جستجوی مقالات مرتبط با کلیدواژه « هم افزایی » در نشریات گروه « گیاهپزشکی »

Root-knot nematodes (Meloidogyne spp.) are amongst the most important plant-parasitic nematodes. These nematodes, which bind the roots of sensitive plants, are obligate parasites of plants. Numerous pathogens, including nematodes, fungi, bacteria, and viruses, cause damage to ornamental plants. Damage caused by these pathogens includes crown and root rots, cankers, and leaf blotches, among others. Given the importance of ornamental plant production and the detrimental effects inflicted by root-knot nematodes and root rot fungi on these plants, the current investigation aimed to assess the response of nine ornamental plants to the nematode Meloidogyne javanica. Additionally, the study sought to determine whether Neocosmospora solani, in conjunction with the nematode, could induce a synergistic effect on Ferocactus.

The response of nine ornamental plants to the root-knot nematode was examined in the present study. Upon isolation from the crowns and roots of different cacti varieties grown in greenhouses containing ornamental plants in Ardabil province, the rot fungus was determined to be Neocosmospora solani. The M. javanica population was cultivated in the Plant Pathology Laboratory of Azarbaijan Shahid Madani University. A suspension of M. javanica eggs and larvae was utilized to inoculate ornamental plants with nematodes. To assess the plants' response to the nematode, several plant growth factors and the quantity of knots on the roots were examined. The present study also assessed the synergistic impacts of two nematode and fungal pathogens on specific growth factors of Ferocactus. Both simultaneous and non-simultaneous inoculation techniques were utilized.

Among the plants with knots on the roots, except for tiger Aloe, in the rest of the investigated plants, there were significant differences among the treatments. Based on the comparisons between plants inoculated with nematodes, the highest number of knots was observed on the roots of Begonia plants and the lowest in Echeveria, Ferocactus and Tiger aloe. Notably, Tradescantia spathace was excluded from the analyses as a result of significant nematode damage and subsequent plant mortality. Based on the absence of any damage observed on the shoots and roots of the control plants of this species, it can be categorized as one of the Meloidogyne-sensitive plants. The growth factors examined in plants were similarly impacted in the majority of the plants that sustained significant damage, with begonia plants exhibiting the most pronounced effect. We observed the presence of diminutive, pallid flowers as well as a reduction in the mass of the roots and aerial components in the spotted begonia. Notwithstanding a minor aberration in the morphology of certain roots and aerial organs, no knots of significance were detected in Myrtillocactus. There were no discernible differences in plant growth factors between the control and inoculated plants; therefore, this particular plant can be deemed the most resistant to Meloidogyne among all the plants that were examined. Given that this plant is frequently utilized as a basal component in grafted cacti, this result may prove to be extremely beneficial. In relation to the synergistic assays conducted on the Ferocactus plant, the outcomes of both approaches demonstrated statistically significant differences among the treatments as determined by variance analysis for all the characteristics under investigation, namely shoot length, shoot weight, root length, and root weight. The treatments were inoculated with nematodes, and the control group exhibited the greatest shoot length. These treatments exhibited the shortest shoot lengths when inoculated with nematodes and fungi. The treatments containing nematode and fungus resulted in the shortest root length and weight, while the control plants devoid of nematode and fungus exhibited the greatest root length and weight.

Overall, the findings of the current study demonstrated that root-knot nematodes have a significant capacity to inflict damage upon the ornamental plants under investigation. However, it was also confirmed that M. javanica and N. solani have synergistic effects on Ferocactus plant damage. The results validate the importance of promptly detecting and managing these organisms within greenhouse environments where ornamental plants are cultivated. Therefore, before the beginning of the infection and with the early detection of these diseases, it is possible to prevent the spread and damage caused by the root-knot nematode and root rot fungus in ornamental plants by using integrated management.

Water is the primary carrier for herbicide applications (it usually makes up about 99% of the spray solution) and deliver them to the target weeds that they are intended to control. The quality of water available for spraying will depend on the source of the water on the vineyard, eg. dam or channel. Many chemical elements can be dissolved in water but six major ions make up the dissolved material in most water: Calcium (Ca++), Magnesium (Mg++), Sodium (Na+), Sulfate (SO4-), Chloride (Cl-), and Bicarbonate (HCO3-). Hard water becomes “hard” because of the presence of carbonates, sulfates, and chlorides of calcium, magnesium, and iron. Water containing calcium and magnesium can reduce the effectiveness of post-emergence herbicides that are weak acids include glyphosate (Roundup), paraquat (Gramaxone), bentazon (Basagran), clethodim (Envoy), sethoxydim (Poast), nicosulforun (Cruise) and 2,4-D (many products).Nicosulfuron is a post-emergence sulfonylurea herbicide that act through inhibition of acetolactate synthase (ALS) and controls many difficult-to-manage monocotyledonous weeds at low rates in corn. Also, 2,4-D is a selective herbicide from the group of auxin-like herbicides that act systematically to control broadleaf weeds in cereals. "Mixing herbicides" can be used to reduce the effect of hardness factors in the water carrying herbicides. The purpose of a good mix is to increase the effect of the compound on weeds without damaging the crop. The primary reasons that herbicides are mixed are to improve bioactivity and reduce costs. Therefore, the application of mixing reduces labor costs, the number of crossings across the farm, equipment depreciation, and mechanical damage to the crop and soil. Interactions of two herbicides can occur in three ways: each herbicide has an independent mode of action (additive effect); one herbicide reduces the action of another herbicide (antagonism), and one herbicide increases the presence of another herbicide (synergism). The question is whether the synergistic effects that occur in some conditions in the mixing of two herbicides can be used to reduce the negative effects of hard water on the performance of hard water sensitive herbicides? Therefore, this study was conducted to evaluate the effect of water hardness on the efficacy of nicosulfuron and 2,4-D tank mixing on the control of velvetleaf (Abutilon theophrastis Medicus.).

 The effect of mixing nicosulfuron (Cruse- OD4%) and 2,4-D amine (U46- SL72%) herbicides on velvetleaf (Abutilon theophrastis Medicus.) weed control in the presence of hard agents carried out as factorial arrangement based on randomized complete block design with three replications at the Research Greenhouse of Ferdowsi University of Mashhad in 2019. The first factor of water hardness applied in four levels including deionized water (non-hard), 0.1 M concentrations of CaCl2, MgCl2, FeCl3 salts (Merck, Darmstadt, Germany). The second factor was mixing nicosulfuron and 2,4-D amine herbicides as 6.25, 12.5, 25, 50 and 100% of the recommended dose. The mixing ratios were (0:100), (25:75), (50:50), (75:25) and (100: 0). In addition, 10 pots were considered as control without spraying.Velvetleaf seeds were collected from a heavily infested corn fields in Mashhad, Khorasan Razavi province in northeastern part of Iran. To obtain uniform seedlings, seeds were treated by sulfuric acid 98% during 1 min. Seven seeds pre-germinated in petri dishes were transplanted at 1 cm deep in 1 L plastic pots in a mixture of soil, sand and cocopeat (1 : 1 : 1 wt ⁄ wt ⁄ wt) containing all necessary macro- and micronutrients. The pots were kept in a greenhouse at natural daylength and a temperature around 25°C during the day. The pots were sub-irrigated daily. Prior to herbicide application, plants were thinned to five uniformly sized plants per pot.The herbicide solutions were applied at the 3-4 leaf stage of the weed using a cabinet sprayer equipped with a flat fan nozzle (No.11004) delivering a spray volume of 390 Lha-1. A four-parameter log-logistic model (equation 1) was fitted to the data using the open-source statistical software R 2.6.2 and the drc statistical addition package.   Y=c+[d-c ⁄ 1+exp[b(log x-log e)]]   (1)where Y is the response expressed as percentage of the untreated control, c and d are the responses at very high and very low herbicide rates, respectively, b is the slope of the curve around the point of inflection, and e  is the herbicide rate giving response halfway between d and c (=ED50). If c = 0, then the four-parameter model reduces to the three-parameter model (equation 2), with the lower limit being zero.   Y=d ⁄ 1+exp[b(log x - log e)] .

The results showed that the net effects of herbicides were affected by hard water factors such as calcium, magnesium and iron III chloride. Besides, their efficiency in controlling biomass, survival percentage and height of velvetleaf were decreased. The inhibitory effect of hardness factors on herbicide performance was different. Calcium chloride and magnesium chloride had the highest reduction effect on nicosulfuron and 2,4-D amine, respectively. Therefore, to reduce the effect of water hardness factors, two herbicides were evaluated by mixing. The results indicated that the type of effect on herbicide mixing in biomass control of velvetleaf was synergistic, and reduced antagonistic effect of water hardness factors. Equal proportions of both herbicides in reducing the effect of calcium chloride and iron III chlorides, high ratio of nicosulfuron in reducing the effect of magnesium chloride, had the best performance in controlling the biomass of velvetleaf. Therefore, depending on the salts involved in the water hardness of the sprayer tank, changing the mixing ratio of the two herbicides nicosulfuron and 2,4-D amine can be achieved the best performance control of velvetleaf.

Today, the control of Rhynchophorus ferrugineus Olivier (Coleoptera: Curculionidae) as quarantine and destructive pest of date plantation due to the inner parts of the tree trunk is limited to chemical control that indiscriminate application of different types of pesticides such as imidacloprid has caused the resistance of this insect. In this study, the lethal effect of botanical compounds including garlic essential oil and its secondary metabolites (diallyl disulfide, diallyl trisulfide) and eucalyptus essential oil and its secondary metabolites (1,8-cineole, aromadendrene) on enzymatic activity (general esterases, glutathione S-transferase, acetylcholinesterase in red palm weevil were studied and compared with imidacloprid (commercial form and technical substance).

Adults (Male and female) of R. ferrugineus (red palm weevil) were collected from infected date palm plantations in Saravan (Iran) and transferred to the laboratory for propagation (25±3°C, 60±5% relative humidity, 12:12-h light: dark cycle). Bioassay tests were performed on larvae of the same age (2nd instar). The toxic effects of all compounds were investigated separately and in binary mixtures. The bioassay experiment was performed using a topical-fumigant method in three replications (10 larvae per replicate) in a completely randomized design. Two μl of different lethal concentrations (LCs) of chemicals were poured on the anterior part of the 2nd instar larval thorax and they were transferred to 8 cm Petri dishes. The mortalities were recorded 24 hours after treatment. Lethal concentrations of LC25 and LC50 were calculated using SPSS software version 21. Then, binary mixtures of LC25 and LC50 concentrations (LC25+LC25, LC50+LC25, LC50+LC50) of the studied compounds were performed to investigate the additive, synergistic, and antagonistic effects with a similar bioassay method. Enzymatic assays were performed using conventional methods. The effect of these binary mixtures, as well as LC25 and LC50 values of the individual status of each toxic compound on the activity of the mentioned enzymes, were evaluated 24 hours after treatment. Lethal concentrations (25 and 50%) and inhibition concentration of 50% of acetylcholinesterase (IC50) activity were calculated using the probit model and SPSS (v. 21). Scatter diagrams and regression lines between different concentrations of chemicals for inhibition of acetylcholinesterase were calculated with Sigma Plot software version 12.3. Also, the comparison between lethal concentrations was performed using the ratio of lethal concentrations and 95% confidence interval. In addition, the mean comparison between the data obtained from biochemical experiments with SPSS software (v. 21) and the Tukey test was performed at a 5% level.

The LC25 and LC50 values of garlic essential oil, diallyl disulfide, diallyl trisulfide were calculated as "9.23 and 23.61", "2.33 and 4.64 ","2.75 and 5.01 "µL mL-1; for eucalyptus essential oil, 1,8-cineole, aromadendrene were as "12.46 and 33.41", "4.26 and 7.83", "3.68 and 7.84 " µL mL-1 and for commercial form and technical substance imidacloprid were as" 0.012 and 0.025 "and" 0.009 and 0.004 µL mL-1, respectively. Results showed that the binary mixtures of LC50+LC50 including "diallyl trisulfide+imidaclopride technical substance", "diallyl trisulfide+aromadendrene","diallyl trisulfide+1,8-cineole","diallyl disulfide+technical substance imidacloprid","diallyl disulfide+aromadendrene","diallyl disulfide+1,8-cineole" had synergistic effects. The results showed a significant increase in general esterases and glutathione S-transferase activity in the larvae treated with the individual status and binary mixtures. A significant decrease in acetylcholinesterase activity was observed in all treatments. Results showed that the lowest and highest concentrations of the studied toxic compounds for 50% inhibition of acetylcholinesterase activity were obtained by 0.328 mg ml-1 of "diallyl trisulfide+1,8-cineole" and 4.485 mg ml-1 of garlic essential oil, respectively. In addition, the results showed that the highest (80.30%) and lowest (6.50%) levels of acetylcholinesterase inhibition were obtained by 2 μl ml-1 of "diallyl trisulfide+1,8-cineole" and 0.1 μl ml-1 of the commercial form of imidacloprid.

Despite the better control of red palm weevil after treatment with imidacloprid compare to botanical insecticides (essential oils and secondary metabolites), however, the resistance to this pesticide has been demonstrated because of long-term exposure. Therefore, according to the results of the synergistic effects of secondary metabolites together or even with imidacloprid, a decrease in the activity of detoxifying enzymes, as well as acetylcholinesterase, was observed, which may indicate the key point that these enzymes have not been able to eliminate these binary mixtures from the hemolymph of red palm weevil, so they could play an effective role in the management of this pest. Therefore, it can be hoped that plant essential oils can control red palm weevil in palm plantation alone or in binary mixture together or with other conventional pesticides. Further studies are needed to make a more confident decision in this regard. One of the problems of plant essential oils as well as their secondary metabolites is the low stability of these compounds in the environment, so one of the issues that can be paid more attention to is increasing their stability in the environment and how to release them in the environment, which can be done with various formulations such as nanoformulations, in particular, assume to solve this problem. Therefore, the study of the stability and formulation of plant essential oils and their secondary metabolites in the environment is a topic that should be considered in future research to be able to implement the potential ability of these compounds in agricultural pest management in practice.

The aim of this study was to evaluate toxic and synergistic effects of ecdysoids compounds and diatomaceous earth on their integrated control along with the entomopathogenic fungus, Metarhizium anisopliae on date palm horned beetle larvae. In this study, the evaluated ecdysoids were Atabron, Dimilinand Nimazol. The fungal mycelium growth and spore germination were evaluated to checking the consistency of the ecdysoids compounds by extract medium mixing method. Then, the toxicity of compounds individually and in conjunction with pathogen M. anisopliae was evaluated by bioassay method. Studies revealed that mycelial growth and spore germination of M. anisopliae occurre in all ecdysoids compounds. The highest compatible index was 76.89 for concentration of 500 microliters per liter of Nimazol extract and the lowest level consistent with the incorporation of Dimilin in 1000 microliters per liter concentration. The combination of ecdysoids compounds with fungal pathogen M. anisopliae had synergistic effect on larval developmental stage of date palm horned beetle. The synergistic effect of Nimazol was higher. The use of diatomaceous earth showed mortality of horned beetle larvae with average lethal concentration equal to 1269.7 mg per liter. It also has synergistic effects on toxicity of fungal pathogen M. anisopliae and anti-synthesis chitin componds. The most powerful synergistic effects were observed in terms of mixing 50 percent lethal concentrations of diatomaceous earth, Nimazole and M. anisopliae.

Oxalis corniculata and Artemisia absinthium plants are widely used in Iranian folklore medicine. The aim of this study was to evaluate the antibacterial activity and determination of phytochemical composition of leaves of these two plant species in northern Iran against tomato pathogenic bacteria in vitro. In this study, the antibacterial activity of aquatic and methanolic extracts of leaves of two plants on Xanthomonas, Pseudomonas and Pectobacterium isolates was performed by disk diffusion methods on agar and macrodilution broth to determine MIC and MBC values. The results showed that the herbal extracts used had antibacterial activity in the inhibitory range of 9 to 19 mm relative to the streptomycin antibiotic (25 mm). MIC and MBC values were 32 to 512 mg/ml according to the microdilution method, respectively. The composition of both extracts indicated the presence of saponins, phenolic compounds, anthraquinone, tannins, flavonoids, steroids and terpenoids, alkaloids, phlobatannin and volatile oils. The highest inhibitory effect was seen as a result of the synergistic activity of the aquatic extract of Oxalis corniculata and methanol extract of Artemisia absinthium (11 to 17 mm). Based on the results obtained, the combined effects of the two plants can be useful as a practical component in the preparation of herbal drug formulations.

Fusarium root rot of common beans is an important economic disease in Iran. It is broadly suggested that farmers use ecofriendly methods of plant disease management, compatible with the sustainable agriculture to minimize the application of pesticides in the fields. The current study was conducted to investigate the effectiveness of native rhizobium, mycorrhiza and chemical treatment. The experiment was carried out in a randomized complete block design in a field experiment at Sarab Changaie Research Station in 2017 with Ofogh red-bean cultivar. The trial treatments exerted as follow, superior native rhizobium isolate Rhizobium etli b.v. phaseoli (CCSM_B011401)(R), Rhizophagus irregularis(M2), Rhizophagus irregularis + Funneliformis mosseae (M1+M2), R. irregularis + F. mosseae + R. etli b.v. phaseoli (R+M1+M2), R. irregularis + R. etli b.v. phaseoli (R+M2), fungicide treatment and control.Rhizobium powder was applied as seed treatment and mycorrhiza was added directly in seedbed during the sowing of seeds. The best result was achieved from co-inoculation of arbuscular mycorrhiza fungi and indigenous rhizobium, which showed a significant increase of the number of seeds per pod, 100 seeds weight, grain yield and biomass yield as 34, 24.9, 51.6 and 38 percent compared to control. In addition, the co-inoculation treatment reduced the incidence of bean root rot disease up to 89%. Results indicated that the synergism of indigenous rhizobia and arbuscular mycorrhiza could be useful for managing of common bean root rot disease, reducing the use of pesticides and producing the crop in a sustainable and optimized manner.

The assessment of the effect of mixtures could be based on various concepts whether we work within toxicology, pharmacology or weed control. Combinations of certain herbicides can give better weed control than use of the individual herbicide alone and/or loss of weed control when use of certain other herbicides in combination. Predicting the joint action of mixtures is extremely difficult, unless the compounds are known to interact at the same site of action. These most common methods to analyze the joint action of herbicide mixtures are the Additive Dose Model (ADM) or the Multiplicative Survival Model (MSM). The ADM assumes the two compounds have similar modes of action (do not interact) in the receiver plant, i.e. effective doses of each component will not change by mixing. ADM has been widely accepted as a valid method to estimate joint action of mixtures sharing the same or similar action mechanisms in the receiver plant. MSM has been reported to yield more accurate results for mixture toxicity than ADM do when the components exhibited different or dissimilar modes of action in the receiver plant. ADM or Concentration Addition (CA) is used here to test for deviation of additivity of doses using the ADM isoboles as reference; any deviation from the ADM is characterized by antagonism when the efficacy of a mixture is lower than predicted by the reference model and synergistic when the efficacy is higher than predicted.
In order to determine joint action of some usable important broadleaf herbicides in sugar beet, six experiments were conducted at the research glasshouse in Faculty of Agriculture, Ferdowsi University of Mashhad, Iran. The plants were sprayed with seven doses of commercial formulation of desmedipham phenmedipham ethofumesate (Betanal Progress- OF®, 427 g a.i. L-1, Tragusa, Spain), chloridazon (Pyramin®, 1361 g a.i. L-1, BASF, Germany), clopyralid (Lontrel®, 149 g a.i. L-1, Golsam, Gorgan, Iran) either alone or in binary fixed-ratio mixtures of the three herbicides. The ratio of the herbicides of the binary mixtures were chosen with the aim of obtaining a contribution to the overall effect of the two herbicides of 100:0, 75:25, 50:50, 25:75, and 0:100 for seven-mixture-ratio experiments. Spraying was performed by overhead trolley sprayer (Matabi 121030 Super Agro 20 litre sprayer), 8002 flat-fan nozzle at 300 kPa and a spray volume of 200 Lha-1. The plants were treated at 21 days (at the four- to six-true leaf stage) after planting. Dose-response curves were estimated by fitting a three log-logistic dose–response model against dose for ED50 and ED90 response levels. ADM was used as reference model of joint action with their equations. As the results with the herbicide mixtures originate from up to twelve separate experiments it was necessary to standardize the x- and y-axes so that the ED50, ED80 and ED90 doses of the herbicides applied separately were always fixed to 1.
Results The results showed that mixtures of chloridazon and clopyralid were less phytotoxic than predicted by ADM particularly in Amaranthus retroflexus at ED50 and ED80 response levels. These binary mixtures of herbicides were either followed ADM or less than predicted by ADM in Solanum nigrum. In contrast, mixture of desmedipham phenmedipham ethofumesate and clopyralid was synergistic in both species. Whereas desmedipham phenmedipham ethofumesate and chloridazon binary mixture was synergistic in Solanum nigrum to followed according to ADM in Amaranthus retroflexus.
The present study has revealed that mixtures of photosystem II, lipid biosynthesis and auxin inhibitor herbicides either followed ADM, or performed better than predicted by ADM, i.e. applying mixtures of these herbicides will not result in an excessive use of herbicide compared to applying the herbicides separately. In contrast, mixtures of chloridazon and clopyralid were trend antagonistic and the two herbicides should not be applied in mixture.

Mixed infection of plants with more than one virus results in different types of interactions. Interaction between two recently identified lettuce infecting viruses in Iran, Lettuce X potexvirus (LeVX) and Rubus Chlorotic Mottle sobemovirus (RuCMV), was studied on co-infected Chenopodium murale and Chenopodium quinoa plants. Plants were mechanically inoculated with either LeVX, RuCMV or both. Co-infected plants of C. quinoa developed much more severe symptoms than the singly infected ones, with enhanced RuCMV accumulation level, as determined by quantitative ELISA and Western blot assay, indicating that the interaction of RuCMV with LeVX is synergistic in C. quinoa. Co-infection of C. murale plants resulted in symptom severity while with no detectable increase in RuCMV accumulation level, indicating that RuCMV interaction with LeVX is not synergistic in this plant. Conversely, LeVX accumulation level in either of C. quinoa or C. murale dually infected plants was significantly reduced, suggesting that LeVX interacts with RuCMV antagonistically in co-infected plants of both Chenopodium species.

In the course of the present study, samples were taken from the non-defoliant strain of Verticillium dahliae (SS-4) from infected olive groves in Toshan area in Southern Gorgan. Root-knot nematode, Meloidogyne javanica, was recovered from infested olive seedlings and after identification was reaned on tomato seedlings cv. Rutgers. During the study, one-year-old seedlings of olive cultivars Zard, Roghani, Koroneiki (resistant to verticilliosis) vs. Manzanilla (sensitive to verticilliosis), were transplanted to pots containing 2000g of sterilized sandy loam soil. The experimental study was conducted in a completely randomized design of 32 treatments and five replications. Treatments consisted of: control, mere nematode, fungus alone, and fungus + nematode. Pots were inoculated with (2000, 3000, 4000) J2 of the nematode and/or (10 no/g soil) microsclerotia of fungus as according to the treatments. Pots were placed on glasshouse benches at a temperature of 25-27°C and in natural light. The experiment was terminated after 10 months past with the following parameters determined: fresh weight of root and stem, no. of galls and egg masses per each root system, percentage of incidence of symptom on aerial parts, browning of vascular tissue, decrease in seedling height and stem/root tissue colonization by the fungus. Results indicated that presence of nematode caused reduction in colonization of the fungus in the root and stem and vice versa, meaning that presence of fungus caused reduction in no. of galls and egg masses produced by the nematode. This was when a maximum percentage of disease symptoms on aerial parts was observed in fungus + nematode treatments. Severe fungal wilt on aerial parts of Zard cultivar was observed in fungus + nematode treatments and mild fungus wilt was observed in mere fungus treatments and in the case of Koroneiki cultivar. The reduction of gall and egg mass production in root system occurred respectively in cvs. Manzanilla, Zard, Roghani and Koroneiki cultivars (p?0.05).