فهرست مطالب سید عبدالرضا کاظمینی

Barley is the fourth most important cereal in the world and is considered one of the least expected crops that has adapted and distributed globally due to its resistance to salinity. The growing world's population has expanded the cultivated domain, which caused the utilization of extravagant chemical fertilizers in modern agricultural cropping systems. This approach has not been cost-effective and has caused severe environmental damages like contaminating the underground water and creating unusual salinity in the fields. Therefore, it seems to be essential to replace risky approaches with eco-friendlier methods. In addition, with increasing environmental stress as a result of climate warming, we need to understand better ways to reduce environmental stress for the sustainable production of barley. Mycorrhiza has been introduced as an essential portion of agricultural ecosystems because of its positive effect on the soil texture, growth, and productivity of almost all host plants. This trend is attributed to reduced chemical fertilizer demands. Mycorrhiza enhances the water relations under stress conditions, water and nutrient uptake by augmenting the hyphae network. In this study we aimed to investigate the role of mycorrhizal inoculation in alleviating the detrimental effects of salinity stress on barley. Our hypotheses were: (i) mycorrhizal inoculation can alleviate the detrimental effect of stress at low to medium levels but not at high levels of salinity, and (ii) there is an interaction effect of low levels of salinity and arbuscular mycorrhizal symbiosis lead to higher the performance of barley.

In order to evaluate the effects of Funneliformis mosseae mycorrhiza on morphological, biochemical and yield of barley, one experiment was conducted in research farm of School of Agriculture, Shiraz University. Field experiment was a split-plot in a randomized complete block design with three replications. Factors included salinity levels (0.4, 4, 8 and 12 dS m-1) as the main factor and the mycorrhiza (with and without) was applied as sub factor.  Data were analyzed by using SAS 9.2 software and the means were separated using LSD test at 5% probability level.

The results of the experiment showed that salinity decreased yield and vegetation traits, including plant height, number of tillers per plant, number of spikes per plant, number of seeds per spike, 1000-grain weight, grain yield, and biological yield. All the measured traits in plants inoculated with mycorrhizal fungi were higher than the non-mycorrhizal plants. The inoculation of plants in most cases improved the effects of stress; i.e., inoculation under high salinity stress (12 dS m-1) increased SOD by 5.7%, CAT by 8.0%, K concentration by 30.8%, K/Na ratio by 131.1%, plant height by 8.1%, number of spikes per plant by 9.4%, number of grain per spike by 6.6%, 1000-grain weight by 4.2%, grain yield by 20.2%, and biological yield by 11.0% compared with non-inoculation plants. Also, Fayaz and Zahedi (2021) reported that mycorrhizal inoculation could promote the growth and salt tolerance of wheat cultivars by improving osmoregulation and antioxidant enzyme activity and reducing the Na+/K+ ratio.

In this experiment, inoculation treatment alleviated the high salinity stress (12 dS m-1) effects in most cases and raised the grain yield and K+/Na+ ratio up to 20.2 and 131.1%, respectively, compared with non-inoculation plants. The results from this experiment showed that Funneliformis mosseae fungi inoculation could promote the growth and salt tolerance of barley by improving antioxidant enzyme activity, and ion homeostasis. In summary, the use of Funneliformis mosseae could reduce salinity damages by improving the physiological and biochemical responses of barley. This study highlighted the potential role of Funneliformis mosseae inoculation, in particular with native strains, as an innovative and eco-friendly technology for a sustainable crop-growing system in arid and semi-arid areas.

The aim of this study was the determine effect of nitrogen fertilizer sourcesand redroot pigweed (Amaranthus retroflexus) densities on nitrogen utilization efficiency and quinoa (Chenopodium quinoa Willd) resistance index. A field study carried out during 2021 growing season in research farm of School of Agriculture, Shiraz University. The experiment was conducted in a split-plot based on a randomized complete block design with 3 replications. Nitrogen fertilizer sources (non‐fertilizer, urea, sulfur coated urea and ammonium nitrate) were assigned to main plots and density of red root pigweed at 6 levels (0, 5, 10, 15, 20 and 25 plants m-2) to the sub-plots. The application of sulfur coated urea in the highest weed density (25 plant m-2) increased dry matter partitioning to grain by 1.2 times, percentage of nitrogen and protein by 1.5 and 1.4 times, photosynthesis rate by 1.2 times and quinoa grain yield by 2.8 times compared to non‐fertilizer. The application of urea, sulfur coated urea and ammonium nitrate in the highest weed density increased nitrogen utilization efficiency by 78.3, 79.8 and 60.4%, respectively compared to non‐fertilizer. In general, the results showed that sulfur coated urea had the maximum grain yield and nitrogen utilization efficiency and was followed by urea and ammonium nitrate, respectively. Therefore, sulfur coated urea is recommended as the most efficient source of nitrogen fertilizer.

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

Sweet corn (Zea mays L. Var saccharata) is an important cereal crop that referred to considerable human nutrition and industrial products of its sugar content, minerals phosphorus, magnesium, iron, zinc, vitamins in most of the literatures. The negative impacts of long-term application of chemical fertilizers on the soil, environment and human health in arid and semi-arid regions have resulted in an increase in application of biological fertilizers in these areas. The application of biological fertilizers is an environmentally-friendly approach to plant growth and production. Bio-fertilizers have been applied in agriculture to significantly reduce the application of chemical fertilizers and it is used as a strategy for improving crop productivity, sustainability soil health, environment friendly and cost effective.

This experiment was carried out as a factorial arranged as randomized complete blocks design with three replications during 2017 growing season at School of Agriculture, Shiraz University. The treatments included water regime at two levels (75% and 100% of water requirement) and five nitrogen rates and sources (no fertilizer, nitroxin, 150 kg urea, 150 kg urea + nitroxin and 300 kg urea). The traits included ear number per plant, row number per ear, grain number per row, canned grain yield, water use efficiency, ear harvest index, urease enzyme activity and soil microbial respiration. Crude protein was determined by Kjeldahl method, multiplied by the 6.25 (N × 6.25) conversion factor, and the results were then calculated as a percentage (%) and soluble sugar was measured by pocket model ATAGO refractometer. Moreover, ear harvest index was determined by the ratio of fresh grain yield (canned yield) per ear yield with husk, and urease enzyme activity and soil microbial respiration were estimated by the modified Kandeler and Gerber and Black et al's methods. Furthermore, yield and yield components were measured. Data were analyzed by using SAS 9.2 software and the means were separated using LSD test at 5% probability level.

The results showed that application of 150 kg urea + nitroxin significantly increased canned yield and its components, grain protein, grain soluble sugar, urease enzyme activity and soil microbial respiration, respectively compared to individual application of nitroxin and or 150 kg urea under water stress levels and there was no significant difference between 150 kg urea + nitroxin treatment and 300 kg urea ha-1. Normal irrigation (100% of water requirement) and combination of 300 kg urea + nitroxin, significantly increased ear number per plant (21.7 and 16.6%), row number per ear (21.4 and 21.4%), grain number per row (19.3 and 11.5%), canned grain yield (41.4 and 30.5%), water use efficiency (45 and 8.4%), ear harvest index (20.3 and 22.1%), urease enzyme activity (40.0 and 68.8%) and soil microbial respiration (12.1 and 1.6%), respectively and there was no significant difference between 150 kg urea + nitroxin and 300 kg urea compared to individual application of nitroxin and 150 kg urea. Therefore, application of nitroxin as a bio-fertilizer combined with 150 kg urea ha-1 produced the optimal canned yield and reduced nitrogen use and can be recommended in the arid and semi-arid regions.

According to the results, to improve the soil biological activity and yield and yield components of sweet corn, the combination of N150 and Ni instead of N300 is recommended and further research is also required to investigate the effects of applying Ni in combination with other bio-stimulants on yield and yield components of sweet corn.

We would like to thank the School of Agriculture, Shiraz University for their support, cooperation, and assistance throughout this research.

 Quinoa (Chenopodium quinoa L.) is a highly nutritional seed crop from the Andean region with huge genetic variability, enabling its cultivation across a wide range of environmental conditions. The area and production under quinoa in the world in 2020 was 189000 ha with 175000 tonnes production. There is some evidence for allelopathic activity of quinoa and this potential could be probably used in terms of integrated weed management. Agronomic practices such as nitrogen fertilization influence weed emergence, growth and competition in a crop. Nevertheless, despite the numerous studies on new and promising crops globally, there is a clear lack of information on the combined effect of weed density and nitrogen fertilizer sources on quinoa crop. Therefore, the purpose of this study was to evaluate the effects of nitrogen fertilizer sources and red root pigweed densities on growth, yield and competitive ability of quinoa (Chenopodium quinoa Willd). This information could be helpful for the overall development of crop and weed management strategies in quinoa crop.
A field study was conducted during the 2021 growing season at the research farm of the School of Agriculture, Shiraz University, to assess the impact of nitrogen fertilizer sources on the growth, yield, and competitive ability of quinoa in the presence of red root pigweed at different densities. The experiment was set up in a split-plot design with nitrogen fertilizer sources (control, urea, sulfur-coated urea, and ammonium nitrate) assigned to the main plots, and red root pigweed densities (0, 5, 10, 15, 20, and 25 plants per square meter) assigned to the sub-plots. There were three replications of each treatment. For the quinoa traits and weed traits, a 2-meter square area was harvested from each plot. Quinoa traits included plant height, leaf area index, number of grains per plant, 1000 grain weight, grain yield, biological yield, and harvest index. The quinoa plants were dried in an oven at 75°C for 72 hours to determine seed yield. Weeds were also harvested from a 2 m2 area in each plot to measure plant height, shoot height, panicle length, and leaf area index. The collected data were analyzed using SAS v. 9.1 software (SAS Institute 2003). When significant differences were found among treatments, mean comparisons were performed using Duncan's multiple range tests at a significance level of P < 0.05.
 The results of the experiment indicated that the use of sulfur coated urea had a positive effect on the competitive ability of quinoa. Weed density had a detrimental impact on various growth and yield parameters of quinoa, including plant height, leaf area index, number of grains per plant, 1000 grain weight, grain yield, biological yield, and harvest index. However, the application of sulfur coated urea mitigated the negative effects of weed density. Specifically, when the highest weed density of 25 plants per square meter was present, the application of sulfur coated urea led to a 1.1-fold increase in plant height, a 2.5-fold increase in leaf area index, a 2.5-fold increase in the number of grains per plant, a 1.1-fold increase in 1000 grain weight, a 2.8-fold increase in grain yield, and a 1.8-fold increase in biological yield compared to the control. At different red root pigweed densities (0, 5, 10, 15, 20, and 25 plants per square meter), the application of sulfur coated urea resulted in significant improvements in quinoa performance. It increased the number of grains per plant by 86.5%, 118%, 139.4%, 168.8%, 149.6%, and 153.4% compared to the control at respective weed densities. Additionally, 1000 grain weight increased by 7.9% to 9.9%, and the ability of quinoa to withstand competition increased by 19.6% to 55%. The findings of this study are consistent with previous research that has demonstrated the positive effects of organic nutrients on reducing weed competition in agricultural systems. It has also been observed that weeds tend to produce more biomass in the presence of fertilizer compared to the control. Therefore, it can be concluded that the improved grain yield of quinoa resulting from the application of sulfur coated urea was primarily attributed to its ability to enhance the plant's competitive ability against weeds.
 The application of sulfur coated urea led to a higher quinoa yield compared to using control. However, weed competition was greater with urea fertilization in comparison with sulfur coated urea fertilizer. In addition, most weeds are highly responsive to soil N, so the application of all fertilizer types should be carefully considered to reduce the competitive advantage of weeds over crops.
Acknowledgements
 We would like to thank the School of Agriculture, Shiraz University for their support, cooperation, and assistance throughout this research.

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

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

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

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

 Sweet corn (Zea mays L. var. saccharata) is an important crop, grown over 2,000 hectares in Iran. The consumption demand for sweet corn in its fresh form or as a processed crop has contributed to a significant increase in its cultivation in recent years. Sweet corn is susceptible to weed competition for nutrients, moisture, and light interception. Herbicides labeled for use on sweet corn are limited. Chemical control can be very important because of the low efficiency and cost effectiveness of mechanical or other methods of weed control. Hence, it is necessary to provide information about the sulfonylurea herbicides and suitable doses. Sulfonylureas such as nicosulfuron, rimsulfuron, and foramsulfuron are effective group of herbicides for annual and perennial weed control in maize. These herbicides provide a new chance for weed management in maize. Their mode of action occurs through inhibiting acetolactate synthase (ALS), thereby interfering with the production of branched-chain amino acids, leucine, isoleucine, and valine. The objectives of this experiment were to evaluate the effect of different doses of sulfonylurea herbicides on weeds control and growth and yield of sweet corn.

 In order to evaluate the effect of different doses of sulfonylurea herbicides on weeds control and growth and yield of sweet corn (KSC403su), a field study carried out during 2015 growing seasons at the Agricultural College of Shiraz University. The experiment was conducted in a randomized complete block design with 4 replications. Treatments included different doses of nicosulfuron (1.5, 2 and 2.5 l ha-1), foramsulfuron + idosulfuron (1, 1.5 and 2 l ha-1) and acetochlor (4.5, 5 and 5.5 l ha-1) herbicides and weed free and weedy control. The number and dry weight of aboveground weeds parts were harvested within three fixed 1 × 1 m quadrats in every plot, separated by species, enumerated, oven-dried at 75 °C for 48 h, and then weighed. Then, percent weed density and dry weight reductions were measured. The traits included ear length, ear diameter, ear number per plant, row number per ear, grain number per row, grain number per ear and canned grain yield. Data were analyzed using SAS v. 9.1 software (SAS Institute 2003). When significant differences were observed among treatments, mean comparisons were made using Duncan's multiple range tests (P < 0.05). Correlation coefficients between different traits were also calculated.

 Results showed that the canned grain yield, 1000 grain weight and number of grain per ear were reduced by weeds up to 73, 33 and 60%, respectively. The highest dry weights reduction obtained were of redroot pigweed (Amaranthus retroflexus) (75.8 and 59.5%), lambsquarters (Chenopodium album) (49.84 and 38.76%), barnyard grass (Echinochloa crus-galli) (58.37 and 40.85%) and bindweed (Convolvulus arvensis) (60.56 and 55.06%), so that applying of nicosulfuron )2.5 l ha-1) and foramsulfuron + idosulfuron (2 l ha-1) herbicides caused reduction in total dry weight of weeds in comparison with weedy treatment, and canned seed yield increased by nicosulfuron )2.5 l ha-1) and foramsulfuron + idosulfuron (2 l ha-1) herbicides in comparison to the acetochlor. Acetochlor was the weakest treatment in the reduction of weed density and dry weight. The highest canned grain yield (8.00 and 7.03 t ha-1), number of row per ear (12.00 and 11.50), number of grain per row (25.00 and 24.75), number of grain per ear (299.00 and 285.50) and 1000 grain weight (325.06 and 308.44 g) were obtained in nicosulfuron )2.5 l ha-1) and foramsulfuron + idosulfuron (2 l ha-1) herbicides, respectively. Positive correlation was found between canned grain yield and 1000 grain weight (r = 0.83, p<0.05) and number of grain per ear (r = 0.96, p<0.05). Applying nicosulfuron showed a high efficiency as compared to the foramsulfuron + idosulfuron and acetochlor for weed suppression.

 It can conclude that nicosulfuron at 2.5 l ha-1 showed the best performance for weed control, especially broadleaved weeds and were associated with the maximum sweet corn canned grain yield. Therefore, due to the restricted use of herbicide in sweet corn, the herbicide used in this experiment is not created serious injury in sweet corn at the recommended rate while effectively controlling weeds. Hence, utilization of this herbicide could be a favorable option in contemporary weed control programs for local or regional sweet corn growers.

In order to investigate the effect of quinoa seed inoculation on photosynthesis rate, yield and competitive ability with weeds, an experiment was conducted as split-plot based on a randomized complete block design with three replications at experimental farm of School of Agriculture, Shiraz University, Shiraz, Iran during 2020 growing season. Treatments were three levels of weed management as main-plot (weedy, weed-free and weeding) and five levels of seeds inoculation with biofertilizers (humic acid, bioumic, seaumic, organic herbicide, and no biofertilizers) as subplots. The results showed that the highest rate of photosynthesis in all weed management levels was achieved in the presence of seeds inoculated with seaumic biofertilizer. The highest grain yield (259.63 g/m2) and grain yield components (1000-seed weight, number of seeds per panicle, and number of panicles per plant) and harvest index (48.73%) were also obtained in weed-free plots when seeds were inoculated with seaumic biofertilizer. Leaf area index and dry weight of the main weed species (wheat) was significantly reduced in inoculation of seeds with biofertilizers compared to the no biofertiliuzer condition. The highest crop’s competitive ability was achieved when the seeds were inoculated with seaumic treatment. The quinoa’s competitive ability was increased by 2.8 times and 94.11% at weedy and weed-free treatments, respectively, compared with control in seed inoculation with seaumic treatment. Thus, our finding suggests that seed inoculation with biofertilizers, especially seaumic treatment is an effective strategy that can be used to enhance germination rate, growth, yield and weed competitive ability in quinoa.

This experiment was conducted in order to study the sensitivity of sesame (Sesamum indicum) and lentil (Lens culinaris) crops to soil residue of three herbicides including total, apirus, and atlantis under greenhouse conditions. It was observed that the low level of atlantis residue reduced the sesame stem length (91.61% compared to control). Besides, the lowest sesame stem length (33.30% compared to control) was observed at high level of the herbicide residue. Total herbicide compared to the other two herbicides had a greater destructive impact (89.93%) on the sesame stem dry weight. The results indicated that the maximum and minimum damages on the lentil stem length were created by the total (46.78%) and atlantis (23.33%), respectively. Furthermore, the values of GR50 and HR50 for sesame were significantly lower than lentil against application of total, apirus, and atlantis. Generally, sesame showed higher sensitivity than lentil against application of total, apirus and atlantis.

ABSTRACT-A field study was conducted to determine the influences of six mulch materials (organic and inorganic), including black plastic, transparent plastic, wheat straw, peat moss, coco peat, and sawdust and the metribuzin on the two weed species vegetative and reproductive growth cycles in a tomato field using a randomized complete block design with three replications at the Research Station of the Agricultural School, Shiraz University, Shiraz, Iran. According to the results of the analysis of variance, all evaluated traits of both weed species, and also tomato, were significantly influenced by treatments at p < 0.01.The longest and shortest time of redroot pigweed (Amaranthus retroflexus L.) emergence were recorded under the plastic mulch treatments at 28 days after transplanting (DAT) and organic mulches as well as metribuzin at 21 DAT, respectively. Plastic mulches deferred the time of lamb's quarters (Chenopodium album L.) emergence more than organic mulches up to 28.0%. Additionally, the longest time of lamb'squarters emergence was observed with coco peat at 29 DAT and the shortest time of its emergence was recorded under the application of clear plastic and sawdust mulches at 23.3 DAT. Results showed that, the highest marketable tomato yield (up to 19.2 kg m-2) was assessed in covered plots with black plastic mulch, while the lowest marketable yield was detected by 3.02 kg m-2 in the plots under the application of the sawdust treatment. In general, results demonstrated that the plastic mulches, particularly the black plastic sheet, could be reliable alternatives for metribuzin to control weed infestations in tomato fields.

In order to evaluate canopy and organs temperature depression (TD) under heat stress conditions and the effects of plant morphology on organs temperature depression and their association with grain yield, two field experiments were conducted using six wheat cultivars (Behrang, Chamran, Kauz, Koohdasht, Karim and Montana) planted on three dates (early, optimum, late) in 2014-2015 and 2015 -2016 cropping seasons in Dashtestan, Bushehr, Iran. In addition, three concentrations of salicylic acid (0, 0.5 and 1 mM) were applied to alleviate the effects of heat stress.  Canopy and organs (flag leaf, peduncle and spike) temperature were measured by a hand-held infra-red thermometer (IRT). Also, some morphological traits in addition to yield components were measured. Results showed that the effects of cultivars and heat conditions were significant for most of the studied traits but salicylic acid application showed no significant effects. Under late sowing date, canopy and organs temperature depression were significantly higher than those at early and optimum sowing dates. No significant differences were found between early and optimum sowing dates for all temperature depressions. Among cultivars, Behrang had higher canopy temperature reduction (CTD), flag leaf temperature depression (FLTD) and peduncle temperature depression (PTD). Spike temperature depression (STD) was higher in Chamran and Kauz cultivars. Among plant organs, peduncle had higher temperature depression followed by flag leaf and spike. Canopy and organs temperature depression had positive correlation with stomatal conductance and grain yield. This research suggests that temperature depression can be used as an important criterion for the selection of stable genotypes under late sowing conditions. This is very helpful to improve wheat productivity under terminal heat stress resulting from late sowing conditions.

To evaluate the effect of residue of sulfonylurea herbicides and  wheat residues on the growth and yield of sunflower, a split factorial experiment was conducted based on a randomized complete block design (RCBD) with four replications at the College of Agriculture, Shiraz University, Shiraz, Iran. The treatments included with and without wheat residues from the tested farm as the main plots, and a combination of three herbicides (Total, Apirus and Atlantis) and their concentrations (recommended and 30% overdose) which were considered as subplots. No herbicide treatment was used as control. The results showed that application of all herbicides reduced sunflower height, seed number and seed weight as well as seed yield of sunflower. The highest reduction in seed yield was recorded when Total  followed by Apirus residues were applied, which caused 95% and 80.6% yield reductions, respectively. Also, the minimum reduction of seed yield (32.7%) observed in Atlantis treatment. Moreover, 30% increase in herbicides dose caused increasing adverse effects and decreasing grain and biological yield compared to the recommended dose. Wheat residues incorporated to the soil increased damage of Atlantis by maintaining it in the soil (reduced seed yield from 3932.3 to 3556.9 kg/ha) and reduced damage of Total and Apirus by further degradation of these herbicides (increased seed yield from 235.4 to 311.6 kg/ha in Total treatment, and from 996.6 to 1161.3 kg/ha in Apirus treatment). But overall, wheat residues increased seed yield (2.1%) in comparison to the removal of plant residue. Therefore, addition of wheat residues as organic matter in the soil can affect the biological changes of herbicides.

Adoption of conservative agriculture at farm level is associated with reducing the production costs and leads to crop yield stability. The aim of this study was to prioritize experimental treatments based on different criteria by applying "technique for order preference by similarity to ideal solution" (TOPSIS).A filed experiment was carried out at Zarghan research station, Fars province, Iran, during 2014-2016 growing seasons. Experimental treatments were three tillage practices including conventional tillage (CT), reduced tillage (RT) and no tillage (NT) that were assigned to main plots and four spring wheat genotypes (Chamran, Sirvan, Picaflor#1 and M-89-10)were randomized in subplots using split-plot arrangements in randomized complete block design with three replications. Selected criteria including two groups of economic- i.e. water cost, weed control cost, production cost and gross margin- and agronomic –i.e. grain yield and soil bulk density criteria used to prioritize the treatments. The weights of bulk density (0.040), grain yield (0.180), gross margin (0.280), water cost (0.0270), weed control cost (0.150), and production cost (0.080) was calculated. Results showed, considering all criteria to prioritize wheat genotypes under different tillage practices, that Sirvan and Picaflor#1 genotypes under RT practice could be the first treatments in 2014-15 and 2015-16 growing seasons, respectively. Therefore, the multiple criteriamethodshould be used for selection of the best tillage practices and wheat genotypes under tillage practices rather than a criterion such as grain yield or production cost.

In order to determine the effect of weeds interference and nitrogen on the sugar beet growth and yield, a field study was performed in the 2010 growing season as a split plot design based on RCBD with three replications in Hana region (Semirom, Esfahan). Treatments were four levels of nitrogen from urea source as the main factor (0, 70, 150 and 210 kg ha-1) and weed interference at five levels (6-leaf, 8-leaf, 10-leaf, 12-leaf, and throughout the growth stages) growth stages in sugar beet as the sub factor. The results indicated that nitrogen and weed interaction had significant effects on the quantitative and qualitative traits of sugar beet (root yield and sugar). With increasing the nitrogen levels from 150 to 210 kg ha-1, the percentages of sugar molasses, sodium, and α-amino nitrogen were increased by 7.48, 24.26 and 21.09%, respectively, while the impurity percentage of sugar, alkalinity coefficient, and extractable sugar content were reduced by 3.09, 8.18, and 4.78% , respectively. The highest  total fresh weight, root fresh weight, root dry weight, total biomass and  root yield (2.1, 2.18, 1.55, 1.73 and 1.33-times, respectively) were achieved under high levels of nitrogen (210 kg ha-1) and weed interference at the 6-leaf growth of sugar beet in comparison to the use of  no nitrogen. Reduced duration of weed competition and /or weed free till 6- leaf growth stage of sugar beet along with application of 150 kg ha-1 N led to reduction in weed interference, detrimental effect of nitrogen on quality characteristics, and increase in the root yield of sugar beet.

The management of soil elements by biological fertilizers is considered as an important attribute of sustainable agriculture. In order to evaluate the interaction effects of Arbuscular mycorrhizal fungi and redroot pigweed (Amaranthus retroflexus L.) on growth and yield of sunflower (Helianthus annuus L.) under water stress conditions, a field study was conducted in 2015 at School of Agriculture, Shiraz University, Shiraz, Iran. Water stress at three levels (60, 80 and 100% FC) as main factor, mycorrhizal fungi at two levels (with and without fungi) and redroot pigweed at two levels (weedy and weed free) were used in three replications based on factorial in sub plots. Results showed that seed yield reduced the by 42% under weedy conditions and applying mycorrhizal fungi compensated the grain yield decrease by 29%. Weed in moderate and severe water stress conditions caused seed yield reductions of 35 and 52%, and applying mycorrhizal fungi compensated grain yield loss by 4 and 51%, respectively. Mean comparisons for severe water stress and weedy treatment interaction showed oil yield, biological yield and harvest index reduced by 57, 36 and 25% and applying mycorrhizal fungi compensated oil yield, biological yield and harvest index decreases by 63, 25 and 20%, respectively. In general, it seems that the application of mycorrhiza can improve growth and yield characteristics of sunflower under water stress and weedy conditions.

Baby corn is a premature ear of maize that is harvested as dehusked vegetable corn at 2-3 days after silking before fertilization. No enough attention has been paid to this kind of maize in the literature. In order to investigate the effect of planting density and pattern on yield and some qualitative and morphological traits in baby corn hybrid KSC403su a field experiment was conducted at College of Agriculture, Shiraz University, Shiraz, Iran in 2014. The treatments were plant density at four levels: 100, 125, 150 and 175 thousands plant ha-1 and three planting patterns: one, two and three rows which arranged in factorial based on a randomized complete block design (RCBD) with three replications. The results showed that yield, solar radiation, total soluble solid (TTS) and a majority of morphological traits of baby corn were significantly affected by the treatments and their interactions. With increasing of the number of rows and plant density, leaf area and  plant height were increased, while the number of tillers per plant, number of ears per plant, husked and dehusked ear yield, husked and dehusked ear weight and ear diameter were decreased. The highest husked and dehusked ear yield were obtained in 150 thousands plant ha-1 and single row planting pattern with average of 1834 and 9128 Kg ha-1, respectively. In general, one row planting pattern at 150 thousands plant ha-1 were considered as the most suitable treatments and could be suggested for achieving acceptable yield and appropriate quality.

This study aimed to investigate the effects of nitrogen fertilizer and a bioherbicide on Egyptian broomrape in a tomato research field at College of Agriculture, Shiraz University, Shiraz, Iran in 2014. Treatments consisted of several levels of nitrate ammonium including 0, 100, 200 and 300 kg ha-1 and a biofertilizer as the first factor and how to use the bioherbicide including soaking seedling roots in bioherbicide, bioherbigation and no bioherbicide application (control) as the second factor. Application of 200 kg ha-1 nitrate ammonium reduced broomrape height and biomass up to 18.7 and 33.7 %, respectively. It increased tomato yield up to 26.8%. Bioherbigation also caused a significant decrease in broomrape height and dry biomass by 44.5 and 58.6 %, respectively. Our results showed that application of 200 kg ha-1 nitrate ammonium along with the bioherbicide can be a promising strategy to decrease the detrimental impact of broomrape and to increase tomato yield.

A two-year field experiment (2015–2016) was conducted as a split plot design with four replications at School of Agriculture, Shiraz University, Iran to investigate the influence of water stress (supplying 50, 70, and 100% of water requirement) and wheat residue rates (0, 25, and 50%) incorporated with soil on physiological traits and canned yield of sweet corn (Zea mays L. V. Saccharata). Net photosynthesis rate was decreased under severe stress (supplying 50% of the water requirement) during vegetative, reproductive and ripening stages of sweet corn by 25.8, 15.8 and 5.5%, respectively, compared to normal irrigation (supplying 100% of the water requirement). Canned yield decreased significantly with supplying 50% of water requirement. The lowest values of canned yield (1.1 t ha-1) and harvest index (23.55%) were obtained in severe stress and no-residue conditions, indicating  approximately 71 and 11% reductions compared to normal irrigation and no-residue treatments, respectively. In all water stress levels, application of residues led to a yield improvement. In this regard, the highest effect was observed under mild water stress with incorporation of 50% wheat residues, as it led to two-fold increase in canned yield compared to the increase observed with no-residue treatment. The increased canned yield is attributed to the 30 and 43% increases in chlorophyll content and net photosynthesis rate, respectively. Overall, it seems that incorporation of wheat residue into soil reduces the effects of water stress through its effects on soil fertility and soil water availability. Therefore, this strategy is suitable for increasing water use efficiency, reducing water stress damage and improving canned yield of sweet corn in areas facing water scarcity.

This field experiment was conducted to study the effects of water limitation stress and planting dates on growth and yield of potato in 2014-15 and 2015-16 growing seasons at Faculty of Agriculture, Shiraz University, Shiraz, Iran. Experimental treatments included, four irrigation levels: 55%, 70%, 85% and 100% of water requirement of potato assigned to the main plots, and three planting dates: March 11, April 9 and May 10 randomized in the sup plots as split plot arrangement in randomized complete block design with three replications. The results showed that plant height and shoot dry weight had a slow growth until 48 days after planting (DAP), however, these two traits considerably increased between 48-104 DAP. At early growth stage, plant height and shoot dry weight was slightly less in March 11 planting as compared with other planting dates, while these two traits were greater in March 11 planting. Water limitation stress reduced plant height, leaf area index, tuber number m-2, tuber yield, biological yield and weight of seed and large tubers weight and increased small tuber weight. There was no significant difference between 100% and 85% of water requirement levels for most of measured traits. In water stress conditions planting date was more important. In 100% water requirement level there was no significant differences between planting dates. Whereas, in stressed conditions, growth and tuber yield of potato were greater in March 11 planting. In conclusion, the results indicated that potato performance was greater in March 11 planting date, particularly in water limited stress conditions, because of better use of precipitation, cooler temperature and lower evaporation in the early season as well as suitable temperature during tuber initation.

 Field experiments were conducted to determine the relationship between plant leaf area as the dependent variable with leaves number, leaf dry weight, and total vegetative components dry weight and plant height as the independent variables. Treatments were two tillage systems (conventional and no-tillage) as main plots, and seven sowing dates (11 May, 18 May, 25 May, 1 June, 8 June, 15 June and 22 June) as sub plots. This research was carried out at the Research Farm of Shiraz University during 2014 and 2015 growing seasons.  The interaction between sowing date and tillage system was significant. The highest leaf area, leaf number, leaf dry weight, total dry weight and plant height were obtained in earlier sowing dates (11 May, 18 May, 25-May and 1-Jun) in both tillage systems and the lowest were obtained in the latest sowing date (22 Jun) in no-tillage in both years. Using polynomial equation for determining algometric relationship between leaf area and vegetative characteristics showed a significant relationship between leaf area with leaf number (R2=0.96 and R2=0.98), leaf dry weight (R2=0.98 and R2=0.98), total vegetative components dry weight (R2=0.96 and R2=0.96) and finally plant height (R2=0.98 and R2=0.95). These allometric relationships contribute to a better understanding of plant growth and development in corn, which is necessary for optimal management of the crop and for genetic improvement.

The critical period of weed control is a part of crop life cycle during which weeds must be kept weed-free to avoid yield losses due to competition. In order to evaluate the effect of deficit irrigation on critical period of redroot pigweed (Amaranthus retroflexus L.) in sunflower (Helianthus annuus L.), an experiment was carried out  as split plot based on randomized complete block design with three replications at the experimental farm of  College of Agriculture, Shiraz University, during 2010 and 2011 growing seasons. Factors were water deficit at three levels (100%, 75% and 50% of field capacity) as main plots and weed interference periods in weedy and weed-free plots at five sunflower growth stages (8-leaf, 12-leaf, head emergence, flowering and maturity) as subplots. Results showed that water deficit decreased grain yield and grain yield components in both years. Critical period of redroot pigweed in normal irrigation with accepting 5% yield loss in sunflower was 35-86 DAP (days after planting) in the first year and 49-94 DAP in the second year. By decreasing irrigation water to 75%FC and 50%FC, the length of critical period increased to 34-100 and 32-105 DAP in the first year and 50-101 DAP and 44-98 DAP in the second year of the study, respectively. Generally, our results showed water deficit extended the length of critical period of redroot pigweed in sunflower. Nomenclature: Redroot pigweed, Amaranthus retroflexus L.; Sunflower, Helianthus annuus L.

To examine the effects of sowing date and water stress on yield and some agronomic traits of three sweet corn hybrids, an experiment was carried out as a strip split-plot design with three replications, at College of Agriculture, Shiraz University, during 2013 and 2014 growing seasons. The main plots composed of two sowing dates (4 and 25 June considered as the optimum and late planting date, respectively) and two levels of water stress (Normal irrigation and withholding irrigation at early silking). Three sweet corn hybrids including KSC403su, Passion, and Signet were considered as sub-plots. Delay in sowing date and water stress significantly reduced fresh ear yield and its components, plant height, ear length, and fresh forage yield in all three hybrids. The KSC403su hybrid showed superiority and the highest fresh ear, kernel, and forage yields when seeds were planted on time and irrigated normally. Under withholding irrigation at early silking and planting on time, yield reduced the most by 45% in KSC403su. Under late planting date and water stress condition, the highest yield reduction was observed in Signet by 44% whereas, the lowest yield reduction was observed in Passion. Therefore, it seems that under recent water shortage of Fars Province, planting of Passion can be recommended as a suitable hybrid in such a region to save water.

To compare the effects of six types of non-living mulches (wheat straw, sawdust, coco peat, peat moss, transparent and black plastic) with metribuzin on yield and yield components of tomato cv "CH" and the weed control efficiency, a study was conducted in a randomized complete block design with three replications at School of Agriculture, Shiraz University in 2012. Plots without mulch (weedy and weed free) were considered as control. The highest and the lowest tomato dry weight accumulation was observed in the black plastic mulch (728.98 g m-2) and weedy treatment (126.22 g m-2), respectively. The highest number of fruits (marketable plus unmarketable fruits) per plant (208.33) under black plastic mulch treatment was observed at harvest time. Tomato yield in plots covered with transparent plastic and black plastic were 20.93, 8.31 kg m-2, respectively and were significantly different from those treated with herbicide (6.06 kg m-2). Weed control efficacy evaluation showed that black (82.23%) and transparent (86.23%) plastic were not significantly different from metribuzin (84.59%). Application of non-living mulches produced tomatoes of higher quality and quantity.

Wheat (Triticum aestivum L.) is one of the most important crops among cereals. Many factors could be responsible for low yield in wheat, but one of the major causes is weed infestation. The efficacy of any herbicide primarily depends on selectivity and the dose of application. Use of herbicides is an effective and efficient means of weed management. In many cases, there are no practical alternatives to chemical weed control methods. However, not only all kinds of weeds do not control by one type of herbicide and continuous use of that, but also lead to increase weed resistance to herbicides over the time (Hall et al. 1999). Of the many weeds that infest wheat fields across southern Iran, wild barley (Hordeum spontaneum L.), foxtail (Setaria viridis L.) and wild oat (Avena fatua L.) are the major weeds causing economic losses .Baghestani et al. (2007) reported that sulfosulfuron at 19.95 and 24.90 g a.i. ha-1 were proper application rates for broadleaf and grass weed control in wheat fields. Sij et al. (2016) reported that sulfonylurea herbicides were more efficient in terms of weed control. Lair and Redente (2004) reported that sulfonylurea herbicide application increased stability and biomass of crop as much as 43% over auxin herbicide and simultaneously reduced the grass weeds up to 71%. Golparvar et al. (2012) reported that limited doses of herbicides provided the same yield as weed free plots, therefore, this could be recommended to the farmers. The present study initiated to investigate the effect of some sulfonylurea herbicides on weed control and grain and biological yield of winter wheat under with/without wheat residue treatments. A field experiment was carried out in split-plot arrangement based on randomized complete block design with four replicates at College of Agriculture, Shiraz University, in 2014 growing season. Treatments included wheat residue at two levels (0 and 1850 kg/ha) as main plot in combination with each of the three of herbicides (Total, Apyrus and Atlantis) in two concentrations (recommended dose and 30% over the recommended dose) as Subplots. A weed infest plot (no herbicide application) was used as control. Wheat (Shiraz cultivar) planted on 5th November 2014, by Pneumatic planter at the rate of 200 kg ha-1 and maintaining 20 cm distance between crop rows. The plot size was 5m × 5m. Measurement of the effects included weed dry weight, weed density, wheat height, grain yield and its components. The data were subjected to the analysis of variance using SAS statistical software and means were compared by Duncan multiple range test (DMRT) at the 0.05 level of significance. Investigation on the effects of different application doses of Total, Apyrus and Atlantis to control weeds in wheat fields under applied wheat residue showed that the wheat residue had negative effect on the efficiency of three types of herbicides and increased weed dry weight by 41.4 percent, as compared to without wheat residue. Wheat residue incorporated to soil, reduced biological yield (from 14865.60 to 12340.40 kg ha-1) in comparison to without residue treatment. Three herbicides reduced weed biomass and the highest (43.56%) and lowest (18.7%) weed control recorded compared to weedy check. In comparison to weed infest control, Total increased wheat grain yield (from 3329.88 to 5283.19 kg ha-1), followed by Apyrus and Atlantis with 46 and 21 % increase in wheat grain yield, respectively. Application of Total, Apyrus and Atlantis herbicides, had increased wheat biological yield in comparison with weed infest control by 30.7, 26.8 and 13.6 %, respectively. Additive dose of herbicides application had better effect on weeds control and increased wheat grain and biological yield more than the recommended dose. Baghestani et al. (2007) reported that the wheat yield increased with increasing application dose of herbicide without any crop injury. Wheat grain yield for Total applied at the recommended dose was 5090.99 kg ha-1 but no significant effect was observed when an additive dose of the Apyrus herbicide was applied. This could be due to strong weed control effect of the Total herbicide at this dose. Interaction effect of herbicides and application dose indicated that Total at additive dose resulted in highest seed yield and weed control. Wheat residue had negative effect on weed control and the highest weed dry weight (~48.5%) observed when Total was applied under no residue conditions. All herbicide treatments increased wheat biological and grain yield as compared with the weed infested control. Application of Atlantis did not provide acceptable weed control in wheat. It is concluded that the most effective herbicide treatment was Total that provided maximum reduction in overall weed dry matter and obtained maximum grain yield. Atlantis had the lowest effect on weed control compared with the other herbicides (Total and Apyrus) and this could be due to poor weed control of the herbicide at both doses.

To investigate salinity tolerance in two safflower cultivars and identify the most important traits affecting salinity tolerance in safflower cultivars (Carthamus tinctorius L.), a greenhouse experiment was conducted as factorial arrangement based on completely randomized design with four replications. Treatments were irrigation water salinity (2, 4, 8 and 12 dS/m) and safflower cultivars (Sofeh and Zendehrud). Plant dry weight in Sofeh cultivar decreased 13, 30 and 58% respectively, while, plant dry weight of Zendehrud cultivar reduced 9, 28 and 40% under salinity levels. The higher concentration of chlorophyll a, b, SPAD, peroxidase and superoxide dismutase activity was found in Zendehrud cultivar under all salinity levels. Enhancement of Na concentration in shoot and root, proline and malondialdehyde was greater in Sofeh cultivar compared to Zendehrud cultivar. Linear regression analysis revealed significant and negative relationships between plant dry weight with Na concentration in leaf and root and proline content. Plant dry weight was significantly and positively associated with Kﳖ ratio, peroxidase, superoxide dismutase and chlorophyll a. In general, it was concluded that Na concentration in root, shoot (stem leaf), peroxidase and superoxide dismutase activity can be used as reliable indicators in identifying salinity tolerant cultivars of safflower