Iran Agricultural Research
Volume:42 Issue: 1, Winter and Spring 2023

Faba bean, although, is widely cultivated, it’s yield is affected by drought and salinity stresses. Biochar can potentially reduce the negative effects of drought and salinity stress. In this study, the interaction effects of biochar, irrigation water regimes and irrigation water salinities on faba bean’s yield, crop water use efficiency (CWUE) and ion concentrations were evaluated under greenhouse condition. The treatments were biochar (0, 1.25 and 2.5% w/w, as B0, B1.25 and B2.5, respectively), irrigation water regime (50, 75 and 100% of crop water requirement, as I50%, I75%, and I100%, respectively) and irrigation water salinity (0.6, 4 and 8 dS m-1, as S0.6, S4 and S8, respectively), that were arranged in a factorial arrangement using a complete randomized design with four replications. Biochar applied at 2.5% w/w significantly decreased actual crop evapotranspiration by 11% in comparison with that obtained in B0. The maximum dry seed yield (14.4 g pot-1) was obtained under B2.5S0.6I100% treatment. The CWUE of 0.47 kg m-3 for B2.5S8I50% was 1.27 times that obtained in B0S0.6I100%. Seed sodium concentration under B2.5S8I50% (0.34 g kg-1) was significantly lower than that obtained in B0S8I50% (0.55 g kg-1). Biochar application increased the plant tolerance to salinity, as the maximum threshold of soil saturated electrical conductivity of 5.2 dS m-1 was observed under B2.5I50% treatment, which was higher than 2.5 dS m-1 obtained in B0I50% treatment. Finally, cultivation of faba bean under 2.5% w/w biochar and 100% non-saline irrigation water level is recommended for maximum faba bean production.

The different landscape positions, the type of parent material and its formation processes, and the soil type significantly impact the distribution, behavior, and mobility of micronutrients. To investigate the effects of landscape and soil types on the distribution and behavior of micronutrient elements of iron (Fe), manganese (Mn), copper (Cu), and zinc (Zn), some genetic horizons samples were collected from sixteen representative pedons in the calcareous soils of southwestern Iran. Subsequently, the concentrations of extractable trace elements were assessed using diethylene triamine pentaacetic acid (DTPA) as well as in their total form through digestion in concentrated nitric acid. The results showed that the change range in the available form of studied micronutrients varied between 2.5 to 31.2, 0.3 to 3, 2.1 to 60.2, and 0 to 3.8 mg kg-1 for Fe, Cu, Mn, and Zn respectively. The examination of the chemical forms of micronutrients in both surface and subsurface samples unveiled that the majority of the investigated chemical forms exhibited higher quantitative levels in the surface samples compared to the subsurface samples. v(%CaCO3) of the soil increased when the soil moisture regime largely depends on the percentage of organic carbon (% OC) content, soil texture, and type and content of clay minerals. The highest amounts of available micronutrient elements were found in Mollisols and Alfisols soil orders. Additionally, the highest available form of Cu, Zn, and Fe were found in lowland soil units (LL), while Mn was detected in piedmont plains (PP) landform. Consequently, it can be inferred that the cycling of micronutrients is influenced by varying levels of soil development, which in turn impact the properties of the soil.

In crop production, one particularly limiting factor is the availability of nitrogen (N) and N derivatives, as they are of much significance in plant metabolism and growth. Various nitrate transporter genes mediate the uptake, transport, and remobilization of N in the plants. However, their role is not quite understood with respect to grain filling stages and plant’s overall yield. Herein, the expression of a number of genes and enzymes with roles in N uptake and metabolism was measured over the course of anthesis and under N-treatment and N-deficit condition in two wheat genotypes, namely Morvarid and Gonbad. The samples were taken 10, 15, and 20 days after anthesis, which is a critical stage in grain filling, and the relation between gene expression, enzyme activity, and days after anthesis was demonstrated. It was observed that N-related gene expression significantly increases under N-deficit condition and over the course of anthesis, suggesting the significance of the N-related genes and enzyme in maintaining the metabolism and growth of the plants under N-deficit conditions.

The innovation of light-emitting diodes (LEDs) has provided a new opportunity to grow plants in controlled environments. In this study, the plantlets of two genotypes of lemon balm were put for seven weeks in an incubator containing LED lamps with red, blue, red + blue (70:30 ratio), and white light spectrum with a light intensity of 300 μmol m-2s-1 and with a light cycle of 16 hours of light and 8 hours darkness and temperature of 25±2°C, and to compare with these conditions; some plantlets were also put in the greenhouse. The plantlets grown in incubators with red + blue LED lamps had higher activity of some antioxidant enzymes including catalase, guaiacol peroxidase, and ascorbate peroxidase, higher amounts of phenolic compounds and the valuable active substance of rosmarinic acid (the latter only in Ilam genotype), and phenylalanine ammonia lyase (PAL) enzyme activity than the plantlets grown in the greenhouse. However, in the Isfahan genotype significant difference in the content of rosmarinic acid was observed only between white LED light with other LED and greenhouse lights. Overall, according to the results of the current study, it can hope to use LED light sources to improve the growth and qualitative and quantitative properties of the medicinal plant, lemon balm, and also to create high-quality plants.

During the surveys conducted from green space in Shiraz City, Iran, in the summer of 2022, leaf chlorosis and mosaic symptoms were observed on the leaves of black-eyed-susans (Rudbeckia hirta), a  Dahlia sp., and Mexican Petunia (Ruellia brittoniana) plants. Total genomic RNA was separately extracted from 10 symptomatic and one symptomless (negative control) leaf samples and subjected to Reverse Transcription-Polymerase Chain Reaction (RT-PCR) using a potyvirus degenerate primer pair (NIb3R, NIb2F). RT-PCR resulted in the amplification of an approximately 350 bp DNA fragment in all symptomatic samples, while no such fragment was amplified from the symptomless plant. The amplified DNA fragment was subjected to Sanger sequencing, and its size was determined to be exactly 350 bp, and confirmed that it belongs to the Nib gene of potato virus Y (PVY). The nucleotide (nt) sequence of the amplicons was compared with the nt sequence of the same region of some other PVY isolates that were available in the GenBank. The sequence analysis revealed that the R. brittoniana isolate exhibited the highest (98.8%) similarity to a PVY isolate from the USA with the Acc. No. of KY_848029.1. Similarly, the R. hirta and the Dahlia isolates showed the highest (98.3%, 98.4 %, respectively ) similarity to a PVY isolate from Kazakhstan with the Acc. No. of ON_583980.1.

Among weeds, parasitic plants have more profound effects on host plants. Due to its wide geographical distribution, high host range, and inefficient management methods, the Cuscuta  (Cuscuta campestris) plant has become one of the most damaging parasites. The present study aimed to control the Cuscuta weed biologically. To this end, an experiment was conducted to investigate the allelopathic effects of the extract of the Rhazya Stricta plant on the control of this weed population in the laboratory of Velayat University of Iranshahr. The experiment was conducted as a completely randomized design with three replicates. In this experiment, negative allelopathic effects of different extracts of the R. stricta plant including acetone, aqueous, methanolic, ethanolic, and hydroalcoholic extracts on the Cuscuta were investigated in comparison with the distilled water (as control treatment). The results of this study revealed that the aqueous extract of R. stricta significantly decreased the germination percentage, germination vigor, germination rate, root length, and stem length of the Cuscuta compared to those of other treatments. Also, the other extracts of the leaves of the R. stricta plant have significant inhibitory effects on seed germination and seedling growth of the tested parasite weed species compared to those of control treatment (distilled water) suggesting the availability of inhibitory chemicals in the leaves of R. stricta to control the Cuscuta weed. It is suggested to test the negative effects of R. stricta leaf and stem extracts, after decomposition, on other weeds and adjacent and sensitive plants to R. stricta.

Applying the reliability concept as a new and profitable design approach can optimize the design and manufacturing of tillage machines. In this study, the Monte Carlo method was used to perform reliability analysis on the whole chassis of a moldboard plow. For this, a complete model of a three-bottom moldboard plow was assumed as the limit mode function. Stochastic soil parameters were applied and the interaction forces of the plow with soil were simulated with finite element method (FEM). The desired output was the soil reaction forces on the plow at the most critical plowing speed and depth. Then, by applying the forces obtained from the FEM model and considering Young’s modulus of the chassis as a random variable, chassis static analysis was performed in different iterations and the stress concentration at different locations was determined. The probability of failure (Pf) and reliability index (β) of different locations of chassis were calculated. The results of the Monte Carlo simulation showed that the highest Pf occurred in crossbars, standards, braces and, masts with the values of 1, 0.296, 0.165 and, 0.033, respectively, which indicates the uncertainty of the design in these parts and the needs to strengthen or optimize the aforementioned parts of the moldboard plow chassis.

This study aimed to determine the effects of adding molasses on the physicochemical and silage fermentation characteristics, and in vitro ruminal fermentation parameters of fresh and ensiled lime pulps. This research was conducted in the form of a completely randomized design with four treatments including fresh lime pulp without additives (FLP), fresh lime pulp mixed with molasses; (FLPM), fresh lime pulp silage (LPS), and fresh lime pulp silage mixed with molasses (LPMS). Three replications were performed in each treatment Digestibility and gas production were determined using rumen liquid taken from two male Ghezel sheep. The results revealed that the application of molasses had no significant impact on the amount of dry matter. However, a marked distinction (P<0.05) was observed between the treatments regarding neutral detergent fiber (NDF), acid detergent fiber (ADF), ash, pH, and water holding capacity (WHC). The potential of gas production for FLPM was significantly (P<0.05) higher than that of other treatments. The addition of molasses to fresh lime pulp enhanced (P<0.05) the digestibility of dry matter in the rumen and total digestive tract. However, the presence of molasses in lime pulp silage reduced (P<0.05) the digestibility of dry matter in the rumen and total digestive tract. The results of this study suggested that the use of molasses would enhance fermentation and digestion by altering the composition of pectin in fresh lime pulp. While the lime pulp can be ensiled without molasses, the addition of molasses boosts the nutritive value and digestibility of silage.

Sulfur (S) plays a crucial role in plant growth and development and serves numerous biological functions in plants. To investigate the role of sulfur in drought stress protection, two experiments were conducted under greenhouse and growth ‎chamber conditions in 2021 Also, to evaluate ‎the influence of foliar application of sulfur on the expression of Pyrroline-5-carboxylate synthase, )P5CS)‎, proline concentration, and antioxidant enzyme activities‎, the plants of wheat Sardari and Ivan cultivars were exposed to two levels of water regimes. Plants under well-watered irrigation and drought stress conditions showed different P5CS expression levels and accumulated proline. The P5CS expression level in the Ivan cultivar was significantly increased by foliar application of S, while the same application had no significant effect on P5CS expression in the Sardari cultivar. Plants exposed to drought stress and foliar-sprayed with S showed a higher proline accumulation The activities of antioxidant enzymes, including peroxidase (POD), catalase, ‎glutathione peroxidase (GP), and glutathione reductase , were increased by 134 %, 40.4 %,  45.4 %, and 77.4 %, respectively, in plants exposed to drought stress. POD and GR ‎were ‎significantly increased‎ by 19.6 % and 51.8 %, respectively, ‎due to S application. Drought-induced plants that were foliar-sprayed with S exhibited a significantly lower rate of ion leakage and higher leaf-relative water content than those of control plants. Based on the results of the present research, it was revealed that S substantially enhances the expression rate of the P5CS gene, leading to proline accumulation, and activates defense reactions in water-stressed wheat.

One of the significant limitations in autumn cultivation of sugar beet is bolting. To investigate the quantitative and qualitative traits of root sugar beet cultivars and their resistance to bolting, a two-year (2018-2020) experiment was conducted as a randomized complete blocks design with three replications at Varsan Agricultural Research Station of Golestan Agricultural and Natural Resources Research and Education Center, Gorgan- Iran. Treatments included commercial autumn sugar beet cultivars [five imported cultivars (Montana, Jerra-kws, Rosagold, Chemineh, and Veles) and a domestic cultivar (Sharif). There was a significant difference in bolting rates of all cultivars in both years. Veles and Sharif cultivars had the highest bolting rate (41.7% and 33.3%) in both years, respectively. The bolting rate was higher in the second than in the first year. There was a significant difference between cultivars for root yield only in 2019. The highest (85.2 t ha-1) and lowest (59.8 t ha-1) root yields were obtained from Jerra-kws Chamine cultivars. There was a significant difference between cultivars for sugar purity, sugar extraction coefficient, and molasses sugar percentage in the second year. There was no significant difference between cultivars for sugar content and harmful nitrogen in both years. The cultivars showed different reactions in terms of bolting rate and other root qualitative traits (pure sugar, extraction coefficient, sodium, potassium, and harmful nitrogen levels) in the two years.

Optimal nutrient supply, either chemical or biological fertilizers, can be customized for water availability and paired with correct tillage systems. This approach is necessary to ensure high production in corn (Zea mays L.). To determine possible impacts of nitrogen (N), various irrigation regimes and tillage systems were evaluated on sweet corn (Zea mays L. var Saccharata). Dependent variables were plant growth, yield, water use efficiency (WUE), and soil characteristics. For this purpose, a two-year experiment (2016-2017) was conducted in a split-factorial design, involving randomized complete blocks with three replications at the Agricultural Experimental Station, School of Agriculture, Shiraz University, Shiraz, Iran. The treatments were two tillage systems [conventional (CT) and decreased (RT)] as the main plot. Five N rates were used (0, nitroxin, 150 kg N ha-1, nitroxin + 150 kg N ha-1, and 300 kg N ha-1). The two irrigation regimes were [100% (normal) and 75% of plant water need (PWR)(Kc)] as subplots, respectively. Also, five N rates and sources (0, nitroxin, 150 kg N ha-1, nitroxin + 150 kg N ha-1, and 300 kg N ha-1) were used in combination with two irrigation regimes [100% (normal) and 75% of plant water requirement (PWR)(Kc)]. The findings provided an indication that the canned yield and WUE could be raised by applying 300 kg N ha-1, 75% of PWR, and the CT system. The highest soil N content occurred in RT systems applied with nitroxin + 150 kg N ha-1 and 75% of PWR in the first year and under CT systems by applying nitroxin + 150 kg N ha-1 and the normal irrigation in the second year. Nevertheless, the maximum soil OC content occurred in the RT system applied with nitroxin + 150 kg N ha-1. To conclude, nitroxin-inoculated sweet corn responded favorably to the RT system with sufficient N rate and irrigation regimes down to 75% of PWR. Moreover, reducing irrigation water volume exerted no notable impact on reducing canned yield while it conserved water more significantly.

The future holds a projection of escalated occurrences of extreme climate events, which are expected to affect insect life substantially. Extensive research efforts in this field have witnessed rapid expansion despite significant gaps in knowledge. This review article addresses a deeper understanding of the impacts of severe climate events on insects that outline promising avenues for future research in this field. Drought has emerged as one of the predominant forms of extreme climate events that have extensively influenced insects, as frequently documented in the literature. The significance of drought occurrences on insects is crucial within the climate change scenario. Furthermore, the increasing occurrence and intensity of drought episodes, which are associated with changes in the climate, can result in elevated salinity levels in water bodies and soils. These changes have far-reaching implications for ecosystems, including impacts on biology, survival, and insect behavior. This review aims to analyze developments in information acquisition with anticipated climate change implications, particularly drought and salinity, on various aspects of insect life.