فصلنامه مطالعات حفاظت گیاهان
سال سی و ششم شماره 4 (زمستان 1401)

 Meloidogyne incognita is the most well-known root knot nematode, with more than 2000 host species. Integrated nematode management (INM) is recommended to manage the destructive plant parasitic nematode. Integrated management is generally performed by using the maximum available management methods (at least two methods) and the minimum use of chemical nematicides to bring the pathogen population below the economic threshold. The use of resistant cultivars is of particular importance in integrated management, due to environmental compatibility, economic efficiency, and sometimes the impossibility of implementing other methods, especially in developing countries. Therefore, it is necessary to evaluate the resistance of the important barley plant (Hordeum vulgare) to prevent damage and also to investigate nematode interactions with it.

 In the current study, the resistance of different barley cultivars (i.e., Nik, Nimrouz, and Zarjow) was evaluated based on plant growth factors (length, fresh, and dry weight of aerial part and roots) and nematode gall index at 60 days post inoculation. Then the activity of superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) enzymes were measured on days 0, 1, 2, 3, and 4 days post inoculation.

 Regarding the mean number of galls, the Nik cultivar showed a significant difference compared to Nimroz and Zarjow cultivars (P ≤ 0.05). However, no significant difference was observed between Nimroz and Zarjow cultivars. Based on plant growth factors, M. incognita nematode was found to have a negative effect on the aerial part length and weight and a positive effect on root weight. Evaluation of the gall index showed Nik is moderately susceptible, and Nimrouz and Zarjow are moderately resistant cultivars. SOD enzyme in Nik, Nimrouz, and Zarjow showed maximum activity in 2.72, 1.91, and 2.15 U mg-1 protein on the 4, 4, and 3 days post inoculation, respectively. The enzyme in Nik was determined to be 1.42 and 1.25 times higher than Nimrouz and Zarjow. There was a significant difference between 0, 1, and 2 with the 3 and 4 days of the infected samples in Nik (P ≤ 0.05). In the other cultivars, enzyme activity increased with a slight slope. CAT enzyme peaked in Nik, Nimrouz, and Zarjow at 0.204, 0.09, and 0.11 μmol min-1 mg-1 protein on the fourth-day post inoculation. In the Nik cultivar, unlike the other two cultivars, the enzyme increased more and had a steep slope from the second to the fourth day. In infected plants of Nimrouz, despite the gradual increase of enzyme, no significant difference was found between any of the days. APX enzyme peaked at 0.26, 0.27, and 0.24 μmol min-1 mg-1 protein in Nik, Nimrouz, and Zarjow on the fourth day, respectively. The activity of the above enzyme had an increasing trend in three cultivars. The maximum activity of this enzyme was at Nimrouz, which was determined to be 1.03 and 1.1 times higher than Nik and Zarjow, respectively. In this cultivar, the upward trend was rapid, although there was a significant difference between all-time points at the level of 0.05. In the current research, it was found that the invasion of the root knot nematode M. incognita reduces the growth of length, fresh and dry weight in the aerial part, reduces the length of the root but increases the fresh weight of it.

The hallmark of inducing pathogenicity in the sedentary root knot nematodes is the formation of special feeding cells named giant cells, which require controlling the expression of host genes and manipulation of plant hormones like auxin and cytokinin hormones. It is obvious that during the invasion of root knot nematodes and the formation of giant cells in host roots, the plant is weakened due to impaired transport of water and nutrients, and the host growth factors, especially in the aerial part, are reduced. However, due to hormonal disorders and the formation of galls, the weight of the roots increases. The higher expression of antioxidant enzymes superoxide dismutase, catalase, and ascorbate peroxidase in Nik possibly has occurred due to the compatible interaction, as a result of lack of necrosis and programmed cell death and to tolerate stress (nematode invasion). Less expression of SOD, CAT, and APX enzymes in Nimrouz and Zarjow cultivars possibly have occurred due to their moderate resistance to M. incognita invasion.

Iris spp. is reported to be affected by several viruses in the family Potyviridae including iris mild mosaic virus (IMMV), iris severe mosaic virus (ISMV), iris fulva mosaic virus,  bean yellow mosaic virus (BYMV), turnip mosaic virus (TuMV), ornithogalum mosaic virus (OrMV), narcissus latent virus (NLV), butterfly flower mosaic virus (BFMV), and gladiolus mosaic virus (tentative name). Narcissus latent virus (NLV) is a member of the genus Macluravirus in the family Potyviridae. It has non-enveloped flexuous filamentous virions of 657 nm long and 13 nm wide, which encapsidate a single-stranded, positive-sense RNA molecule of approximately 8,000 nt long. NLV is distributed widely throughout the major planting areas of Japan, New Zealand, and European countries. It is one of the most common viruses infecting narcissus, iris, gladiolus, and nerine, causing significant yield losses and quality deterioration in their bulbs and flowers. Due to the presence of asymptomatic infection of NLV in iris and narcissus, the relevance of its infection in host plants may be severely underrated. As Khorasan Razavi province is one of the major producing areas of ornamental plants in Iran, identification of this virus is a concern. In this study, we attempted to identify NLV infecting iris plants and compare Iranian NLV isolates with other sequences from different geographical regions to provide the first detailed information of phylogenetic characterization of this virus in Iran.

Iris leaf samples showing virus-like symptoms of leaf chlorosis and mosaic were collected from field-grown plants in Khorasan Razavi province. Total RNA was extracted from the field samples using Promega SV Total RNA Isolation Kit (USA). Reverse-transcription polymerase chain reaction (RT-PCR) was performed using specific primer pair CPU-F (5΄-CATTACACCCGACCTGGAACT-3΄) and CPU-R (5΄-CCATTTCAGGGCATTGGAGGA-3΄), which were designed to amplify a 1066 bp fragment of the 3΄-region of NLV genome (encompassing partial NIb (25 nt), complete CP (894 nt), and partial 3'UTR (147 nt)). PCR products and DNA ladder were separated by agarose gel electrophoresis, visualized using DNA Green viewer staining, and photographed with ultraviolet-illumination. Amplified fragments of the expected size were purified, cloned into pTG19-T vector and bi-directionally sequenced. Obtained sequences were phylogenetically compared with the corresponding isolates available in the GenBank after multiple alignments. The phylogenetic tree was constructed based on the nucleotide sequences of the CP-UTR using the neighbor-joining method by MEGA11.

Amplification product (1066 bp) was obtained from five infected samples, but not from healthy samples. The most typical symptoms in positive samples were mosaic, and interveinal chlorosis. Three selected PCR positive samples were cloned into the pTG19-T vector and sequenced. BLASTn analysis of the sequenced data revealed that the PCR-amplified fragments belonged to NLV. Three selected isolates which are referred to as IR, IR2, and IR3 were deposited in GenBank. The previously identified and conserved amino acid sequence motifs described in CP of macluraviruses were present in Iranian CP sequences. The phylogenetic tree placed the NLV sequences into two distinct phylogroups I and II; the Iranian isolates clustered together with isolates from Poland, New Zealand, and United Kingdom into group II. Phylogenetic analysis showed that Iranian isolates shared 77.47 to 98.12% nucleotide sequence identity and 77.70-99.34% amino acid sequence identity with other isolates of NLV. Also, identity of these three isolates in the nucleotide and amino acid levels ranged between 97 to 97.84% and 97.38 to 99.02%, with each other, respectively. Iranian isolates showed the highest nucleotide sequence identity with NLV5_1 isolate (JX270766) from Poland (between 97.65 to 98.12 %) and the lowest with NLV3 isolate (JX270762) from Poland (between 77.47 to 77.95 %).

NLV is a major constraint to iris and narcissus production worldwide. The phylogenetic analysis showed a low correlation between genetic and geographic distances which further emphasizing the importance of the exchange and use of virus-free propagating organs in preventing the dissemination of this virus. It seems that contaminated vegetative organs from some European countries (e.g. Netherlands), which are the major producer and the largest exporters of flowers and ornamentals in the world, can play a significant role in the worldwide distribution of the virus. Identification and the use of more isolates are recommended for a better understanding of the genetic structure and variation of NLV populations on a large geographical scale. The data obtained in this study will be beneficial to improve control strategies for this virus in Iran.

The competition for limited resources is a common ecological interaction among animals. In most of insect parasitoid communities, different species compete for specific resources both in larval and adult stages. Intraspecific competition play a role in the size, structure, stability of insect communities and even it determines the fitness of species. Moreover, understanding how competition influences on different insect species is essential for basic ecological studies and pest control issues. The outcome of competition between adult parasitoid insects depends on host finding, ability to disperse, reproductive capacity, ability to fight, and physiological coordination with the host.While the outcome of competition in the larval stage can be influenced by differences in the growth rate of the parasitoid, the stage and physiological state of the attacked host, the order and the time interval between oviposition and the evolutionary history of the species. Competition between larvae can affect the development of adult parasitoids because the surviving individual or winners might to pay high costs for competency due to quantitative and qualitative changes in host resources.

The current study was carried on to determine the effect of intraspecific competition on searching efficiency and oviposition strategy of Habrobracon hebetor Say on 4th instar larvae of Heliothis viriplaca (Lep.: Noctuidae) at seven competition and four adult density levels (1, 2, 3 and 4) of parasitoid wasps per the spring chickpea plant (c.v. Bionij). All plants were grown under controlled climate conditions (25 ± 1 °C, and a light period of 16: 8 hours). Then, 10 fourth instar larvae of H. viriplaca per plant were released and allowed to feed and establish prior starting the experiments (about three hours). Then, fertile female wasps with different densities (2, 3 and 4) in separate treatments and a control treatment without the presence of a competitor (one fertile female wasp per plant) introduced to each microcosm unit and after 24 and 48 hours, the number of parasitized and oviposited larvae on each host plant counted, but the number of eggs oviposited on each host larvae recorded at the end of 48 hours. All eggs laid at each competitive level were kept separately until the emergence of adults to record sex ratio and mortality rate.

The results showed that, the searching efficiency of H. hebetor decreased with increasing the level of competition, so that, the highest searching efficiency was recorded after 48 hours, in non-competitive treatment (control) and at a density of four parasitoid individuals as 0.178 ± 0.002 /hour and the lowest value at the level of competition 12 and density of two parasitoid females as 0.023 ± 0.004/ hour. As the density levels of parasitoid increased, the searching efficiency was decreased to a density level of three, but then it increased at four individuals per chickpea plant. The interaction effect of density × competition was not significant, in other words, these two factors independently influenced on searching efficiency of H. hebetor. Time had a positive effect on searching efficiency so that, at all levels of competition and at different densities of parasitoid wasp, the difference was statistically significant. With increasing density of H. hebetor per plant, at all competition levels, the oviposition rate was increased, which means that the simultaneous presence of several parasitoid individuals does not have any negative effect on oviposition rate. Competition had a negative effect on the oviposition rate of female H. hebetor, as the highest oviposition rate recorded at one individual and lowest competition level as 14.7 ± 2.1 eggs and the lowest rate occurred at four individuals per host plant and competition level of 12 as 6.4 ± 0.05 eggs. According to linear regression line equation, the interference coefficient was calculated as -0.134. The negative slope of the regression line indicates the existence of mutual interference between the H. hebetor adult females. In other words, the interaction had a slight negative effect on parasitoid searching. At all competition levels, regardless of density, sex ratio was not affected by competition and other factors sounds influential in this regard, however, the difference between the ratio of female to male population at competition levels of one and two was greater than other levels. Moreover, the mortality rate has increased with the increase of the level of competition, so that the lowest mortality percentage occurred at the level of one and two and the highest at the level of competition 10 and 12.

The occurrence of interference between parasitoid wasps in laboratory environments could not be used as indicative of real conditions, because high pest densities in field conditions moderate the intraspecific competition intensity among parasitoid individuals. Given the significant differences in searching efficiency and other factors studied, it can be concluded that the number of competing larvae in a host can affect the suitability and vigor of adult parasitoid wasps. It should be noted, however, that in some cases competition does not directly affect searching capability, but instead, by reducing other factors, such as morphological characteristics (body size, ovary size, number and size of eggs, size of hind legs, wing size), number of embryonic eggs, oviposition days duration, and other biological characteristics will influence on the searching abilities of parasitoids indirectly.The study of H. hebetor parasitoid wasp foraging behavior showed that in high densities, it avoids competing with other conspecific individuals. Anyway, regarding the prevalency of competition among released natural enemies in greenhouses and fields, the study of this interaction from laboratory to fields is being recommended.

 Water is the most frequently used carrier for herbicide applications. Thus, the physicochemical properties of water in spray mixture can affect the activity of herbicides. A high concentration of Na+, K+, Ca2+, Mg2+, Fe3+ and other cations in hard water can decrease herbicide efficacy. Weak acid herbicides that have been antagonized by one or more of the above cations include sethoxydim, 2,4-D, 2,4-DB, clethodim, imazethapyr, tralkoxydim, and glufosinate and glyphosate. Approaches to minimize hard water antagonism have included decreasing the spray carrier volume and using water-conditioning additives that have proven effective at ameliorating cation-caused antagonism include ammonium sulfate, ammonium nitrate, potassium phosphate, and citric acid. Passing hard water containing Ca2+, Mg2+ or Na+ through an external magnetic device results in the nucleation and crystallization of the respective carbonates. As a result, hard water can be softened for a period. Considering that the hardness of Iranian agriculture is increasing and adding an adjuvant to spray solution is also considered to be more environmental contamination, therefore, the physical conversion of hard water to soft water via its passage through a magnetic field is definitely a good alternative. The objectives of this research were to investigate the effect of adding CaCO3, MgCO3, Na2CO3, K2CO3, or Fe2(CO3)3 to distilled water on glyphosate efficacy to jimsonweed (Datura stramonium L.), and to compare the chemical hard water softening methods (ammonium sulfate, ammonium nitrate, citric acid and potassium phosphate) to a new physical hard water softening method (passing carrier through a magnetic field) to Reduce the incompatibility of hard water cations with glyphosate.

 The seeds of jimsonweed were collected from plants in the fields of Qazvin city, Iran. They were stored in the dark at room temperature until use. Bioassays were conducted in a greenhouse located on the Ferdowsi University of Mashhad, Iran. To increase seed germination before starting the experiment, the seeds were washed every 1 hour for 7 days to remove seed germination inhibitors. Twenty-five seeds were sown at 0.5 cm depth in 2 L plastic pots filled with a mixture of sand, clay loam soil, and peat (1:1:1 by volume). At cotyledon-leaf stage, the seedlings were thinned to four per pot. The pots were irrigated every four days with tap water. Treatments were sprayed at the four-leaf stage. The experiment was arranged as a completely randomized design with four replications as a factorial design with factors of carrier type (distilled water alone or containing 0.5 g L-1 of CaCO3, MgCO3, Na2CO3, K2CO3, or Fe2(CO3)3) and hard water softening method (ammonium sulfate, ammonium nitrate, potassium phosphate, citric acid, and passing through a magnetic field) and glyphosate dose (0, 12.81, 25.62, 51.25, 102.5 and 205 g a.i. ha-1). For magnetizing the carriers, it was passed 10 times through a magnetic treatment device modified from Rashed-Mohassel (30). The mixing order for treatment solutions was (i) adding CaCO3, MgCO3, Na2CO3, K2CO3, or Fe2(CO3)3 to distilled water, then (ii) adding/using water conditioning method, and after 15 min (iii) adding glyphosate. Then, the solutions were sprayed after about 5 min using a calibrated moving boom sprayer at 180 L ha-1 at 200 kPa with 11002 flat-fan nozzle. Shoots were harvested four weeks after treatment, dried for 48 h at 70°C, and dry weight was determined. The data of shoot dry weight were subjected to a non-linear regression analysis for determination of ED50 values (herbicide dose needed to obtain 50% reduction in dry weight) using the following logarithmic logistic dose-response model. The relative potency (R), the horizontal displacement between the two curves, was also calculated.

 As judged by the relative potency values given in Table 1, the hard water softening methods decreased the ED50 values when distilled water was used as the carrier. Therefore, the activity of glyphosate against jimsonweed was significantly increased in the presence of the hard water softening methods. There were significant differences in performance among hard water softening methods as ammonium sulfate was the most effective method. Glyphosate activity was not decreased when applied in a K2CO3 solution but it was decreased when applied in Na2CO3, MgCO3, CaCO3 or Fe2(CO3)3 solutions. Except potassium phosphate which had only a significant effect at reducing the antagonism in the CaCO3 carrier; all hard water softening methods could restore glyphosate activity in hard water contaminated carriers to efficacy levels comparable to glyphosate alone in distilled water. There was no statistical difference in response between the magnetized carrier and ammonium sulfate when they were used in Na2CO3, MgCO3, or Fe2(CO3)3 solutions. It is reported that hard water softening methods may adjust the spray solution pH so that more active ingredient can transport across the leaf surface into the plant via ion trapping phenomenon. Ammonium sulfate was the most successful method to ameliorate the decreased glyphosate activity due to antagonism with Na+, Mg2+, Ca2+, or Fe3+ in the spray solution. By adding ammonium sulfate, the sulfate ion () conjugates with the hard water cations and removes free cations from solution by forming cation-SO4 molecule, allowing ammonium ion () to form glyphosate-NH4 molecule. A glyphosate-NH4 molecule diffuses across the cuticle easier and quicker. A mechanism for physical hard water softening method is illustrated in Fig. 2.

 Although the physical hard water softening method was not effective as compared to some chemical hard water softening methods (ammonium sulfate and citric acid), from the point of view of economical and agricultural, applying the physical hard water softening method will be benefit because it needs no chemical.

 Rice (Oryza sativa L.) is one of the world’s most important food crops. Currently, more than one third of the human population relies on rice for their daily sustenance. Rice is predominantly grown by transplanting seedlings into puddled (conventional wet-tillage) soil and kept flooded for most part of the growing season. The puddled soil ensures good crop establishment, weed control with standing water, and reduces deep-percolation losses. However, the conventional method of rice crop establishment requires a large amount of water, labour, and energy, which are gradually becoming scarce and more expensive. Thus, reducing the profitability and sustainability of puddled transplanted rice. Dry direct seeded rice has shown promise under several ecologies and production systems to overcome these challenges, and is considered as potential alternative to puddled transplanted rice. Weed infestation in direct-seeded rice fields remains the single largest constraint limiting their productivity. An effective early weed management tactic is imperative for any direct-seeded rice production technology aiming at achieving higher productivity and profitability.

 In order to investigate the effect of different weed managements on yield and yield components of rice in the direct crop system, an experiment was conducted in 2020 on farms located in Babolsar (Behnamir). The experiment was performed as a factorial based on randomized complete block design with three replications. Experimental factors include rice cultivars (Shiroudi, Khazar and Hashemi) as well as other treatments including weed control by increasing the competitiveness of rice seeds by coating and weed management at five levels including coating the seeds with CaCl2 and KCl, weeding, chemical control (Council active) and control  (no weeding).

 Weed management by coating rice seeds with calcium chloride, potassium chloride, chemical control and weeding was reduced 26, 26, 23 and 63% dry weight of broadleaf weeds and 14, 27, 9 and 36% dry weight of narrow leaf weeds, respectively, compared to control treatment. The maximum emergence percentage in Shiroudi cultivar with 99, 97 and 95% was obtained under weeding, coating the seeds with CaCl2 and KCl treatment, respectively. Also, the highest emergence rate was observed under the management of weeding and coating of potassium and calcium chloride seeds. Seed coating with CaCl2 and KCl substantially improved the stand establishment under drought and well-watered conditions owing to early completion of pre-germination metabolic activities during priming. In general, the results of mean comparison showed that weed management improved rice height compared to the control treatment. The results of this study attributed the increase in height to the effect of pretreatment on increasing the rate of emergence and better establishment of seedlings due to better plant use of related resources. The results showed that the maximum number of seeds per panicles with 137 were obtained in Khazar cultivar. The highest number of seeds per panicles with 127, 124 and 122 seeds was under weeding management and coating with CaCl2 and KCl, respectively. The results of cultivar effect showed that the maximum 1000-seed weight with 23.83 g was observed in Shiroudi cultivar. Also, 1000-seed weight in Khazar and Hashemi cultivars were 22.1 and 21.09 g, respectively. The reason for the increase in the number of 1000-seed weight in Shiroudi cultivar can be attributed to the genetic potential and physiological quality of this cultivar. Also, the results of weed management effect showed that coating rice seeds with calcium chloride and potassium chloride, chemical control and weeding increased 14, 26, 4 and 33% of grain yield and 4, 14, 2 and 18% of biological yield compared to control treatment, respectively. Improved yield by seed coating in direct seeded rice might be the result of enhanced dry matter partitioning toward the panicles that resulted in improved kernel yield.

 According to the results of this study, seed coating treatments with CaCl2 and KCl in rice cultivars can increase rice yield by improving seedling characteristics. Therefore, farmers can be advised to use a simple and inexpensive crop management method to pretreated seeds with CaCl2 and KCl.

 Maize (Zea mays L.) is the third most important cereal after rice and wheat, which is widely grown in the world and used as a primary staple food in many developing countries.  The area and production under maize in the world in 2020 was 202 M ha with 1162352997 tonnes production and contributed almost 5% of the world’s dietary energy supply. Recent projection indicates that by 2020 the demand of maize in all developing countries will overtake the demand of wheat and rice, with Asia accounting for nearly 60% of the global demand for maize.  Chemical control can be very important because of the low efficiency and cost effectiveness of mechanical or other methods of weed control. Hence, it is necessary to provide information about the sulfonylurea herbicides and suitable doses. Sulfonylureas such as iodosulfuron, nicosulfuron, rimsulfuron, and foramsulfuron are effective group of herbicides for annual and perennial weed control in maize. These herbicides provide a new chance for weed management in maize. Their mode of action occurs through inhibiting acetolactate synthase (ALS), thereby interfering with the production of branched-chain amino acids, leucine, isoleucine, and valine The objectives of this experiment were to evaluate the effect of different doses of MaisTer OD herbicide in comparison to the other herbicides on weeds control and growth and yield of corn.

 In order to evaluate the effect of different herbicides on weeds control and growth and yield of corn, a field study carried out during 2015 growing seasons at Seydan, Marvdasht, Fars province, Iran. The experiment was conducted in a randomized complete block design with 3 replications. Treatments included different rates of MaisTer OD (1, 1.5 and 2 l ha-1), Acetochlor (4.5, 5 and 6 l ha-1), Cruz (1.5, 2 and 2.5 l ha-1), Ultima (1, 2 and 3 l ha-1) and 2,4-D+MCPA (1.5, 2 and 2.5 l ha-1) herbicides and weed free and weedy control. The number and biomass of aboveground weeds parts were harvested within three fixed 1 × 1 m quadrats in every plot, separated by species, enumerated, oven-dried at 75 °C for 48 h, and then weighed. Then, percent weed density and biomass reductions were measured. The traits included ear length, row number per ear, grain number per ear, grain number per row, 1000 grain weight, grain yield, biological yield and yield loss percentage. Data were analyzed using SAS v. 9.1 software (SAS Institute 2003). When significant differences were observed among treatments, mean comparisons were made using Duncan's multiple range tests (P < 0.05). Correlation coefficients between different traits were also calculated.

 Results showed that the application of herbicide could reduce density and biomass of weed. The lowest biomass of redroot pigweed (Amaranthus retroflexus), lambsquarters (Chenopodium album), bindweed (Convolvulus arvensis), purple nutsedge (Cyperus rotundus) and foxtail millet (Setaria italica) was obtained, so that applying of MaisTer OD herbicide at 1.5 l ha-1 could be cause 47.10 and 27.36%, 69.38 and 56.22%, 66.79 and 70.94%, 66.85 and 74.26% and 66.85 and 80.15% reduction in density and total biomass of weeds in comparison with weedy control treatment, and grain yield increased by using MaisTer OD  herbicide at 1.5 l ha-1 in comparison to the other herbicides including Acetochlor (5 l ha-1), Cruz (2 l ha-1), Ultima (2 l ha-1) and 2,4-D+MCPA (2 l ha-1) by 53.3, 36.7, 5.7, and 56.7%, respectively. Grain yield and grain number per ear were reduced by weeds up to 60 and 50%, respectively. Highest row number per ear (16 and 15.30), grain number per row (41 and 41), grain number per ear (656 and 628.70), 1000 grain weight (286.33 and 276.33 g), grain yield (9.41 and 8.68 t ha-1) and biological yield (20.12 and 18.74 t ha-1) were obtained in weed free and MaisTer OD (1.5 l ha-1) treatments. Applying MaisTer OD herbicide showed lowest yield loss percentage (6.63%) and highest grain yield as compared to the other herbicides for weed suppression. 

 It can conclude that MaisTer OD herbicide at 1.5 l ha-1 showed the best performance for weed control, especially broadleaf weeds and were associated with the maximum corn grain yield. Therefore, due to the restricted use of herbicide in corn, the herbicide used in this experiment is not created serious injury in corn at the recommended rate while effectively controlling weeds. Hence, utilization of this herbicide could be a favorable option in contemporary weed control programs for local or regional corn growers.

The competition of different weed species with native species for ecosystem resources is a serious threat to reduce global biodiversity. Among the invasive species, Arundo donax is considered one of the most invasive invasive plant species in coasts, rivers and temperate regions. Knowing the relationship between changes in environmental conditions and climate change and Arundo donax with respect to the growth of native coastal species, as well as understanding the water wastage by this plant compared to native coastal plants, is vital to eliminate this plant in the current situation where there is drought in most areas.

In order to investigate the effect of drought and salinity treatment on the sprouting stages and growth time of rhizomes of Arundo donax an experiment was performed using rhizomes collected from Gorgan ecotype and in a completely randomized design with 4 replications in the growth chamber separately at 5 temperature levels (5, 10, 15, 20, 25 and 30 °C) at Ferdowsi University of Mashhad in 2020. Experimental treatments included different levels of drought stress {0 (distilled water), 0.4, -0.8 and -0.12 MPa} and different levels of salinity stress {0 (distilled water), 4, 8 and 12 dS. m}.

The general results of the experiment showed that increased levels of salinity and drought decreases the sprouting rate of rhizomes. The results also showed that sprouting of the rhizomes of the reed plant is possible from 5 °C to 30 °C, but the greatest sprouting rates occurred with the control treatment (no stress) at 15 °C (75%) and 20 ° C (66%) respectively. The lowest sprouting percentage (4%) was observed with 15 and 30 °C under the maximum salinity and drought levels. Sprouting percentage and other corresponding indices decreased with decreasing temperature from 15 °C to 5 °C, the same trend was observed with increasing temperature from 20 °C to 30  C, which shows that the best The temperature for the growth of reed rhizome buds is between 15 and 20 °C. The effect of salinity and drought on sprouting at different temperatures showed that with increasing salinity and drought stress level, the sprouting rate decreases, but with increasing drought level, the sprouting percentage decreased more than the salinity level and decreased the growth of reed rhizome buds more. Was affected by increasing soil dryness. The results of sprouting rate and sprouting percentage under environmental stresses also indicated that drought stress more than salinity stress can affect the growth of reed rhizome buds, in other words, this plant is more sensitive to drought stress. It is somewhat resistant to salinity stress, and perhaps this is why the abundance of this plant in the northern regions of Iran is higher than other regions. The triple interaction effect of salinity, dryness and temperature was significant in all parameters except the adjusted germination rate at the 99% probability level, which shows that the germination of the rhizome of Arundo donax plant is strongly affected by dryness, salinity and different temperatures and the existence of each of these treatments in natural conditions, it can disrupt its germination.

The results of the cultivation of Arundo donax rhizome at different temperatures and under salt and drought stress conditions showed that the growth of the rhizome of this plant was greatly affected by the stresses and the increase in the amount of stress led to a decrease in germination percentage. Also, rhizome cultivation at different temperatures led to determining the optimal germination temperature for the Arundo donax plant related to the ecotype in the northern regions of Iran and showed that the suitable temperature for the rhizome germination of this plant is 15 to 20 degrees Celsius. The results of the germination rate and the germination percentage under the applied environmental stresses also indicated that drought stress can affect the growth of Arundo donax rhizome buds more than salt stress, and in other words, this plant is more sensitive to drought stress and to some extent It is resistant to salt stress, and this is probably the reason why the abundance of this plant is more in the northern regions of Iran than in other regions. It grows best in well-drained soils where plenty of moisture is available and can spread from the water's edge to the shore far beyond the area previously occupied by woody coastal vegetation. It grows well in places where the water level is close to the soil surface or near it, which may be due to the sensitivity of this plant to drought stress, and on the other hand, small colonies of this plant can tolerate excessive salinity, but in conditions of widespread presence in one area, their tolerance to salinity decreases.