فصلنامه مطالعات حفاظت گیاهان
سال سی و هفتم شماره 2 (تابستان 1402)

Rice is one of the most important grains in the world and large part of its consumption is related to Middle East. Iran ranks 23rd in production, 26th in cultivation, and 13th in rice consumption with nearly 560,000-hectare rice lands and an annual production of nearly 2.5 million tons. In natural and agricultural ecosystems, plants are associated with large populations of microorganisms in the rhizosphere, endosphere (inside the root), leaves (phyllosphere), as well as pollen and seeds. These microorganisms spend all or part of their life cycle inside the healthy tissues of host plant without any obvious sign of disease. The stable coexistence between endophytes and plants is due to production of biological secondary metabolites with a unique structure, which positively affects the survival of plant growth in adverse conditions. Studies have shown that endophytic fungi increase resistance to drought, insects, diseases and host tolerance level, especially in stress conditions. Considering the increase in the risk of dehydration and the lack of sufficient water resources and the development and adoption of aerobic rice cultivation, it is important to identify endophytic fungi that increase tolerance to drought stress and improve the growth factors of the host plant. There are relatively few studies on endophytic fungi that colonize healthy tissues of rice plants under aerobic conditions. Therefore, the aim of this study is to evaluate endophytic fungal collections in different parts of aerobically cultivated rice plants.

In this study, in order to identify endophytic fungi in aerobic cultivation of rice in Golestan province, sampling were carried out from several aerobic rice fields in Golestan province, including Gorgan, Kordkuy, Bandar Gaz, Aliabad and Kalaleh cities during the months of May to September in 2019-2020. Plant tissues were transferred to the laboratory (Department of Plant Protection) in separate paper bags along with specifications. Purification was performed on a 2% water-agar medium using Hyphal tip method. Based on investigations and morphological data, a number of isolates were selected as representatives for molecular identification. Genomic DNA was extracted from mycelia grown in PDB (Potato Dextrose Broth) culture medium according to the CTAB method with a slight modification, and the polymerase chain reaction (PCR) was performed according to Nemati and Abdulhazadeh method. The ITS region (ITS4-5.8S-ITS5) of the selected isolates was amplified during the PCR reaction using ITS5 (5'-GGAAGTAAAAGTCGTAACAAGG-3') and ITS4 (5'- TCCTCCGCTTATTGATATGC-3') primers and The β-tubulin region was amplified by T1 (5'-AACATGCGTGAGATTGTAAGT-3') and β Sandy-R (5'-GCRCGNGGVACRTACTTGTT-3') primers. Purification and sequencing of PCR products was done by Pishgam Biotechnology Company. The sequences of ITS and β-tubulin regions were modified and extracted using Chromas 2.6.6 software. Nucleotide sequences of the selected isolates were compared with the available sequences in the Gene bank by Blast algorithm and the sequences data were submitted in the NCBI database website. Phylogenetic trees were drawn using the Maximum likelihood method and MEGA 6.06 software.

Based on preliminary morphological studies, 20 isolates were selected as representatives of purified isolates and were identified by molecular analysis. In this study, a total of 39 fungal isolates were obtained, that the highest number of the isolates belonged to the pods of rice plants with the frequency of 17 isolates and the lowest number of isolates belonged to the roots of rice plants with 10 isolates. Among the 6 genera identified in this research, the largest number of isolates was belonged to Alternaria and Fusarium genera, with 18 and 6 isolates, respectively, and the highest number of species was belonged to Fusarium genus with 6 species. Fungal species include: F. chlamydosporum, F. proliferatum, F. incarnatum, F. solani, F. fujikuroi, F. verticillioides, S. bactrocephalum, N. sphaerica, N. oryzae, A. alternata, E. nigrum, C. cladosporioides. Among these species, Nigrospora sphaerica, E. nigrum and S. bactrocephalum are reported for the first time in this study as rice plant endophytes in Iran.

Investigation of endophytic fungi in the present study indicates that some of these isolates, including F. chlamydosporum, F. proliferatum, F. fujikuroi are pathogenic fungi. It means that range of the endophytic life and pathogenic life cannot be separated and determined and environmental conditions and nutritional status determine the type of interaction. F. chlamydosporum causes Fusarium root and crown rot, is reported in some sources as an endophytic fungus in various plants.

One of the most effective ways to preserve biodiversity is to convert conventional systems into organic ones. The organic farming system reduces the negative effects of intensive management. The biomass of the soil ecosystem has different responses in management methods including tillage, fertilizer and defense inputs, and organic modifiers. Understanding the role and responses of biomass in different cropping systems is essential to support sustainable horticultural practices in managing plant-parasitic nematode.

Sampling has been done from two organic farming systems, conventional and pasture, in order to identify the morphology of soil plant parasitic nematodes, soil physicochemical characteristics, and microbial respiration. Plant parasitic nematodes were extracted, killed, fixed, and transferred to glycerin and permanent slides were prepared. The effect of the type of cultivation system on the abundance and diversity of plant parasitic nematodes in common and organic apple and peach orchards compared to pasture were investigated by multivariate analysis of variance (MANOVA) in Xlastat 2020 software.

20 Genera belonging to 11 families of plant-parasitic nematodes were identified, which had different frequencies based on the type of cropping systems and crops. The comparison of the type of organic cultivation system with the common showed that it had a significant effect on the frequency and diversity of plant parasitic nematodes; the highest frequency of the nematode genus in organic peach cultivation system is Gracilacus and the lowest frequency is Scutylenchus genus in common apple cultivation. The abundance of nematode family in organic system is more than common and the abundance of nematode family in peach organic system is more than apple organic system. It should be mentioned that the common apple system is close to pasture in terms of abundance. The abundance of nematode family in the common system of peach is more than the common system of apple. The type of cultivation system had a significant effect on the frequency and diversity of Pratylenchus, Helicotylenchus, Tylenchus, and Rotylenchus genera, while it did not have a significant effect on the  Gracilacus genus. Type of host plant had a significant effect on the frequency and diversity of plant parasitic nematodes definitely in all soil condition variables. The type of host plant was significant on the frequency of all plant nematodes except Tylenchus and a significant effect on the diversity of all except Tylenchus and Rotylenchus. Among all soil factors, microbial respiration, EC, OC, K, P, and texture (percentage of soil particles including sand, silt, and clay) showed a significant effect on all lineages of nematodes.

Significant differences in community structure in plant parasitic nematode communities in three systems were recorded. The results of the present study have shown that the frequency and diversity nematodes are different from the results of other researchers in apple and peach orchards, that plant types and cultivars, basic genotype, or soil management practices affect the composition of plant parasitic nematode community groups. In this study, the abundance and diversity of nematode in the organic system was more than in pasture, and conventional agriculture with more than 10 years of history, including tillage and chemical inputs, and organic matter loss, erosion, and low in the soil agroecosystem. The reduction of the plant parasitic nematode in the conventional system compared to the organic system is caused by the reduction of organic matter, tillage, or chemical inputs. The results showed that the type of product and management practices affect nematode communities. The composition of soil nematode communities is significantly different in organic, conventional, and pasture farming systems. The organic peach and apple system is facing an increase in nematodes more than conventional. It seems that plant parasitic nematodes are sensitive to soil management practices. Soil nematodes are useful indicators to evaluate the intensity of management and sustainable management of horticultural ecosystems on soil ecosystem performance; because they have several feeding habits in soil, and micronutrient networks and play an important role in the food cycle, pest suppression, and regulation of microbial communities. There were high pest pressure of nematodes in the organic peach farming system in comparison to the apple farming system. In this research, apple is better than the peach for organic production in Damavand orchards. In addition, growers consider peaches better than apples due to market and price considerations. With the increase in the demand and price of organic products, the organic system is facing high pest pressure due to fewer management options compared to the conventional system, which requires the development of integrated plant nematode management strategies.

The seeds of common bean plants (Phaseolus vulgaris) are among the most important food sources worldwide. The plant pathogenic fungus Rhizoctonia solani causes seed rot and seedling damping-off of bean plants and is one of the most important soil-borne pathogens in most cultivation areas of this plant. R. solani plays an important role in reducing the yield and quality of this crop. Biological control is a promising, effective, and sustainable solution for managing soil-borne fungal diseases. The simultaneous use of biological control agents, especially agents with different mechanisms of action, might increases the chance of success in disease management. Indeed, two living agents can show different types of interactions based on their inherent characteristics and ecological conditions. In the current research, the potential of co-application of mycorrhizal fungi and bacterial strains from different taxonomic groups was evaluated on increasing the growth of beans and suppression of bean damping-off.

In this research, the effect of 14 different bacterial strains on the mycelial growth of R. solani was investigated by dual culture and by the volatile compound production tests in the laboratory. The list of bacterial strains included: Bacillus megaterium B15, Bacillus thuringiensis B48Pet, Bacillus subtilis BS (B.s), B. subtilis AS, Lysinibacillus boronitolerans RUPB71 (Lysin), Pseudomonas putida RUP1, Arthrobacter citreus B27Pet, Alcaligenes faecalis 1624, Bacillus pumilus INR7, Bacillus thuringiensis 32B (B.thur), Azotobacter vinelandii RUA1 (Azoto), Delftia tsuruhatensis PIIR (Delft), Stenotrophomonas maltophilia S37 and Bacillus velezensis JPS19 (B.vel). In the dual culture test, B.s, B.vel, Alca, Azoto, Lysin, and Delft strains significantly reduced the mycelial growth of the pathogen. In volatile compounds production test, three strains, Alca, Azoto, and B.thur, significantly reduced the mycelial growth of the pathogen. Four bacterial strains, including B.s, B.vel, Alca, and Azoto, were selected for greenhouse experiment. The selected bacterial strains as separate and combined application with two species of arbuscular mycorrhizal fungi (AMF), including Funneliformis mosseae (F.moss) and Glomus claroideum (G.cla) were investigated for inhibiting the disease caused by R. solani, and for their effect on the growth parameters of bean plants in the presence of the pathogen. The greenhouse experiment was conducted as a completely randomized design with 16 treatments and five replications.

Many of the greenhouse treatments that were applied in this study, significantly reduced the severity of the disease compared to the diseased control. They significantly increased the fresh and the dry weight of the shoots, root fresh weight and root dry weight. Four treatments (F.moss, B.s, Alca and Azoto) significantly enhanced the root length and four treatments (Alca, B.s, B.vel+G.cla and Alca+G.cla) increased the shoot length. In terms of the effect on the disease, the B.s strain was the best treatment, which reduced the disease severity by 36.5% and showed the greatest effect in promoting the vegetative characteristics of the plant. Although the bacterial and mycorrhizal strains showed compatibility in many combined treatments, G.cla+B.vel was the only double treatment that showed an increasing effect on the fresh weight and shoot length compared to the separate applications. The other double treatments did not have an additive or synergistic effect in reducing the disease and improving plant growth. Even in some double treatments, in terms of reducing disease and improving plant growth, a weaker effect was seen than their single treatments. Among different treatments, Alca+G.cla and Alca+F.moss showed the highest and B.s+G.cla showed the lowest mycorrhizal colonization.

The effect of bacteria on mycorrhizal colonization was increasing, decreasing, or null depending on the combination of bacterial and mycorrhizal strains used. In many cases, there was no direct relationship between the amount of mycorrhizal colonization and disease control. Overall, before the commercial use of the combination of biological agents, it is necessary to check their interactions in greenhouse and field experiments and ensure their compatibility and lack of antagonistic effect on each other. If the biological agents present in a consortium are compatible, its biocontrol effect will be more stable, efficient and reliable, and it will be possible to use it in a wider range of variable soil ecological conditions. Moreover, the interaction of individuals within a given consortium is strain-specific, and the results of an experiment on specific strains cannot be generalized to other strains of the same species.

Trogoderma granarium (Everts) is an economic insect pest of stored grains in Iran and many tropical and subtropical regions. If stored products contaminated with this insect are consumed by humans, it would cause serious digestive diseases. To control T. granarium in storage, chemical insecticides and fumigants are often used, but due to their extreme toxicity to humans and other dangerous side-effects, their application has been limited. Therefore, in order to develop alternative control methods with minimal harmful effects to humans and other non-target organisms, there is a need to understand feeding performances of the pest on different cultivars. The use of insect-resistant plants is one of the effective methods in integrated pest management programs. Study of nutritional indices of stored product insects is one of the important methods of measuring the resistance in plant cultivars.

Nutritional indices of T. granarium larvae were investigated using the gravimetric method provided by Wadbauer (1968). The grains of wheat genotypes including N-91-9, Heidari, Aftab, Tirgan, N-92-19, Gaskojen and Kouhdasht were crushed using a grinder. Then, first instar larvae were reared on the grains of these genotypes under 33 ± 1°C, 65 ± 5% R.H., and 14:10 (L:D) h. After emergence of fifth instar, the weight of larvae, before and after feeding, and the amount of grain eaten by the larvae were measured. The data were analyzed using one-way ANOVA using SPSS ver.16. Then, Tukey's HSD test, with a probability level of 5%, was used to investigate the statistical differences among the means.

There were significant differences in the nutritional indices of T. granarium fifth instar larvae on grain of different wheat genotypes. The larvae raised on line N-91-9 had the lowest weight of food consumption (24.33 ± 3.38 mg/10 larvae) compared to other genotypes tested. Larvae fed with line N-91-9 (5.33 ± 0.33 mg/10 larvae) and cultivars Aftab (3.00 ± 0.57 mg/10 larvae) and Heidari (3.00 ± 0.57 mg/10 larvae) showed lower weight gain than those fed with other genotypes. The highest efficiency of conversion of ingested food (ECI) was on cultivars Gascojen (36.56 ± 1.46 %) and Tirgan (33.42 ± 0.60 %), and the lowest was observed on cultivars Aftab (7.32 ± 1.51 %) and Heidari (7.86 ± 1.38 %). The highest relative consumption rate (RCR) was found on cultivar Gascojen (1.08 ± 0.05 mg/mg/day) and line N-92-19 (0.95 ± 0.02 mg/mg/day), and the lowest was seen on line N-91-9 (0.16 ± 0.03 mg/mg/day), and cultivars Heidari (0.19 ± 0.02 mg/mg/day) and Aftab (0.24 ± 0.02 mg/mg/day). As compared with the other examined genotypes, the relative growth rate (RGR) was the highest on cultivar Gascojen (0.394 ± 0.022 mg/mg/day). Larvae feeding from cultivar Gascojen (5.61 ± 0.17 mg/day) had the highest growth rate (GR), and larvae feeding from line N-91-9 (0.76 ± 0.04 mg/day) and cultivars Heidari (0.42 ± 0.08 mg/day) and Aftab (0.42 ± 0.08 mg/day) had the lowest GR value. The change in the nutritional indices of T. granarium larvae can be due to the differences in physical and chemical characteristics of the grains of tested wheat genotypes. The ECI index represents the ability of an insect to use eaten food to increase its body size and weight. In other words, the increase in ECI value on cultivars Gaskojen and Tirgan indicates the high ability of fifth instar larvae to convert the eaten grain into body biomass. This finding may be due to the high protein content and low grain hardness of these cultivars. The low weight of food eaten and body weight in larvae fed with cultivar Heidari and line N-91-9 may be due to the high grain hardness of these genotypes.

Our results showed that line N-91-9 and cultivars Heidari and Aftab had lower nutritional value than the other tested genotypes for T. granarium larvae, because the amount of food eaten, larval weight gain and nutritional indices of larvae fed with these genotypes were lower than other genotypes tested. So, these two genotypes can be used in genetic engineering programs to minimize the damage of T. granarium. The presence of defensive chemical compounds, grain hardness or the lack of essential nutrients for the development of the pest may be the reason why some of the tested cultivars are unsuitable for T. granarium feeding.

Tehran, in terms of extent, is the 26th megacity of the world. Tehran’s urban green landscape per capita is 15.5 square meters per person. Weeds annually financially damage green landscapes in Tehran, the cost of weed management in a lawn is 1500 rials per square meter. One of the tools and methods that can improve weed management is to map their distribution. These map help researchers. 1- Areas affected by the population of different species. 2- Identify areas of the invasive weed infested areas. So far, the study of community structure and species diversity in weeds in the green space of Mashhad, Khorshid park Mashhad, and grass fields of Shiraz University have been done, but a similar research has not been done in Tehran. A research was conducted in parks of 22 districts of Tehran in order to assess, specify diversity, density, dominance and distribution map of weeds in Tehran.

This study was conducted in years 2014-2015 in 48 parks of 22 districts of Tehran. Sampling was conducted in summer using W systematic method. The parks in each area were chosen according to the extent of green area, the location of the park in the twon (whether the park was in the suburbs of Tehran or other parts of the area) and according to the three following scales. In the 5 hectare parks, 10 samples, 6 to 15 hectare parks, 15 samples and in 16 and more than 16 hectare parks 25 samples were taken. In the 5 hectare parks, 25 meters, 6 to 15 hectare parks, 40 meters and in 60 and more than 60 hectare parks 70 meters of margin was considered for each park. Latitude, longitude and altitude were recorded. Weeds of each quadrat were identified and counted according to their species and finally, using Thomas equations (1985), their frequency, uniformity, average aggregation and dominance index were calculated. In order to create distribution map of weeds Arcgis and Arcmap soft-wares were used for determine the distribution of dominant species of weeds and other species in the city of Tehran. Shannon-Wiener and uniformity indexes were calculated for all parks. For comparing and grouping 22 districts, cluster analysis was performed using SPSS software.

 A total of 52 weed species from 21 families were observed. Maximum weed densities respectively were found in the Region 17 and Region 16 with 34.38 and 36.25 plant/m2. The 28 species of 52 species belonging to four families, Asteraceae,Poaceae, Fabaceae, and Chenopodiaceae, with 10, 7, 6 and 4 species, respectively. Based on a abundance index (AI). Lion′s tooth (Taraxacum officinale), knotweed (Polygonum patulum), greaet plantain (Plantago major), bermuda grass (Cynodon dactylon) and Sow thistle (Sonchus oleraceus) were dominant species. Parks in district 2 with 3.30 had maximum diversity in weed community and parks in districts 15, 21, 11, 18, 12, 14, 3 with 2.25, 2.25, 2.25, 2.19, 2.31, 2.33, 2.12, respectively had minimum diversity. Also presence of Beggarticks (Bidens parviflora Willd), garden anchusa (Anchusa italic Retz), garden orache (Atriple hortensisL.), common reed ((Phragmmites austrialis (Cav.) Trinexsteud), ribwort plantain (Plantago lanceoleta L.), nappola minor (Xanthium brasilicum), yellow sweet clover (Mellilotus officnalis L. Desr), common mallow (Malva sylvestrisL.) weeds in some specific areas makes it necessary to control these weeds to stop their reproduction in these specific area and expansion of infected seeds from these areas to other areas of Tehran. Lion′s tooth distribution maps, as the most dominant broad leaf weed showed that the highest plant density above regions 21, 18, 16, 17, 19 and the lowest density in regions 4, 1, 5, 22, 3 there. Bermuda grass distribution maps, as the most dominant weed of slim leaf showed that the highest plant density above regions 2, 4, 5, 8, 9, 10, 16, 21 and the lowest density in regions 12, 13 there.

Determination of density, type, species and life cycle of weeds in Tehran parks, allows to manage and reduce weeds damages and also by using integrated weed management system it is possible for better management and reduce weeds population and stop spreading of them from one area to another. Also close monitoring and precise management of other parameters such as soil and manure is effective in reducing the population of weeds in all areas.

Drought stress is one of the main environmental factors affecting the growth and productivity of plants around the world. Periods of severe drought are predicted to increase significantly in the near future, particularly as a result of extreme heat waves. Salinity is also one of the most important challenges facing the food supply for the world's population in the future, and the degree and time of exposure to stress can make this challenge stronger or weaker.Environmental limitations affecting plant growth, development and performance of physiological processes during plant response to stress provide important information about the plant mechanism, which is useful for eliminating or reducing the harmful effects of stress in plant tissues. The negative effects of climate change (such as drought, sea level rise, and global warming), as well as the salinization of agricultural land, and have been cited as one of the most important problems of the World Agriculture Organization (FAO).Understanding the relationship between changes in environmental conditions and climate change and Arundo donax with regard to the growth of coastal native species and also understanding the water wastage by this plant compared to coastal native plants is vital to remove this plant in the current situation where there is drought in most areas.In this situation, it is necessary to know how different environmental factors such as salinity levels, dryness, temperature, nutrients, light and fire affect the growth and invasion of Arundo donax for long-term and large-scale control. The purpose of this research is to obtain valuable information about the growth and development of existing ecotypes of the Arundo donax plant in Iran and the effect of various environmental factors on the germination, growth and fertility of this plant in order to plan for the long-term restoration of river ecosystems and how to control and The fight or its optimal use should be determined.

In order to investigate the effect of drought and salinity treatment on the growth and establishment of the rhizome of Arundo donax, an experiment was conducted in 2021 using rhizomes collected from the ecotype of Gorgan city and factorially in the form of a randomized complete block design in 3 replications in the research farm of Ferdowsi University of Mashhad. The experimental treatments included different levels of drought stress {100%, 75% and 50% of crop capacity} and different levels of salinity stress {0 (distilled water), 4, 8 and 12 dS/m}.

The general results of the experiment showed that the presence of salinity and drought stresses both decrease the growth and development indicators of this plant, and the presence of these two environmental stresses can increase the indicators of biomass of aerial organs, biomass of underground organs, plant height, and stem diameter. The effect of salinity stress on the reduction of the measured indices was less than that of drought stress, so that the difference between the levels of salinity stress at different levels of drought stress in all the measured indices, except the shoot biomass, had insignificant differences with each other, but in the comparison of the effect of drought stress at different levels of the surface together we come to the conclusion that drought stress alone leads to a significant decrease in growth indicators compared to the control treatment. The maximum amount of shoot biomass in non-stress conditions (control) was 2840 (gr), and with the increase of salinity and drought stress levels, this value decreases, so that the lowest amount of biomass in drought stress and maximum salinity conditions was 988 (gr). The biomass of the shoots of Arundo donax increased over time in different levels of salinity and drought stress, and its value was from less than 300 grams at the beginning of the growing season in all stress levels to more than 1000 to 2500 (gr) at the end of the growing season in different stress levels. 

The parameters obtained from the effect of salinity and drought stress on the stem diameter, plant height and leaf surface of Arundo donax showed that this plant showed some resistance under minor drought stress and these indicators decrease less in it, but in severe drought stress this amount decreased sharply. The results of analysis of variance of this experiment also showed that salinity and drought treatment and their interaction led to a significant difference with the control treatment. The simple effect of salinity treatment showed a significant difference in other indices compared to the control treatment, except for the index of leaf area and stem diameter, however, the simple effect of drought treatment showed significance in all the measured indices.

Vicia hyrcanica grows in crop fields and field margins, pastures, meadows, orchards, vineyards, uncultivated areas, and other open areas in western parts of Iran. This is an annual, cool-season weed, which can reduce crop yield substantially. The population of this weedy species during last yeard has been increased and it is now considered as an invasive weed in the cuktivated areas of west of Iran. Hence, the aim of this study was to determine the diversity, density and dominance of Vicia hyrcanica compared with other weed species infesting wheat and chickpea fields in Kuzaran city in Kermanshah province, Iran. Furthermore, another aim of this experiment was to prepare the map of contaminated areas with V. hyrcanica as well as the endanger fields for being invaded by this weedy species.

 For conducting this study, a list of important areas for growing wheat, chickpea, rainfed and irrigated in Kuzran city was prepared, then the distribution of this weed was evaluated during growing season of 2020. 300 farms of both irrigated and rainfed wheat and chickpea farms of Kuzaran city, Kermanshah province, Iran were selected for sampling. The selected fields were monitored in such a way as to cover all important areas of wheat and chickpea production areas in Kuzran city. The selection of farms at a distance of approximately 3-5 km before the emergence of wheat spike gradually began in late April from different parts of the city and continued until late May. Sampling time in different parts of the province was from the beginning of stem emergence to the end of wheat clustering. In order to identify seedlings, they were labeled in the field and seedling identification keys were used to identify them. Parameters related to relative abundance, species richness, density and relative uniformity as well as diversity and dominance indices were measured to determine the importance of the mentioned weed species at the farm level. Through using GIS technique, the distribution map of yellow flower vetch in these areas was drawn.

 In addition to yellow vetch, another 21 species of geraminae weeds were observed. The highest average species density with 35.2 plants per square meter and the highest relative abundance of 36.3% is related to Vicia hyrcanica and two species Tragopogon major and Melilotus officinalis both with 0.27 and 0.26, respectively, had the lowest mean species density and relative abundance. In adition, the most common broadleaf species included Catchweed bedstraw (Galium tricornutum Dandy), yellow vetch (V. hyrcanica), wild mustard (Sinapis arvensis L.) and Makhobeli (Cephalaria syriaca (L.) Roemer & Schultes). Uniformity index in irrigated and rainfed wheat fields of Kuzran city of Kermanshah province shows that the differences between species were very close in terms of uniformity and ranged from 0.53 (Sinapis arvensis) to 95% (related to Silybum marianum).

 The highest prevalence index was related to species (V. hyrcanica) and all other weed species had a dominance index of less than 100. Based on the results obtained, among the species identified in wheat and chickpea fields of Kuzran city, five species with the highest prevalence of Simpson species were introduced as the species with the highest relative importance. Differences in species diversity and dominance indices were related to the amount and type of management operations on farms. Caspian vetch and Catchweed bedstraw were identified as the main invasive species. The predominance of these weeds, especially the Caspian vetch, as a weed, creates problems for farmers in the production of important crops, such as peas, because these crops are similar to vetch, and they separate it from the seeds of the crop. It is difficult and somewhat impossible by Bojari devices. Therefore, presence of this weed in these fields is critical and their spread should be prevented. In addition to seed contamination, endrils of vetchs allow V. hyrcanica to attach to crop plants, which results in hindering crop harvest and reducing its yield. Finally, totally, these attributes help to increase the infestation area by this weedy species and my explain its invasion status in the region.

Prediction of weed emergence time is one of the valuable decision-making tools in integrated weed management, which can be used to optimize weed control programs. Among human agricultural practices, tillage is one of the main drivers of weed communities. The emergence pattern has sensitive receptors that may change with a manipulation such as tillage or any other management activity. Johnson grass (Sorghum halepense (Pers.) L.) from the Poaceae family is a C4 perennial weed and one of the most invasive weeds in the world. This weed has spread in one third of the world's regions, which has led to a major reduction of biological and agricultural diversity in Asia, Africa, America and Europe. It ranks sixth in the list of 30 worst weeds in the world in 53 countries and has become endemic in millions of hectares of the world. Cutworms have been reported in crops including wheat (Triticum aestivum L.), soybean (Glycine max L.), corn (Zea mays L.), cotton (Gossypium hirsutum L.), vegetables and fruit trees.

In order to predict the time of emergence of seedlings from seeds and rhizomes, a field experiment was conducted during the spring and summer of 2022 in the research farm located in the Agricultural Campus of Tehran University located in Karaj. The experiment was conducted as a randomized complete block with four replications. The investigated treatments were four tillage dates including 15 May, 30 May, 15 June and 30 June. 20 plots with dimensions of 2 ×1 m2 were prepared in a part of the research farm which has a high level of Johnson grass contamination based on previous monitoring. Tillage is done up to a depth of 20 cm in the plots. In each plot, three quadrates with dimensions of 0.5 × 0.5 m2 were installed, and seed seedlings and rhizomes were counted at weekly intervals until the end of the season. Four models (Logistic, Sigmoidal, Gumpertz and Weibull) were used to investigate the emergence pattern of seedlings obtained from seeds and rhizomes. Analysis of variance was done with the help of SAS 9.1 software. Sigma plot software was used to brush the models.

The minimum square standard error model with an explanation coefficient of 0.85 and also the root mean square error of 5.35 has been able to predict the cumulative emergence of the seedlings of Johnson grass seeds. These values were 0.94 and 3.8 respectively in predicting the cumulative emergence of seedlings from the rhizome, which indicates the higher accuracy of the model in predicting the emergence from the rhizome. The results showed that, in general, the used models had close values of the corrected coefficient of explanation and root mean square error, so these indicators were not able to distinguish the more accurate model. But in general, since models with a lower Akaike index are more accurate anyway, the logistic model was chosen as the best model. The effect of plowing was significant on the germination pattern of seed and rhizomes. May plowing dates were associated with a high population of seed and rhizome seedlings, but in the same proportion in the population. Seed seedlings emergent in a smaller number and during a shorter period of the season, while rhizome shoots are observed in a longer period and with a much higher number in the field. In general, the emergence of seed seedlings started earlier, slightly before rhizome seedlings. With the gradual increase in temperature from May 15 to June 30, the response of rhizome seedlings to temperature has been variable among the studied squares. A similar trend regarding the increase of germination variance can be seen in the case of seeds, with the difference that the variance was much higher in the case of seed seedlings. This indicates that the seeds are more sensitive to the increase in temperature and their variable response to environmental changes.

The plowing dates during June were associated with a decrease in the population of seed seedlings and an increase in rhizome seedlings of the Johnson grass population. Considering that the rhizome population in the farm is high at all times, it is suggested to write and implement control programs based on the rhizome population. This point is more important in late tillage and late planting dates.