Journal of Crops Improvement

Abstract In order to study the effect of Cobalt, Molybdenum, and Nitrogen on the growth of Phaseolus vulgaris in soilless culture, a pot experiment was conducted in 2015-16 and in July, at 25˚C and light intensity of 40,000 lux as a factorial based on a CRD with 36 treatments and three replications in the greenhouse of Zanjan University. The test factors consisted of four levels of Nitrogen (50, 100, 150, and 200 mg/l), three levels of Molybdenum (0.067, 0.2, and 0.6 mg/l) and, three levels of Cobalt (0.006, 0.06, and 0.3 mg/l). Factor levels were prepared by adding ammonium nitrate, ammonium molybdate, and cobalt chloride to a stock solution. Results of morphological traits showed that the highest pod dry weight was obtained in N100Mo0.6Co0.06 treatment which had a maximum difference of 47.9% with other treatments. The highest dry weight of shoots was obtained from N150Mo0.6Co0.006 treatment and the highest root dry weight was obtained from N150Mo0.6 and N150Co0.3 treatments. Also, the highest number of pods was obtained in N150Mo0.6, N100Co0.3 and Mo0.6Co0.3 treatments with values of 235.2, 266.4, and 220.8 g/pot, respectively. Investigation of physiological traits showed that the highest concentrations of Nitrogen, Molybdenum, and Cobalt were obtained from N200Mo0.6Co0.3, N150Mo0.6Co0.3, and N150Mo0.067Co0.006 treatments, respectively. Overall, it can be stated that the application of N100Mo0.6Co0.06 treatment can positively affect the dry weight of pods, which are economically productive and improve the performance of P. vulgaris (Talash cultivar).

Abstract Objective: In recent years, the use of conservation tillage methods has been widely considered in the world, and the use of conventional tillage methods has become outdate in some parts of the world. Conservation tillage systems are usually implemented in arid and semi-arid regions. In semi-arid regions, the key to increasing agricultural production is to maximize surface water infiltration. In addition, techniques that reduce evaporation from the soil and increase the amount of water available to plants during drought are very important. Therefore, an experiment was conducted in 2022-2023 and 2023-2024 to evaluate the effect of tillage systems on the quantitative and qualitative yield of forage and the activity of antioxidant enzymes in forage legumes. An experiment was conducted in the research farm of the Lorestan Agricultural and Natural Resources Research and Education Center Khorramabad city, in 2022-2023 and 2023-2024.
Methods This experiment was conducted in a split plot based on a randomized complete block design with three replications. Tillage methods (conventional, low-tillage, and no-tillage) were considered as the main factor and forage legumes (Broujerd landrace faba bean, Lamei cultivar vetch, Grass pea, Barakat and Feyz cultivar faba bean) were considered as secondary factors.
Results The results showed that the interaction effect of tillage system and forage legumes was significant on all measured traits except for quality parameters including digestible dry matter, crude protein, crude fiber, ash, water soluble carbohydrates and neutral detergent insoluble fiber was significant at the 1% level of error probability. The highest fresh forage yield (10671.52 and 10581.11 kg h-1), leaf dry weight (16.86 and 16.82 gr) and stem (20.46 and 20.42 gr) in conventional and reduced tillage systems were observed in the Lamei variety of vetch, while the dry forage yield (2820.91 and 2352.82 kg h-1) in conventional tillage systems was observed in the Lamei variety of vetch and the Barakat variety broad bean, and the catalase enzyme (54.09 OD micro gr protein min-1) in the conventional tillage systems was observed in the Lamei variety of vetch. A review of the changes in qualitative traits among forage legumes also showed that the highest digestible dry matter, ash, and crude protein were obtained from Lamei variety of vetch, and the highest water soluble carbohydrates, crude fiber and insoluble fiber were obtained from Barakat variety and Borujerd landrace broad bean.
Conclusion: According to the results, implementing a conventional and low-tillage system compared to a no-tillage system and planting the forage legume, the Laami variety of vetch, had a more beneficial effect on increasing yield characteristics, antioxidant enzyme activity, and forage quality traits.

Abstract Objective: This experiment was conducted to evaluate the forage quality and yield of three forage plants: Pennisetum glaucum (Nutrifeed variety), maize (Single Cross 260), and sorghum (Speedfeed variety) under the influence of combined levels of poultry manure and chemical fertilizers with the aim of reducing the use of chemical fertilizers and improving the quantity and quality of forage.
Materials and Methods: This study was conducted over two growing seasons (2023–24 and 2024–25) using a split-plot design based on a randomized complete block design with three replications at the Research Farm of University of Kurdistan, Dehgolan. The main factor was the forage species (Pennisetum glaucum, sorghum and maize) and the sub-plot factor consisted of fertilization systems: control; 4 t.ha-1 poultry manure; 3 t.ha-1 poultry manure + 50 kg.ha-1 Nitrogen from urea + 25 kg.ha-1 phosphorus from triple superphosphate; 2 t.ha-1 poultry manure + 100 kg.ha-1 Nitrogen from urea +50 kg.ha-1 phosphorus from triple superphosphate; and full chemical fertilization (200 kg.ha-1 Nitrogen from urea + 100 kg.ha-1 phosphorus from triple superphosphate). Qualitative traits (water-soluble carbohydrates, crude fiber, crude protein, neutral detergent insoluble fiber, acid detergent insoluble fiber, and ash) and quantitative trait (biological yield) of forage were measured, and the data were analyzed with SAS version 9.4 software.
Results: The results showed that the highest water-soluble carbohydrate of forage in the treatment of complete chemical fertilizer and 100 kg/ha nitrogen fertilizer from urea source + 50 kg phosphate from triple superphosphate source was corn plant. The lowest crude fiber of forage was in the treatment of 2 tons/ha chicken manure + 100 kg/ha nitrogen fertilizer from urea source + 50 kg phosphate from triple superphosphate source of pearl millet, the highest crude protein of forage was in the treatment of 2 tons/ha chicken manure + 100 kg/ha nitrogen fertilizer from urea source + 50 kg phosphate from triple superphosphate source in corn plant, which had no statistically significant difference with the percentage of crude protein of forage in the treatment of 3 tons/ha chicken manure + 50 kg/ha nitrogen fertilizer from urea source + 25 kg phosphate from triple superphosphate source (14.06%). The highest amount of neutral detergent insoluble fibers was obtained in the treatment of applying 4 tons per hectare of poultry manure to pearl millet plants. The highest forage ash was related to the treatment of applying pure chemical fertilizer. Also, the application of 2 tons per hectare of poultry manure + 100 kg per hectare of nitrogen fertilizer from the urea source + 50 kg of phosphate from the triple superphosphate source resulted in the highest biological yield.
Conclusion: Combined fertilizer treatments (2 t.ha-1 of poultry manure + 100 kg.ha-1 of nitrogen fertilizer from urea source + 50 kg of phosphate from triple superphosphate source) resulted in significant improvement in forage quality and yield in corn as well as improvement in some quality indicators in Pennisetum glaucum and sorghum. Using poultry manure in combination with chemical fertilizer can reduce costs and environmental impacts, while maintaining or increasing crop productivity.

Abstract Objective: In safflower, a considerable proportion of photosynthates remains in vegetative organs and is not efficiently translocated to developing grains. Moreover, the occurrence of high temperatures during pollination and seed filling markedly reduces the yield potential of the crop. Improving the partitioning of assimilates from vegetative to reproductive sinks may enhance safflower performance under unfavorable environmental conditions. The present study aimed to evaluate the effects of abscisic acid and jasmonic acid on remobilization of stored photoassimilates and grain yield of spring safflower.
Methods: The experiment was conducted at the research farm of the Faculty of Agriculture of Meshgin-Shahr during the 2024 growing season. A randomized complete block design with three replications was used. Experimental treatments included: 1) irrigated plants without hormone application as control, 2) rainfed plants without hormone application, 3) irrigated plants sprayed with abscisic acid, and 4) irrigated plants sprayed with jasmonic acid. Both hormones were applied after completion of pollination in three consecutive sprays. Traits were measured at three developmental stages, namely the beginning of capitulum formation before spraying, the onset of seed growth one week after the last spray, and physiological maturity.
Results: At the beginning of capitulum formation, plant height and total biomass were greater in irrigated than in rainfed plants. In most cases, the experimental treatments did not show significant differences at the early stage of seed growth. Evaluation at physiological maturity indicated that rainfed conditions and application of abscisic and jasmonic acids significantly reduced biomass, capitulum weight, and number of seeds per plant compared with the control. The highest amount of remobilization was observed in plants treated with jasmonic acid. The value of this trait in the abscisic acid treatment, rainfed plants, and the control ranked next, respectively. The greatest grain yield per plant and harvest index were obtained from the irrigated control without hormone spraying. Rainfed conditions as well as external application of abscisic and jasmonic acids significantly decreased grain yield in comparison with the control plants.
Conclusion: It appears that the effect of applying abscisic and jasmonic acids on reduction of current photosynthesis and production of assimilates was much greater than their role in enhancing remobilization and improving partitioning of photo-assimilates to grains. There is a possibility that the use of these hormones after the first half of grain filling, when current photosynthesis declines, may lead to higher remobilization and better grain yield. Further studies under diverse environments are recommended to confirm these findings and optimize application timing.

Abstract Objective: Excessive nitrogen use causes severe economic and environmental problems. Therefore, developing sustainable cropping systems with high nitrogen use efficiency is essential. This study investigated the effects of nitrogen (N) and sulfur (S) fertilization on the photosynthetic characteristics, physiological responses, and nitrogen use efficiency (NUE) of guar (Cyamopsis tetragonoloba). The main goal was to determine the optimal fertilizer rates for sustainable production.
Methods: To evaluate the growth performance and nitrogen productivity of guar (Cyamopsis tetragonoloba), a field experiment was conducted during the 2024 growing season at the Research Farm of Tarbiat Modares University. We used a factorial arrangement based on a randomized complete block design with three replications. The treatments included four nitrogen rates (0,50,100,0, 50, 100,0,50,100, and 150 kg N ha−1 and two sulfur rates (0 and 100 kg S ha−1)
Results: Nitrogen application significantly influenced leaf area index, leaf greenness, photosynthetic rate, cumulative shoot nitrogen, agronomic and physiological nitrogen efficiency, nitrogen recovery, and grain yield. While the leaf area index and greenness of guar increased in response to nitrogen up to 100 kg/ha, higher application rates yielded no further significant changes. Leaf photosynthetic rate, however, continued to increase up to 150 kg/ha of applied nitrogen. Compared to the unfertilized control, nitrogen treatments increased cumulative shoot nitrogen 67.2 percent and the highest agronomic, recovery, and physiological nitrogen efficiencies were all recorded at the 100 kg/ha N rate. Grain yield also responded strongly to nitrogen, showing increases of 12.8%, 33.8%, and 16.9% at 50, 100, and 150 kg/ha, respectively. Regarding sulfur, its application boosted the photosynthetic rate by 25.9 percent during the grain-filling period; however, despite this physiological improvement, it did not significantly affect final grain yield (1203 kg/ha) compared to the untreated control (1235 kg/ha). The lack of significant effect of sulfur application on guar growth traits could be related to the adequacy of sulfur in the soil of the experimental site. Grain yield also strongly correlated with LAI (r=0.75), shoot nitrogen accumulation (r=0.73), leaf greenness (r=0.62), and photosynthetic rate (r=0.50). Overall, applying optimal nitrogen use management can not only increase fertilizer use efficiency while maintaining optimal yield, but also prevent nitrogen losses and environmental consequences resulting from excessive use of nitrogen fertilizers.
Conclusion: Overall, under the soil and climatic conditions of the study area, application of 100 kg N ha⁻¹ optimized seed yield while maximizing nitrogen use efficiency, suggesting that this rate represents a sustainable fertilization strategy that can improve fertilizer use patterns and reduce environmental risks associated with excessive nitrogen application.

Abstract The aim of this research was to evaluate the average concentrations of micronutrients including: Copper (Cu), Iron (Fe), Manganese (Mn) and Zinc (Zn) in the shoots of different cultivars of wheat in stem elongation stage in a soil contaminated with cadmium (Cd). The treatments consisted of three levels of Cd (0 (as control, Cd₀), 40 (Cd₄₀) and 80 (Cd₈₀) mg Cd/kg soil) and fourteen different cultivars of wheat (‘Bahar’, ‘Alvand’, ‘Niknezhad’, ‘Pishtaz’, ‘Azadi’, ‘Shahriyar’, ‘Pishgam’, ‘Marvdasht’, ‘Parsi’, ‘Sivand’, ‘Shiraz’, ‘Omid’, ‘Roshan’ and ‘Navid’), respectively. The results showed the effect of Cd on concentrations of micronutrients were highly significant. Cu concentration was decreased in shoot of all studied cultivars, as levels of Cd were increased. Except two cultivars (‘Pishgam’ and ‘Omid’) which showed an increase in Fe concentration in Cd₄₀ comparing with control, Fe concentration was decreased in other cultivars. Most and least Cd concentration in Cd₄₀ was recorded by Niknezhad (7 mg/kg DW) and Parsi (2 mg/kg DW), respectively. Also, most and least Cd concentration in Cd₈₀ was observed in ‘Pishgam’ (20 mg/kg DW) and ‘Navid’ (6 mg/kg DW). Generally, ‘Niknezhad’ and ‘Pishgam’ had the highest reliability of cadmium uptake. Also the lowest reliability of cadmium uptake was observed about ‘Parsi’ and ‘Navid’.

Abstract Sesame could be an appropriate oilseed crop for water limited environments. This research was aimed at studying growth, leaf chlorophyll fluorescence, proline content, yield and yield components of sesame cultivars under different moisture regimes. A 4-replicate split plot RCBD field experiment was conducted at the Lavark Research Farm, College of Agriculture, Isfahan University of Technology, Isfahan, Iran in 2007. Three levels of irrigation consisting I1 = control (no water deficit), I2 = moderate water deficit and I3 = severe water deficit, representing irrigation after 75, 110 and 145 mm evaporation from the standard Class A Pan, respectively, served as main plots. Four sesame genotypes consisting ‘Non Branching Naz’, ‘Yekta’, ‘Varamin’ and ‘Oltan’ were considered as sub plots. Irrigation regimes and cultivars differed in terms of Fm at grain filling stage, though they did not differ in terms of leaf chlorophyll content and Fv/Fm. The latter trait decreased non-significantly from 0.81 at the I1 to 0.77 at the I3 level of irrigation. Leaf proline content increased from 3.5 at I1 to 8.6 mgg-1 at the I3 level of irrigation. Severe water deficit decreased LAI, pod/plant, seed/pod, grain yield and dry matter by 55, 42, 37, 48 and 49 percent, respectively. Severe water deficit led to a significant decrease in grain yield from 1212 to 625 kg/ha. It seems that water deficit affects sesame growth and grain yield significantly and this negative effect is mainly through a reduction in the photosynthetic surfaces, rather than a decrease in the maximum of quantum efficiency for photosystem II of the present genotypes. Yekta and Varamin sesame were more productive compared to the rest of cultivars.

Abstract In order to evaluate the yield components, seed yield, and oil content of Camelina doubled haploid lines, an experiment has been conducted based on a randomized complete block design with 40 doubled haploid lines (as treatments) and three replications in the research farm of College of Aburaihan- the University of Tehran, Pakdasht during 2020. Since the yield characteristics and oil content of Camelina lines are unknown in the Iranian climate, the study investigates seed yield components, as well as oil yield and oil content of 40 Camelina lines. The results show a very significant difference between Camelina lines in terms of yield components, which ultimately leads to significant differences in grain yield, thus affecting the grain oil yield. Although none of the lines has had absolute superiority in all components of grain yield, in terms of final grain yield, line of 134 with 3178 and line of 110 with 3120 kg/ha are identified as superior lines. Therefore, according to the purpose of this study, in order to select the best Camelina line with maximum grain and oil yield, 134 and 110 lines are introduced and recommended as superior and promising lines that are compatible with the climatic conditions of the Pakdasht region.  

Abstract The effect of gibberelic acid (GA3) and ethanol on the postharvest quality and vase life of gerbera cut flowers was investigated. Freshly cut flower stems of gerbera cultivar ‘Good timing’, were put in vases containing zero, 50, 100, 150, 200 or 300 mgL-1 GA3 for 48 hr and then held in vases containing 2.5 percent ethanol and three percent sucrose in two methods. In the first method, the vase solutions were not replaced but in the second method, the vase solutions replaced and refreshed when solution uptake was measured. The vase was placed in chambers at 25°C and relative humidity about 70 percent with 14 hr photoperiod that was maintained using fluorescent lamps (light intensity of 15 µmolm-2s-1). Data were recorded for vase life, fresh weight, solution uptake, membrane stability, total soluble solid over time and analyzed statistically. Results revealed that GA3 with 50 mgL-1 was the most effective treatments for vase life, fresh weight, solution uptake, membrane stability and total soluble solid of gerbera cut flowers. Also results show that application of ethanol in second method (refreshing) was better than application in the first method as constant vase solution.

Abstract In this study, the amount of total phenol, chlorogenic acid, catechin, quercetin, phloridzin, cyanidin and antioxidant activity of apple (Malus domestica) skin and flesh of six Iranian cultivars, including: ‘Golab Kohanz’, ‘Sib Torsh Dirras’, ‘Ghara Yapragh’, ‘Torkman’, ‘Ghezel Alma’ and ‘Abbasi Mashhad’, and four commercial cultivars including: ‘Golden Delicious’, ‘Red Delicious’, ‘Braeburn’ and ‘Fuji’ was investigated. ‘Fuji’ had the highest amount of cyanidin 3-galactoside (3711.9 µg.g-1 fresh weight) and ‘Golab Kohanz’ had the greatest amount of quercetin 3-galactoside (3133.8 µg.g-1 fresh weight) and phloridzin in the skin (642.2 µg.g-1 fresh weight) and ‘Ghara Yapragh’ showed the greatest amount of flesh phloridzin (98.1 µg.g-1 fresh weight). ‘Abbasi Mashhad’ had the largest amount of flesh (484.3 µg.g-1 fresh weight) and the skin's (298.1 µg.g-1 fresh weight) chlorogenic acid, ‘Ghezel Alma’ had the greatest amount of catechin of skin (255.2 µg.g-1 fresh weight) and ‘Sib Torsh Dirras’ showed the highest catechin of flesh (76.9 µg.g-1 fresh weight). The regression analysis of total phenol and antioxidant capacity showed a positive correlation between the amount of total phenol and the antioxidant activity. The highest amount of total phenol and antioxidant activity in ‘Fuji’ was observed.

Abstract Enzymaticactivity and biochemical responsesof two citrus rootstocks [sour orange (Citrus aurantium L.) and trifoliate orange (Poncirus trifoliata Raf.)] to in vitro salinitystress were studied. Explants of both rootstocks were transferred to Murashige and Skoog (MS) solid proliferation medium containing 8.9 µM Benzyladenine (BA) and 0.5 µM Naphthaline Acetic Acid (NAA) supplemented with 0, 50, 100, 150, 200 mM of sodium chloride (NaCl) with six replicates. After six weeks, results showed that, rootstock, salinity levels and their interaction, had a significant effect on all of the measured parameters. Antioxidant enzymes activity such as: catalase, peroxidase, ascorbate peroxidase, proline content, soluble sugars and malondialdehyde (MDA) content increased in both rootstocks by increasing salinity level. The amounts of increasing in sour orange rootstock were greater than trifoliate orange, except for peroxidase enzyme and MDA. Total protein content decreased by increasing salinity level in both rootstocks. Sour orange rootstock has higher total protein content than trifoliate orange. According to the results, sour orange rootstock was more tolerant to salt stress.

Abstract In order to study adapatability and yield stability of irrigated bread wheat cultivars Alvand, Alamout, Zarrin, Navid, Azar 2, Sabalan, Omid and Bezostiya this experiment was conducted in RCBD during three cropping seasons (2007-2010) in six cities. Simple ANOVA and combined analysis of variance for three years in every location and also combined analysis of variance for three years and six locations were implemented. Lin and Binns parameter, environmental variance, Rick Ecovalance method and Shukla stability variance were used for determination of stable cultivars. Results of combined ANOVA (three years × six locations) showed that interaction effect of year × location × genotype was significant. The highest and lowest grain yield belonged to Alvand (3/74 tha1) and Azar 2 (2/72 tha1) cultivars. Results of stability analysis with Lin and Binns method showed that Zarrin cultivar had the lowest inside location variance for grain yield and the lowest environmental variance belonged to Azar 2 cultivar. Results of stability analysis with Shukla Stability variance method showed that Zarrin and Sabalan cultivars had the lowest Shukla stability variance, respectively. Also results of Rick Ecovalance method showed that Zarrin cultivar had the highest amount for this parameter. Zarrin and Sabalan cultivars had the lowest yield stability and can be recommended for studied locations.