akbar aliverdi

Sometimes, the spray solution must be stored for some time. This study aimed to answer the following questions: how long can an aryloxyphenoxypropionate herbicide be kept in the tank without losing efficacy? Is it dependent on pH? The experiment was designed as a completely randomized design with three factors including the labeled dose of herbicides (clodinafop, cyhalofop, diclofop, fenoxaprop, fluazifop, haloxyfop, propaquizafop, and quizalofop), the pH of spray solution (5, 7, and 8), and the storage time of spray solution (0, 12, 24, 36, 48, 60, and 72 h). The efficacy of herbicides on winter wild oat Avena sterilis subsp. ludoviciana Durieu. was not affected by changing the pH of the spray solution when the spray solution was applied immediately after preparation. When the spray solutions were stored, the herbicides' highest and lowest efficacy were generally observed at pH 5 and 9, respectively. At pH 9, except for fluazifop and haloxyfop, the effectiveness of other herbicides was reduced after 12-h storage of spray solution. The efficacy of all herbicides was reduced with 24-h spray solution storage. At pH 7, the efficacy of cyhalofop and fluazifop remained stable with 72-h storage of their spray solution. In contrast, at pH 5, the efficacy of clodinafop, cyhalofop, diclofop, fluazifop, haloxyfop, and quizalofop remained stable with 72-h storage of their spray solution. Therefore, if it is necessary to keep the spray solution of aryloxyphenoxypropionate herbicides for a short time, it is recommended to use a lower pH to avoid reducing their efficacy.

After preparing the spray solution of herbicide, there are situations where the farmer intentionally or unintentionally has to store the prepared spray solution for some time, even several days, in the sprayer tank. For example, when weather conditions for spraying become unfavorable, when a piece of failure in herbicide application equipment occurs, or when the spray solution at night is prepared to use at dawn. Herbicides either decompose chemically or react with compounds in the water, decreasing the efficacy of controlling weeds. Now, the first question that comes to mind is: how long can the herbicide be kept in the sprayer tank without losing its efficacy? In the water, herbicides inhibiting acetyl coenzyme A carboxylase (ACCase) undergo hydrolysis or photolysis, producing metabolites that do not have herbicidal properties. Therefore, the stored spray solution of ACCase-inhibiting herbicides cannot effectively control weeds. For this reason, it is suggested such a spray solution should be thrown away. The metabolites from ACCase-inhibiting herbicides, while not having herbicidal properties, are leached faster in the soil, have a higher half-life, and are more toxic to non-target organisms. Therefore, the suggestion to throw away the stored spray solution of ACCase-inhibiting herbicides does not seem logical not only from the environmental point of view but also from the economic point of view. Now, the second question that comes to mind is: what is the solution to reduce the speed of hydrolysis or photolysis? This study was carried out to investigate (i) the effect of the storage time of the spray solution of three ACCase-inhibiting herbicides (haloxyfop-r-methyl, fluazifop-p-butyl, and sethoxydim) on their efficacy in controlling wild barley (Hordeum spontaneum) and (ii) the effect of two factors of pH and light on the relationship above.

For each herbicide, an experimental three-factorial arrangement (6 × 2 × 9) as a completely randomized design with 4 replications. The first factor was six doses of herbicide (0, 20, 40, 60, 80, and 100% of the labeled dose); the second factor was two pHs of spray water (5 and 8); and the third factor was nine storage time/conditions (0, 24, 48, 96, and 192 h storage in the dark, 12+12, 24+24, 48+48, and 96+96 h storage in the dark+light). The spray solution corresponding to the zero level of the aforementioned third factor was prepared on the same day of spraying. For other levels of this factor, the relevant spray solution with a volume of one liter was prepared in the previous days (24, 48, 96, and 192 h before the day of spraying) and stored in transparent polyethylene terephthalate plastic bottles. The bottles were kept in two outdoor conditions: 1) kept in complete darkness - for this purpose, the bottles were kept in black plastic packed in a carton; and 2) kept in the darkness of the night and the light of the day - for this purpose, the bottles without any cover were exposed to the darkness of the night as well as to the sunlight. The treatments were applied at the four-leaf stage of wild barley; four weeks later, they were harvested, oven-dried, and weighed. A methodology known as dose-response curves was used to analyze the data to obtain the dose required for 50% control (ED50).

When the solution was sprayed immediately after preparation, reducing the pH from 8 to 5 did not significantly affect the ED50 of haloxyfop-r-methyl and fluazifop-p-butyl. While the ED50 of sethoxydim significantly decreased from 136.64 to 113.35 g a.i. ha-1, indicating that pH reduction can improve the efficacy of sethoxydim in the control of wild barely. The possible reason can be related to the difference in the formulation of the above herbicides. Haloxyfop-r-methyl and fluazifop-p-butyl are formulated as pre-herbicide. Under each condition (in terms of pH and light), when the time of storing the spray solution of herbicides was prolonged, a steady reduction of efficacy was observed. In the case of haloxyfop-R-methyl spray solution, when pH was not changed (pH 8), 24 h storage in the dark (43.78 g a.i. ha-1) and 12+12 h storage in the dark+light (41.44 g a.i. ha-1) significantly increased the ED50 as compared to the control treatment (0 h storage (34.60 g a.i. ha-1)). While when pH was reduced (pH 5), the efficacy of five treatments (including: 24 and 48 h storage in the dark and 12+12, 24+24, and 48+48 h storage in the dark+light) did not differ significantly from the efficacy of the control treatment. In the case of fluazifop-p-butyl spray solution, when pH was not changed (pH 8), all storage treatments significantly increased the ED50 as compared to the control treatment (0 h storage (80.64 g a.i. ha-1)). While when pH was reduced (pH 5), the efficacy of two treatments of 24 and 48 h storage in the dark did not differ significantly from the efficacy of the control treatment. In the sethoxydim spray solution, when pH was not changed (pH 8), all storage treatments significantly increased the ED50 as compared to the control treatment (0 h storage (136.64 g a.i. ha-1)). When pH was reduced (pH 5), the efficacy of all storage treatments still did not differ significantly from the efficacy of the control treatment.

If the pH of the spray solution was reduced, the spray solution of haloxyfop-r-methyl can be stored for at least 48 h in each light condition without losing its efficacy. If the pH of the spray solution was reduced and stored in the dark, the spray solution of fluazifop-p-butyl can be stored for 48 h without losing its efficacy. Sethoxydim is very sensitive to the storage of its spray solution. Changing the storage conditions, especially the pH, not only does not help in maintaining the efficacy but also causes a further loss in its efficacy.

This study aimed to assess the effect of a time gap between adding adjuvant and herbicide to the tank on hard-water antagonism of trifloxysulfuron under greenhouse conditions. Treatments consisted of herbicide dose (0, 0.75, 1.5, 3, 6, and 12 g ha-1), spray carrier (distilled water ± 600 mg MgCl2, CaCl2, and FeCl3 L–1), the order of adding adjuvant and herbicide to the spray carrier (herbicide alone, the addition of 20 g ammonium sulfate L-1 or 300 mg citric acid L-1 15 min before, at the same time, and 15 min after adding trifloxysulfuron to the spray carrier). The dry matter of velvetleaf was regressed over the doses of trifloxysulfuron to obtain herbicide doses in which 50 and 90% velvetleaf control occur (ED50 and ED90, respectively). The presence of Mg2+, Ca2+, and Fe3+ in the spray carrier increased the ED50 from 2.41 to 5.07, 7.65, and 9.78 g a.i. ha-1 and the ED90 from 5.88 to 16.56, 28.48, and 28.19 g a.i. ha-1, respectively, indicating a hard-water antagonism of trifloxysulfuron as Fe3+ = Ca2+ > Mg2+. Generally, the best order was adding adjuvants 15 min before adding trifloxysulfuron to the tank. It could completely overcome the hard-water antagonism of trifloxysulfuron. In contrast, the order of adding adjuvants 15 min after adding trifloxysulfuron to the tank had no significant effect on overcoming the hard-water antagonism of trifloxysulfuron, resulting in additional costs for farmers.

Whether fenoxaprop-p-ethyl activity could be affected by the carrier volume and whether this relationship can be affected by two types of bio-surfactants, rhamnolipid and surfactin, was assessed under greenhouse conditions. Treatments consisted of herbicide dose (0, 18.75, 37.5, 56.25, 75, and 93.75 g ha-1), spray volume (60, 120, 240, and 480 L ha-1), surfactant type above, and surfactant concentration (0, 0.125, 0.25, 0.5, 1, 2, 4, and 8x critical micelle concentration (CMC). The dry matter of sterile oat was regressed over the doses of fenoxaprop-p-ethyl to obtain a dose causing 50% sterile oat control (ED50). Without surfactant, a 38% increase in the ED50 with increasing the spray volumes from 60 to 480 L ha-1 (44.7 and 72.1 g ha-1, respectively) revealed a negative relationship between fenoxaprop-p-ethyl activity and spray volume. In other words, a low-volume spray solution, creating smaller, more concentrated spray droplets, is necessary to get the optimal action of fenoxaprop-p-ethyl. This relationship could also be observed when both surfactants were used at 0.125 to 1x CMC. At 2 to 8x CMC, the relationship mode changed from negative to neutral for rhamnolipid, while it did not change for surfactin. This study shows that, unlike surfactin, rhamnolipid worked better at a low concentration in a low-volume spray solution to get the optimal action of fenoxaprop-p-ethyl.

Despite the availability of nozzle types, the role of nozzle on the performance of unmanned aerial sprayer has received less attention. The study was performed in factorial as a completely randomized design to investigate the effect of factors of nozzle type (standard, anti-drift, and air induction) and nozzle orifice number (single, twin, and triplet flat fans) on the deposition of spray droplets at the target site and their drift up to a distance of 5 m from the target site and the efficacy of herbicide haloxyfop-R-methyl against volunteer barley. In all types of nozzles, with increasing the nozzle orifice number, drift increased. Except for the standard nozzle, in other nozzles types, with increasing the nozzle orifice number, the deposition of spray droplets at the target site and herbicide efficacy increased. The lowest (2.7%) and highest (22.5%) drift was observed with the air induction single flat fan nozzle and the standard triplet flat fan nozzle, respectively. The highest (35.2%) and the lowest (8.3%) deposition at the target site was observed with the air induction triplet flat fan nozzle and the standard triplet flat fan nozzle, respectively. The lowest control was observed using the standard triplet flat fan nozzle (38.3%). The highest control of barley with haloxyfop-R-methyl was observed when the air induction twin flat fan (94.3%) and air induction triplet flat fan (91.7%) nozzles have been used; therefore, the selection and installation of these two nozzles on UAV, not only better weed control is achieved, but also an effective step is taken to prevent environmental pollution.

Since the leaves of a grass species are perpendicularly oriented to the ground, spraying an ACCase inhibitor with a conventional hydraulic nozzle can not cause an adequate control. In such a situation, it is well established that a large endo-drift of the spray droplets can be occurred. Recently, a new spray technique, angled spray, has been introduced to maximize the deposition of spray droplets on a vertical target surface (i.e., grassy species). This technique is simple, inexpensive, and available to farmers. Therefore, it can be noteworthy to them. This reserech aimed to study the effect of many angled sprays by three flat fan nozzle types on the efficacy of haloxyfop-R-methyl against winter wild oat.

This study was conducted as dose-response bioassay at the research greenhouse of Bu-Ali Sina University in 2019. Haloxyfop-R-methyl at seven doses (0, 5.06, 10.12, 20.25, 40.5, 60.75, and 81 ml a.i. ha-1) were sprayed at 300 kPa spray pressure using three flat fan nozzle types having different atomization quality (standard (Fine: 144–235 µm), anti-drift (Medium: 236–340 µm), and air induction (Extremely Coarse: 503–665 µm)) in seven angled sprays (vertical spray and non-vertical sprays with 10, 20, 30, 40, 50, and 60° forward) on winter wild oat at the three-leaf stage. The haloxyfop-R-methyl dose required to give a 50% reduction in dry weight of winter wild oat (ED50) was detected.

The ED50 values were significantly affected by the nozzle type and the spray angle. With a vertical spray, the ED50 values of 32.51, 44.05, and 53.98 ml a.i. ha-1 was obtained from the flat fan nozzles of standard, anti-drift, and air induction, respectively. The best efficacy of haloxyfop-R-methyl was obtained using a 30° forward angled spray by standard flat fan nozzle (ED50 = 15.10 ml a.i. ha-1), a 40° forward angled spray by anti-drift flat fan nozzle (ED50 = 17.13 ml a.i. ha-1), and a 50° forward angled spray by air induction flat fan nozzle (ED50 = 17.61 ml a.i. ha-1).

From this experiment, the following points were obtained: 1) with a vertical spray, there is a negative correlation between the herbicide efficacy and the spray droplet size; 2) with a non-vertical spray, there is a neutral correlation between the herbicide efficacy and the spray droplet size; 3) when the droplets produced by a nozzle is larger, the more non-vertical spray is required to obtain maximoum herbicide efficacy.

Whether a soil is settled on velvetleaf Abutilon theophrasti (Malvaceae) or not, it was not clear if the concentration of spray droplets could influence the effectiveness of trifloxysulfuron. In an experiment, 12 g ha–1 trifloxysulfuron was sprayed at 135 l ha–1 on velvetleaf treated with 0, 4, 8, 12, 16, and 20 kg soil ha–1 through two soil treatment methods, one within a soil dust chamber and the other with a simulated muddy rain. In another experiment, velvetleaf was treated with 20 kg soil ha–1 and exposed to the airflow of 0 and 10 km h–1. Then 12 g ha–1 trifloxysulfuron was sprayed at 135, 180, 225, 270, 360, and 450 l ha–1. The effectiveness of trifloxysulfuron was negatively correlated with the rate of soil settled on velvetleaf. When the source of soil was a simulated muddy rain, compared to the soil dust chamber, it had a more negative effect on the effectiveness of trifloxysulfuron. Besides, it was not removed from velvetleaf by the airflow before spraying. The effectiveness of trifloxysulfuron was correlated with carrier volume. Correlation type was affected by soil settled on velvetleaf. A positive correlation was observed in soil-treated velvetleaf, especially within the soil dust chamber. Therefore, larger, more diluted droplets were needed to obtain the best trifloxysulfuron efficacy. Unlike in non-treated velvetleaf, a negative correlation was observed. Therefore, larger, more diluted droplets were required to get the best trifloxysulfuron effectiveness.

The most important principle in the rain-fed cropping system is to maintain and optimal use of soil moisture. In this regard, selecting the appropriate cultivar and planting density is one of the most important management decisions. The open canopy structure, short stature, limited leaf area, and the slow growth rate of chickpea is responsible for its poor competitive ability against weeds. In rain-fed cropping systems, weeds can also play an important role in soil moisture depletion and can aggravate drought stress on crop at the end of the growing season. Among the weed control cropping methods, it is possible to select a competitive cultivar and/or increased planting density. After introducing a new cultivar from rain-fed chickpea, researchers have always compared it with older cultivars in terms of competitive ability against weeds. So far, there has been no comparative study of competitive ability or tolerance of a new rain-fed chickpea cultivar, Adel, against weeds with older cultivars. Consequently, the effect of planting density of this new rain-fed chickpea cultivar on the response of weeds was not investigated. Therefore, the aim of this study was to investigate the interaction of this new and old cultivars and planting density on weeds damage under rain-fed conditions in Kermanshah. 

This research was carried out at the research farm of the faculty of agriculture and natural resources of Razi University, Kermanshah, during 2013-2014 growing season. Wheat was planted in the same farm during the previous growing season. During the experiment, the total rainfall was 85.51 mm. After preparing the land to plots of 6 × 2 m2, the chickpea cultivars were manually planted with the distance of 40 cm on each row on 5 February 2013. The experiment was a factorial (3 crop densities × 4 chickpea cultivars × 2 weed interferences) in a completely randomized block design with three replications. Planting densities were 31.3, 38.5, and 50.0 plants m-2. Chickpea cultivars were Arman (FLIP90-96C), Azad (FLIP93-93C), Adel (FLIP99-66C), and Hashem (FLIP84-48C). The factor of weed interference was at two levels of weeding and unweeding. The crop was harvested on 28 June 2014 to evaluate yield and yield components. The samplings of weeds were performed to determine the total biomass using a 1 m2 quadrate on 20 May and 12 June 2014, which were coincident with the flowering time and physiological maturity of chickpea, respectively.  

In general, the economic yield was decreased by increasing the plant density in all chickpea cultivars. The planting densities of 38.5 and 50.0 plants m-2 reduced the economic yield up to 8.9 and 42.6% in Azad cultivar, 30.5 and 37.2% in Arman cultivar, 23.7 and 40.2% in Hashem cultivar and 32.9 and 36.3% in Adel cultivar compared to planting densities of 31.3 plants m-2, respectively. Azad cultivar produced the highest economic yield (146.4 g m-2) under weeded condition, while the lowest economic yield (45.2 g m-2) belonged to Arman cultivar under un-weeded condition. The presence of weeds resulted in a reduction of 59.1, 51.9, 61.2, and 46.3%, in the economic yield of Azad, Arman, Hashem, and Adel cultivars, respectively. During the first weeds sampling, the highest (25.7 g m-2) and the lowest (17.7 g m-2) weed biomass were observed at planting density of 31.3 and 38.5 plants m-2, respectively- whereas during the second weeds sampling, the highest (60.0 g.m-2) and the lowest (42.8 g. m-2) weed biomass were observed at 31.3 and 50.0 plants m-2, respectively. Moreover, during the second sampling of weeds, the highest (54.7 g m-2) and the lowest (40.8 g m-2) weed biomass were observed at the plots of Hashem and Adel cultivars, respectively. 

In this research, the planting density of 31.3 plants m-2 was optimal planting density for all four chickpea cultivars. It seems that the increase of planting density to control weeds in rain-fed chickpea cropping system is an unsuitable technique. Therefore, it is necessary to consider other techniques to control weeds in rain-fed chickpea cropping systems. An interesting observation in this study was that, although the economic yield of Adel cultivar was lower, the lower biomass of weeds in the plots of this cultivar was observed compared to other cultivars. This observation can be related to allelopathic compounds produced by Adel cultivar which is costly for the crop itself and has reduced its yield.

Since rainfall occurs often in the fall and winter, water is an important limiting factor to subsequent growing crops especially those in hot seasons like soybean. Therefore, there is a growing focus on increasing water use efficiency in crops in recent years. Recently, an irrigation technique so-called magnetized water has been introduced to increase water use efficiency. The researchers have reported that the physical and chemical properties of water including electrical conductivity, volatility, pH, solubility, surface tension, and viscosity can be affected by its passage through the magnetic field. Subsequently, these changes lead to alterations in soil electrical conductivity, soil nutrient mobility, soil water holding capacity, water passage through the soil profile and soil pH. Increased water use efficiency in soybean (11%) and many leguminous crops have been demonstrated through their irrigation with magnetized water. However, those studies have provided no information about the status of bacterial nodulation on legume root in such an irrigation method. Therefore, the main purpose of this study was to investigate the effect of irrigation with magnetized water on five soybean varieties on their symbiosis with specific bacteria (Bradyrhizobium japonicum). The experiment was conducted in the open air at the Bu Ali Sina University of Hamedan in 2018. A completely randomized design with two factors (soybean cultivar and irrigation water type) and eight replications was applied. The soybean cultivar had five levels (Amir, Zan, Saba, Kosar, and Hobbit) and irrigation water type had two levels (untreated and magnetically treated water). An equal volume of water (1 liter) was added to each pot every two days. Before adding water to pots for the irrigation with magnetized water, we passed it through a magnetic tube with a 35 cm long, 1-inch radius and a 0.68 T magnetic field intensity. On August 26, the plants of the half of replications were harvested to measure shoot dry weight, root dry weight, number of nodules, nodule dry weight, shoot nitrogen content and root nitrogen content. On September 10, the plants of the other half of replications were harvested to measure individual seed yield and its components (number of pods per plant, number of seeds per pod and 100-seed weight). By dividing the seed yield obtained from each pot to the total volume of water added to each pot during the growing season, water use efficiency can be calculated. The soybean seedlings irrigated with magnetized water were green 1 to 2 days earlier than those irrigated with untreated water. The number of seeds per pod was not affected by soybean cultivar, irrigation water type, and their interaction. In other traits, the simple effects of soybean cultivar and irrigation water type and their interaction were significant at the 5% level of probability. The cultivars of Amir and Saba irrigated with magnetized water led to a higher shoot dry weight to root ratio, indicating the allocation of more resources to the shoot than to the root. The number of nodules formed on the root of all soybean cultivars (Amir (33.7%), Zan (55.3%), Saba (40.1%), Kosar (62.7%) and Hobbit (51.6%)) increased when they were irrigated with magnetized water. However, only in Zan (0.70%) and Kosar (45.1%), irrigation with magnetized water significantly increased the dry weight of nodules. The individual seed yield in all soybean cultivars (Amir (34.8%), Zan (35.1%), Saba (43.4%), Kosar (26.8%) and Hobbit (21.3%)) was significantly increased by irrigation with magnetized water, indicating an improved water use efficiency in soybean irrigated with magnetized water. Based on previous research, the most suitable soil pH range for bacterial growth and activity was found to be between 6.5 and 7.0. On the other hand, other researchers have shown that irrigation with magnetized water reduces the soil pH by approximately 0.5 units. Hence, in our experiment, irrigation with magnetized water probably caused the initial soil pH which was 7.6 to be closer to the optimal range for bacterial activity. Also, according to previous study, bacterial activity is also dependent on soil dry conditions. On the other hand, other researchers have shown that irrigation with magnetized water increases soil water storage capacity due to reduced water vaporization. Therefore, in our experiment, irrigation with magnetized water probably provided good moisture conditions for bacterial activity. The results showed that the irrigation of soybean with magnetized water improved its symbiosis with its specific rhizobium. Improved symbiosis increased plant seed yield and water use efficiency. Therefore, improved symbiosis by irrigating soybean with magnetized water can reduce the reliance on nitrogen fertilizer application in this plant. It can also improve the status of soil fertility for other crops in crop rotation.

By understanding the diversity and dominance of weed species, which is affected by changes crop management systems and weed control practices, these plants can be managed more efficiently. In this study, the diversity of weed species of irrigated wheat fields was studied in an area of ​​less than one, one to two, two to four, four to eight and more than eight hectare in the central region of Arak, Iran, in 1919. A total of 74 weed species were identified from 25 plant families, of which 61 species were dicotyledons and 13 species monocotyledons, 78.38% annual and 21.62% perennial as well as 95.95% C3 and 4.05% C4. Also, Asteraceae and Brassicaceae families among dicotyledons and Poaceae family among monocotyledons had the highest species diversity. According to the dominance index, ten dominant weed species were flixweed (Descurainia Sophia), binweed (Convolvulus arvensis), foxtail grass (Alopecurus myosuroides), common thistle (Cirsium arvense), Iranian knapweed (Centaurea depressa), lowgrass (Polygonum aviculare), corn cleavers(Galium tricornutum), Syrian mustard (Eeuclidium syriacum), goldbachi (Goldbachia laevigata) and nodding hypecoum(Hypecoum pendulum). There was a significant inverse relationship between field size with Shannon-Wiener and Pielou's uniformity indices and their highest values (2.58 and 0.84, respectively), was obtained in the fields less than 1 ha and the lowest values (1.48 and 0.61, respectively), in the fields more than 8 ha. In contrast, the relationship between field size and Simpson's dominance Index was positive and significant and its value was calculated 0.1 and 0.33 for fields less than 1 ha and more than 8 ha, respectively. In total, the results of this study showed that a few weed species in most wheat fields in this region were well distributed and had high density, abundance, uniformity and dominance index and if the usual farm management methods continue, there is a possibility that species diversity will decrease and the problematic weeds will dominate.

The dust deposited on the foliage of weeds can have an adverse effect on the efficacy of herbicides, thus this effect should be eliminated somehow. In this greenhouse study conducting at Bu-Ali Sina University in 2018, the response of fresh : dry weight ratio of winter wild oat to the 6 doses of oxyfluorfen (0, 28.8, 60, 120, 240, and 480 g a.i. ha-1), paraquat (0, 36, 75 , 150, 300, and 600 g a.i. ha-1), and glufosinate (0, 60, 125, 250, 500, and 1000 g a.i. ha-1) sprayed with 240, 480, or 240 L ha-1 plus mepiquat at 50 g ha-1 under conditions of 0 and 20 Kg dust ha-1 were investigated. In the absence of dust, the addition of mepiquat to oxyfluorfen and paraquat spray solutions did not have a significant effect on their efficacy but the addition of it to glufosinate spray solution gave a significant negative effect on its efficacy. In the presence of dust, the addition of mepiquat to oxyfluorfen spray solution did not have a significant effect on its efficacy but the addition of it to glufosinate spray solution has 6-fold negative effect on its efficacy. While, the addition of mepiquat to paraquat spray solution had a positive effect on its efficacy and increased the efficacy by 62.07%. Whether dust was applied or not, increasing spray volume from 240 to 480 L ha-1 resulted in an improvement in the efficacy of all herbicides to desiccate the foliage of winter wild oat.

Selection of suitable nozzle type, regarding the size of droplets and the volume of spray to apply herbicides optimally is necessary. In the spray deposition experiment, conducted using a factorial (six nozzle types × two nozzle sizes) arranged as a completely randomized block design, the moisture-sensitive papers were used and localized in four positions. In dose-response experiment, six doses of clodinafop-propargyl(0, 8, 16, 32, 48, and 64 gr.a.i. ha-1) were sprayed using six nozzle types with two nozzle sizes (11002 and 11004) at five-leaf growth stage of winter wild oat. As the nozzle number increased, more surface area of all moisture sensitive papers was wetted. Although the size of droplets increases with increasing the size of nozzles, the efficacy of clodinafop-propargylto controlwinter wild oat was increased. For the nozzles size of 11004, the performance of nozzles in the efficacy of clodinafop-propargylbased on the ED90 values was as Twin Fan Standard > Standard Flat Fan > Compact Fan Air > Twin Fan Low Drift > Fan Low Drift > Twin Fan Air.

Although “the pesticides are a global human rights concern” (24), they can secure global food security provided that the rational herbicide application technique is taken into consideration (7). The principal elements of rational herbicide application technique include the selectivity of herbicide, the application of appropriately timed herbicide and the accuracy of application equipment (4). The hydraulic spray nozzle atomizes the spray solution into droplets (9). Thus, it is a key component to influence on the accuracy of spraying (17). The nozzle technology is always improving, resulting in the introduction of more than 60 nozzle types that all are available to apply in different situations. High nozzle diversity can cause some difficult to select a proper nozzle, particularly when wind speed at time of application is authorized or unauthorized for spraying. The present study aims to compare 14 nozzle types in relation to the efficacy of sethoxydim to control winter wild oat at two wind speeds.
The seeds of winter wild oat (Avena sterilis ssp. ludoviciana) were treated to germinate (2). Then, the 9 seedlings were planted within each pot and grown in the Research Greenhouse of Bu-Ali Sina University, Hamedan, Iran and thinned to 6 plant pot-1 at the one-leaf stage. At the five-leaf stage, they were treated with 0, 23.5, 47, 94, 187.5, and 375 g sethoxydim ha-1 using 14 nozzle types at two wind speeds of 0.5 and 9.5 m s-1 in outdoor conditions. A standard 210 L ha-1 carrier volume was sprayed at a pressure of 3 bar with the 11002 yellow nozzles of Twin Fan Standard (TFS), Fan Low Drift (FLD), Standard Flat Fan (SFF), Turbo Wide Angle Flat (TWAF), Low Pressure Air Induction Twin Flat (LPAITF), Low Pressure Air Induction Flat (LPAIF), Compact Fan Air (CFA), Compact Fan Air-Tilt (CFA-T), Turbo Twin Flat (TTF), Air Induction Twin Fan 3070 (AITF3070), Twin Fan Low Drift (TFLD), Air Induction Turbo Twin Flat (AITTF), Twin Fan Air (TFA), Turbo Air Induction Flat (TAIF). Four weeks after spraying, the dry weight of plants were obtained and the date were fitted to analyze using a four-parameter log-logistic model to estimate the Effective Doses (ED) (19).
The ED10, 50 and 90 values of sethoxydim on the control of winter wild oat were affected significantly by nozzle type or wind speed. When spraying was done at 0.5 m s-1 wind speed, the lowest and the highest ED50 values were obtained with the TFS and TAIF nozzles, requiring 12.81 and 62.72 g sethoxydim ha-1 to give a 50% reduction in dry weight of winter wild oat, respectively. In such a situation of wind speed, the ranking of the nozzle types based on the sethoxydim dose required to give a 50% reduction in dry weight of winter wild oat was TAIF > TFA > LPAIF > TFLD > LPAITF > AITTF > CFA > CFA-T > FLD > TTF > TWAF > AITF3070 > SFF > TFS (Table 1). It can be concluded that the endo-drift by TFS nozzle at low wind speed is lower than other nozzles. When spraying was done at 9.5 m s-1 wind speed, the lowest and the highest ED50 values were obtained with the AITF3070 and TFS nozzles, requiring 45.13 and 87.35 g sethoxydim ha-1 to give a 50% reduction in dry weight of winter wild oat, respectively. In such a situation of wind speed, the ranking of the nozzle types based on the sethoxydim dose required to give a 50% reduction in dry weight of winter wild oat was TFS > FLD > TAIF > TFA > SFF > CFA-T > TWAF > LPAIF > TFLD > AITTF > CFA > TTF > LPAITF > AITF3070. It can be concluded that the exo-drift by TFS nozzle at high wind speed is higher than other nozzles. It seems that a limiting factor for the performance of nozzles categorized as VC to UC at high wind speed can be the spray carrier volume.
As a proper nozzle to spray sethoxydim with 210 L carrier volume ha-1 at a pressure of 3 bar to control winter wild oat at low and high wind speed, the TFS and AITF3070 nozzles can be applied to obtain an optimal herbicide efficacy, respectively.

Watching Television and soap operas, is one of the most important activities of most people, particularly women, worldwide. There are various motives for watching T.V, such as obtaining serenity and entertainment, filling up the leisure hours, forgetting daily problems, and gaining information. The present study seeks to study the dimensions of satisfaction obtained from watching T.V soap operas by women. It also aims to find out the social correlations of obtained satisfaction, as well as their probable inter-correlations. The study utilizes Survey method, and data is collected through questionnaire along with interview. Since the “Use and satisfaction”, is the theoretical framework of the study, four-dimensional model of McQuail (including; gaining personal identification, achieving information, establishing social interactions, and obtaining serenity and entertainment) is applied to measure motives of watching (or sought satisfaction) and obtained satisfaction. Motives of watching and obtained satisfaction are considered as dependent variables and measured by investigator-made scales, on the basis of the McQuail model as well as previous research. Some social factors (such as level of education, employment status, socio-economic status-SES-, and rate of watching) are considered as independent variables. To measure the validity of the scales, Content Validity is applied and Alpha Chronbach is used to calculate reliability of the scales. The overall reliability coefficients for motives of watching and obtained satisfaction scales are. 661 and. 911, respectively; indicating strong internal consistency of the scales. The sample study consists of 383 married women residing in Isfahan city within the age range of 20 to 54 years old. SPSS (version 16) software is employed to analyze the collected data. Descriptive findings of the study indicate that slight majority of women have low education and income; while the great majority of them are married and housewives who belong to low SES families. The analytical findings of the study show that the strongest and weakest motives of watching soap opera for women are gaining personal identification and obtaining serenity and entertainment, respectively. On the other hand, the highest and lowest satisfactions which women obtained are the establishing social interactions and achieving information, respectively. Furthermore, there are significant correlations between different dimensions of sought and obtained satisfaction. Finally, the mean of watching motives and obtained satisfaction decreased in contrast with increasing level of education and SES. It seems that the women in this study reinforce their cultural and religious values, acquire socially accepted values, recognize and improve their social and familial status, and explore realities (which are used as criterions to measure gained personal identification) via watching soap operas. However, the subtle analysis indicates that although “gaining personal identification” was the strongest motive of women for watching soap opera, but they reported slight satisfaction in this regard. It appears that soap operas are mostly amusing and establish social interactions rather than inform and give personal identity.