فصلنامه مطالعات حفاظت گیاهان
سال سی و هفتم شماره 1 (بهار 1402)

Downy mildew disease caused by Plasmopara viticola (Berk. & Curt.) Berl. & Toni is one of the most important diseases of vine. Especially in wet areas, it causes qualitative and quantitative damage to the crop. Although all green parts of the grapevine are susceptible, the first symptoms of downy mildew of grapes are usually seen on the leaves as soon as 5 to 7 days after infection. Foliar symptoms appear as yellow circular spots with an oily appearance (oilspots). Young oilspots on young leaves are surrounded by a brownish-yellow halo. This halo fades as the oilspot matures. The spots are yellow in white grape varieties and red in some red grape varieties (e.g., Ruby Red). Under favorable weather conditions, large numbers of oilspots may develop and coalesce to cover most of the leaf surface. After suitably warm, humid nights, a white downy fungal growth (sporangia) will appear on the underside of the leaves and other infected plant parts. The disease gets its name "downy mildew" from the presence of this downy growth. In late summer and early fall, the diseased leaves take on a tapestry-like appearance when the growth of the pathogen is restricted by the veinlets. Confirmation of active downy mildew is made by the "bag test." To do this test, seal suspect diseased leaves and/or fruit bunches in a moistened (not wet) plastic bag and incubate in a warm (13-28ºC), dark place overnight. Look for fresh, white downy sporulation beneath suspect oilspots or on shoots or fruit bunches. Note that mature berries, although they may be symptomatic and harbor the pathogen, may not support sporulation even when provided with ideal conditions. Infected parts of young fruit bunches turn brown, wither, and die rapidly. If infections occur on the young bunch stalk, the entire inflorescence may die. Developing young berries will either die or, if between 3 and 5 mm in diameter, become discolored. Berries become resistant to infection within 2-3 week after bloom, although all parts of the rachis may remain susceptible 2 months after bloom. The pathogen survives the winter period as oospores embedded in dead leaves and other host tissue on the vineyard floor. Oospores may be released from the decaying plant material on the soil surface. Oospores typically produce sporangia. These sporangia, in turn, produce zoospores. Sporangia and zoospores are splashed by rain or carried by wind to the lower leaves and tissues of the grapevines. The conditions necessary for oospore germination are wet soils with temperatures above 10ºC. Sporangia for secondary infections are produced on sporangiophores that emerge through stomata of infected leaves and other grapevine tissues. Sexual reproduction occurs towards the end of the season. The resulting oospores are thick-walled and serve as survival spores.

 The experiment was conducted in grape orchards located in Hamadan, Bojnourd, and Faruj, which had a history of Downey mildew. Different cultivars of grapes were selected for the experiment. The experimental design used was a randomized complete block design (RCBD) with 8 treatments and 4 replications.The control treatments included plots without any spraying and plots sprayed with water. The remaining treatments involved the application of specific treatments at three different stages. The first spraying was done before flowering, the second spraying after fall petals, and the third spraying 10 days after the second spray. Ten days after the final spraying, samples were collected from the grape leaves, and the percentage of disease incidence and disease severity were calculated. The data obtained for disease incidence and severity were analyzed using statistical software, such as SAS, and the means of these traits were compared using Duncan's multiple range test at a significance level of one percent. This test helps determine significant differences between the treatment means.

 The analysis of variance conducted on the data obtained from the evaluation of treated grape leaves revealed a statistically significant effect of the treatments on reducing the percentage of disease severity and disease incidence. Among the treatments, Profiler® at concentrations of 3 ml L-1, 2.5 ml L-1, and 1 ml L-1, Mishocap® at 3 ml L-1, and Captan at 3 ml L-1 demonstrated high efficiency in controlling grape Downey mildew disease. The new fungicide Profiler® at a concentration of 3 ml L-1 exhibited an efficacy of 94% in Hamadan, 67% in Bojnourd, and 47% in Faruj. Profiler® at a concentration of 2.5 ml L-1 had slightly lower efficacy, but the difference was not statistically significant compared to Profiler® at 3 ml L-1. Interestingly, the control treatments, including water spraying and no spraying, did not show a significant difference in disease control compared to the treated plots. These results indicate that Profiler® at appropriate concentrations and Mishocap® and Captan at their recommended concentrations can be effective options for controlling grape Downey mildew disease.

 Because both Profiler® 3 and 2.5 ml L-1concentrations are effective in controlling the disease, therefore in order to protect the health of the consumer and the environment as well as reduction in costs, the preferred dose is 2.5 ml L-1.

Due to the process of quality control of agricultural products and accurate assessment of pesticide residues in products exported to destination countries, the application of biological control has become essential. In order to use biological control, biological agents must either be purchased from countries with the technology of mass production of natural enemies, or to meet the needs of the country, the technology of mass production of predators and parasitoids must be developed. In the case of mass rearing of predatory mites, which are mostly used to control spider mite, the problem of mass prodaction has been partially resolved and some companies are rearing, but in mass rearing of these predators, destructive effects on non-target natural enemies and mold growth on the rearing media of predatory mites are problematic. The predatory mite, Amblyseius swirskii (Athias-Henriot) is one of the most common biological agents for control of two-spotted mite, whitefly and onion thrips in greenhouses, which is widely used in greenhouse crops worldwide. The importance of this study is to facilitate the mass production of this predatory mite. In mass production of this predator, a medium with eggs, nymphal stages, and mature mites of Carpoglyphus lactis Linnaeus was used at 25 ± 1 ° C, 70 ± 5% RH and L: D 16: 8. One of the most important limitation in the production of this predator is infection with some fungi such as Rhizopus spp., Aspergillus spp,and Penicillium spp., which caused the deterioration of the medium and consequently the death of dried fruit mites and predatory mites in the production environment.
To investigate the efficacy of five componds on fungal control, an experiment was achieved with twelve treatments in a completely  randomized design in three replication. From the culture medium (800 g of elm flour, 195 g of wheat bran and 5 g of palm pollen) plus 1g/kg of compounds: tebuconazole, baking soda (sodium bicarbonate), Caliban® (potassium bicarbonate), Chitosan®, and carbendazim and in treatments where two compounds were mixed, 0.5 g/kg was used.
The analysis of variance for the treatments revealed significant differences in fungal infection reduction and the population dynamics of the mites. The treatments that showed the highest reduction in fungal infection compared to the control were treatments 1 (tebuconazole®), 3 (Caliban®), and 6 (Trichocara®), with reductions of 66.33%, 63.25%, and 28.62%, respectively.
In terms of the population increase of the prey mite C. lactis, the treatments that exhibited the highest increases were treatments 1 (tebuconazole®), 10 (Chitosan = tebuconazole), and 6 (Trichocara®), with population increases of 80.22%, 65.75%, and 65.15%, respectively.
Regarding the population increase of the predatory mite A. swirskii, the treatments that showed the highest increases were treatments 1 (tebuconazole®) and 6 (Trichocara®), with population increases of 76.33% and 72.66%, respectively, in the first group. In the second group, treatments 3 (Caliban®), 2 (soda), and 10 (Chitosan + tebuconazole) exhibited population increases of 56.33%, 54.66%, and 53.66%, respectively.
These results demonstrate the effectiveness of treatments 1 (tebuconazole®) and 6 (Trichocara®) in reducing fungal infection and promoting the population growth of both prey and predatory mites. Treatments 3 (Caliban®), 10 (Chitosan = tebuconazole), and 2 (soda) also showed positive effects on the population dynamics of the mites.
The predator mite population of A. swirskii is able to complete its growth on growth substrates with prey mite C. lactis. This predator has a high potential in feeding on dry fruit mite C. lactis. Therefore, this bait can be a suitable food for the mass production of A. swirskii mites. The most important problem in rearing large numbers of predatory mites is saprophytic fungi, which cause the destruction of a large number of predatory mites and their prey due to their sudden expansion. In general, according to the results of our study, the use of tebuconazole fungicide at a rate of one per thousand of commercial material and also the biological compound of Trichocara® (Trichoderma virens) with a concentration of one per thousand are recommended to control saprophytic fungi in mass production environment of predatory mite,A. swirskii,. Each of these two compounds has its advantages and disadvantages. In terms of availability, tabuconazole is more readily accessible compared to Trichocara®, which is a biological compound and considered more environmentally safe. However, Trichocara® may darken the color of the culture medium slightly due to the growth of Trichoderma virens in the medium. Considering the economic aspect and cost reduction in mass production of predatory mites, baking soda and Caliban®, which were part of the second group of effective treatments, offer economic value and are much cheaper than other compounds. They can effectively reduce the severity of fungal infections at minimal cost. Among the different compounds tested, the use of tebuconazole fungicide at a rate of one gram per thousand grams of substrate showed the most significant effect in controlling fungi. Although sodium bicarbonate and potassium bicarbonate were found to be less effective, they are still viable options due to their non-toxic nature.

The Indian meal moth, Plodia interpunctella (Lepidoptera: Pyralidae) (Hubner, 1813) is one of the most important and well-known stored-product pests in most parts of the world. The larvae of this insect are omnivorous and have the ability to grow and reproduce on a wide variety of grains, dried fruits, dried vegetables, nuts, oil seeds, chocolate, animal feed and various processed products. Therefore, it causes economic losses to various agricultural and stored products. On the other hand, this insect is used as a host in the rearing of various useful insect species. In general, the Indian moth eats carbohydrate-rich foods, and its growth and development is highly dependent on biochemical compounds and especially the quality and quantity of nutrients in its diet. The enzymes like amylase and pectinase in the digestive system of the lepidoperan larvae, which are secreted by the cells of the midgut, play an effective role in the digestion and absorption of food. Investigating some of the biological and physiological properties of this insect on various types of foods will help to optimize the rearing of this insect for management studies and also as a host for rearing of other pest insect’s predators and parasitoids.
In this study, we investigated the effects of different diets, namely raisin, fig, pistachio, peanut, almond, and walnut, which are known to be the main hosts of the Indian meal moth, on the protein content in the last instar larval gut. We compared their protein patterns and content using SDS-PAGE. Additionally, we measured the activities of the digestive enzymes alpha-amylase and pectinase using the DNS (Dinitrosalicylic acid) assay. Alpha-amylase activity was assessed using 1% starch as a substrate, while pectinase activity was measured using pectin as the substrate. To facilitate a better comparison of the relative enzymatic activities, the activities were calculated as a percentage of the highest enzymatic activity. Furthermore, we compared several biological parameters, including the incubation period, larval period, pupal period, adult longevity, life span, and adult emergence.
The results of the study revealed that the Indian meal moth larvae had the lowest amounts of gut protein when fed on figs and raisins, while the highest amounts were observed in larvae fed on pistachios, peanuts, almonds, and walnuts. The determination of protein levels using the Bradford method and SDS-PAGE gel electrophoresis yielded consistent results, clearly indicating the protein concentrations in the samples. The activity of the alpha-amylase enzyme in the larvae's gut was highest in those fed on pistachios and lowest in those fed on figs. Similarly, the pectinase enzyme showed the highest activity in larvae fed on pistachios and the lowest activity in those fed on raisins. The embryonic period of the Indian meal moth remained consistent across different diets. However, when comparing the duration of the larval period, pupal period, and overall growth period, the shortest duration was observed in larvae fed on pistachios, while the longest duration was seen in those fed on raisins. The length of the growth period tends to increase when the insect is fed on less desirable food sources. Regarding lifespan, the shortest duration was observed in the diets consisting of almonds and pistachios, while the longest lifespan was recorded in those fed on raisins. When examining adult emergence, the diets of almonds and figs showed the highest and lowest values, respectively. In conclusion, pistachios, almonds, and walnuts were found to be more favorable diets for the Indian meal moth larvae compared to peanuts, figs, and raisins.
This study aimed to determine the optimal diet for rearing the Indian meal moth. The investigated diets, which are major food sources for this insect, were found to have an impact on the amount and concentration of intestinal protein in the last instar larvae, as well as the activity of alpha-amylase and pectinase enzymes. Significant differences were observed in various physiological and biological components among the diets. The highest values for all these components were observed in the larvae reared on a pistachio diet, while the lowest values were found in those reared on fig and raisin diets. Based on the findings of this research, it can be concluded that pistachio, walnut, and almond diets are favorable and suitable for laboratory breeding of the Indian meal moth, compared to peanut, raisin, and fig diets. Among these diets, pistachio was identified as the most optimal choice.

Saffron is one the most expensive crops and like other agricultural products, attacked by pest such as bulb Mite Rhizoglyphus robini Claparede (Acari: Astigmata). The bulb mite is one of the most important soil pest attacking plants with bulbs, corms and also tubers. In Iran it has been reported by Rahimi and Kamali (1993) for the first time on saffron corms from Gonabad and Qaen cities. Also it has been recorded that the bulb mite feeding on soil born fungi (Diaz et al., 2000; Nesvorna et al., 2012). On the other hand, there are many saprophytic fungi into the soil of saffron fields. Subsequently it may question whether the mite is primary or secondary pest on saffron corms. Despite many literatures on biology and ecology of Rhizoglyphus mites, there is not sufficient evidence on understanding the biology, behavior and colonization of R. robini regarding its damage to saffron corms when arriving after establishment of the soil born fungi.
To investigate the impact of soil-borne fungi on the biology of the bulb mite, we obtained a cohort of even-aged eggs from the mites in our stock culture. These eggs were then transferred to individual experimental units and monitored until they reached adulthood. Daily observations were made and recorded.
To assess mite fecundity, we selected thirty young ovipositing females and divided them into two groups: one group was exposed to fungal infection while the other group was not. Each saffron corm was placed in a 50mm Petri dish lined with wet filter paper. A starved mated female was added to each dish, and every three days for a period of 21 days, the number of eggs laid per dish was counted and then removed. The number of eggs per day per female was calculated based on these counts.
To study the attraction of bulb mites to the fungus, saffron corm sections with and without fungal infection were placed in a 50mm Petri dish. Four sections, with equal distances from each other and from the center, were arranged. Female R. robini mites were introduced into the dish, and after a four-hour period, the number of mites on each section was recorded.
For evaluating the population dynamics of the mite, we used four types of saffron corms: healthy corms, corms infected by the fungus, mechanically injured corms, and corms both infected and injured. Each experimental unit consisted of three saffron corms of the same size placed in an 80mm Petri dish. Five adult mites were added to each unit. Continuous observations were made daily to track the initial penetration and colonization of the mites in each treatment. The numbers of all motile stages of mites in each experimental unit were recorded using a stereomicroscope. These observations continued until the corms were completely destroyed by the feeding mites.
After culturing of sections of infected corms and mite body, the fungi, Penicillium spp., Aspergillus niger Vantieghem, Embelisia sp. and Fusarium oxysporum Schlecht were isolated and identified mutually in both samples. As the fungus F. oxysporum was the most abundant species, then it was used in the experiments. The fungus significantly affected the generation time (from egg stage to egg produced by adult) of the mite (Table. 1). Also mite fecundity was significantly higher on infested corms with the fungus than on non-infested ones (t = 10.79, d.f.= 27.31, P<0.001)(Figure 1). An obvious attraction of the females was observed toward fungal infected sections and significantly more mites were recorded on them than non-infected ones (W = 400, P<0.001)(Figure. 2).These findings are supported by some other studies (Czajkowska, 1995; Kasuga and Honda 2006; Ofek et al., 2013). Higher fecundity and faster development when mites were fed on the fungus on the infected corms are probably due to availability of a special nutrient source (mycelium). The ability of the bulb mite to digest fungi has been attributed to chitinase-producing symbiotic bacteria (Zindel et al., 2013). Based on the evidence provided by this study and previous ones (Okabe and Amano, 1990; Ofek et al., 2013), the mite R. robini was attracted more to fungal infected corms, it might because of metabolites and alcoholic secretions of the fungi. These findings demonstrate the suitability of saffron corms infected with soil fungi for development and population increase of the Robine mite.
The result on mite penetration and population dynamics on four types of treated corms indicated that the mite on infected corms penetrated within two weeks and thereafter population increased exponentially until the end of 5th week. In comparison on healthy corms and even injured ones the mite showed almost no increase during first three weeks and it was not able to penetrate and develop a stable colony on these corms. Also on infected and injured treatment similar population dynamics was observed as on infected ones (Figure. 3). These observations implying that the mite for penetrating into healthy corms encounters some difficulty and considerable time is needed to establish and colonized on such environment. Okabe and Amano (1991) has been found similar results and suggested that earlier penetrations of mites result in a faster population growth and colonization.
For many years the saffron bulb mite has been considered as a primary pest and historically control strategies has relied on the use of chemical miticides (for disinfection and etc.,) and some non-chemical methods. Subsequently the role of soil born fungi has receiving limited attention in this regards. According to the results of the present study, this acarine pest relies on the soil born fungi to penetrate and establish on the saffron corms. In other words, a close relationship exists between fungal infection and damage by R. robini on saffron bulbs. It suggest that for improving management strategies in regards of this pest, we should consider the role of saprophytic fungi as a main cause which provides condition for the bulb mite colonization and occurring damage. Further researches is proposed using appropriate methods to suppress soil born fungi and subsequent the bulb mite damage on saffron.

The effectiveness of herbicides is influenced not only by the active ingredients and their toxicity but also by the formulation of the herbicide. Conventional herbicide formulations include wettable powder and emulsifiable concentrate (EC). EC formulations are prepared by mixing the active ingredient with solvents and surfactants. However, these formulations can have negative phytotoxic effects due to hazardous solvents and can be unsafe for operators during application. As an alternative to EC formulations, capsule suspension (CS) formulation has been considered. EPTC is a thiocarbamate herbicide used to control the growth of germinating annual weeds, including broadleaves, grasses, and sedges, in crops such as tobacco in Iran. EPTC acts by inhibiting cuticle formation during the early stages of seedling growth. It is available in formulated products such as emulsifiable concentrate (EC) liquids containing up to 87.8% active ingredient and granular (G) formulations containing up to 25% active ingredient. However, there have been few studies on the production of microcapsule formulations of this herbicide. This experiment aimed to evaluate the weed control effectiveness of EPTC microcapsule formulation, which was synthesized for the first time in Iran. Additionally, the study examined the effect of the herbicide extender, Ammonium thiosulfate, at different doses and application methods.

To investigate the effectiveness of different herbicide formulations and application methods, a three-way factorial experiment was conducted in Tirtash Research and Education Center in Mazandaran province, Iran, during the 2014 growing season. The experiment followed a randomized complete design (CRD) with three replications.
The factors studied in the experiment were:
Herbicide formulation:
Emulsifiable concentrate formulation (Eradicane® EC 82%)
Emulsifiable concentrate formulation with Ammonium thiosulfate
Microcapsule formulation
Herbicide dose:
50% of the recommended active ingredient (2.46 kg a.i. ha-1)
75% of the recommended active ingredient (3.69 kg a.i. ha-1)
100% of the recommended active ingredient (4.92 kg a.i. ha-1)
Herbicide application method

Soil-incorporated pre-planting
Pre-planting
A control plot with no herbicide application was also included. Throughout the growing season, weed density, weed dry weight, and tobacco yield were measured. The relative weed control compared to the control treatment was used to evaluate the efficiency of the different treatments. The collected data was subjected to analysis of variance using Minitab (Version 18), and mean comparisons were performed using the honestly significant difference (HSD) test at a significance level of 0.05.

Based on the relative frequency of weeds, Setaria viridis L. and Amaranthus retroflexus L. were dominant species. The experimental results show the effects of formulation type, application dose and method of application on weed density and weed dry weight and tobacco yield were statistically significant difference. The microcapsule formulation increased weed control efficiency and tobacco yield significantly compared to EC formulation and the highest weed control performance and tobacco yield belong to the soil incorporated of microcapsule formulation with recommended dose.

The results indicated that the utilization of a microcapsule formulation allows for a 25% reduction in the application dose of the EPTC herbicide, without compromising weed control or tobacco yield. Consequently, there were no significant differences observed between applying 75% of the recommended dose using the microcapsule formulation and applying 100% of the recommended dose using the EC formulation, with or without the extender. Based on these findings, it is crucial to promptly mix the herbicide with the soil immediately after spraying in order to maintain the efficiency of EPTC. Furthermore, it was discovered that employing two-thirds of the recommended dose of the microcapsule formulation yields the same level of effectiveness as the recommended dose of other formulations. Additionally, incorporating the EPTC herbicide with soil in all formulations enhanced weed control efficacy. In contrast to previous research suggesting the positive impact of extender adjuvants such as ammonium thiosulfate on herbicide efficiency, this study did not observe similar effects. This discrepancy may be attributed to the varying soil and climatic conditions at the test site.

Introduction Wheat (Triticum aestivum) is one of the most important crops in Fars province and Iran. The area under cultivation of this crop is 337,000 hectares in Fars’s province. The weeds are one of the most famous factors limiting in the production of wheat in Iran and the world. Weeds can decrease grain yield of wheat by competing for resources such as water, light and nutrients and production of allelopathic compounds. If weeds are not controlled at this crop, cause great damage to the wheat. The amount of weed damage in wheat fields of Iran has been reported to be about 20 to 25%. The most important weeds of wheat in Fars are including Mavla neglecta Wallr., Centaurea solstitialis L., Veronica persica L., Carthamus oxyacanthus M.B., Capsella bursa-pastoris, L., Descurainia Sophia (L.) Webb&Berth, Hirschfeldia incana L., Lolium rigidum L., Avena fatua L., Bromus tectorum L. Application of herbicides is the most prevalent method of weed control in wheat fields. There are 26 herbicides registered for weed control in wheat in Iran, which are mainly used post-emergence. Herbicides are recommended for weed control in wheat included of Total, Othello, Atlantis, Geranestar, Bromicid MA, Apiros, Tapik and Axial. Therefore, it is necessary to register new herbicides with different site of action in this crop. This experiment was conducted to investigate the new herbicide efficacy of clodinafop propargil+ metribuzin in control of wheat fields, determination of the most appropriate dose, comparison of the effectiveness of new herbicide with the herbicides was recorded in wheat and the reaction of wheat to the herbicideMaterials and Methods In order to study the effect of herbicides to control weeds of wheat fields, an experiment was conducted during 2020- 2021 at Fars Agricultural and Natural Resources Research and Education Center, Darab, Iran. Plots were located on a clay loam soil with pH 7.9. This experiment was carried out in randomized complete block design with 13 treatments and 4 replications. The treatments included post emergence application of Total (methsulfuron+ sulfosulfuron, 80% WG) at dose rate of 40 g ha-1, Othello (mesosulfuron+iodosulfuron+ diflufenican, 6% OD) at dose rate of 1.6 L ha-1, Tapik (clodinafop propargil, 8% EC) + Geranestar (tribenuron, 75% DF) at dose rates of 0.8 L ha-1+ 20 g ha-1, Tapik (clodinafop propargil) + Bromicid MA (bromoxynil+ MCPA, 40% EC) at dose rates of 1 L ha-1+ 1.5 L ha-1, ACM– 9 (clodinafop propargil + metribuzin, 29% WP) at dose rates of 500, 600, 700 g ha-1, Shagun 21-11 (clodinafop propargil+ metribuzin, 54% WG) at dose rates of 200, 300, 400, 500, 600 g ha-1 and weeding control. The herbicides were applied using a Matabi sprayer equipped with an 8002 flat fan nozzle tip delivering 350 L ha-1 at 2 bar spray pressure. Weed numbers and dry weights were determined in random 0.50-m2 quadrates per plot. The grain yield and biological yield were recorded for a 2 m2 and 0.50 m2 from each plot, respectively. Parameters were recorded including and control percentage of density, weed biomass, plant height, grains per spike, number spikes, 1000 grains weigh, grain yield and biological yield. Statistical analyses of data were done with SAS var 9 software and comparison of mean was tested using the LSD test at 5% level.Results and DiscussionThe weed infestations in the study consisted of Hirschfeldia incana L., Centaurea pallescens L., Veronica persica L., Malva neglecta L., Lolium rigidum L., and Convolvulus arvensis L. Among these weeds, Centaurea pallescens had the highest relative weight at 24%, while Convolvulus arvensis had the lowest relative weight at 8%. In terms of relative density, Veronica persica had the highest value at 44%, while Convolvulus arvensis had the lowest at 7%. Statistical analysis of the data revealed that the application of herbicides significantly reduced weed density and biomass. It also led to increased plant height, number of spikes per m2, grains per spike, 1000 grains weight, grain yield, and biological yield. Visual observations confirmed the effective control of these weeds using the ACM herbicide at a dose rate of 700 g ha-1. The best herbicide treatment for weed control was Tapik+ Bromicid MA, followed by ACM herbicide at a dose rate of 700 g ha-1. The ACM herbicide at a dose rate of 700 g ha-1 resulted in a significant reduction in biomass for Malva neglecta (87%), Lolium rigidum (76%), Hirschfeldia incana (81%), Centaurea pallescens (90%), Veronica persica (86%), and total weed (80%) compared to the weed control. Furthermore, when the ACM herbicide was applied at a dose rate of 700 g ha-1, the grain yield and biological yield were 5.65 and 14.51 tons ha-1, respectively. This treatment also led to a 26% increase in grain yield and a 25% increase in biological yield compared to the control.Conclusion Results showed that applications of powder formulation of clodinafop+ metribuzin herbicide at dose rate of 700 g ha-1 had acceptable weed control efficacy and increased wheat yield. Therefore, the application of clodinafop+ metribuzin (WP) herbicide at dose rate of 700 g ha-1 is suggested for wheat fields.

 The world's population continues to grow, and agriculture must keep pace with increasing demand for food production. Many challenges threaten crop yields, such as herbivorous insects, plant pathogens and weeds, the occurrence or risk of each one often requires the use of pesticides. Despite the usefulness of pesticides in crop protection, their excessive and irrational use can endanger human health and the environment. On the other hand, the very costly application of chemical fertilizers, especially nitrogen, which is a key element in plant nutrition under insufficient soil fertility conditions, can cause groundwater pollution with nitrate and air pollution with nitrogen oxide (21). Although herbicides are intended to protect crops, they can potentially pose a threat to the activity of rhizobium that symbiosis with legumes, thereby reducing the nitrogen fixation of symbionts. If symbiotic nitrogen fixation is adversely affected, crop yield will subsequently be adversely affected (6). All previous studies on the effect of herbicides on crop-rhizobium symbiosis under a certain soil pH have been evaluated. Therefore, it is important to understand the interaction between soil pH and the toxicity severity of herbicides on crop-rhizobium symbiosis, because soil acidification or alkalization (4) can occur over several years in intensive agricultural ecosystems. Therefore, this study aimed to investigate whether the severity of herbicide toxicity on crop-rhizobium symbiosis in different soil pH conditions can be attributed to variations in the electrical charge properties of herbicides. Based on this hypothesis, three herbicides were selected: ethalfluralin, a non-ionic herbicide, imazethapyr, an acidic herbicide, and metribuzin, a basic herbicide (23). The objective was to examine their toxicity on soybean-rhizobium symbiosis under three soil pH levels.
 The soil required for this experiment was prepared from the educational farm of Bu-Ali Sina University of Hamedan, which had a pH of 7.2. This soil is considered as natural soil. Based on a pre-test results on natural soil, adding and mixing 0.2 g sulfur and 5.5 g lime with each kg natural soil could create artificial soils with pH of 6.4 and 8, respectively. The pot experiment was performed in a completely randomized factorial design under open-air conditions. Herbicidal factor included control, pre-planting application of 990 g ethalfluralin ha-1, post-planting application of 450 g metribuzin ha-1and post-emergence application of 108 g imazethapyr ha-1. Soil pH factor was 6.4, 7.2 and 8. Soybean seeds (cv. Hobbit) were disinfected with 1% sodium hypochlorite for five min and washed and dried with water. They were then immersed in commercial soybean inoculum (BiosoyTM) for five min and dried again. Inside each pot, four seeds inoculated with bacteria were planted at two cm depth. Separately, an inoculated seed treatment under natural soil conditions without herbicide application was considered to investigate the effects of seed inoculation. Growth parameters including height, dry weight of stem and root, number and dry weight of nodes formed on root, the nitrogen content of stems and roots were measured and analyzed statistically using SAS software. The means were compared with the LSD test at the level of 5% probability.
In comparing the two treatments of seed inoculation and non-inoculation with a commercial soybean inoculum and their cultivation in natural soil, it was found that seed inoculation had a significant positive impact on various growth parameters. Specifically, it led to increased plant height, dry weight of shoots and roots, as well as nitrogen content in both shoots and roots. Additionally, there was a notable decrease in the shoot-to-root dry weight ratio. Previous studies have also reported similar results, indicating changes in the photosynthetic response pattern due to bacterial seed inoculation in different soybean genotypes (16). In treatments where no herbicide was used (control), soybean nodulation and certain growth parameters were significantly influenced by soil pH. The highest level of nodulation was observed at soil pH values of 7.2 and 8.The lowest number of nodes (21.3 node plant-1) and the lowest dry weight of nodes (491.8 mg plant-1) were also observed in soil with a pH of 6.4. Poor nodulation observed at acidic soil pH may be associated with hydrogen ion toxicity, which may prevent the onset of nodulation, as reported in previous studies (3). The results showed that the toxicity severity of imazethapyr and metribuzin on nodulation (number and dry weight of nodules) depended on soil pH. As the pH of the soil increased, the toxicity of imazethapyr decreased, but the toxicity of metribuzin increased. While the toxicity severity of ethalfluralin on nodulation was not affected by soil pH.
 Despite the advantages of herbicide application, it can have negative effects on soybean-rhizobium symbiosis, limiting the capacity of rhizobium for nitrogen fixation. Consequently, the reliance on chemical fertilizers increases to meet the nutritional needs of soybeans. Additionally, in acidic soils where herbicides are less absorbed by soil particles, further disruption of the soybean-rhizobium symbiosis can occur. Our experiment revealed that the use of metribuzin in alkaline pH soil or imazethapyr in acidic pH soil can cause severe damage to the soybean-rhizobium symbiosis. As soil acidity or alkalinity can change rapidly in agricultural ecosystems due to conventional farming practices such as lime or sulfur addition to adjust soil pH, it is crucial for farmers to consider the electrical charge of herbicides and the pH of their soil. This awareness can help minimize the herbicide toxicity on soybean-rhizobium symbiosis.

 Quinoa (Chenopodium quinoa L.) is a highly nutritional seed crop from the Andean region with huge genetic variability, enabling its cultivation across a wide range of environmental conditions. The area and production under quinoa in the world in 2020 was 189000 ha with 175000 tonnes production. There is some evidence for allelopathic activity of quinoa and this potential could be probably used in terms of integrated weed management. Agronomic practices such as nitrogen fertilization influence weed emergence, growth and competition in a crop. Nevertheless, despite the numerous studies on new and promising crops globally, there is a clear lack of information on the combined effect of weed density and nitrogen fertilizer sources on quinoa crop. Therefore, the purpose of this study was to evaluate the effects of nitrogen fertilizer sources and red root pigweed densities on growth, yield and competitive ability of quinoa (Chenopodium quinoa Willd). This information could be helpful for the overall development of crop and weed management strategies in quinoa crop.
A field study was conducted during the 2021 growing season at the research farm of the School of Agriculture, Shiraz University, to assess the impact of nitrogen fertilizer sources on the growth, yield, and competitive ability of quinoa in the presence of red root pigweed at different densities. The experiment was set up in a split-plot design with nitrogen fertilizer sources (control, urea, sulfur-coated urea, and ammonium nitrate) assigned to the main plots, and red root pigweed densities (0, 5, 10, 15, 20, and 25 plants per square meter) assigned to the sub-plots. There were three replications of each treatment. For the quinoa traits and weed traits, a 2-meter square area was harvested from each plot. Quinoa traits included plant height, leaf area index, number of grains per plant, 1000 grain weight, grain yield, biological yield, and harvest index. The quinoa plants were dried in an oven at 75°C for 72 hours to determine seed yield. Weeds were also harvested from a 2 m2 area in each plot to measure plant height, shoot height, panicle length, and leaf area index. The collected data were analyzed using SAS v. 9.1 software (SAS Institute 2003). When significant differences were found among treatments, mean comparisons were performed using Duncan's multiple range tests at a significance level of P < 0.05.
 The results of the experiment indicated that the use of sulfur coated urea had a positive effect on the competitive ability of quinoa. Weed density had a detrimental impact on various growth and yield parameters of quinoa, including plant height, leaf area index, number of grains per plant, 1000 grain weight, grain yield, biological yield, and harvest index. However, the application of sulfur coated urea mitigated the negative effects of weed density. Specifically, when the highest weed density of 25 plants per square meter was present, the application of sulfur coated urea led to a 1.1-fold increase in plant height, a 2.5-fold increase in leaf area index, a 2.5-fold increase in the number of grains per plant, a 1.1-fold increase in 1000 grain weight, a 2.8-fold increase in grain yield, and a 1.8-fold increase in biological yield compared to the control. At different red root pigweed densities (0, 5, 10, 15, 20, and 25 plants per square meter), the application of sulfur coated urea resulted in significant improvements in quinoa performance. It increased the number of grains per plant by 86.5%, 118%, 139.4%, 168.8%, 149.6%, and 153.4% compared to the control at respective weed densities. Additionally, 1000 grain weight increased by 7.9% to 9.9%, and the ability of quinoa to withstand competition increased by 19.6% to 55%. The findings of this study are consistent with previous research that has demonstrated the positive effects of organic nutrients on reducing weed competition in agricultural systems. It has also been observed that weeds tend to produce more biomass in the presence of fertilizer compared to the control. Therefore, it can be concluded that the improved grain yield of quinoa resulting from the application of sulfur coated urea was primarily attributed to its ability to enhance the plant's competitive ability against weeds.
 The application of sulfur coated urea led to a higher quinoa yield compared to using control. However, weed competition was greater with urea fertilization in comparison with sulfur coated urea fertilizer. In addition, most weeds are highly responsive to soil N, so the application of all fertilizer types should be carefully considered to reduce the competitive advantage of weeds over crops.
Acknowledgements
 We would like to thank the School of Agriculture, Shiraz University for their support, cooperation, and assistance throughout this research.