with the collaboration of Iranian Society of Plant Physiology
Volume & Issue: Volume 12, Issue 1 - Serial Number 23, June 2021, Pages 1-239 
Original Articles Agronomy

Evaluation of morphological and physiological traits of chickpea (Cicer arietinum L.) under Kermanshah region climate condition

Pages 12-25

https://doi.org/10.22067/ijpr.v12i1.79618

Hanieh Hajishabani, Farzad Mondani, Alireza Bagheri

Abstract Introduction
In recent decades, agricultural production systems have already explored many methods to increase the crops yield. Most of these methods involved increasing the efficiency of resources utilization such as nutrients, solar radiation, and atmospheric CO2. Crop growth and yield are considered as a function of photosynthetically active radiation (PAR) that is intercepted by plant as well its utilization efficiency to produce dry matter. Net primary production has often been found to be linearly related to the photosynthetically active radiation (PAR) intercepted by crops. The slope of this relationship is light use efficiency (LUE). Several authors have found close correlation between crop growth and yield with the radiation absorption and the LUE. Although, it was previously believed that the LUE is constant during the crop growing season and it is controlled more genetically, but environmental factors and management practices such as change in the sowing date, plant density, cultivars, climate, soil fertility, especially soil available nitrogen due to its specific role in photosynthesis, affect greatly the LUE. Therefore, the objectives of the present study were to evaluate light absorption and use efficiency in different sowing date for chickpea cultivars in Kermanshah regionlight absorption and use efficiency in different sowing date for chickpea cultivars in Kermanshah region climatic.
 
Material and Methods
A split plot experiment was conducted based on Randomized Complete Block Design during 2016-2017 at the research farm of the faculty of agriculture and natural resources of Razi University, Kermanshah, Iran (34°, 19´ N, 47°, 50´ E and altitude 1317 m). The average annual rainfall was 455 mm, and the long-term average of maximum and minimum air temperature was 22.6 and 5.9°C, respectively. Main plots had three sowing dates (February 29, Match 10 and April 6) and sub plots were composed of chickpea cultivars (Bivanij, Adel, Arman and ILC482). The measured indexes were leaf area index (LAI), radiation absorption, total dry matter (TDM), light use efficiency (LUE) and grain yield of chickpea. The LUE was calculated based on g MJ-1 through the slope of linear regression between total dry matter accumulation (g m-2) and cumulative absorbed photosynthetically active radiation. Chickpea grain yield was measured at the physiological maturity stage.
 
Results and Discussion
The results showed that the maximum LAI of different chickpea cultivars decreased with the delay in sowing date. The greatest LAI (3.8) was related to Arman cultivar with the sowing date of March 1 and the lowest LAI (1.9) was related to ILC482 cultivar with the sowing date of April 6. The light absorption had the similar LAI trend that with the delay in sowing date decreased about 51%. The highest (15.9 MJ m-2) and the lowest (13.4 MJ m-2) light absorption were observed for Arman cultivar with the sowing date of March 1 and ILC482 cultivar with the sowing date of April 6, respectively. Combined analysis of variance of the results indicated that the effects of sowing date and cultivars were significant on TDM and grain yield, but the interactions of sowing date and cultivars were not significant for TDM and grain yield. The results indicated that the delay in sowing date led to reduce in the grain yield (45%) and TDM (33.5%). The highest (158 g m-2) and the lowest (102 g m-2) grain yield were related to Bivanij and Arman cultivars, respectively. The grain yield of Bivanij cultivar was higher (35%) compared to other cultivars. The highest LUE (1.6 g MJ-1) was observed for Adel cultivar with the sowing date of March 1 and the lowest LUE (0.7 g MJ-1) was related to Arman cultivar with the sowing date of April 6. Late sowing dates of March 11 and April 6 reduced LUE compared to early sowing date of February 29 about 4.2% and 2.7% in Bivanij cultivar, 9.4% and 27.3% in Adel cultivar, 43.4% and 40.3% in Arman cultivar and 19.1% and 16.8% in ILC482 cultivar, respectively.
 
Conclusion
In general, the results of this study show that the delay in sowing date, which is unavoidable under some climatic conditions by the farmer, lead to reduce in measured traits such as grain yield and LUE of chickpea. However, it seems that late sowing could help with the selection of suitable chickpea cultivars that could offset the yield loss due to unsuitable environmental condition such as drought stress by end of the growing season.

Original Articles Agronomy

Morphophysiological and biochemical characteristics of bean (Phaseolus vulgaris L.) in response to tea waste mulch and weed control

Pages 26-40

https://doi.org/10.22067/ijpr.v12i1.80185

Majid Ghanbari, Ali Mokhtassi-Bidgoli, Parniyan Talebi-Siah Saran, Seyed Ramin Hosseini

Abstract Introduction
Legumes are the most important source of vegetable protein supply. Seed bean contains 25-22 percent protein, and it has a high nutritional value for human which is a major source of protein supply in most modern societies. Today protein deficiency is one of the acute nutritional problems in the diet of millions of people in developing countries. Bean ranks third after pea and lentil in Iran as one of the developing countries with dry and semi-arid climate. Moreover, as to the weeds management of the cropping systems, weeds are controlled by hand as an earliest means, and by airplanes, chemical pesticides, hormones, and viruses as the most complete tools. Various studies show that weed control treatments especially hand weeding treatments caused higher yield than control treatment, indicating the importance and priority of hoeing in the cultivation of beans. Mulch as a new phenomenon in agriculture has caused a fundamental change in the use of chemical pesticides, controlling weeds in fields, preventing soil erosion, and increasing water penetration in soil layers. Also, the use of plant mulch can compensate soil nutrients and increase the organic nitrogen content of the soil. The advantages of using plants mulch could be increasing soil nitrogen for the main plant, protecting soil erosion, increasing soil quality, reducing evaporation, and increasing water penetration in the soil, improving water use efficiency, maintaining good soil temperature and suppressing weeds. Considering the growing need for weed control in bean fields through non-chemical and mulch applications as an ecological alternative for sustainable agriculture, an experiment was conducted to investigate the effect of tea waste mulch and weed control on morphophysiological and biochemical characteristics of bean.
 
Materials and Methods
This study was conducted at the Research Farm of Tarbiat Modares University, with a factorial experiment using a RCBD with three replications. Five time of weed control including no weed control, and weed control every 1, 2, 4 and 6 weeks and three rates of tea waste mulch at 0, 5 and 10 ton.ha-1 were used. Common bed preparation techniques such as plowing, disc and leveling was done in a land area of 1000 m-2. The dimensions of each plot were 4 m by 3 m. The planting was carried out on March 20, with a density of 25 plants m-2, with a spacing of 50 cm between the planting rows and eight centimeters on the planting row. The first irrigation was carried out immediately after planting using T-tape. The next irrigation intervals were every 5 days.
 
Results and Discussion
The results showed that the combined effects of weed control and tea waste mulch on all measured traits were significant. Also, the two-way interaction of these factors was significant for soluble carbohydrate, starch, number of pods per plant of bean and dry weight of weed. The highest yield and yield components of bean were observed in weed control once per week and 10 tons tea waste mulch per hectare. The highest photosynthesis rate and water-soluble carbohydrate content was observed in the same treatment. Weed control reduced the competition of weeds with bean and could provide more resources to the crop. Thus, the application of tea waste mulch affects the absorption of nutrients by the roots. Other studies reported that dandruff mulch, such as mulch, was more effective in control of weeds than light cleared mulches due to the lack of light on the surface of the soil and produces good grain yield. The researchers reported that the highest grain yield was obtained from mulch clichés treatment, which were categorized by black and white plasterboard treatments in a statistical group.
 
Conclusion
The results of this study suggest that weed control and application of 10 tons tea waste mulch per hectare could improve photosynthesis rate, reduce protein content and increase starch and water-soluble carbohydrate contents of bean seed. Weed control once per week after bean emergence and application of five and 10 ton ha-1 mulch reduced weed dry weight by 45.48% and 74.12%, respectively. Finally, application of 10 tons tea waste mulch per hectare and weed control every 2 weeks is recommended for bean fields. Overall, it appears that application of tea waste mulch and weed control at the beginning of emergence was superior for seed production comparing to the late weed control and without mulching.

Original Articles Agronomy

Response of yield and yield compounds of rain-fed chickpea cultivars (Cicer arietinum L.) to plant density and weed interference

Pages 41-57

https://doi.org/10.22067/ijpr.v12i1.74983

Arsalan Fallahi, Goudarz Ahmadvand, Farzad Mondani, Akbar Aliverdi

Abstract Introduction
The most important principle in the rain-fed cropping system is to maintain and optimal use of soil moisture. In this regard, selecting the appropriate cultivar and planting density is one of the most important management decisions. The open canopy structure, short stature, limited leaf area, and the slow growth rate of chickpea is responsible for its poor competitive ability against weeds. In rain-fed cropping systems, weeds can also play an important role in soil moisture depletion and can aggravate drought stress on crop at the end of the growing season. Among the weed control cropping methods, it is possible to select a competitive cultivar and/or increased planting density. After introducing a new cultivar from rain-fed chickpea, researchers have always compared it with older cultivars in terms of competitive ability against weeds. So far, there has been no comparative study of competitive ability or tolerance of a new rain-fed chickpea cultivar, Adel, against weeds with older cultivars. Consequently, the effect of planting density of this new rain-fed chickpea cultivar on the response of weeds was not investigated. Therefore, the aim of this study was to investigate the interaction of this new and old cultivars and planting density on weeds damage under rain-fed conditions in Kermanshah.
 
Materials and Methods
This research was carried out at the research farm of the faculty of agriculture and natural resources of Razi University, Kermanshah, during 2013-2014 growing season. Wheat was planted in the same farm during the previous growing season. During the experiment, the total rainfall was 85.51 mm. After preparing the land to plots of 6 × 2 m2, the chickpea cultivars were manually planted with the distance of 40 cm on each row on 5 February 2013. The experiment was a factorial (3 crop densities × 4 chickpea cultivars × 2 weed interferences) in a completely randomized block design with three replications. Planting densities were 31.3, 38.5, and 50.0 plants m-2. Chickpea cultivars were Arman (FLIP90-96C), Azad (FLIP93-93C), Adel (FLIP99-66C), and Hashem (FLIP84-48C). The factor of weed interference was at two levels of weeding and unweeding. The crop was harvested on 28 June 2014 to evaluate yield and yield components. The samplings of weeds were performed to determine the total biomass using a 1 m2 quadrate on 20 May and 12 June 2014, which were coincident with the flowering time and physiological maturity of chickpea, respectively.
 
 
Results and Discussion
In general, the economic yield was decreased by increasing the plant density in all chickpea cultivars. The planting densities of 38.5 and 50.0 plants m-2 reduced the economic yield up to 8.9 and 42.6% in Azad cultivar, 30.5 and 37.2% in Arman cultivar, 23.7 and 40.2% in Hashem cultivar and 32.9 and 36.3% in Adel cultivar compared to planting densities of 31.3 plants m-2, respectively. Azad cultivar produced the highest economic yield (146.4 g m-2) under weeded condition, while the lowest economic yield (45.2 g m-2) belonged to Arman cultivar under un-weeded condition. The presence of weeds resulted in a reduction of 59.1, 51.9, 61.2, and 46.3%, in the economic yield of Azad, Arman, Hashem, and Adel cultivars, respectively. During the first weeds sampling, the highest (25.7 g m-2) and the lowest (17.7 g m-2) weed biomass were observed at planting density of 31.3 and 38.5 plants m-2, respectively- whereas during the second weeds sampling, the highest (60.0 g.m-2) and the lowest (42.8 g. m-2) weed biomass were observed at 31.3 and 50.0 plants m-2, respectively. Moreover, during the second sampling of weeds, the highest (54.7 g m-2) and the lowest (40.8 g m-2) weed biomass were observed at the plots of Hashem and Adel cultivars, respectively.
 
Conclusion
In this research, the planting density of 31.3 plants m-2 was optimal planting density for all four chickpea cultivars. It seems that the increase of planting density to control weeds in rain-fed chickpea cropping system is an unsuitable technique. Therefore, it is necessary to consider other techniques to control weeds in rain-fed chickpea cropping systems. An interesting observation in this study was that, although the economic yield of Adel cultivar was lower, the lower biomass of weeds in the plots of this cultivar was observed compared to other cultivars. This observation can be related to allelopathic compounds produced by Adel cultivar which is costly for the crop itself and has reduced its yield.

Original Articles Agronomy

The effect of cycocel spraying on yield and yield components of spring chickpea (Cicer arietinum L.) under rainfed conditions

Pages 58-67

https://doi.org/10.22067/ijpr.v12i1.80708

Dariush Safari, Mitra Azadikhah

Abstract Introduction
Chickpea (Cicer arietinum L.) is one of the herbaceous plants. Most of the producing countries of this crop are in arid and semi-arid regions, and about 90% of the world's chickpea is produced in rainfed conditions. Chlormequat chloride or cycocel (2- Chloroethyl 3 methyl ammonium chloride) is a choline esters derivative. Chlormequat chloride interacts with the gibberellic acid biosynthesis pathway, inhibits the activity of ent-kaurene synthesis and reduces plant height. Reports have shown that the use of cycocel reduced the stem height, increased the number of tillers per plant, the number of seeds per spike, cold resistance, salinity, fungi, and insects. Studies show that cycocel solubilization increases cytokinin from root to stem, which increases the growth period, photosynthesis, and increased yield. The aim of this study was to investigate the response of yield and grain yield components of two chickpea cultivars to three concentrations of cycocel foliar application under rainfed conditions.
 
Materials and Methods
In order to study the yield and yield components of chickpea in response to different levels of cycocel in rain fed conditions, a factorial experiment was conducted in a randomized complete block design with three replications at the research farm of Sararood Research Center of Kermanshah. The treatments consisted of two factors of cycocel concentration in three levels: zero (water as control), 200 and 400 mg L-1 as the main factor and two cultivars of Chickpea bionij (local cultivar Mahidasht) and Samin as a minor. Cycocel treatments were sprayed manually until the water was checked from leaves and air organs. In order to maintain the effects of cycocel, the treatments were applied in two steps, including 45 days after planting (one week before flowering) and 60 days after planting (50% flowering) for the planned plots. At the same time the experiment coincided with the onset of drought stress in the study area. In each experimental unit, two rows of five rows and a half meter from the beginning and the end of the rows were considered as the range. To determine the yield components after harvest, 10 plants were selected randomly from each plot. Plant height, number of branches, the number of shells per plant, shell weight per plant, seed weight per plant, 1000-grain weight, biological yield, grain yield and harvest index were measured. Data were analyzed by SAS Ver. 9.1 and the minimum significant difference test (LSD) at the probability level of (p≤0.05) was applied for comparisons between treatment means.
 
Results and Discussion
The results of analysis of variance showed that the simple effects of cultivar and cycocel on all studied traits were significant at level of (p≤0.01), and their interactions on harvest index and 1000-seed weight was significant at level of (p≤0.01), and finally the number of lateral branches, pod weight per plant, the number of seeds per pod, biomass yield, grain yield was significant at level of (p≤0.05). High cycocel (400 mg L-1) treatments increased yield and yield components compared to other treatments. According to the studied traits, Bionij cultivar had more yield than Samson cultivar. Generally, the growth mobility through the change in the photocells and the direction it directs to the target increases the yield. Cycocel also increased the grain weight and yield in plants due to the changes in the allocation of the material to seed filling.
 
Conclusion
The results of this study showed that Samson had the highest plant height among the other cultivars, while the highest number of secondary branches, weight of pod per plant, the number of seeds per plant, 1000 seed weight, seed number per pod, grain yield, biomass yield and harvest index was observed in Bionaj. All studied traits were positively affected by cycocel. In most cases, soluble cycocel with a concentration of 400 mg L-1 had the greatest effect on growth and yield of chickpea cultivars. It seems that spraying chickpea plants, especially Bionij cultivar with a concentration of 400 mg L-1 of cycocel is recommended for similar climatic conditions.

Original Articles Agronomy

Evaluation of response of Red bean cultivars with two different growth habits on weed competition

Pages 68-87

https://doi.org/10.22067/ijpr.v12i1.81211

Seyede Zahra Tabatabaiepour, Zahra Tahmasebi, Alireza Taab, Sajad Rashidi Monfared

Abstract Introduction
Common bean (Phaseolus vulgaris L.) has been considered as an important source of protein and calorie. This plant plays an important role in supplying the human's protein. Bean crop is highly susceptible to weeds due to low growth rate early in the growing season. Therefore, competition with weeds causes a significant reduction in grain yield at the end of the growing season. Weed competition is a kind of non-living stress, which affects plant yield. Weeds and crops are always competing for obtaining nutrients, water, light and space (CO2). Examining the effect of weed interference time during the critical period provides valuable information regarding the physiological outcome of competition between weeds and crops. Red bean cultivars, with different morphological and genetic characteristics, show different responses in the presence of weeds, which may ultimately result in possible difference in yield. Unlimited growth genotypes showed higher competitive ability than those with limited growth genotypes. However, there are contradictory reports about the effect of growth habits on competitive ability. Measurement of growth indices is necessary to study the competitive ability of species during the growth period. The aim of this study was to investigate the response of some morphophysiological traits of three red bean cultivars with two different growth habits to weeds.
 
Materials and Methods
A field experiment was conducted to investigate the morphological and physiological characteristics of three red bean cultivars with two different growth habits (semi erect and erect) under weed competition in the experimental research station at the Faculty of Agriculture, University of Ilam, Iran. The experiment was conducted as factorial based on a randomized complete block design with two factors including: cultivars (Sayad, Derakhshan and line D81083) and weed competition at two levels (weed free and infested during the growing season) with three replications. The traits related to red bean such as plant height, biomass, chlorophyll a, b and total chlorophyll, anthocyanin and carotenoid at the stages V4, R6, R7 and grain yield and yield components were measured at physiological maturation stage. The importance value of weed (IVW) was measured in two stages V4 and R9. Competitive index (CI) was used to evaluate the competitive ability of common bean varieties against weeds. The software of SPSS 22, SAS 9.4 and Excel 2013 were used for test normality, data analysis and drawing charts, respectively. Means comparison was performed by the least significant difference test (LSD).
 
 
Results and Discussion
 
Convolvulus arvensis had the highest importance value of weed (IVW) index from the beginning of growth until stage V4. At stage R9, the Purtulaca oleracea and Amaranthus retroflaxus had the highest values of IVW by 27.33% and 21.92%, respectively. The latter are dominant species in the western regions of the country. The results showed that cultivar type and weed competition had significant effects on the bean crop height at all studied stages. In addition, the effect of interaction between cultivar and weed competition was significant on leaf area (LA) and height at V4 and R7 stages, respectively. At all stages, traits such as height and leaf area of red bean cultivars were significantly decreased owing to weed competition compared to the weed control. Line D81083 and Sayad had the highest and lowest leaf area in competition with weeds during all stages, respectively. The effect of interaction between cultivar and weed competition was significant on grain yield and number of pods per plant. Line D81083 and Derakhshan cultivars had the highest and lowest seed yield in competition with weeds, respectively. Line D81083 had the most competitive index among the cultivars. There were no significant differences between Sayad and Derakhshan in all studied traits. Weed competition had a significant effect on chlorophyll a, b and total chlorophyll at V4 and R7 stages. Anthocyanin and carotenoids were not affected by the treatments at V4 stage. Overall, chlorophyll a, b and total chlorophyll were significantly increased in the absence of weeds. The effect of differences in anthocyanin value was significant based on the cultivar and weed presence, while carotenoid content was only affected by the cultivar type at R7 stage.
 
Conclusion
The present study showed that use of line D81083 could increase grain yield of red bean up to 2-fold under weed free conditions compared to crop-weed interference conditions. Line D81083 had the highest grain yield, pod per plant, 100-grain weight, and competition index when full-season weed competition occurred.

Original Articles Agronomy

Effect of priming and foliar application of different amino acids on yield and yield components of lentil (Lens culinaris Medik.) in late sowing

Pages 88-99

https://doi.org/10.22067/ijpr.v12i1.83900

Ali Heidarzadeh, Seyed Ali Mohammad Modarres-Sanavy, Hossein Ebrahimi Esborezi

Abstract Introduction
Lentil is used mainly for human consumption as a source of protein and carbohydrate in soups, stews and vegetarian dishes. It is grown to improve economic returns to producers, diversify and lengthen crop rotations, and reduce nitrogen fertilizer requirement. Lentil, a member of the legume family, Leguminosae, can supply a significant portion of its nitrogen requirement by fixing nitrogen from the air when it is inoculated with the appropriate rhizobial inoculant. The pattern of nutrients in the proximal composition of lentil is similar to that of other grain legumes, but with seed protein content of 19.5–35.5%. Fiber concentration is low and is largely within the seed testa, so the fiber in lentil meal can be reduced if it is de-hulled before grinding. In addition to high-quality protein, essential amino acids, and major minerals, its seed contains iron up to 505 mg per kg and zinc up to 330 mg per kg on a whole seed basis. Amino acids help in tissue protein formation. Some amino acids are not synthesized in the body and it is necessary to take them in diet. Lentils contain different amino acids that can be used by most people. This research was carried out to study the effect of different Amino Acids on the activity of antioxidant enzymes, proline content and seed yield of Lentil in delayed planting.
 
Materials and Methods
In order to study the effect of different amino acids on yield and biochemical traits of lentil, a factorial experiment was conducted based on a randomized complete block design with three replications in the research farm of agricultural faculty, Tarbiat Modares University, through May to July 2018. The factors studied included mode of application (priming, spraying and priming+spraying) and type of amino acids (Arginine, Aspartic acid, Proline, trade amino acid and distilled water (control)). The amount of amino acids used was 1 g per liter. In this study, leaf, stem, pod and total fresh weight, leaf area, leaf to stem, chlorophyll content (a, b and total), the number of pods per square meter, 1000 grain weight, harvest index and seed yield were determined. Statistical analysis of data was performed using SAS software version 9.4. To compare the means, the least significant difference (LSD) test was used at a 5% probability level. Also Excel software was used to obtain different equations and draw curves and chartsharts.
 
Results and Discussion
The results showed that the highest total chlorophyll (16.18 mg gF.W-1), chlorophyll a (13.92 mg gF.W1) and chlorophyll b (2.53 mg gF.W-1) was obtained from the priming with aspartic acid. The number of pods per plant (13.11) was more than the others in priming and spraying with aspartic acid. Amino acid application produced more leaf than control (distilled water). The arginine, aspartic acid, proline and commercial amino acids produced 46, 55, 20 and 52% more leaf fresh weight, respectively. The application of aspartic acid with 88.87 g m-2 produced the highest yield (more than three-fold relative to the control), followed by the application of arginine (55.51 g m-2), commercial amine (44.4 g m-2) and proline (32.78 g m2). The application of aspartic acid via both priming and spraying is suggested as the best treatment.
 
Conclusion
Plants create amino acids from primary elements they absorb from the environment. Carbon and oxygen are obtained from the air. Hydrogen and nitrogen are obtained from the soil. Inside the plant, amino acids are formed through metabolic pathways. Plants, like all other forms of life, require amino acids to create cells. These cells are then used to build various vital parts of a plant like roots and leaves. Amino acids are quite literally the foundation of life, especially when it comes to plants. If plants can utilize supplementary amino acids without creating them out of oxygen, carbon, nitrogen, hydrogen and sometimes sulfur, they would have much more available energy to use where it is necessary. When amino acids are properly applied, the impacts are profound. According to the results of this study, amino acids can reduce the stress of delayed planting. In the absence of amino acid, yield reduction will be higher. The application of aspartic acid via both priming and spraying is suggested as the best treatment.

Original Articles Agronomy

Evaluation of yield components, yield and competitive power of chickpea cultivars under weed interference

Pages 100-110

https://doi.org/10.22067/ijpr.v12i1.84964

Seyed Mohsen Seyedi, Javad Hamzei

Abstract Introduction
Weeds are among the main limiting factors in agriculture. In fact, the problem of weeds is a basic problem in farms, which can lead to major yield loss. Weeds can decrease soil nutrients and threaten crops by competing for water and light or by their allelopathic effects. Crop yield losses due to weeds depend on a number of factors such as grown species, weed number per area, weed competitive value, and crop developmental stage. Weeds can decrease grain quality, cause unequal maturation and harvesting difficulties, and act as the hosts for pathogens and pests. In addition, environmental and human health impact of herbicides, increasing resistance to herbicides, scarce by herbicides and increased conservation agriculture were the main factors stimulating the interest in developing new weed control methods. Chickpea is a weak crop against weed. Chickpea (Cicer arietinum L.) is one of the earliest cultivated legumes and has been found in the Middle East 7500-years ago. It plays an important role in human nutrition as a source of protein, energy, fiber, vitamins, and minerals for large population sectors in the developing world and is considered a healthy food in many developed countries.
 
Materials and Methods
In order to evaluate yield components, yield and competitive power of chickpea cultivars, an experiment was conducted on a sand claysoil at the Agricultural Research Station (latitude 35˚1' N, longitude 48˚31' E and 1690 m altitude), Faculty of Agriculture, University of Bu-Ali Sina, Hamedan, Iran. The long-term average air temperature and average air temperature during the growing season was 12.5˚C and 22˚C, respectively. The experiment was done within two seasons, 2013 and 2014. The same field was used in both years and the same treatments were applied to the same plots. Experiment was conducted as the factorial based on randomized complete block design (RCBD) with three replications. Experimental treatments included weeding, no weeding of weeds, and five cultivars of chickpea (Tork, Hashem, Arman, Azad and Mahali). Analysis of variance was used for statistical analyses (Version 9.2, SAS). Differences between treatments were compared by least significant difference (LSD) test at the 5% probability.
 
Results and Discussion
Analysis of variance showed that the effect of weed control on all traits except harvest index was significant. The effect of cultivar on all traits except harvest index was significant. The effect of weed control × cultivar interaction was statistically significant only on grain and biological yield. The highest grain yield (136.00 g m-2) was obtained for Hashem cultivar in weeding condition. The lowest value of this trait with about 75% reduction was obseverd for Mahali cultivar under no weeding condition. Maximum biological yield (394.75 g m-2) was observed for Hashem cultivar under weeding condition and the lowest value, with about 70% reduction, was found for Mahali cultivar under no weeding condition. Maximum and minimum weed biomass (104.99 and 52.50 g m-2, respectively) and weed density (20.50 and 10.67 per m2) was found for Hashem and Mahali cultivar, respectively. Therefore, results showed that the highest ability withstand competition (52.30) was observed for Hashem cultivar, and the lowest value of this index (39.12) was for the Mahali cultivar. The results showed that increasing the biomass of chickpea plants increased the ability withstand competition index, and decreased weed density and weed biomass. Therefore, Hashem cultivar can be known as a resistant cultivar against weeds, but Mahali cultivar has the lowest ability against weed invasion. In general, the use of resistant varieties is a good solution to reduce weed damages.
 
Conclusion
The results of this experiment showed that the yield of different chickpea cultivars decreased in the presence of weeds. However, yield reduction in different cultivars was not the same. As a result, Hashem and local cultivars were identified as the strongest and weakest cultivars against weeds, respectively. By evaluating the yield of different chickpea varieties and competitiveness index, the varieties with good competitive ability in the presence of weeds can be identified. Additionally, this has the potential for weed control management without chemical herbicides.

Original Articles Response to biotic and abiotic stresses

Symbiosis effects of Mycorrhizal and Pseudomonas on morphophysiological traits of mung bean (Vigna radiata (L.) Wilczek) under moisture stressed condition

Pages 111-126

https://doi.org/10.22067/ijpr.v12i1.84409

Mohammad Salehi, Ali Faramarzi, Manochehr Farboodi, Nasser Mohebalipour, Jalil Ajalli

Abstract Introduction
Environmental stresses especially drought are important and effective factors reducing plant production. Mung bean (Vigna radiata (L) Wilczek) from leguminosae family mostly grows in tropical areas and has a lower water requirement compared to other legumes. The role of mycorrhizal symbiosis to protect plants under drought conditions is considerable. The main effects of drought stress at the flowering stage are aborting flowers and eventually declining seed yield while the major effects of drought stress are on reproductive organs of plants in the pod filling stage. Therefore, effects of drought stress occurring due to lack of water are in different growth stages which can be divided into flowering and pod filling stages. The aim of this study was to improve some morphophysiological traits, nitrogen, protein, root colonization, mycorrhizal dependency and mycorrhizal growth response percentage of mung bean by Glomus mosseae and Pseudomonas fluorescence strain 169 symbiosis under different imposed moisture stress conditions.
 
Materials and Methods
A split plot Randomized Complete Block Design experiment with three replications was conducted in the research farm of Islamic Azad University of Miyaneh branch, Iran, during 2016. The main factors allocated to three levels of drought stress included: normal irrigation (control), stopping irrigation in flowering stage, stopping irrigation in pods formation stage. Sub-factor was considered for four treatments of inoculation including: non-inoculation (control), inoculation by G. mosseae, P. fluorescens strain169 and G. mosseae+P. fluorescens strain169. Parto variety of mung bean (Vigna radiata L. Wilczek) used in this study was provided by Seed and Plant improvement Institute, Karaj, Iran. Suspension solutions of Pseudomonas fluorescens strain169 with 108-109 live and active bacteria per ml (CFUml-1) were provided by Water and Soil Research Institute, Karaj, Iran. Glomus mosseae was obtained from Zist Fanavaraneh Turan biotech firm, which had approximately 30 live fungi per gram and was produced by culturing in host plants, used in the form of soil mixed spores and hyphae. Inoculation of seeds by Pseudomonas fluorescence strain 169 was done in the morning by mixing them in an aluminum paper. The 2% glucose solution was added to increase the number of bacteria attached to seeds, and the seeds were then allowed to be dried in shadow. In order to increase the efficiency of fungi and bacteria in sowing time, seeds were not sterilized. Based on physicochemical analysis, the soil clay and organic carbon, nitrogen, phosphorus and potassium amount in the experimental farm was 1.5%, 0.1%, 5.70 (mg.kg-1) and 301 (mg.kg-1), respectively. In this study, traits such as protein of seed (%), nitrogen of seed (%) and root colonization (%), relative water content (%) as well as mycorrhizal dependency (%) and mycorrhizal growth response (%) were measured, and the average of ten samples from each plot for plant height (cm), the number of leaves per plant, dry weight of leaves (g), dry weight of stem+pod (g), dry weight of plant (g), stem diameter (mm) and the number of branches were collected and calculated. All measured data were analyzed for simple analysis of variance using MSTAT-C software. Mean comparison was carried out by the Duncan test at 5% probability level using SPSS (Ver.16).
 
Results and Discussion
Results displayed significant variation among drought stress treatments for the majority of growth characteristics. Based on inoculation treatments, there were significant differences between all measured traits except the number of leaves per plant and stem diameter. Drought stress decreased the majority of morphophysiological traits. Glomus mosseae increased dry weight of leaves and dry weight of plant by 44.3% and 8.45% respectively. G.mosseae was more effective to increase growth characteristics of mung bean. According to water requirement, pods forming stage was the most sensitive growth stage. Co-inoculation of P. fluorescence strain 169+G. mosseae synergistically affected root colonization percentage and nitrogen percentage of seeds. Protein content of seeds in drought stressed condition was more than normal irrigation plots. Plants located in cutting irrigation in pods filling stage plots plus inoculated by G. mosseae+P. fluorescence 169 had the highest protein content of seed with average 16.560%.
 
Conclusion
This study indicated that major differences between G. mosseae, Pseudomonas fluorescence strain 169 and interaction of them for their ability to enhance growth characteristics of mung bean. G. mosseae and P. fluorescence strain 169 could alleviate drought stress effects through enhancing the plant height directly. Pod formation stage was identified as a susceptible growth stage of the plant under water deficit condition. In addition, stopping irrigation in pod formation stage had a high negative influence on the number of leaves and branches in plant. The majority of measured growth characteristics was positively affected by soil microbial mass. Plants inoculated by P. fluorescence 169+G.mosseae under cutting irrigation in pod filling stage had the highest root colonization by 55.3%. Synergistic effects of G. mosseae and P. fluorescens 169 increased dry weight of stem+pod, dry weight of plant, which seems to be an important finding for physiologists and soil scientists. Glomus mosseae individually improved plant height and dry weight of leaves in cooperation with other treatments.

Original Articles Agronomy

Evaluation of yield and yield components of green bean and bell pepper under replacement and additive intercropping systems

Pages 127-143

https://doi.org/10.22067/ijpr.v12i1.81231

Alireza Koocheki, Mehdi Nassiri Mahallati, Mohammad Hassan Hatefi Farajian

Abstract Introduction
The use of intercropping as an effective component in sustainable agriculture, while increasing the ecological and economic diversity, cause increasing yield per unit area, yield stability under adverse environmental conditions, increasing the quantity and quality of the product, increasing water use efficiency, control of soil erosion, reducing pesticides use and increasing stability in agroecosystems. Plants from the family of legumes are among the plants that have a special place in intercropping because of their nitrogen fixation ability. Usefulness of intercropping cultivation of sweet corn and green bean has been reported to be better than monoculture. This study was designed and conducted with the aim of studying the effect of replacement and additive intercropping green bean with bell pepper on yield, yield components and land equivalent ratio in Mashhad weather conditions.
 
Materials and Methods
The experiment was conducted in 2015-2016 growing season based on a randomized complete block design with three replications at the Research Farm of Agriculture Faculty, Ferdowsi University of Mashhad. Experimental treatments were 25% green bean+75% bell pepper, 50% green bean+50% bell pepper in replacement intercropping, 20% green bean+100% bell pepper and 40% green bean+100% bell pepper in additive intercropping and monoculture of green bean and bell pepper. Green beans have planted by seed and bell pepper transplants were sown at the same time in June 2016 in rows with a distance of 50 cm. In 4-leaf stage, green bean was thinned with an optimum density of 20 plants per square meter. In addition, the spacing on the row was considered 30 cm for transplants of bell pepper; in this case, its optimum density was 6.66 plant per square meter. At harvest time, green pod yield for green bean, fruit yield for bell pepper, other yield components and plant dry weight for two plants were measured, and land equivalent ratios were also calculated.
 
Results and Discussion
The highest green pod yield and plant dry weight for green bean with 57921.7 and 1051.03 kg ha-1, respectively, was observed in monoculture and the lowest values for 20% green bean+100% bell pepper with 11252.5 and 525.8 kg per ha, respectively. With the increase in the presence of green bean in replacement and additive intercropping, the green pod yield of green bean increased due to increasing of biological nitrogen fixation. For bell pepper, the highest fruit yield with 32766.7 kg ha-1 was observed in monoculture and the highest plant dry weight with 7816.6 kg ha-1 was observed for 75% bell pepper+25% green bean and the lowest fruit yield was obtained for 50% bell pepper+50% green bean and 100% bell pepper+20% green bean with 21183.3 and 21886 kg ha-1, respectively, and the lowest plant dry weight was obtained for 50% bell pepper+50% green bean with 3533.33 kg ha-1. Due to the fact that the highest number of fruits per plant was observed in monoculture of bell pepper, therefore, monoculture has higher fruit yield because it has more space for plants. The highest value of total land equivalent ratio (1.28 and 1.25) was obtained in ratios of 40% green bean+100% bell pepper and 50% green bean+50% bell pepper, respectively, indicating 28 and 25% yield advantage of intercropping compared to pure stands of species of these two plants. The lowest value of total land equivalent ratio (0.86) was observed in ratio of 20% green bean+100% bell pepper.
 
Conclusion
Comparison of different patterns of replacement and additive intercropping showed that cultivation pattern of 25% green bean+75% bell pepper was superior for most of the traits evaluated in green bean and bell pepper compared to other patterns. Additive intercropping pattern of 40% green bean+100% bell pepper had the highest total land equivalent ratio (1.28) which indicate the beneficial effect of mixed cropping pattern over pure cropping. Since green bean through biological nitrogen fixation, leads to reduction in the use of chemical fertilizers, intercropping of this plant with other plants such as bell pepper can increase the resources efficiency and improve yield quantity for bell pepper.

Original Articles Agronomy

Effect of biological and chemical fertilizers and weed control methods on lentil (Lens culinaris Medik.) biomass and seed yield

Pages 144-155

https://doi.org/10.22067/ijpr.v12i1.84970

Ebrahim Eizadi-Darbandi, Arash Maghsoudi

Abstract Introduction
Lentil is the second most important of legume crops in Iran and is mostly cultivated in the rainfed conditions. Weed competition is a major limitation to lentil production worldwide due to its slow early growth rate, short height, and lack of protective canopy development. Since the level of competition between weeds and crops is highly dependent on nutrient availability, proper nutrient management is considered as a method of weed management. Various aspects of nutrient management such as fertilizer type, application time, amount of application, and form of fertilizer can also change weed interference conditions with crop. It is believed that the application of biofertilizers, while providing environmental security and economic benefits, is a sustainable and beneficial method of plant nutrition and reducing the adverse effects of weeds. In Iran, two herbicides registered for lentil including pendimethalin and promethrin, that both of which are pre-emergence. Applying a single management method alone, in addition weed adaptation, leads to agroecosystem instability. Integrated weed management can increase the efficiency of management methods and also contribute to the sustainability of farming systems. This study was conducted to compare the effects of biological and chemical fertilizers in combination with chemical and mechanical weeding to improve crop yield and management of weeds in lentil farms.
 
Materials and Methods
The experiment was conducted as factorial based on randomized complete block design with three replications at Research Farm of Ferdowsi University of Mashhad, Iran. Investigated factors included five levels of plant nutrition (inoculation of lentil seeds with phosphorus-releasing bacteria (Phosphorobacter), inoculation of lentil seeds with potassium-releasing bacteria (Potapowerobacter), inoculation of lentil seeds with mycorrhizal fungi, inoculation of lentil seeds with a mixture of Phosphoraverbacter, Potapaverbacter and Mycorrhizal fungi, and application of chemical fertilizers based on soil test results without inoculation with biological fertilizers) and three weed control methods (weeding twice before flowering and pod filling lentil stage, respectively, weed control with pendimethalin as pre-emergence herbicide, and weed control with pyridate as post-emergence herbicide). Lentils were planted at 100 plants m-2 density. Biological fertilizers were sprayed on lentil seeds in lab, before planting. Chemical fertilizer (mixture of potassium sulfate and urea) was distributed at the rate of 50 kg ha-1 in the plots after sowing. Pentimethalin and pyridate were applied with a dose of 3.7 and 1.2 L ha-1, respectively, in 3-4 leaf stage of weeds. Weed sampling was done in three lentil growth stages (flowering, pod filling, and crop harvest) from 0.5 m-2. Matured crops were harvested from 1 m-2 and placed in lab for 48 hours to be dried for biomass and seed yield measurements.
 
Results and Discussion
The results showed that despite significant weed control, the application of pyridate damaged lentil crop and reduced biomass and seed yield. Pendimethalin resulted in the highest lentil biomass and seed yield and no damage to lentil crop. Among the fertilizers, chemical fertilizer increased weed density and biomass, also increased lentil biomass and seed yield. Among the biofertilizers, Petapowerbacter (potassium fertilizer) showed that the highest yield of lentil (730.8 g m-2), and the biofertilizer mixture resulted in a decrease the yield and biomass of lentil compared to the other fertilizers. Due to the interactions between the control methods and the fertilizers, the highest biomass (800 g m-2) and seed (164 g m-2) yield were obtained in the integration of potassium biofertilizer with pendimethalin.
 
Conclusion
According to the results of the experiment, application of chemical fertilizer resulted in the highest crop yield and also increased weed density and biomass compared to biofertilizers. Among the biofertilizers, Petapowerbacter, which contains potassium-stabilizing bacteria in the soil, had the best effect on crop yield. However the effects of biofertilizers on weed traits, the lowest density and biomass of weeds were related to mycorrhizal treatment and the other treatments were not significantly different. Among the weed control methods, pendimethalin had the greatest effect on improving crop yield. Although pyridate weed control was better, but caused damage to the crop and yield was decreased. Therefore, according to the results this experiment, we recommend the use of pendimethalin in combination with Petapowerbacter in integrated weed management of lentil.

Original Articles Agronomy

Effect of different irrigation intervals on some morphophysiological characteristics of different genotypes of Guar (Cyamopsis tetragonoloba)

Pages 156-170

https://doi.org/10.22067/ijpr.v12i1.83229

Monireh Dadgar, Somayeh Rastegar, Hosein Piry

Abstract Introduction
Guar (cluster bean) Cyamopsis Tetragonaloba is one year plant belongs to the leguminous family. Guar has high nutritional value for humans. Global demand for guar has increased dramatically in recent years, which has led to the introduction of the plant in several countries. Water stress is the most important factor limiting planting and reducing food crops, especially in arid and semi-arid regions of the world. Therefore, identification of resistant plants and mechanisms that lead to optimal water use and high crop yields are critical. Given the limited water resources in the country, the evaluation of guar stands under drought stress is of particular importance.
 
Materials and Methods
The experiment was carried out at the Research Farm of Iranshahr Agricultural and Natural Resources Faculty in 2017-18. The experiment was conducted as a split-plot in a randomized complete block design with three replications. Three levels of irrigation interval (7, 5, and 9 days) and six guar stands (Sarbaz, Saravan, Iranshahr, RGC1033, Indian, and Grembit) were considered as main and sub-factors, respectively. After planting in the 5-leaf stage, the stress operation began and continued until the seeds were harvested. At the end of the growing season, samples were transferred to the laboratory and shoot length and root length, fresh and dry weight of shoot, fresh and dry root weight, number of branches, 100 seed weight were measured. Leaf chlorophyll index was measured using Spad 502 Minolta chlorophyll meter. The chlorophyll fluorescence was measured using a Handy-PEA portable fluorometer (Hansatech Instruments). Finally, statistical analysis was performed using SAS software and mean comparisons were made using the LSD test at 5% probability level.
 
Results and Discussion
Increasing irrigation intervals significantly decreased plant height in Sarbaz and Saravan. The results showed that at 9-day irrigation period, the highest plant height (77.5 cm) was related to RGC1033 which did not show any significant difference with Saravan. The lowest plant height (42.03cm) was related to Sarbaz ecotype. Results showed that the 9-day irrigation interval increased root length in RGC1033, Iranshahr and Sarbaz and significantly reduced root length in Indian ecotype. The results showed that in 9-day irrigation period the number of branches in Iranshahr and Grambit decreased but increased in Saravan and RGC1033 genotypes. While the irrigation interval had no effect on Sarbaz ecotype. Most of the branches were 5.7 in RGC1033 ecotype. The Indian ecotype lacked a branch at all irrigation intervals. At 9-day irrigation period, Saravan and Iranshahr had the highest leaf dry weight. In Iranshahr and RGC1033 genotype, fresh and dry weight increased. Increasing irrigation interval resulted in a significant decrease in the dry weight of Indian root. The irrigation period had no significant effect on Saravan and Grambit ecotypes. Increasing irrigation intervals did not have a significant effect on the Sarbaz, Grambit, and Indians. With increasing irrigation intervals in RGC1033, Saravan and Iranshahr dry weights increased. The simple effect of ecotype type on seed weight showed that Saravan, Indian, and Iranshahr had the highest seed weight, respectively. Whereas, the SG, RGC1033, and Grambit had the lowest seed weight without any significant differences together. Saravan ecotype at all irrigation levels showed more biological function than other ecotypes. Results showed that the harvest index decreased with increasing irrigation intervals. In the 5-day irrigation treatment, the Grambit and Saravan ecotypes had the highest and the lowest harvest index, respectively. The 9-day irrigation period significantly reduced Fv/Fm in Sarbaz, Grambit, and Iranshahr. RGC1033 and Indian populations had the highest Fv/Fm in leaves and Saravan and Iranshahr had the lowest Fv/Fm in leaves at 7 days irrigation period, respectively. The number of pods per plant, number of lateral branches, 100 seed weight and plant height have a direct and positive effect on guar yield. Under drought stress, plant height and leaf number decrease, resulting in lower shoot dry weight. Some researchers showed that decreasing plant height under water stress is associated with loss of protoplasmic water, resulting in reduced cell division and development. The harvest index decreased with decreasing number of pods, thereby reducing economic yield. Differences between susceptible and resistant ecotypes appear in high-stress conditions and high Fv/Fm ratio ecotypes have higher photosynthetic efficiency under severe stress conditions. Chlorophyll fluorescence is considered as a criterion for assessing the integrity of the thylakoid membrane in the relative efficiency of electron transfer from Photosystem II to Photosystem I.
 
Conclusion
Mean root length, the number of branches, fresh and dry weight of RGC1033 were not affected by a 9-day irrigation interval. In the 9-day irrigation period, the highest mean dry weight of leaf, main stem weight and seed weight were related to Saravan ecotype. The highest biological yield was observed in the irrigation period of 7-day and Saravan ecotype. In general, the results showed that irrigation had different effects on different guar populations. RGC1033 and Saravan ecotypes showed the lowest percentage of stress-affected variations.

Original Articles Response to biotic and abiotic stresses

Relationships between some agronomic traits related to yield in Chickpea genotypes (Cicer arietinum L.) under Aschochyta blight stress conditions

Pages 171-186

https://doi.org/10.22067/ijpr.v12i1.84166

Mohadese Rahmatpour, Fakhtak Taliei, Hossein Sabouri, Masoume Kheirgu

Abstract Introduction
Chickpea (Cicer arietinum) is an edible legume grown widely for its nutritious seed, which is rich in protein, minerals, vitamins, and dietary fiber and is the third most important food legume of the world after common bean and pea. Ascochyta blight, caused by Ascochyta rabiei, is one of the most important diseases of chickpea that limits its cultivation and production in most parts of the world, including Iran. The use of resistant cultivars is the most effective and economical strategy for management of Ascochyta blight. Therefore, identifying the genetic resources of resistance in chickpea germplasms against Ascochyta blight is very important in designing breeding programs. Furthermore genetic diversity in chickpea collection can be used in breeding program for selection of genotype with desirable agronomic traits. Studying relationships between agronomic traits under disease stress conditions would assist breeders to identify the effective traits and use proper selection intensity in their breeding programs.
 
Materials and Methods
In order to assess the resistance to Ascochyta blight, and the relationship of some yield related traits and relative resistance to Ascochyta blight disease, research was conducted with 77 advanced chickpea genotypes received from ICARDA in a randomized complete block design with three replications at the Agricultural Research Station of Gonbad-e-Kavous in 2017. Plants were inoculated by applying uniformly scattered infected chickpea debris after seedling emergence. The degree of susceptibility and resistance to disease of each line was determined using 1-9 rating scale and area under disease progress curve was also calculated. Various phonological and morphological traits including yield and yield components were measured.
 
Results and Discussion
According to the results of ANOVA, there was a significant difference among genotypes for all traits (p< 0.01) which revealed genetic variation among them. Genotype of 76 and 55 with an average of 118.67 and 14.81 kilograms grain per hectare had the highest and lowest yield, respectively. The results of phenotypic correlation under disease-stress condition showed that plant height had the highest correlation
(-0.586, p< 0.01) with Ascochyta blight progress. AUDPC was also correlated to grain yield negatively. Genotypes 13, 27, 29, and 34 which belong to the most sensitive group to the disease, had the lowest grain yield and the resistant genotype of 34, had the highest grain yield. AUDPC had also negative correlation
(p< 0.01) with plant height and height of the first pod from ground. There was a positive correlation at 1% probability level between AUDPC and days to 50% flowering and days to physiological maturity revealed that as the disease progresses, those two factors become longer. Genotypes 34 and 35 which had the longest days to physiological maturity were belonging to disease sensitive group. Stepwise regression analysis introduced AUDPC, number of two seed pods and plant height with 42% justify changes as the most effective traits. According to the results of stepwise regression, plant height had the highest effect on grain yield. The results of Path analysis showed that plant height had the most direct effect on grain yield (0.357) and the most indirect effect was related to AUDPC via plant height (-0.1151). Therefore, plant height can be used as a superior trait in indirect selection programs. Based on agronomic traits under disease stress conditions, cluster analysis set the genotypes into two groups using the square Euclidian distance and Ward method. The genotypes of first cluster, had the highest average in plant height, height of the first pod from ground, number of two seed pods, grain yield and 100-grain weight compared to the other one. The second group was earliness and had higher days to 50% flowering, days to physiological maturity and grain filling period. According to the results of cluster analysis for disease parameter based on the square Euclidian distance and Ward method, the genotypes classified in three clusters including tolerant, sensitive, and resistant where 25, 37, and 15 genotypes were placed in resistant, tolerant, and susceptible groups, respectively. The sensitive group had less grain yield than the others. Genotype 26 was highly susceptible and genotypes 6, 22, 43 and 65 were identified as highly resistant.
 
Conclusion
The findings of this study showed that management of Ascochyta blight is essential to provide increased and stable yields where conditions are suitable for the disease. According to the results, the studied chickpea germplasm, are valuable resources, in addition to possess new traits provide high diversity for breeders to improve the new varieties and can be employed as resistant sources in chickpea breeding programs to develop resistant cultivars to Ascochyta blight.

Original Articles Response to biotic and abiotic stresses

Selection of sieved drought tolerant lentil (Lens culinaris Medik) genotypes via five new tolerance indices in Mashhad conditions

Pages 187-204

https://doi.org/10.22067/ijpr.v11i2.75861

Mohammad Hasan Vafaei, Mehdi Parsa, Ahmad Nezami, Ali Ganjeali

Abstract Introduction
Drought is one of the most important stresses which reduce yields of crops and is one of the most important production constraints in arid and semi-arid regions. Iran with annual mean rainfall of 257 mm was classified among the arid regions of the world. Lentil is a pulse crop, rich in proteins and have 18 of the 20 amino acids including all 8 essential amino acids. Thus, lentils play an important role in human diet, especially in low-income people in the developing countries. In Iran, lentil is usually grown in rainfed areas. The average lentil yield in Iran is 476 and 1195 Kg.ha-1 in rainfed and irrigated farms, respectively. Identification of drought-tolerant genotypes is essential for cultivation in arid areas. To identify and select tolerant genotypes, researchers have proposed many drought indices based on a mathematical relationship between grain yield under stress and non-stress conditions, which are based on tolerance or susceptibility to drought genotypes. The aim of this study was to identify indicators that can identify high-yielding and drought tolerant genotypes in rainfed conditions of Mashhad.
 
Materials and Methods
This research was carried out at the Agricultural Research Station, Ferdowsi University of Mashhad, during growth season 2015. In this research, nine genotypes were used that eight genotypes of them were relatively drought tolerant in stress conditions and one genotype (MLC121) susceptible to drought stress were cultivated. These genotypes were selected from 73 genotypes including native populations and ICARDA genotypes in the seed bank of the Ferdowsi University of Mashhad, which were planted in the same plot at last year. Experiments were conducted as completely randomized design with non-stress and drought stress conditions (providing 100% and 40% water requirement of the plant) with three replications.
 
Results and Discussion
The analysis of variance showed a significant difference between yield genotypes in non-stress and drought stress conditions. Based on the results, in non-stress conditions, MLC356 and MLC121 genotypes produced the highest and lowest grain yields per hectare with 2621 and 993 kg.ha-1 respectively. Under stress conditions, Cabralinta and MLC121 genotypes produced the highest and lowest grain yields per hectare with 876 and 288 kg.ha-1, respectively. The mean yield of genotypes in non-stress and stress condition were 1616.7 and 625.6 kg.h-1, respectively that showed a decrease of 61.3% in water stress condition. Correlation between yields in stress and non-stress condition with tolerance indices showed that the old indices of STI, GMP, REI, HM and MP and the new K2STI index had a positive and significant correlation with yield in stress and non-stress conditions. The 3D Charts of the K2STI index with Yp and Ys showed that MLC356, Cabralinta and MLC025 genotypes had the highest rate of this index under non-stress and drought stress. The biplot drawing showed that high yielding genotypes are in D region. In this area, the old indices of YI, HM, GMP, REI, STI, the new indicators of SNPI K2STI and all of which are consistent with the Ys. The sharp angle between Ys, SNPI and YI indices shows a strong and positive correlation between these indices and indicates their superiority in separating high-tolerance genotypes with stress conditions and having relatively high performance in non-stress conditions. Considering this criterion, Cabralinta, MLC025, and MLC356 genotypes which had the highest correlation with the two indices, can be selected.
 
Conclusion
In all, the results of this study showed that SNPI and YI indices have a high correlation (99.9%) with performance in stress conditions, as well as K2STI, HM, GMP, REI and STI indices, all of which in D area. They have the most positive and significant correlations with each other and with performance in two conditions of non-stress and stress as the most suitable and effective criteria for identifying and selecting genotypes tolerant to drought stress. In all, if the goal is to introduce three genotypes, Cabralinta, MLC025 and, MLC356 genotypes which are the most susceptible genotypes are suggested compared to the stress conditions, but if the goal is to introduce only one genotype, Cabralinta genotype that has the highest and most stable yield under stress condition and in comparison with MLC356 genotype under stress conditions, 10.2% more yield could be introduced for arid and severe stress areas. For lentil planting in areas with mild stress, a high yielding genotype and tolerant, MLC356 genotype is recommended. It is also suggested that again to increase the accuracy of the experiment, three selected genotypes are again cultivated in the field.

Original Articles Response to biotic and abiotic stresses

Evaluation and selection of chickpea (Cicer arietinum L.) Deci types for salinity tolerance introduction

Pages 205-220

https://doi.org/10.22067/ijpr.v11i2.78306

Jafar Nabati, Mohammad Kafi, Ahmad Nezami, Elahe Boroumand Rezazadeh

Abstract Introduction
The agricultural sector needs to reduce the use of freshwaters and using low quality waters instead of increasing demand for domestic and industrial water uses, along with the reduction of groundwater level. Therefore, using saline water in the future for agricultural production is unavoidable. The soil fertility has been reduced due to decreasing the quality of water resources and increasing salinity in agriculture lands. Saline water and saline soil contain high concentrations of salts such as calcium sulfate and sodium carbonate, although sodium chloride is the dominant salt. Salt stress affects various physiological and metabolic processes in plant and may eventually impede crop production depending on the extent and severity of the stress. In the early stages, a high concentration of solutes present in the soil brings about osmotic stress which reduces the capacity of root systems to absorb water and, that start the loss of leaves water. This is accompanied by ion-specific effects that cause the accumulation of toxic concentration of Na+ and Cl− in the cells, which manifest in the form of chlorosis and necrosis. Planting legumes in saline soil is important for conservation of sustainability of production. However, legumes, including chickpea, show low-salinity tolerance and loss yield in saline conditions. To permit crop growth on natural saline soils considerable enhancement of salinity tolerance could be required for the chickpea which is a relatively salt sensitive legume. Therefore, identification and introduction of salt tolerated chickpea cultivars help sustainable crop production in moderate saline areas.
 
Materials and Methods
This study was carried out under hydroponic conditions in the greenhouse of Research Center for Plant Sciences, Ferdowsi University of Mashhad. The experiment was conducted as a completely randomized design with three replications to evaluate salinity tolerance of 140 Deci-type chickpea genotypes during seedling stage in a salinity level of 12 dSm-1 NaCl. Hoagland solution had been used in the sand culture method. Recirculating nutrient system was applied, nutrient solution was replaced weekly and salinity of nutrient solution was adjusted daily, but no acidity adjustments were made in the Hoagland solution. Four weeks after salinity application, growth stages, height plant, branch number, survival percentage, remained leaves, shed leaves, membrane stability index, sodium and potassium concentration were measured.
 
Results and Discussion
Results indicated that survival percentage of 21 genotypes was more than 76% among which, six genotypes of MCC18، MCC22، MCC29، MCC59، MCC136 and MCC430 showed 100% survival. In the survival range of 76-100, 51-75, 26-50 and 0-25%, 43, 57, 42 and 16 percent of genotypes were in the post-flowering stages, respectively. Plant height increased with increasing survival range, so that the genotypes in the survival range of 76-100% were 4, 5 and 12 cm higher than the survival range of 51-75, 26-50 and 0-25%, respectively. The highest plant was observed in MCC59 genotype with 100% survival range. The lowest number of branches per plant was observed in the 0-25% survival range. With increasing survival range percentage of shed leaves decreased and the percentage of remained leaves increased. The same percentage of shed leaves and the remained leaves were observed in the survival range of 76-100% and 51-75%. In three survival range 76-100%, 51-75%, and% 26-50, the shed leaves were about 50%. The highest percentage of remained leaves (73%) was observed in MCC177 genotype with 75% survival. The membrane stability index increased with raise up survival range. There were no difference in survival range of 26-50 and 51-75% in membrane stability index, but in the survival range of 76-100%, membrane stability 6% increased compared to the two previous survival ranges. The highest membrane stability index observed at MCC34 (53%) and MCC179 (52%) with 85%, 51% survival, respectively. However, among genotypes in 100% survival some genotypes, such as MCC29 and MCC136, had a relatively low membrane stability index. With rising up survival range, sodium concentration decreased and potassium increased. Sodium to potassium ratio was also decreased with increasing survival range. Dry matter productions per plant increased with improving survival range. Dry matter from 0-25% to 26-50%, 51-75% and 76-100% survival range, increased 16%, 24%, and 38%, respectively. MCC4, MCC43, MCC22, MCC49, MCC59 and MCC85 had the highest dry matter productions.
 
Conclusion
The correlation between traits showed the positive correlation between survivals and remained leaves which is depended on maintaining membrane stability and decreasing sodium uptake in plant. Based on this information, chickpea genotypes have salt tolerance mechanisms and it is possible to use these genotypes for breeding programs for moderate salinity stress conditions.

Original Articles Agronomy

Evaluation of the effect of weed diversity and evenness on lentil (Lens culinaris L.) yield

Pages 221-234

https://doi.org/10.22067/ijpr.v12i1.77217

Negin Zargarian, Alireza Bagheri, Iraj Nosrati, Farzad Mondani

Abstract Introduction
Lentil is one of the most important legumes in rainfed and irrigated cultures, which is sensitive to weeds due to its low density and growth rate in early stages of growth. Therefore, lentil weed control is essential to prevent crop loss. Most studies of weed and crop competition have focused on mono-species competition, while generally there is not observed and the multispecies competition effects of weed populations are important. On the other hand, studies have shown that the presence of weeds in agricultural ecosystems is not always negative, even the presence of different weed species along the crop with increased diversity and nutrient cycling can lead to positive effects. Therefore, the knowledge of the effects of presence of different weed species on a field and the relationship between them is important. In this study, the relationships between weed communities in a lentil field and the effect of diversity indices on lentil yield were investigated.
 
Material and Methods
This experiment was conducted on one of rainfed lentil fields of the Agricultural and Natural
Resources Campus of Razi University in Kermanshah during 2016 growing season. Systematic sampling was performed in two stages (before flowering and before physiologic maturity) to record weed density, height and dry matter as well as lentil grain yield. In addition, weed diversity and evenness indices (Shannon Weiner, Simpson, Smith and Wilson and Camargo Indices) were calculated using weed record data. The relationships between weeds and lentils were extracted by stepwise regression using SPSS statistical software V.20 and the spatial maps of weeds and lentil diversity were drawn using ArcGIS 10.2.2 software.
 
Results and Discussion
The results of this study showed that a total of 45 weed species were recorded in the first stage of sampling and 28 species in the second stage of sampling. Recorded weed species in the studied lentil field were according to the important weed species of lentil farms in the west of Iran. So that, Brassicaceae, Asteraceae and Convolvulaceae were most frequented families, in addition, the most of the recorded species were broadleaves and the narrow leaves did not have much frequency. The results also showed that lentil yield was significantly affected by weed density and dry matter in the first and second stages of sampling, respectively. It has been stated that the high density of weeds during the vegetative period decreases biological yield and subsequently grain yield of the crops. Researchers also reported a negative correlation between yield and dry weight of weeds. The results of the effect of weed population evenness and diversity on lentil yield in the first sampling stage showed that Smith and Wilson evenness index and Simpson diversity index had a significant positive effect on lentil yield. In the study of, also there was a significant positive relationship between yield and weed diversity indices. However, in the second stage of sampling weed evenness and diversity did not have a significant effect on lentil yield. The study of spatial maps of lentil yield, Smith and Wilson evenness index and Simpson diversity index showed that the lentil yield was spatially correlated with weed evenness and diversity. In areas with low lentil yield, weed evenness and diversity were also low and in areas where lentil yield was high weed evenness and diversity were also high. This suggests that increased diversity and evenness in the fields can reduce the negative effects of weeds on crop yield.
 
Conclusion
It can be concluded that the presence of weeds in the first and second stages of sampling led to decreased lentil yield, while the weed diversity and evenness had a positive and significant effect on lentil yield. In fact, by increasing the diversity and evenness of weeds and increasing the positive and negative interactions between them with other organisms, it seems that there was a positive effect on the lentil yield. In fact, increasing the weed diversity and evenness in farms could results in a fairer division of resources and less damages of some weed species on yield. The spatial distribution of the weed diversity and evenness, and its comparison with lentil yield showed a positive spatial relationship between increasing the weed diversity and evenness and lentil yield. Hence, increasing knowledge about weeds as well as their relationship with crops can reveal the positive aspects of weed presence in farms and, consequently, better weed management by increasing awareness in this field.