultural production, it is necessary to seek ways for precisely discrimination of weeds in the field to minimize the use of herbicides. In this research the feasibility of weed detection due to the reflected ultrasonic waves from some common weeds including Portulacaceae, Chenopodium album L, Tribulus terrestris L, Amaranthus retroflexus L and Salsola iberica, was investigated.
An electronic circuit with several parts such as a microcontroller, a power supply (5 DC volts), a RS-232 output port, and an ultrasonic wave generator and detector was constructed. It emits a 40 KHz ultrasonic wave and receives the recursive wave which is reflected from the weed canopy. It can be mounted on an adjustable tripod that is aligned along the three main directions (X, Y, and Z) and can also be turned around the X axis. The data acquisition was accomplished in the research field of the College of Agriculture, Ferdowsi University of Mashhad. The experiments were performed by mounting the system at constant height of 4 cm from the crop canopy. To avoid interfering of the recursive wave with the emitted wave, the generator and the detector were placed far apart. For each experiment the temperature and the relative humidity were recorded in a check list. For the Neural Network the so called BDLRF algorithm was used for training the network and started with a relatively constant large step size of learning rate and momentum term . Before destabilizing the network or when the convergence is slowed down, these values are decreased monotonically (22). In this study Double Sequential Classification Method was used for weed discrimination. This classification method can better simulate the human procedure for classification of different objects, from each other. The human being at the first stage, and based on some distinguishable criteria classifies the things into some main groups and then sorts each group to some other distinguishable subgroups and this procedure will continue up to all things to be classified from each other. Therefore, if a feature can separate more class from others, it is selected as optimum feature. But the optimum feature can only separate the limited numbers of groups in each stage. Other groups are separated with other optimum feature in some sequence stages. In this study the Double Sequential Classification Method is employed for the calcification of the weed species.
Results showed that due to different surface and morphological characteristics of the crop canopy of the weed species under study, the pattern and the amplitude of the reflected ultrasonic waves are significantly different. The comparison of means of statistical features extracted from the reflected ultrasonic waves confirmed these differences. A Multi-Layers Perceptron (MLP) neural network, which was trained with a reduction learning rate, was developed and evaluated. The simultaneous separation of the five weed species showed that the error of detection during the training phase of Chenopodium album L was the highest among other species and was 16.67 percent, while the system was able to detect other species completely. However, the detection error for all species in the evaluation phase was more than 50 percent. Hence, a double sequential classification method was used through four sequential stages. In this method 11 neural networks were designed and finally four neural networks were selected. Results showed that Tribulus terrestris L was identified and separated completely from other species in the first stage, subsequently, Amaranthus retroflexus L in the second stage and Portulacaceae in the third stage, respectively. The remaining two species including, Chenopodium album L and Salsola iberica were successfully discriminated in the fourth stage.
Results showed that this method can be a promising technique for real time identification and discrimination of different weed species in the field. It can be replaced with the conventional, laborious and expensive methods to reduce the final costs of agricultural production. Besides, it can reduce the consumption of herbicides in the fields. However, some efforts are required to implement the technique on the existing herbicide applicators or as a new machine for precision agriculture.

The occurrence and activity of mites in stored foods cause a variety of qualitative and quantitative damages, including reduction in the germinating power of the grains, bronchial asthma and allergic skin reactions. Among the mites associated with stored products, species of order Sarcoptiformes especially some species of Astigmatina including the genera Acarus, Suidasia and Tyrophagousare have economic importance and a worldwide distribution. The members of family Histiosomatidae also are cosmopolitan and often found in moist organic materials. In Iran, there have been a considerable number of studies on astigmatic mites. Kamali et al. have provided a list of stored product mites. fthe work of Bahrami et al. on species diversity of Acaroidea in Tehran, Ardeshir on population of stored grains in different seasons in Iran;Sayedi et al. on mites associated with stored rice in Guilan can be mentioned. Reviewing the literature revealed that in the only study that has been carried out in the study area, only 6 species of storage mites have previously been reported from Khorasan-e- 䖬� province). Literature review showed that although Oribatida consists of 9000 known species in the world, the number of recorded species from Iran is not considerable. Iranian studies on oribatid mites have limited to a few specific areas and recent years. By considering the limitation of knowledge on species diversity of stored product mites in the study area, the present study aimed to improve our knowledge on the mite associated with the stored food products in Mashhad city and the vicinity.
Material and During years 2011−2012 a variety of food storages in Mashhad region were visited and sampled. These stored food products included wheat, barley, wheat bran, rice, flour mill, factories of pasta and bakeries, stockpiles of livestock’s food, and potato and onion storages in different parts of Mashhad. Mite specimens were extracted from infested materials by using Berlese-Tullgreen funnel. The specimens were cleared using either pure Lactic acid or Nesbitt’s mixture and then mounted in Hoyer's medium as microscopic slides. Using relevant references, mites were identified and then sent to the third and fourth authors for confirmation. Type specimens are held in the Acarological laboratory, Department of Plant Protection, Ferdowsi University of Mashhad, Iran.
Among the identified species, Histiostoma sapromyzarum (Dufour) has reported from Iran for the first time. New records for the study area are indicated by an asterisk. The list of identifying species is as below: I- Astigmatina- 1- Family Acaridae: Aleuroglyphus ovatus (Troupeau)*, Caloglyphus berlesie Michael, Acarus siro Linnaeus, Rhizoglyphus echinopus (Fumouze & Robin)*, R. robini Clapared, Tyrophagus longior Gervais*, T.putrescentiae (Schrank), 2- Family Chortoglyphidae: Chortoglyphus arcuatus (Troupeau)*, 3- Family Glycyphagidae: Lepidoglyphus destructor (Schrank)*, 4- Histiostomatidae: Histiostoma feroniarum (Dufour)*, H. sapromyzarum (Dufour), 5- Suidasiidae: Suidasia nesbitti Hughes*.
II- Oribatida- 1- Family Aphelacaridae: Aphelacarus acarinus (Berlese)*, 2- Family Cosmochthoniidae: Cosmochthonius sp.*, 3- Family Ctenacaridae: Ctenacarus araneola (Grandjean)*, 4- Family Galumnidae: Galumnadis cifera Balogh*, Galumnakarajica Mahunka & Akrami*, 5- Family Haplozetidae: Haplozetes sp.*, 6- Family Mesoplophoridae: Mesoplophora sp.*, 7- Family Oppiidae: Lasiobelba sp.*, 8- Family Oribatulidae: Oribatula (Oribatula) sp.*, O. (Zygoribatula) sp.*, O.(Zygoribatula) connexa Berlese*, O. (Zygoribatula) exarata Berlese*, 9- Family Scheloribatidae: Scheloribates fimbriatus Thor*.
In this study, 12 species of Astigmatina belonging to 9 genera of 5 families and 13 species of oribatid mites were collected and identified. Among them, one species, namely Histiosomas apromyzarum (Dufour) is a new record for the fauna of Iran. Twenty species were reported for the first time from Khorasan-e- Razavi province. Certainly, this list is far from reality. As many parts of the province have not been explored faunistically, with further research in different parts of the province, the recorded mite species would be considerably increased. Not only more faunistic studies are required further research on the biology and ecology of the recorded species is suggested. Also, it should be noted that on the basis of our records, the species T. putrescentiae was found to be the most common mite in the stored food products in Mashhad city and its vicinity.

Lysiphlebus fabarum Marshall (Hymenoptera: Braconidae: Aphidiinae) is a common aphidiine parasitoid in central Europe, where it attacks more than 70 species of aphids. Although both unisexual (thelytokous) and bisexual (arrhenotokous) strains of L. fabarum have been reported in Iran, the former appear to be more widely distributed. Aphid control in Iran relies heavily on pesticides in both field and greenhouse settings, whereas any availability of new biological control agents such as L. fabarum would likely aid in reducing pesticide use. One of the most important aspects of implementing a parasitoid as a biological control agent is to determine the best density of parasitoid in the host access, in mass rearing. Parasitoid wasps display a wide array of strategies to dispose of host resources. Superparasitism is parasitism of a host by parasitoids of the same species. In solitary parasitoids, superparasitism almost occurs when hosts are limited or parasitoid density in a patch is high. Acceptance or rejection of a host usually depends on a female parasitoid’s ability to distinguish parasitized and unparasitized hosts. Previously, superparasitism was thought to be a maladaptive strategy, wasteful of both eggs and time, while it is now recognized as adaptive in a number of situations, e.g. under conditions of low host availability, as a mechanism for overwhelming the immune response of hosts.
In the present study, stock colonies of the unisexual and bisexual strains of the parasitoid were established from materials collected from Zanjan province and Khuzestan province fields, respectively. Both populations of the parasitoid were collected from parasitized black bean aphids feeding on the broad bean, Vicia fabae L. A stock colony of black bean aphids was established with material collected from bean fields in Khuzestan province. The synchronous cohorts of both strains of L. fabarum were produced at 21±1 ºC, 50–60% r.h., and L14:D10 photoperiod, and then introduced (one day old) separately into 40 2nd instar nymphs in different densities (1, 5, 10, 15 and 30). The females were removed after 24 hours and parasitized aphids were dissected three days after parasitism to determine the number of wasp larvae in each host. As well as, in another experiment the super parasitized aphids were dissected in three consecutive days (3.5, 4.5 and 5.5) to determine the process of competitors’ elimination.
According to results, in both strains, wasp densities affected on parasitism rates. In the bisexual strain, females parasitized more aphids in 20 and 30 densities treatments than one density treatment, while this rate did not differ significantly between 1, 5, 10 and 15 densities treatments. In the unisexual strain, single females significantly parasitized fewer hosts than other treatments, but there was no difference between other densities treatments. When in each density, percentage parasitism was compared between two strains, in the density of one female, bisexual females parasitized significantly higher than unisexual ones, in contrast to the density of 30, which significantly more larvae were counted in hosts of the unisexual strain than bisexual ones. In other densities, there was no significant difference between two strains. In the second experiment, which the rate of superparasitism was compared in different densities, in bisexual strain, the rate of superparasitism significantly was lower in the density of one female than other treatments. The number of larvae did not differ significantly between other densities treatments. In the unisexual strain, the rate of superparasitism significantly was lower in the density of one female than other treatments. The most rate of superparasitism was observed in 20 and 30 density treatments. When in each density, the rate of superparasitism was compared between both strains, in 1, 5 and 10 densities, bisexual females superparasitism significantly higher than unisexual ones, in contrast to the density of 30 females, which significantly more larvae were counted in hosts of the unisexual strain than the hosts of bisexual ones. In association with the process of competitors’ elimination, bisexual strain larvae eliminated rival larvae over time (in three consecutive days, including days 3.5, 4.5 and 5.5), as the numbers of larvae were decreased in densities of 5, 20 and 30 females. While in unisexual strain, elimination of rival larvae was not observed over time.
Wasp densities affected by parasitism rates and the rate of superparasitism in both strains. In mass rearing, the best density of wasps can be defined as the density that most available hosts are parasitized with a minimum of superparasitism, because superparasitism can depredate the time and eggs of female foragers. The results showed that densities of one and 5 females (for 40 individuals of 2nd instar nymphs) can be suggested as the proper densities of females in bisexual and unisexual strains, respectively. The results of this study can be useful in mass rearing and release of both L. fabarum strains.

South Khorasan province is the main area for production of Berberis vulgaris (family), Crocus sativus (family) and Ziziphus zizyphus (family). Nematodes belong to superfamily Aphelenchoidea are easy to be identified by the size of the body, stylet without knobs, large median bulb, long overlapping on the intestine and placement of the vulva in the posterior part of body. In this survey, we identified nematodes belong the superfamily Aphelenchoidea in these three important plant. Four species of genus Aphelenchoides and one species of each genus Aphelenchus, Aprutides and Ektaphelenchoides were identified. Among them, two species Aphelenchoides lichenicola and A. varicaudatus are new records for Iranian nematofauna.
Soil sampling: 360 soil samples were collected from the rhizosphere of three important yields (B. vulgaris, C. sativus and Z. zizyphus) in south Khorasan province. Samples were taken from the depth of 5-40 cm different points with a soil auger, put in polyethylene bags with necessary labeling and brought to the laboratory, kept in the refrigerator at 4 °C, until processed.
Processing of samples and Preparation of slides: Nematodes were extracted from soil samples using the Jenkins (1964) and Whitehead (1965) method. They were then handpicked, killed and fixed according to De Grisse (1969) method. Genera and species were identified based on morphological and morphometerical characters by valid keys and references.
Measurements and drawings: Measurements were done with an ocular micrometer of “Olympus” model microscope
This survey resulted in 10 species belong to superfamily Aphelenchoidea which two species of them are new for Iranian nematode fauna. Aphelenchoides lichenicola and A. varicaudatus are new records from South Khorasan province. lichenicola characterized by: Body straight to slightly arcuate ventrally. Lip region rounded, offset by constriction. Transverse striae of cuticle faint, about 0.8 µm apart near mid-body. Lateral fields with four incisures, inner ones faint. Stylet about 9.5-10.5 µm, conus 42-44% of stylet length. Median oesophageal bulb oval to somewhat rectangular with rounded corners, offset from procorpus. Oesophageal glands dorsal to intestine, extending to 46-58µm. Nerve ring just behind isthmus. Excretory pore opposite or close to posterior margins of nerve ring. Vulva a transverse slit, raised. Vagina usually directed anteriorly. Ovary outstretched, with a single row of oocytes. Post-vulval uterine sac half or more of vulva-anus distance. Vulval-anus distance 127-211 µm. Rectum about 1.5 times anal body-width long. Tail elongate-conoid with terminus bearing a ventral somewhat stellate projection whose axial ray is more prominent than the others. Varicaudatus characterized by: The elongate body is slightly curved ventrally when killed by heat. Lip region distinctly offset with rounded sides and flattened anteriorly. Cuticular annulations are fine. Lateral fields with four incisures. Stylet 12.5-14 µm long with small basal thickenings. Median oesophageal bulb roundly rectangular just slightly longer than wide. Excretory pore placed in 63-75.5µm from the anterior end. Nerve ring behind the Excretory pore. Vagina slopes forward into the body. Reproductive tract with a single anterior ovary which is often reflexed, sometimes almost back to the beginning of the ovary. Post vulval sac prominent, extending one third to half the vulva to anus distance. Tail terminus variable, sometimes bifid, often with the dorsal process decreased to give an angular indented region adjacent to the longer ventral mucro, occasionally the tail terminus tapers gradually to a terminal mucro.

Mass production of natural enemies has been considered a necessity for biological control programs. Most beneficial insects have a relatively short shelf-life, so suppliers do not have a sufficient number of biocontrol agents. The development of storage techniques for biocontrol agents provides flexibility and efficiency in mass production. Cold storage by prolonging insect development times provides a steady and sufficient supply of insects and synchronizes a desired developmental stage of biocontrol agents with times of pest outbreaks; so it reduces the cost of biocontrol programs by enlarging the production period over several months. Cold storage is usually associated with major fitness costs. Even if the insects remain alive after cold storage, a reduction of fitness may be observed, so the production of high quality natural enemies must be ensured. Developing effective methods is necessary in mass-producing. It has been reported that using fluctuating thermal regimes (FTR) (i.e. cold exposure interrupted by periodic short pulses of high temperature) versus constant thermal regimes (CTR) can progress the quality of biological control agents and significantly reduce rates of mortality. In this study, the impact of fluctuating thermal regimes versus constant low temperatures on the emergence rate, sex ratio, post-storage development time, adult size, egg load and egg size of the parasitoid wasp, Lysiphlebus fabarum (Marshall) was studied. The test was examined in three cold storage periods (1, 2, or 3 weeks). Lysiphlebus fabarum is an aphidiine parasitoid which attacks more than 70 species of aphids. Although both sexual (arrhenotokous) and asexual (thelytokous) populations of L. fabarum have been reported in Iran, the former population has been studied in this research. A stock colony of black bean aphid, Aphis fabae Scopoli (Hemi., Aphididae) was established from material collected in bean fields in Khuzestan province, Iran, in spring 2012. A sexual population of the parasitoid wasp, L. fabarum was collected from black bean aphids feeding on broad bean, Vicia fabae L. The synchronous cohort of L. fabarum was produced on the 2nd instar of aphid (at 21±1 ºC, 50–60% r.h., and L14:D10 photoperiod), then 30 two-day-old mated females were introduced into aphid colony consisting of 200 2nd instar individuals. The females were removed after 10 hours and parasitized aphids were reared for 54 hours (±6) to complete development to the late-instar larvae. These parasitized aphids, which were harboring late-instar larvae of wasp, were subjected to 6 ºC (as constant temperature regime) or were stored at 6 ºC with 2 hours daily exposure to 21±1 ºC (as the fluctuating temperature regime). The experiment was replicated with three cold storage periods (1, 2, or 3 weeks) with a control (direct development at 21±1 ºC). After completion of each storage temperature treatment, insects were transferred back to 21 °C until the emergence of adult wasps. Accordingly, the survival rate and the sex ratio (% females) were determined. The emerged wasps were then exposed to alcohol vapor for 2 minutes. The hind tibia of both gender was measured. Subsequently, the ovaries of each female were dissected to determine the egg load and egg size. According to results in CTR, survival of larvae was significantly reduced after one week of storage, and there was a gradual decrease in the second week, but there was no difference between survival of wasps that were stored after one and two weeks of storage. In FTR, emergence rate was decreased after one and two weeks of storage in comparison to the control, and the least survival was observed in the third week. When the survival was compared between different thermal regimes, FTR increased the survival in the first and second weeks, whereas after three weeks of storage there was no significant difference between two thermal regimes. In CTR, the least sex ratio of wasps was observed in those stored for two weeks, although there was no significant variation in sex ratios for control, one week and three week of storage. In FTR, cold storage did not affect on sex ratios of treatments. When the sex ratio was compared between different thermal regimes, for two and three weeks of storage, it was significantly higher in FTR and CTR, respectively. In females and males, larval storage increased development time relative to controls, in CTR. While in FTR, developmental time was decreased after two and three weeks of storage, in FTR. When developmental time was compared between two thermal regimes, post-storage development was slower in CTR after two and three weeks of storage in comparison to FTR, in both genders. In both thermal regimes, cold storage of wasps as larvae resulted in smaller male and female wasps relative to controls over all the storage periods. Egg load and egg size at emergence were progressively diminished as a function of the storage period, regardless of the thermal regimes. Egg load of wasps stored in CTR compared with FTR, was significantly higher for three weeks of storage. For all storage periods, egg size was significantly higher in FTR than CTR. Collectively, our results confirmed the beneficial effect of FTR relative to CTR, when larvae of L. fabarum were stored for two weeks at 6 °C. Although FTR reduced the development time, which could be a problem during delivery for mass release of natural enemies in the field, but the emergence rate, the sex ratio, the body size and the egg size were significantly higher in FTR than those in CTR. For three weeks of storage, FTR was more stressful than the CTR, as the wasps that were stored in CTR had significantly more post-storage development, sex ratio, body size and egg load than the fluctuating ones.

Macrosiphum rosae is one of the most important members of the Aphididae (Hemiptera) which feeds on plant juices, colonizes underside of leaves,stems and buds. This pest is a polyphagous insect vastly found in Europe, Asia and America. Coccinella septempunctata (L.) (Col: Coccinellidae) is the successful biological control agent against aphids in under the greenhouse and field conditions. In the present study, the effects of constant temperature on the demography of C. septempunctata which feds on M. rosae was investigated.
The predators were originally collected from the field (Sorke hesar park in Tehran) in march 2012 and reared on aphids in the germinator at 25 ± 1°C, 60 % ± 5 % relative humidity and photoperiod of 16L: 8D/h to lay their eggs and then females were removed after oviposition. These eggs were used for further examination. The life table parameters of C. septempunctata were measured under laboratory conditions at constant temperatures (14, 25 and 31) °C, relative humidity 60 ± 5 % and photoperiod of 16 hours light and 8 hours darkness with 100 repetitions. The different stages of the ladybeetles were fed with 20-100 aphids from different stages of M. rosae. The developmental time of immature stages of beetles were recorded every day. When adult females emerged, an adult male was introduced into the cells to fertilize of them and after that number of offspring produced was counted daily. SAS software v 9.1 was used for data analysis. One-way ANOVA was run to determine the significant differences between demographic parameter of C. septempunctata at two constant temperatures. If there were significant differences, the Tukey's multiple tests were used for multiple comparisons (P There was no ovipostion at 14 °C. The intrinsic rate of increase (rm) of C. septempunctata at 25 and 31 ˚C were 0.170 and 0.186, the net reproductive rate (R0) were 187.55 and 76.74,the finit rate of increase were 1/18 and 1/20 and the mean generation time (T) of ladybird were 30.78 and 23.32 days, respectively. The lifetime oviposition and mean ovipositon rate were highest at 25 °C and lowest at 14 °C. The average total fecundities of C. septempunctata at 25 and 31 °C were 307.46 and 125.8 (eggs / femal). The average of adultʼs survival rate at three studied temperatures was analyzed by Weibull model. The maximum of life expectancy rate is at 14 °C and the minimum rate is related to 31 °C. Considering the high value of rm obtained from lifetime table of C. septempunctata in 25°C and 31°C, it can be concluded that the reproduction rate of this variety is at a high level. Among the three studied temperatures, in 31°C, the beetle had the highest intrinsic rate of natural increase and the maximum rate of fertility calculated in 25°C.
Considering that the rose bush is on the main vegetation in the urban area and M. rasae is rose̕ s main pest, high amount of pesticides are used for fighting this pest in the parks and in planted areas each year. In addition to removing natural enemies, these poisons cause environmental pollution and pose hazardes for the citizens who are directly exposed to this pollution. The higher values of rm in comparison to values calculated in studies of the other researchers with similar temperatures, shows the appropriate feeding value of this predator for C. septempunctata. thus, application of biological control, supporting natural enemies of pests and breeding and releasing of fruit full insects like C. septempunctata, are the alternative ways to using poisons and pesticides.

Cleome viscose Linn. with a common name as “Asian spiderflower”, belongs to the Capparidacea family. It is an annual, sticky herb found as a common weed all over the tropical regions of the world. It is a very competitive weed of annual crops. This plant is currently introduced as an invasive plant in soybean fields of Golestan province. There is no management recommendation to control Asian spider flower. Thus large quantities of soybean destroyed by this weed every year. Germination and emergence are the two most important stages in the life cycle of plants. Environmental factors such as temperature, light, pH, planting depth and soil moisture are known to affect seed germination and emergence of weeds. An understanding of the germination biology of Asian spider flower would facilitate the development of better management strategies for this weed. Therefore, the purposes of this research were to study the effects of temperature and water potential on Asian spider flower seed germination.
Material and To evaluate the effect of temperature and water potential on seed germination and determination of seed germination cardinal temperatures of Asian spider flower, an experiment was conducted as Factorial Experiment in Completely Randomized Design with 4 replications in Agricultural Research and Natural Resources Center of Golestan Province during 2013. Treatments were included temperatures with seven levels (15, 20, 25, 30, 35, 38 and 400C) and water potentials with six levels (0, -2, -4, -6, -8 and -10 bar). Germination was monitored daily until germination discontinued and the number of the germinated seeds was recorded. Seeds were observed twice daily and considered germinated when the radical was approximately >2mm long. To quantify the response of germination rate to temperature and to determine the cardinal temperatures for germination original beta, and modified beta, segmented and dent models were used. Water potential data showed a sigmoid trend and a three-parameter logistic model was fitted to data (Equation 1).
Y=Gmax/ [1(X/X50)b] where, G is the total germination (%) at concentration x, Gmax is the maximum germination (%), x50 is the osmotic potential required for 50% inhibition of the maximum germination and Grate indicates the slope of the curve in x50. Statistical Analysis System (SAS) was used for analyzing the data.
Results showed temperature, water potential and interaction between them significantly affected germination percentage and germination rate, the time required to reach 5% (D05), 10% (D10), 50% (D50), 90%(D90) and 95% (D95) seed germination of Asian spiderflower. The results showed that by increasing the temperature to 30 °c, seed percentage and germination rate increased and then decreased. Water potential reductions declined seed germination percentage and germination rate. Comparing different models to determine seed germination cardinal temperatures, indicated that the segmented model described germination rate changes to temperature better that the others. Based on the output of this model, germination base, optimum and ceiling temperatures of the plant were 15.46, 33.21 and 39.64 0C, respectively. The result revealed that increasing the PEG concentration, increased the base temperature and decreased optimum and ceiling temperatures. The Logistic model fitted with germination percentage of seeds in different water potentials to different temperatures. Parameters of the model showed the maximum seed germination percentage occurred in the 25 to 35 0C. Highest and lowest X50 parameter (potential required for 50% inhibition of the maximum germination) observed at 30 and 38 0C, respectively. The results showed that the germination ability of Asian spiderflower occurred at less potentials water in the optimum temperature range.
The results showed that high temperatures were required for seed germination of Asian spider flower. Although water potential has reduced the germination of the weed, we can say this is somewhat drought tolerant plants. Based on the segmented model, cardinal temperature for germination, including base, optimum and ceiling temperatures of the plant were 15.46, 33.21 and 39.64 0C, respectively. Check the seed germination, percentage changes in water potentials at different temperatures showed that the desired temperature the plant's ability to withstand in adverse environmental condition increases. Results of this experiment can be concluded that environmental factors affected the germination of Asian spider flower, and this information could help to predict the spread of Asian spider flower in new areas.

The harmful plant mites not only feed on crops, but also have irreversible damage to humans. The synthetic pesticides can be replaced with natural products for pest control. The agricultural products, health and hygienic of humans can be treated with harmful caused by the mites (Wooley, 1988). The citrus red mite (CRM) Panonychus citri (McGregor) (Acarina: Tetranychidae) is one of the most important herbivorous pests in citrus growth area. For the first time, this pest was reported from Mazandaran province in 1940. The nymph and adult of these pests create identified small, silver and gray spot on leaves and fruits. As a result of feeding, contamination can cause necrosis of leaves, loses of young leaves and reduce the plant freshness. The synthetic of pesticides has been used for controlling of this pest for a long time. The application of non-normative methods for control of the mites can cause pest outbreaks and destroy the natural enemies of the pest. This pest has been resistant to a wide range of pesticides such as; Dicofol, Hexythiazox, Abamectin and Pyrothroids in field conditions. In recent decays, the organic agriculture has been grown dramatically. Lio (2003) has reported that at least 30 countries produce organic citrus fruit. So, for growing organic citrus in Iran, it also suggested to use the low impact pesticides to the environment and the human health. In this research, the comparison toxicity of three botanical pesticides Tondexir (red pepper extract), Sirinol (garlic extract), Palizin (eucalyptus extract) with two common chemical pesticides (Hexythiazox and Fenpyroximate) and common mineral oil has been investigated against adult and protonymph of citrus red mite P.citri.
The citrus red mite (CRM) has been collected from infected trees from citrus orchard and brought into the lab; after that, the adult and nymphs were separated. The citrus red mite has been reared on citrus leaves in growth chambers with constant condition (25 ±2oC, 16:8 L/D and 60% RH conditions). The primary test has been done to identify the maximum and minimum concentration. For bioassay experiments, the citrus leaves were washed and cleaned with distilled water and prepared in 20 mm diameter leaf disc. The bioassay was carried out using leaf dip methods with different concentration of the following pesticides after primary experiment: Mineral oils (2000, 2828, 4000, 5657 and 8000 ppm), Tondexir (1000, 1368, 1871, 2559 and 3500 ppm), Sirinol (750, 1102, 1620, 2381 and 3500 ppm), Palizin (2000, 2378, 2828, 3364 and 4000 ppm), Hexythiazox (250, 370, 548, 811 and 1200 ppm) and Fenpyroximate (500, 679, 922, 1252 and 1700 ppm). The mortality was recorded at 24, 48 and 72 h after-treatments. All experiments were conducted with three replications. The statistical analyses were performed by SPSS version16.0 software.
The Probit analysis was shown that the LC50 value of the mineral oils on protunymph and adult of citrus red mite were 1743.6 and 1898 ppm, the LC50 value of the Tondexir were1305.9 and 1549 ppm, the LC50 value of the Sirinol were 666.1 and 693.9 ppm, the LC50 value of the Palizin were 2206 and 1969.2 ppm and the LC50 value of the Hexythiazox were 223.6 and 227.3 ppm at 72 h post-treatments, respectively consequently and the probit analysis was revealed that the LC50 value of the Fenpyroximate on protonymph and adult of citrus red mite were 480 and 439.3 ppm at 72 h post-treatments, respectively. Consistent with our result, the acaricide, Hexythiazox had higher toxicity on adult and protonymph of CRM in comparison to the other pesticides. Among three botanical pesticides, Sirinol has the highest toxicity. Due to the low risk of three botanical pesticides, they should be considered in IPM program.
The data analysis of this research was shown that among different compounds, the highest and lowest toxicity on adult and protonymph were obtained with Hexythiazox and Plazin consequently respectively. By comparison the LC50 values, the protonymph was more susceptible than adult. With regards of being low risk and natural products of the botanical pesticides and mineral oils for humans, it is better to use these products to control red mites.

Elimination or reduction of tillage in conservation agricultural systems has led to wide variations in germination, emergence, and growth of weeds and has caused variations in the density and diversity of weeds under such systems. Maintaining crop residues on the soil surface has many potential benefits in agricultural production systems; such as reducing water and wind erosions, increasing the soil organic matter content, improving the soil structure and sowing conditions, as well as a better weed management through allelopathy or physical interference provided by the crop residues. Crop residue and tillage system cause potential changes in the soil temperature and water content, which influence soil density, structure, moisture, as well as soil temperature and nutrients. Crop residues act as mulches and can effect on weed seed germination and seedling emergence. Therefore, the objectives of current study were to evaluate the effects of no-tillage systems on: (i) narrow- and broadleaved weed densities, (ii) crop yield and (iii) water productivity (WP).
A two-year field study based on a split plot experiment in a randomized complete block design with four replications was carried out in Zahedshahr, Fars province, Iran (latitude 28˚44΄N, longitude 53˚48΄E, 1180 m altitude) during 2009-10 and 2010-11 growing seasons. The planting practices including moldboard plow, disk and leveler were practiced in conventional tillage plots and crop planting was performed using a drill seeder (made by Kohorasan Co., Iran). The no-tillage plots were directly planted without any soil disturbance and removing wheat residues of the last year using a direct planter machine (model Berteni, Argentina). Furrow irrigation was used at both systems and a water counter (model WD, size DN100) was applied to measure the amount of used water based on m3 ha-1. 1 x 1 m quadrates that were installed at the center of each plot. Crop density, narrow and broadleaved weed densities were recorded at 30 days after the beginning of crop emergence. Wheat grain yield was calculated at harvest time. Comparison of the means was conducted based on protected LSD (PLSD) at 0.05 significant levels.
Tillage systems indicated a significant effect on wheat density. The average number of crop seedlings in no-tillage plots was 27 % higher than in the conventional tillage plots. Maintaining crop residues on the soil surface provided a better site for crop germination and emergence. The response to tillage system and year effects varied depending on the weed species. Results showed that the effect of tillage systems, year and their interactions were significant on the density of Lolium temulentum and Sinapis arvensis, while in the case of Phalaris minor and Hordeum spontaneum just the tillage regimen significantly influenced the weed density. L. temulentum and S. arvensis plants showed an almost similar pattern in their response to tillage systems and year effects. The density of these two species significantly decreased under no-tillage system compared with conventional tillage operations. Moreover, their densities in conventional tillage plots were significantly greater in the second year of the experiment than the first year. The lower seedling emergence of P. minor and H. spontaneum under no-tillage circumstances is not surprising, as crop residues prevent from reaching the light on the soil surface and the light requirement for germination of these species has been reported in several studies. The water productivity of the no-tillage plots was greater than of the conventional ones at both two years of the experiment. Preservation of wheat residues on the soil surface decreases soil temperature via shading and causes reduces the evaporation rate from the soil surface. Although there was no significant difference between wheat yields in the two growing seasons under conventional tillage environment, wheat yield in no-tillage plots was significantly greater in the second year of the experiment than that of the first year. Low weed densities and high WP were observed under no-tillage conditions, although the crop yield was greater in conventional tillage plots. It seems that this yield reduction in no-tillage plots is mostly due to greater C/N ratio in no-tillage plots than conventional tillage ones.
According to the results, although wheat yield decreased under no-till system, increased water productivity, weed control and reduced cultivation costs might justify the adoption of no-tillage cropping systems by local farmers. Other principles of conservation agriculture including suitable crop rotation systems and planting cover crops must be incorporated into the no-till cropping system. As the occurrence of autumn rainfall is usual in these dry regions, employment of the stale seedbed might be another promising technique which controls early season weed species in no-tillage systems.

Land use change, deforestation, grazing, intentional and unintentional fire and invasive pests and diseases are all the major cause of damage to the Zagros forest ecosystem. The green oak leaf roller (Tortrix viridana L.) is one of the important pests of Zagros forests. Larvae of the pest significantly damage the oak forests with feeding on leaves and buds of different species of oaks each year. Larvae enter 2'd instar after eating the internal contents of oak buds, then the third and 4th instars larvae consume whole buds and even oak leaves. After development to the 5th larval instar, they roll the leaves and enter the pupal stage. The attacked trees revitalize by creating new leaves from early May onwards. New leaves, pale green and are smaller than normal leaves. Continuation of the pest activity on Quercus species causes gradual weakness the trees and readiness to accept a variety of secondary pests and diseases in later years. Based on the status of Zagros forests and their importance in the conservation of soil and water sources, the nutritional indices of Tortrix viridana larvae of two species of Oak i.e. Quercus infectoria and Q. libani were determined to get a better understanding of this pest.
Since early April, with regular visits, last instar larvae (5th instar) of T. viridana in oak forests in Perdanan areas (around the village Ghabr Hossein) were collected and transferred to the laboratory chamber. The larvae were fed on the two oak species. The leaves of these species were collected and transported to the laboratory in a room at a temperature of 25°C and suitable photoperiod conditions. The larvae were fed individually or in a group. In a grouping method, 10 larvae in two replicates and in individually method 40 larvae (one larva per replicate) for each host were considered. Larval weight, amount of consumed food and weight of feces were estimated by using a sensitive digital Carriage scale (0.001 gr). Relative consumption rate (RCR), relative growth rate (RGR), the efficiency of conversion of ingested food (ECI), the efficiency of conversion of digested food (ECD) and approximate digestibility (AD) were also calculated. For statistical analysis t-test and SPSS17 software were used to compare the mean of the data.
Results of t-test (α=5%) indicated that the larval biomass, RGR, ECI, and AD were significantly different among the hosts in both methods of grouping and individually rearing of the larvae. In this study, Q. libani showed the lowest rate of digestibility. The larvae fed on Q. infectoria have the higher rate of AD than Q. libani because of high RCR, RGR, ECD and ECI. Also, the results related to the comparison of two methods (grouping and individually rearing of the larvae), on nutritional indices were significantly different and in both host trees, the rate of RGR, ECI and ECD in grouping method was more than individually rearing method. RCR is the indication of the insect's exploitation speed of food. In the other words, it shows feeding rate regarding insect's weight at the specific point of time depending on the amount of water and other nutrition physicochemical characteristics in insects. The result showed that this index rate in group rearing method on two host species is equal, but in individual rearing method on Q. infectoria, it is more than Q. libani. The possible reasons are more feeding of larvae in individual rearing method due to the lack of competition stress, the more likelihood of the desirability of Q. infectoria compared to Q. libani, the probability of the existence of antixenosis in Q. libani. The similar study investigating individual and group rearing methods in one insect species is not available. This result confirms that T. viridana larvae’s has a tendency toward social life and in the group situation, they eat effectively. In fact, although larvae in individual form feed more because of lack of competition stress, but in the group they make use of that little food in the best way.
In this study, Q. libani had low food quality. As a result, its relative consumption rate, relative growth rate, the efficiency of conversion of ingested food and efficiency of conversion of digested food was less than Q. infectoria. According to the results, Q. infectoria is an appropriate host for this pest. Also, it shows that the larvae were more considering the rate of larval biomass, RCR, RGR, ECI and ECD in grouping method than the single method.

Seed germination is an important stage in the life history of plant affecting seedling development, survival, and population dynamics. Germination begins with seed, water uptake and terminates with the elongation of the embryonic axis from the seed coat. Germination and seedling emergence are the most important phonological development stages in pigweed and have a vital role in its establishment. Accordingly, predicting the phenological stages would be resulted in improvement of crop management as the number and time of pigweed emergence could be quantified. Sigmoidal curves, also known as growth models, have wide application in agricultural research and can be evaluated by means of nonlinear models, which operates through data modelling by a nonlinear combination of parameters depending on one or more independent variables. This study was conducted to evaluate various regression models to describe the response of germination rate to temperature range in two pigweed ecotypes (Alborz and Fars).
A glasshouse experiment was carried out as a completely randomized design with four replicates. The seeds were sterilized by soaking in a 3% solution of hypochlorite sodium for 30 seconds. After the treatment, the seeds were washed several times with distilled water. 25 seeds were put in each Petri dish (with 9 cm diameter). The petri dish is monitored on a daily basis and afterwards germinated seeds (according to exit of radicles to the size of 2 mm) were measured and recorded daily in each Petri dish. Six regression models were applied to quantify the germination patterns of two pigweed ecotypes (Alborz and Fars) under a range of temperature between 5 to 35 °C. For both regions, during spring and summer, the range of temperatures was selected in order to simulate the temperature changes. The models were included Weibull, Lognormal, Logistic, Gompertz, Sigmoidal and Chapman. Some criteria were used to describe the goodness of fits of the models, including coefficient of determination (R2), root mean square of error (RMSE) and Akaike index (AIC). Moreover, a simple program called Germin was used to calculate D10, D50 and D90 (the time interval to maximum 10, 50 and 90% of germination, respectively).
Results showed that Weibull four-parameter and logistic models were the best for describing the germination rate in Alborz and Fars ecotypes, respectively compared to the other models. The difference between ecotypes could be attributed to their base temperatures and thermal time requirements at each developmental stage. Therefore, it can be concluded weed germination during different seasons is not a random phenomenon. However, the germination and emergence of a clear pattern over time follows the pattern of different environmental conditions is subject to change. Results also indicated that the time to D90 was only 4 and 5 days in Alborz and Fars ecotypes, respectively meaning that with increasing temperature during early spring, this weed would germinate much sooner than spring crops and consequently resulted in crop damage. The results showed that the in Alborz population, with increases temperature from 10 to 30 °C, germination percentage linearly increased and with increasing temperature to the desired temperature, it decreased. However, germination in Fars ecotype showed that, in temperatures 10, 15 and 20 °C respectively, the germination was 36, 56 and 84 percent, while, with an increase in temperature from 25 to 35 °C, this component was always a constant process. Germination rate increased with increasing temperature from 10 to 35 °C which was higher in Alborz ecotype compared to Fars. At lower temperatures, the main reason for less germination rate could be decrement of water imbibition and enzyme activity in biochemical processes of germination.
Increasing public awareness and concern about the impacts of herbicides on the environment, development of herbicide-resistant weeds, and the high economic cost of herbicides have increased the need to reduce the amount of herbicides used in agriculture. Prediction of weed emergence timing would help reduce herbicide use through the optimization of the timing of weed control. It was concluded that Weibull four-parameter and logistic models could be used as decision making tools in Alborz and Fars, respectively, to predict seed emergence of pigweed which in turn resulted in efficient management as well as reduction of herbicides usage. Future research should be addressed to determine a wider validation of the models, which could be valuable tools for farmers and practitioners for adequate timing of control in pigweed weed.

Herbicides are the most widely used of chemical pesticides for agricultural production and landscape management. The environmental risk of herbicides should be evaluated near sites of application, even though basic ecotoxicological tests have been conducted before they can be registered for marketing. For example, triazine herbicides, which are photosynthetic PSII herbicide that considered only slightly or moderately toxic to many susceptible plants, soil microorganisms, mammals and humans, however, concerns have arisen because this herbicide are members of a class claimed to be carcinogenic, or may affect the development as reproductive toxins. For this reason, most reliable evidence is needed to test these claims and investigate their ecological effects. Prometryn is a herbicide belongs to triazine family that may leave residual activity in the soil for extended periods, causing injury and yield reduction of susceptible soil microorganisms and crops in rotation. Compared with other methods, the rapidity of response, sensitivity, high level of precision, simple process and easy operation are the advantages of bioassay methods for the routine monitoring of biologically available photosynthesis-inhibiting herbicides present in agricultural soils.
A pot experiment was conducted under greenhouse conditions in order to study the sensitivity of 4 different crops to prometryn soil residue at the College of Agricultural Sciences, Ilam University, Ilam, Iran in 2014. Experimental type was completely randomized design in a factorial arrangement with three replications. Treatments included 4 different crops (lettuce, barley, rapeseed and beet) and prometryn simulated concentrations residues in soil (0.0033, 0.0166, 0.033, 0.066, 0.1 and 0.166 mg. kg-1soil). 15 cm diameter pots were filled with a modified soil and 10 of seeds of crops were planted in 5 regular positions. The plants were thinned to five plants per pot after germination. The pots were kept for 30 days under controlled conditions. Shoot and root biomass production was measured 30 days after emergence. At harvest, growth parameters including the dry weight of shoots and roots were determined. The data were subjected to analysis of variance by computer facilities, using Mstatc software. Plant response to prometryn residues was fitted with sigmoidal 3 and 4 parametric equations to the shoot biomass data as a function of the herbicide residue concentrations and was used to calculate the doses for 50% inhibition of shoot growth (ED50). In another experiment the effect of prometryn concentrations (0, 0.0033, 0.0166, 0.033, 0.066, 0.1 and 0.166 mg. kg-1soil) on soil microbial activity was determined using titration method in controlled conditions.
Plant response to increasing concentration of prometryn, in general, followed a classical dose response relationship. The logistic model fitted well to the root and shoot plants response herbicide concentrations. Results showed that the shoot and root dry matter were significantly affected by increasing prometryn soil residue in all crops (plettuce>beet>barely. Based on the mechanism of action of prometryn and its best efficiency on board leaf plants control, the least biomass reduction obtained for barley is understandable. In general, this is safe to plant a susceptible species if the plant-available residue were less than the species ED10 value, and there would be a great risk for different levels of crop damage if the plant-available residue were higher than ED50 values of the species. Comparisons between species allow the safe selection of a crop that has a critical ED50 level lower than the residue level in the soil. Alternatively, planting a sensitive species could be delayed until the residue level in the soil is less than the critical level. In the Southwest areas of Iran, these crops are often sown few months after the application of a residual herbicide in the preceding crop. This large variation in plant sensitivity to prometryn residues indicates that there is potential for considerable damage to some of the rotational crops. In second experiment the results clearly indicating that in initial days of prometryn application used drastically reduced the C, N and total microbial in treated soil compared with the untreated (Control) soil.
According to the results of this studyt the study crops are very suitable for use in bioassays for the side-effects of prometryn at low concentration rates. In this study prometryn herbicide provided symptoms of phytotoxicity to the crops, whereas seed germination of crops was not adversely affected. In the other words, this condition indicating that the application of prometryn in agricultural soil leads to decrease the total biomass of soil microorganisms at initial period. By possibly knowing the level of prometryn residual in the soil, producers could have some flexibility in crop rotations if sensitive crops such as rapeseed are to be planted following triazine herbicide use on crops.

Tribenuron methyl, an ALS inhibiting herbicide, labeled for post-emergence use in wheat and barley fields and is extremely effective on broadleaf weeds. This herbicide plays a critical role in post-emergence weed management options for cereals especially in Golestan province in Iran. Recently, failures to control wild mustard (Sinapis arvensis L.) and turnipweed (Rapistrum rugosum L.) with recommended dose of tribenuron methyl applications have been reported for wheat fields (6 and 20). It motivated us to trace resistant populations and evaluate their degree of resistance and find a quick and cost-effective method to identify resistant populations in wild mustard and turnipweed .
At first, seeds were collected from wheat fields in Golestan province. These fields had been treated annually with tribenuron-methyl for more than 5 years, so wild mustard and turnipweed control had become erratic with this herbicide in recent years. Seeds were also collected from a site that had not been applied to any herbicide. This biotype was considered as tribenuron-methyl-susceptible (S). Plants obtained from the seeds collected were screened with recommended dose of tribenuron-methyl to indicate of resistant populations (R). Then greenhouse and laboratory experiments were conducted to investigate resistance level to tribenuron-methyl. The broken dormancy seeds were sown in suitable pots and were put in the greenhouse under natural sunlight. Plants with three to four true leaves were sprayed by different tribenuron-methyl rates based on a logarithmic scale. Above-ground biomass from the plants in each pot was harvested 4 weeks after treatment. Dry biomass data were expressed as a percentage of the untreated control within each biotype. For seed bioassay, different solution of teribenuron methyl was prepared with technical and commercial herbicide. A non-treated control was included and in these petri dishes added water instead of spraying herbicide. Seven days after trial initiation, shoot and root lengths were measured from the crown to the tip of the root or shoot to discriminate between R and S biotypes. Analyses of dose-response data in whole plant and seed bioassay were performed using the R software by fitting the data to a nonlinear log-logistic regression model.
In our study, the responses of the collected wild mustard and turnipweed populations after treated with the field rate of Granstar (tribenuron-methyl) confirmed that some of these populations are resistant to this herbicide. In these experiment 14 and 10 resistant biotypes (R) for wild mustard and turnipweed respectively according to results of screening test, and one susceptible biotype (S) were used for investigation of R biotypes response to increase concentration of herbicide. The concentration of tribenuron-methyl led to 50% inhibition shoot growth in control treatment was 9.93 and 10.90 gr a.i ha-1, whereas for R biotypes it was 2.6 to 6.6 and 2.2 to 16.8 fold more resistant relative to the S biotype for wild mustard and turnipweed respectively. Quick resistance test in petri dishes showed ability of this method for easy and reliable assessment of resistance in these plants. The results obtained by using commercial herbicide as well as shoot length data were not suitable for bio-evaluation and there were extreme variability when assayed, resistance would be more reliably detected using assays conducted on seeds of suspected R populations by root length measurement. Response of resistant populations to increasing concentrations of tribenuron-methyl herbicide were quite different from that of control treatment. Assays to determine the dose required to reduce root lenght by 50% indicated a resistance factor (RF) of 17.47 to 2.30 for wild mustard and 9.56 to 2.76 for turnipweed. On the other hand, the RF using whole plant dose–response assays were lower than petri dish assay. There is high correlation between the degree of resistance to obtained results from greenhouse and laboratory (90% and 83% wild mustard and turnipweed respectively).
The continuous advent of resistant weeds is a concern. Wheat is an important crop in Iran, which is mainly grown in monoculture and, only the used methods to remove the weeds is applying the herbicides especially in Golestan province. Probably the lack of crop and herbicide rotations are the main reasons of resistance to tribenuron-methyl in this regions. Having a rapid and reliable seedling bioassay is a useful tool to plan the best herbicide strategy for using in the field. Petri dish assay can be more convenient, potentially cheaper and give quicker results than pot tests but are not suitable for all weeds and herbicides. For this case, this test was done in turnipweed and wild mustard successfully.