An experiment was conducted to determine the effects of salinity and temperature on the germinati... more An experiment was conducted to determine the effects of salinity and temperature on the germination responses of three of the more commonly cultivated millet varieties in SouthEast regions of Iran, including common millet (Panicum miliaceum), pearl millet (Pennisetum galucum) and foxtail millet (Setaria italica). Seeds were exposed to different salinity levels equal to six osmotic potentials of 0 to-1.25 with-0.25 MPa intervals and three constant temperature treatments (15, 25 and 35°C). Cumulative germination percentage and germination rate were analyzed under different exerted treatments. Germination rate was calculated as the reciprocal of time to 50% germination in each combination of treatments. Our results indicate that temperature is more important than salinity level to obtain more favorable germination. The highest values of germination percentage and germination rate were obtained for higher temperatures with lower salinities. Also, decreased temperature alleviated the detrimental effects of salinity on studied traits, which indicates a synergistic effect of higher temperatures on detrimental effects of salinity. The lowest values of studied characters also were associated with lower temperatures, independent of salinity level. Results indicate that germination of seeds at high temperatures with low salinity levels, and high temperatures and high salinity levels was better than when seeds were germinated at low temperatures (independent of the salinity conditions). Also, foxtail millet had the highest germination percentage and germination rate at all salinity levels and temperatures while the lowest values belonged to pearl millet.
Abstract Due to the reports regarding unsuccessful control of Avena sterilis subsp. ludoviciana (... more Abstract Due to the reports regarding unsuccessful control of Avena sterilis subsp. ludoviciana (Durieu) Gillet & Magne by haloxyfop-R-methyl in canola fields, the following study was conducted to investigate the resistance of this weed to haloxyfop-R-methyl. Five out of 22 accessions were resistant to haloxyfop-R-methyl. These biotypes were then subjected to various rates of clodinafop propargyl, sethoxydim, pinoxaden and mesosulfuron methyl + iodosulfuron-methyl herbicides and their cross-resistance to clodinafop propargyl and sethoxydim was confirmed. However, no resistance was observed to pinoxaden and mesosulfuron-methyl + iodosulfuron-methyl herbicides. Indirect study of metabolism by P450 using 1- aminobenzotriazole and piperonyl butoxide showed that this enzyme had no contribution to occurrence of resistance in the studied biotypes. Allele-specific PCR results indicated that Ile-2041-Asn mutation is responsible for resistance of A. sterilis subsp. ludoviciana biotypes, which was confirmed by sequencing of the samples. Since pinoxaden negatively affects canola, the growers face a serious limitation in their choice for chemical management and thus, implementation of integrated weed management such as introduction of row crops such as faba bean in crop rotation and increasing the diversity of herbicide mode of action by cultivation of crops such as sugar beet in crop rotation may prove helpful. In fields under canola-wheat rotation, it is also possible to use pinoxaden in wheat. Also, trifluralin, cycloxydim and clethodim herbicides may be tested on A. sterilis subsp. ludoviciana. This was the first case of A. sterilis subsp. ludoviciana resistance to ACCase inhibitors in canola fields.
ABSTRACT Seed germination is strongly dependent on temperature. Reduced germination rate as a con... more ABSTRACT Seed germination is strongly dependent on temperature. Reduced germination rate as a consequence of seed aging might be due to changing the type of response function to temperature or changing the parameters that govern the function. The objectives of this research were: (1) to determine the effect of seed aging on the type of response function describing the relationship of germination rate to temperature, and (2) to evaluate how the parameter(s) of the response function are changed when the germination rate is reduced as a result of seed aging. Seeds (cv. ‘Zagros’) were kept at a high temperature (43°C) and high relative humidity (90-95%) to create different classes of seed aging. Seed aging had no effect on the type of response function or cardinal temperatures. A dent-like function adequately described the response of germination rate to temperature in all the aging treatments. Cardinal temperatures of 2.2°C for the base, 28.6°C for the lower optimum, 38.0°C for upper optimum and 45°C for ceiling temperatures were obtained. Inherent maximum rate of germination (Rmax) was the sole parameter that was affected by seed aging periods and characterized differences between seed aging periods with respect to germination rate at various temperatures.
Advances in Plants and Agriculture Research, May 14, 2014
This study aimed to compare the effects of different crop residues (with various C:N ratios) on g... more This study aimed to compare the effects of different crop residues (with various C:N ratios) on grain yield and yield components of wheat (N8019 variety), plant tissue nitrogen content and soil N mineralization.
Advances in Plants and Agriculture Research, Nov 13, 2014
Plants response to temperature is an important issue. In order to determine cardinal temperatures... more Plants response to temperature is an important issue. In order to determine cardinal temperatures and its related germination responses to temperature three varieties seeds of milk thistle (Shomal, Mollasani and Majarestan) were exposed to six constant temperatures (10, 15, 20, 25, 30 and 35°C) in a four replicated factorial arranged, completely randomized design. Results indicated that the temperature and variety had a significant effect on the maximum germination percentage (MGR), germination uniformity (GU), germination rate (reciprocal time to 50% germination), and time to 5, 10, 50, 90 and 95% germination, but the interacted effect of temperature and variety was not significant. Assessment of three non-linear regression models, including segmented, dent-like and beta models revealed that the beta model was an appropriate model for all varieties. Base and ceiling temperatures for all three varieties were estimated at near to 0 and 40°C, respectively. Optimum temperature for Shomal, Mollasani and Majarestan varieties was estimated as (28.79, 29.97 and 29.58°C), respectively. Biological time for 50% germination for Shomal, Mollasani and Majarestan varieties also was estimated at 43.61, 42.61 and 45.85hours, correspondingly. It was concluded that these model can be used to quantify response of milk thistle germination to temperature and to obtain cardinal temperature of germination. These parameters are required to predict milk thistle germination and emergence.
The present study was performed to compare four nonlinear regression models (segmented, beta, bet... more The present study was performed to compare four nonlinear regression models (segmented, beta, beta modified, and dent-like) to describe the emergence rate-temperature relationships of six lentil (Lens culinaris Medik) cultivars at field experiment with a range of sowing dates, with the aim of identifying the cardinal temperatures and physiological days (i.e., number of days under optimum temperatures) required for seedling emergence. Models and statistical indices were calibrated using an iterative optimization method and their performance was compared by root mean square error (RMSD), coefficient of determination (R 2) and corrected Akaike information criterion correction (AIC). The beta model was found to be the best model for predicting the response of lentil emergence to temperature, (R 2 = 0.99; RMSD= 0.005; AICc=-232.97). Based on the model outputs, the base, optimum, and maximum temperatures of seedling emergence were 4.5, 22.9, and 40°C , respectively. The Six physiological days (equivalent to a thermal time of 94 °C days) were required from sowing to emergence.
Determining the mode of action of allelochemicals is one of the challenging aspects in the allelo... more Determining the mode of action of allelochemicals is one of the challenging aspects in the allelopathic studies. In this research, the methanolic extracts of wild poinsettia (Euphorbia heterophylla Linn.) at different concentrations (0, as untreated control, 8%, 12% and 16%) were tested for genotoxic and inhibitor activity on morphological, biochemical and molecular traits of sunflower (Helianthus annuus L.). Seedling emergence was reduced with wild poinsettia leaf extracts in sunflower. Leaf extracts of wild poinsettia decreased chlorophyll a and b levels and consequently the soluble sugar content was proportional to the increase in the concentrations of the leaf leachates. Some changes occurred in random amplification of polymorphic DNA (RAPD) profiles, profiles of protein bands and total soluble protein of germinated treated seed. These included variation in band intensity, loss of bands and appearance of new bands compared with control. Increased concentration of extracts caused increasing the total soluble protein content, decreasing genome template stability (GTS) value and increasing polymorphism values, the results indicated that they were dose dependent. For instance, the highest and lowest amounts of GTS were observed in 8% and 16%, respectively. In a dendrogram constructed based on genetic similarity coefficients, the treatments were grouped into two main clusters: (a) 8%, 12% and 16% dose clustered together and (b) untreated control grouped alone. Also, we concluded that the basis of interaction between plants, like allelopathy, may be related with genotoxic effects.
Optimal use of lands heavily relies on careful assessment of agro-ecological resources. Evaluatio... more Optimal use of lands heavily relies on careful assessment of agro-ecological resources. Evaluation of potential lands for various cultivated crops is the first strategic priority to increase production and optimized use of resources. This present study was aimed to identify effective climatologic, topographic and soil-related factors on rainfed wheat cropping in Qaresoo basin of Golestan province and determination of suitable areas to produce this crops usings Geographical Information System (GIS) and Analytic Hierarchy Process (AHP). At first, ecological requirements of rainfed wheat was identified from scientific literatures and then were classified to provide thematic maps. In this study, minimum, average and maximum temperatures, precipitation, slope, aspect, elevation and EC were considered. The Analytical Hierarchy Process (AHP) was used to find weight of each factor. Finally, the maps were provided and overlaid in GIS media and afterward the zoning of areas for rainfed wheat cultivation was done. Results showed that wheat grown lands would be located in four suitability classes. About 5170 hectares (6%) of the agricultural areas and 3% of the total area of the Qaresoo basin were located in high suitable class for rainfed wheat cultivation. Suitable precipitation, lower slope and projecting to south slopes and also the desirable electrical conductivity were the reasons make these regions suitable. Also, results showed that about 909 hectares (1.5%) of Qaresoo basin lands that now are cultivating by rainfed wheat, have not required potency to produce this crop.
American-Eurasian Journal of Agricultural and Environmental Science, 2010
Wheat (Triticum aestivum L.) is the most important crops in Iran. Growing conditions, N, as one o... more Wheat (Triticum aestivum L.) is the most important crops in Iran. Growing conditions, N, as one of the main inputs for cereal production systems. The increasing need to reduce pollution from N fertilizer is concomitantly strengthening the importance of improving the understanding of nitrogen use efficiency (NUE) of these crops. The objective of this study was to determine the significance and magnitude of variation in NUE, yield and grain protein concentration among diverse wheat genotypes in years of release. Field experiments were conducted during the growing seasons of 2007-2008 and 2008-2009 under well-watered conditions in Iran. Sixteen wheat cultivars were sown in a randomized complete block design with three replications. The study revealed that most breeding effects on NUE were associated with change in nitrogen utilization efficiency (NUtE). Genetic improvement of grain yield was not paralleled by improvement of grain protein concentration (GPC) in a manner that with years of release grain yield improved but quality of grain not improved.
Residue management is one of the optimistic options for sustaining agroecosystems. In order to in... more Residue management is one of the optimistic options for sustaining agroecosystems. In order to investigate NO3 and NH4 dynamism with the application of soybean and cotton residues incorporated with a silty-clay-loam soil (0-30 cm), an aerobic incubation experiment was carried out using three residue treatments (including cotton residue, soybean residue and cotton residue+urea to eliminate immobilization). The residue amount was determined in order to provide 150 Kg ha of Kjeldahl nitrogen after incorporation with soil (this was done using the nitrogen factor method).The samples were incubated for 175 days under a controlled environment at 25 ̊C. The NO3 and NH4 concentration and bacteria, fungi and Actinomycete populations were measured 7, 14, 28, 67, 109 and 175 days after incubation began. The results confirmed microbial activity dynamism during time. Cotton residues revealed a non significant prevalence on soybean residue with respect to cumulative nitrate and ammonia, which were released during the incubation period. In all cases, the cotton + urea treatment was better than both other treatments. These results were not interpretable based on the C:N ratio and the results showed that the lignin content is probably more important than the C:N ratio (lignin percentage of cotton and soybean residues are equal to 0.7-1.6% and 14%, respectively). In this study, the relationship between nitrate and ammonia dynamism with microbial communities have been analyzed.
Archives of Agronomy and Soil Science, Feb 16, 2015
A 2-year field experiment (2012-2013) was conducted to evaluate the yield and water use efficienc... more A 2-year field experiment (2012-2013) was conducted to evaluate the yield and water use efficiency (WUE) response of maize (Zea mays L.) to different soil water managements at different sowing dates. The experiment included three sowing dates (22 June, 6 July and 21 July) and four irrigation regimes based on maximum allowable depletion (MAD) of the total available soil water (TAW). The irrigation treatments were marked by I 1 to I 3 as 40%, 60% and 80% MAD of TAW, respectively, and with no irrigation. The results showed that grain yield reduced when planting was delayed in both years, ranging from 6105 to 4577 kg ha −1 in 2012 and from 7079 to 5380 kg ha −1 in 2013. However, WUE increased when planting was delayed from 22 June until 21 July. Also the highest grain yield was observed in the first irrigation treatment (MAD = 40%) in both years, and the highest WUE was obtained in the second irrigation treatment (MAD = 60%) with 1.64 and 1.61 (kg m −3) in 2012 and 2013, respectively. These findings suggest that delay in planting date and the use of MAD = 60% treatment in Mediterranean-type region such as Golestan, Iran, can be useful in saving water that is highly important in such regions.
An experiment was conducted to determine the effects of salinity and temperature on the germinati... more An experiment was conducted to determine the effects of salinity and temperature on the germination responses of three of the more commonly cultivated millet varieties in SouthEast regions of Iran, including common millet (Panicum miliaceum), pearl millet (Pennisetum galucum) and foxtail millet (Setaria italica). Seeds were exposed to different salinity levels equal to six osmotic potentials of 0 to-1.25 with-0.25 MPa intervals and three constant temperature treatments (15, 25 and 35°C). Cumulative germination percentage and germination rate were analyzed under different exerted treatments. Germination rate was calculated as the reciprocal of time to 50% germination in each combination of treatments. Our results indicate that temperature is more important than salinity level to obtain more favorable germination. The highest values of germination percentage and germination rate were obtained for higher temperatures with lower salinities. Also, decreased temperature alleviated the detrimental effects of salinity on studied traits, which indicates a synergistic effect of higher temperatures on detrimental effects of salinity. The lowest values of studied characters also were associated with lower temperatures, independent of salinity level. Results indicate that germination of seeds at high temperatures with low salinity levels, and high temperatures and high salinity levels was better than when seeds were germinated at low temperatures (independent of the salinity conditions). Also, foxtail millet had the highest germination percentage and germination rate at all salinity levels and temperatures while the lowest values belonged to pearl millet.
Abstract Due to the reports regarding unsuccessful control of Avena sterilis subsp. ludoviciana (... more Abstract Due to the reports regarding unsuccessful control of Avena sterilis subsp. ludoviciana (Durieu) Gillet & Magne by haloxyfop-R-methyl in canola fields, the following study was conducted to investigate the resistance of this weed to haloxyfop-R-methyl. Five out of 22 accessions were resistant to haloxyfop-R-methyl. These biotypes were then subjected to various rates of clodinafop propargyl, sethoxydim, pinoxaden and mesosulfuron methyl + iodosulfuron-methyl herbicides and their cross-resistance to clodinafop propargyl and sethoxydim was confirmed. However, no resistance was observed to pinoxaden and mesosulfuron-methyl + iodosulfuron-methyl herbicides. Indirect study of metabolism by P450 using 1- aminobenzotriazole and piperonyl butoxide showed that this enzyme had no contribution to occurrence of resistance in the studied biotypes. Allele-specific PCR results indicated that Ile-2041-Asn mutation is responsible for resistance of A. sterilis subsp. ludoviciana biotypes, which was confirmed by sequencing of the samples. Since pinoxaden negatively affects canola, the growers face a serious limitation in their choice for chemical management and thus, implementation of integrated weed management such as introduction of row crops such as faba bean in crop rotation and increasing the diversity of herbicide mode of action by cultivation of crops such as sugar beet in crop rotation may prove helpful. In fields under canola-wheat rotation, it is also possible to use pinoxaden in wheat. Also, trifluralin, cycloxydim and clethodim herbicides may be tested on A. sterilis subsp. ludoviciana. This was the first case of A. sterilis subsp. ludoviciana resistance to ACCase inhibitors in canola fields.
ABSTRACT Seed germination is strongly dependent on temperature. Reduced germination rate as a con... more ABSTRACT Seed germination is strongly dependent on temperature. Reduced germination rate as a consequence of seed aging might be due to changing the type of response function to temperature or changing the parameters that govern the function. The objectives of this research were: (1) to determine the effect of seed aging on the type of response function describing the relationship of germination rate to temperature, and (2) to evaluate how the parameter(s) of the response function are changed when the germination rate is reduced as a result of seed aging. Seeds (cv. ‘Zagros’) were kept at a high temperature (43°C) and high relative humidity (90-95%) to create different classes of seed aging. Seed aging had no effect on the type of response function or cardinal temperatures. A dent-like function adequately described the response of germination rate to temperature in all the aging treatments. Cardinal temperatures of 2.2°C for the base, 28.6°C for the lower optimum, 38.0°C for upper optimum and 45°C for ceiling temperatures were obtained. Inherent maximum rate of germination (Rmax) was the sole parameter that was affected by seed aging periods and characterized differences between seed aging periods with respect to germination rate at various temperatures.
Advances in Plants and Agriculture Research, May 14, 2014
This study aimed to compare the effects of different crop residues (with various C:N ratios) on g... more This study aimed to compare the effects of different crop residues (with various C:N ratios) on grain yield and yield components of wheat (N8019 variety), plant tissue nitrogen content and soil N mineralization.
Advances in Plants and Agriculture Research, Nov 13, 2014
Plants response to temperature is an important issue. In order to determine cardinal temperatures... more Plants response to temperature is an important issue. In order to determine cardinal temperatures and its related germination responses to temperature three varieties seeds of milk thistle (Shomal, Mollasani and Majarestan) were exposed to six constant temperatures (10, 15, 20, 25, 30 and 35°C) in a four replicated factorial arranged, completely randomized design. Results indicated that the temperature and variety had a significant effect on the maximum germination percentage (MGR), germination uniformity (GU), germination rate (reciprocal time to 50% germination), and time to 5, 10, 50, 90 and 95% germination, but the interacted effect of temperature and variety was not significant. Assessment of three non-linear regression models, including segmented, dent-like and beta models revealed that the beta model was an appropriate model for all varieties. Base and ceiling temperatures for all three varieties were estimated at near to 0 and 40°C, respectively. Optimum temperature for Shomal, Mollasani and Majarestan varieties was estimated as (28.79, 29.97 and 29.58°C), respectively. Biological time for 50% germination for Shomal, Mollasani and Majarestan varieties also was estimated at 43.61, 42.61 and 45.85hours, correspondingly. It was concluded that these model can be used to quantify response of milk thistle germination to temperature and to obtain cardinal temperature of germination. These parameters are required to predict milk thistle germination and emergence.
The present study was performed to compare four nonlinear regression models (segmented, beta, bet... more The present study was performed to compare four nonlinear regression models (segmented, beta, beta modified, and dent-like) to describe the emergence rate-temperature relationships of six lentil (Lens culinaris Medik) cultivars at field experiment with a range of sowing dates, with the aim of identifying the cardinal temperatures and physiological days (i.e., number of days under optimum temperatures) required for seedling emergence. Models and statistical indices were calibrated using an iterative optimization method and their performance was compared by root mean square error (RMSD), coefficient of determination (R 2) and corrected Akaike information criterion correction (AIC). The beta model was found to be the best model for predicting the response of lentil emergence to temperature, (R 2 = 0.99; RMSD= 0.005; AICc=-232.97). Based on the model outputs, the base, optimum, and maximum temperatures of seedling emergence were 4.5, 22.9, and 40°C , respectively. The Six physiological days (equivalent to a thermal time of 94 °C days) were required from sowing to emergence.
Determining the mode of action of allelochemicals is one of the challenging aspects in the allelo... more Determining the mode of action of allelochemicals is one of the challenging aspects in the allelopathic studies. In this research, the methanolic extracts of wild poinsettia (Euphorbia heterophylla Linn.) at different concentrations (0, as untreated control, 8%, 12% and 16%) were tested for genotoxic and inhibitor activity on morphological, biochemical and molecular traits of sunflower (Helianthus annuus L.). Seedling emergence was reduced with wild poinsettia leaf extracts in sunflower. Leaf extracts of wild poinsettia decreased chlorophyll a and b levels and consequently the soluble sugar content was proportional to the increase in the concentrations of the leaf leachates. Some changes occurred in random amplification of polymorphic DNA (RAPD) profiles, profiles of protein bands and total soluble protein of germinated treated seed. These included variation in band intensity, loss of bands and appearance of new bands compared with control. Increased concentration of extracts caused increasing the total soluble protein content, decreasing genome template stability (GTS) value and increasing polymorphism values, the results indicated that they were dose dependent. For instance, the highest and lowest amounts of GTS were observed in 8% and 16%, respectively. In a dendrogram constructed based on genetic similarity coefficients, the treatments were grouped into two main clusters: (a) 8%, 12% and 16% dose clustered together and (b) untreated control grouped alone. Also, we concluded that the basis of interaction between plants, like allelopathy, may be related with genotoxic effects.
Optimal use of lands heavily relies on careful assessment of agro-ecological resources. Evaluatio... more Optimal use of lands heavily relies on careful assessment of agro-ecological resources. Evaluation of potential lands for various cultivated crops is the first strategic priority to increase production and optimized use of resources. This present study was aimed to identify effective climatologic, topographic and soil-related factors on rainfed wheat cropping in Qaresoo basin of Golestan province and determination of suitable areas to produce this crops usings Geographical Information System (GIS) and Analytic Hierarchy Process (AHP). At first, ecological requirements of rainfed wheat was identified from scientific literatures and then were classified to provide thematic maps. In this study, minimum, average and maximum temperatures, precipitation, slope, aspect, elevation and EC were considered. The Analytical Hierarchy Process (AHP) was used to find weight of each factor. Finally, the maps were provided and overlaid in GIS media and afterward the zoning of areas for rainfed wheat cultivation was done. Results showed that wheat grown lands would be located in four suitability classes. About 5170 hectares (6%) of the agricultural areas and 3% of the total area of the Qaresoo basin were located in high suitable class for rainfed wheat cultivation. Suitable precipitation, lower slope and projecting to south slopes and also the desirable electrical conductivity were the reasons make these regions suitable. Also, results showed that about 909 hectares (1.5%) of Qaresoo basin lands that now are cultivating by rainfed wheat, have not required potency to produce this crop.
American-Eurasian Journal of Agricultural and Environmental Science, 2010
Wheat (Triticum aestivum L.) is the most important crops in Iran. Growing conditions, N, as one o... more Wheat (Triticum aestivum L.) is the most important crops in Iran. Growing conditions, N, as one of the main inputs for cereal production systems. The increasing need to reduce pollution from N fertilizer is concomitantly strengthening the importance of improving the understanding of nitrogen use efficiency (NUE) of these crops. The objective of this study was to determine the significance and magnitude of variation in NUE, yield and grain protein concentration among diverse wheat genotypes in years of release. Field experiments were conducted during the growing seasons of 2007-2008 and 2008-2009 under well-watered conditions in Iran. Sixteen wheat cultivars were sown in a randomized complete block design with three replications. The study revealed that most breeding effects on NUE were associated with change in nitrogen utilization efficiency (NUtE). Genetic improvement of grain yield was not paralleled by improvement of grain protein concentration (GPC) in a manner that with years of release grain yield improved but quality of grain not improved.
Residue management is one of the optimistic options for sustaining agroecosystems. In order to in... more Residue management is one of the optimistic options for sustaining agroecosystems. In order to investigate NO3 and NH4 dynamism with the application of soybean and cotton residues incorporated with a silty-clay-loam soil (0-30 cm), an aerobic incubation experiment was carried out using three residue treatments (including cotton residue, soybean residue and cotton residue+urea to eliminate immobilization). The residue amount was determined in order to provide 150 Kg ha of Kjeldahl nitrogen after incorporation with soil (this was done using the nitrogen factor method).The samples were incubated for 175 days under a controlled environment at 25 ̊C. The NO3 and NH4 concentration and bacteria, fungi and Actinomycete populations were measured 7, 14, 28, 67, 109 and 175 days after incubation began. The results confirmed microbial activity dynamism during time. Cotton residues revealed a non significant prevalence on soybean residue with respect to cumulative nitrate and ammonia, which were released during the incubation period. In all cases, the cotton + urea treatment was better than both other treatments. These results were not interpretable based on the C:N ratio and the results showed that the lignin content is probably more important than the C:N ratio (lignin percentage of cotton and soybean residues are equal to 0.7-1.6% and 14%, respectively). In this study, the relationship between nitrate and ammonia dynamism with microbial communities have been analyzed.
Archives of Agronomy and Soil Science, Feb 16, 2015
A 2-year field experiment (2012-2013) was conducted to evaluate the yield and water use efficienc... more A 2-year field experiment (2012-2013) was conducted to evaluate the yield and water use efficiency (WUE) response of maize (Zea mays L.) to different soil water managements at different sowing dates. The experiment included three sowing dates (22 June, 6 July and 21 July) and four irrigation regimes based on maximum allowable depletion (MAD) of the total available soil water (TAW). The irrigation treatments were marked by I 1 to I 3 as 40%, 60% and 80% MAD of TAW, respectively, and with no irrigation. The results showed that grain yield reduced when planting was delayed in both years, ranging from 6105 to 4577 kg ha −1 in 2012 and from 7079 to 5380 kg ha −1 in 2013. However, WUE increased when planting was delayed from 22 June until 21 July. Also the highest grain yield was observed in the first irrigation treatment (MAD = 40%) in both years, and the highest WUE was obtained in the second irrigation treatment (MAD = 60%) with 1.64 and 1.61 (kg m −3) in 2012 and 2013, respectively. These findings suggest that delay in planting date and the use of MAD = 60% treatment in Mediterranean-type region such as Golestan, Iran, can be useful in saving water that is highly important in such regions.
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