s. a. siadat

Water is now the main limiting factor for crop production in arid and semi-arid regions. Water-cut or irrigation interruption has been suggested as one of the main strategies agro-technique to get the most benefit from limited water resource available. In this regard, plant growth stage, time of stress induction and the genotype are the main key factors to determine the degree of success. Canola is one of the most important oil crop. It can survive some degree of water stress while there is a need for research to find the most appropriate genotypes for plantations in water-limited areas.

In order to determine the effect of water stress at the various growing stages of canola genotypes a split-plot experiment was conducted based on the randomized complete block design with three replications at the research farm of the department of plant production and genetics, Agricultural Sciences and Natural Resources University of Khuzestan, Iran during 2020-2021. Main plots included three irrigation treatments: control (without interruption of irrigation), interruption of irrigation in the beginning of the flowering stage (phenology code 60) to the formation of 50% pods (phenology code 75), and interruption of irrigation in the stage of formation of pods until harvest (Phenology code 99) in the main plots and the cultivars (Long pod, Aram, RGS 003, Jankom, Solar, Hayola 4815, Mahtab, Julius, Agamax and Sala) were arranged in sub-plots with respect to irrigation treatments. At the end of the growing season, plant height, number of branches, silique length, number of pods per plant, number of seeds per pod, 1000 grain weight, and grain oil percentage were measured. Also, after removing the marginal effect, economic performance, biological performance and harvest index were measured.

Our results revealed there was a significant interaction effect between irrigation interruption stress and genotype on all studied traits. The number of sub-branch among cultivars varies as a result of Irrigation interruption stress. The genotypes of the long pod and Hayola 4815 had the highest number of branches compared to other genotypes when irrigation was interrupted at the flowering stage up to 50%, while when applied stress at the stage of flowering up to harvest, genotype, solar exhibited the highest number of sub-branch. The lowest number of sub-branches in all interruption of irrigation and control treatments was obtained by Jankom genotype. The mean comparisons in the conditions without irrigation interruption (control) the highest percentage of seed oil was obtained from Solar (48.3%), Hayola 4815 and 4815 (46.3%), stress application in flowering stage up to 50% sowing of a long pod (45%) and Hayola 4815 (43%) genotypes in the sowing stress to harvest the highest percentage of seed oil from Sala and Long pod genotypes with average (44.3%) the lowest percentage of seed oil in all present treatments belonged to Jankom genotype. In the present study, the highest (2093.8 kg.ha-1) and the lowest (540 kg.ha-1) grain yield and the highest (986.51 kg.ha-1) and the lowest (191.21 kg.ha-1) grain oil yield in both conditions without irrigation interruption (control) and terminal drought stress were obtained from Hayola 4815 and Jankom genotypes, respectively.

The highest and the lowest grain yield, seed oil and biological yield were obtained from Hayola 4815 and Jankom, respectively. According to the results, Hayola 4815, long pod and Solar are highly recommended to cultivate in the regions where there is terminal water stress at the end of the growing season.

An experiment Was carried out Study of heat stress on rice cultivars grain milling quality of Khuzestan province in a split-plot arrangement using randomized complete blocks design with three replications in 2006 and 2007 cropping seasons at Shavoor Agricultural Research Station, Dependent in Research Center of Agricultural and Natural Resources of Khuzestan. For exposing rice cultivars to different higher temperature regimes, main plot was assigned to three sowing dates from 5 May with 20 days' intervals and cultivars; Hoveizeh, Hamar (heat tolerance) Ghermez Anbori, Champa (heat sensitive) and Danial (relatively heat tolerant) were randomized in sub-plots. The results of combined analyses showed that was a significant different in planting date by variety interaction in all of trades. On the other hand, the related temperature condition, varieties had different reaction. The highest of grain elongation obtained in Ghermez Anbori, Danial and third sowing date. The elongation ratio was higher in third; second sowing date and Ghermez Anbori. The heat tolerant cultivars had highest Gel consistency (Gc) and Amylose content (Ac). The highest Gelatinization temperature (Gt) obtained in third sowing date.

Water limitation can damage pigments and plastids, reduce chlorophyll a, chlorophyll b, rate and grain filling period. One approach to improve the water stress problem is the use of plant growth promoting rhizobacteria (PGPR) and Mycorrhiza. The PGPR are a group of rhizosphere colonizing bacteria that produces substances to increase the growth of plants, synthesize different phytohormones, including auxin, cytokinin, and gibberellin, synthesize enzymes that can modulate plant growth and development. Arbuscular mycorrhizal fungi (AMF) symbiosis is considered a valuable component in most agricultural systems due to their role in plant nutrition and soil health. Silicon (Si) is considered as quasi-essential for plant growth and development, and alleviates toxic effects caused by various environmental stresses in plants. So, it seems that application of nano silicon and bio-fertilizer can improve wheat yield under water limitation conditions.

In order to study the effect of nano silicon and bio-fertilizer on yield and grain filling components of wheat in different irrigation levels, a factorial experiment was conducted based on randomized complete block design with three replications at the research farm of faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili in during 2018-2019. The experimental factors were included irrigation in three levels (full irrigation as control, moderate water limitation or irrigation withholding at 50% of heading stage; severe water limitation or irrigation withholding at 50% of booting stage) based on codes 55 and 43 of the BBCH scale, foliar application of nano silicon (foliar application with water as control, 30, and 60 mg L-1) and bio-fertilizer (no application as control, mycorrhiza application, both application of flavobacterium and pseudomonas, both application of flavobacterium and pseudomonas with mycorrhiza). Mycorrhiza fungi (mosseae) was purchased from the Zist Fanavar Turan corporation and soils were treated based on method of Gianinazzi et al. (2001). Psedomunasand flovobacterium were isolated from the rhizospheres of wheat by Research Institute of Soil and Water, Tehran, Iran. A two part linear model was used to quantifying the grain filling parameters. In this study, total chlorophyll, chlorophyll a, b, carotenoid, grain filling components and yield of wheat were investigated. Grain dry weight and number were used to calculate the average grain weight for each sample. Total duration of grain filling was determined for each treatment combination by fitting a bilinear model: Effective grain filling duration (EGFD) was calculated from the below equation: EGFD = the highest grain weight (g)/rate of grain filling (g day-1).

Means comparison showed that highest grain filling rate (3.04 mg day-1), grain filling period (37 day), effective grain filling period (30.44 day) and grain yield (4593 kg ha-1) were obtained at foliar application of 30 mg L-1 nano silicon, both application of flavobacterium and pseudomonas with mycorrhiza under normal irrigation. Also, maximum of chlorophyll a, chlorophyll b, total chlorophyll and carotenoid content (2.04, 0.93, 2.87 and 9.89 mg g-1 FW-1 respectively) were obtained at foliar application of 60 mg L-1 nano silicon in seed inoculation with flavobacterium and pseudomonas under normal irrigation. Maximum of volume and root dry weight were obtained at foliar application 60 mg L-1 nano silicon and mycorrhiza application fungi under normal irrigation. The highest leaf area index was obtained at both applications of flavobacterium and pseudomonas with mycorrhiza, foliar application 30 mg L-1 nano silicon under normal irrigation.

Generally, it seems that application of bio-fertilizers and nano silicon can be recommended as appropriate management factors for increasing grain yield and grain filling components of wheat under water limitation conditions.

After moisture, temperature is the main driving force affecting seed germination. Population-based models are useful tools for describing and predicting germination in relation to time and temperature. These models estimate the thermal thresholds for seed germination, taking into account both the speed and final percentage of germination in different temperature regimes. The population-based approach has been widely used to model the thermal response of various plant processes such as germination and dormancy of seeds as well as seedling emergence in the field. However, the assumptions of this approach on the germination of seeds of some plant species, especially weeds, are not always correct. Therefore, in this research, the accuracy of prediction of different thermal-time approaches for modeling the germination time courses of bishop's weed (Ammi majus L.) in response to constant temperature regimes was evaluated. Bishop's weed was selected because there are no reports regarding the germination response thresholds of this species to temperature in the scientific resources.

Experiment was conducted at the Seed Technology Laboratory of Agricultural and Natural Resources University of Khuzestan in November 2017. In this study, germination response of bishop's weed was evaluated at different constant temperatures. The seeds of bishop's weed were collected from the margins of several wheat fields at the time of their natural dispersal in June 2014. The seeds of bishop's weed were incubated in the dark using incubators with controlled environments at eight constant temperatures of 8, 12, 16, 20, 24, 28, 32 and 36 ºC with a range of ±0.2 ºC. These temperature regimes cover both the sub- and supra-optimal temperature ranges. The trial was performed in a completely randomized design with four replications. The germinated seeds (criterion, radicle protrusion of > 2 mm) were counted and removed at frequent time intervals. The event-time approach (package drc in R environment software) was applied to determine the time taken for cumulative germination to reach subpopulation percentiles of 20, 50 and 80% of maximum in each temperature regimes. Experimentally obtained cumulative-germination curves were used to perform a non-linear regression procedure to assess the relative accuracy of different thermal-germination models in predicting germination response under constant incubation temperatures. Assessment of goodness-of-fit was performed by the Akaike information criterion (AIC).

The values of RMSE and AIC showed that the model had better and more accurate fit to bishop's weed germination data when the Tb (base temperature) and θTm (thermal-time required to complete germination at temperatures greater than optimal (To)) were assumed to be constant for the whole seed population, and Normal distribution was used to describe the variation in θT(g) (thermal-time required to complete the germination of each given seed fraction at a temperatures between the Tb and To) and Tm(g) (maximum temperature (Tm) for seed thermo-inhibition of given fraction g at temperatures between the To and Tm). Based on this approach, the Tb and θTm for this plant were estimated to be 1.06 ºC and 1155.41 ºC h, respectively. The values of θT and Tm for seed fraction of 50% (θT(50) and Tm(50)) were determined as 2708.62 ºC h and 34.55 ºC, respectively. The value of To was not constant for different germination fractions (To(g)), and for fraction 50% (To(50)) was determined to be 24.51 ºC. Thermal-time analysis is considered by many researchers to have physiologically and ecologically relevant parameters and, in its standard form, provides several useful indices of seed germination behavior in response to temperature. Despite its popularity, the generality of its assumptions has not been examined systematically. If these assumptions do not hold, at least approximately, in a particular situation, misleading interpretations can easily arise. The thermal-germination model presented here explained some of the adaptive characteristics of the germination response of bishop's weed to ambient temperature. Seed thermo-inhibition in this weed species occurred at temperatures beyond 25.43 ºC. In other words, the seeds of bishop's weed do not germinate when temperature will exceed this limit and thus remaining capable of germinating until the environmental conditions change.

In summary, in this study, the thermal thresholds for seed germination of bishop's weed were identified. Our results showed that the Tb was constant for the whole seed population. The thermal-germination model described here gave an acceptable explanation of the observed seed germination patterns. Almost all the concepts and mathematical models described in this study can be applied to modeling seedling emergence in the field.

Grain yield of bread wheat (Triticum aestivum L.) is reduced by heat stress، particularly when occurs in reproductive phase، in many countries worldwide، including Iran. In order to study the effects of different levels of nitrogen and cytokinin on wheat yield and yield components at normal and heat stress conditions in Khuzestan، Iran، this research was conducted at Ramin Agriculture and Natural Resources University in 2010-2011. This study was carried out in two separate factorial experiments in randomized complete block design with four replications. The first experiment was planted in a normal date and the second experiment was planted late (Terminal heat stress). In both experiments، nitrogen (N) was applied in four levels (0، 75، 150، and 225 kgha-1) and Cytokinin (Ck) sprayed in three levels (0، 50 and 100 µM). The results of both experiments (normal and stress conditions) showed that by increasing the N rate، the grain yield (5652. 1 and 3874. 7 Kg/ha respectively)، biological yield، number of spikes per m2، spikelet’s per spike، grains per spike were significantly (p<0. 01) increased. Application of Ck at normal sowing date increased the grain yield (4856. 7 kg/ha) and 1000 grain weight (41 gr) significantly (p<0. 01) and at late sowing date only increased 1000 grain weight (30. 2 gr) significantly (p<0. 01). Application of N and Ck in both experiments significantly increased grain yield (p<0. 05) and only at late sowing date increased 1000 grain weight significantly (p<0. 01). Based on our findings، application of N and Ck may lead to the amelioration of terminal heat stress effects on bread wheat in hot regions such as Ahwaz.

In order to investigate the effect of Filter Cake application on some morpho-physiological characteristics and yield of sweet corn (Zea mays var saccharata) under different irrigation regimes، an experiment was conducted in Ramin Agriculture and Natural Resources University، Khuzestan، in 2012. The experiment was arranged in split-plot design in RCBD (Completely Randomized Block Design) with three replications. Treatments were drought stress (irrigation after 25، 50 and 75% depletion of available water content) in main plots and Filter Cake (0، 10، 20 and 30 tonha-1) arranged in sub-plots. Results showed that drought stress increased electrolyte leakage (EL) and proline content (PC) while height of plant، relative water content (RWC)، chlorophyll stability index and ear and grain yield were decreased. The intensive drought stress had the greatest effect on EL and PC (54% increase)، and decreased ear and grain yield by21 and 37% compared to control، respectively. Application of filter cake on non-stress condition increased height of plant and economic yield. But Filter Cake in intensive stress reduced RWC and yield and increased EL compared to control. Also، the application of 30 tonha-1 of Filter Cake in intensive stress condition decreased ear and grain yield by 14. 5 and 10. 7% respectively. Thus، positive effect of Filter Cake application was clear on non-stress condition، but on drought stress condition it decreased the economic yield.

studies show that organizations using transformational leadership، achieve high levels of growth and development. For this reason، in recent decades، transformational leadership has become an unavoidable necessity، because through transformational leadership organizations can improve their competitive advantage such as organizational learning. Therefore، the main purpose of this paper is to investigate the relationship between transformational leadership and organizational learning at Isfahan University of Medical Sciences.

Research method was descriptive-correlative. To collect data، 117 employees at Isfahan University of Medical Sciences were surveyed. Research instruments were to questionnaires: 1) Bass and Avalio’s transformational leadership، and 2) Neif’s organizational learning. Reliability coefficients were. 87 and. 88 respectively، using Chronbach’s formula. The collected data were analyzed using one- sample t-test، and Pearson correlation.

Findings showed that there are a positive and significant relationship between transformational leadership and its components (Idealized Influence، Inspirational Motivation، Intellectual Stimulation، and Individualized Consideration) with organizational learning. T test results showed that transformational leadership and organizational learning are in a rather good status.

according to the findings، it can be suggested that the existence of transformational leadership can result in the improvement of organizational learning.

In order to study the effects of biofertilizer and phosphate fertilizer on yield and yield components of spring wheat a factorial experiment based on randomized completed blocks design with replications was conducted at the Mohsenabad, Mehran Research station in Ilam, Iran during 2009-2010. Experimental factors consisted of phosphorus chemical fertilizers at four levels(0, 90, 135 and 180 kg ha-1) and bio-fertilizer at four levels (non-inoculation, inoculating with Azotobacter chroococcum, Pseudomonas Putida and Azotobacter plus Pseudomonas). Results of analysis variance showed that using chemical fertilizer significantly effected grain yield, harvest index, biological yield, plant height and protein content. The highest grain and biological yields were produced by applying180 kg ha-1, while its effects on other traits were not significantly different from that of 135 kg ha-1. Biological fertilizers, on the other hand increased grain yield, harvest index, biological yield, plant height and protein content as compared to non inoculation treatment. The highest grain yield, harvest index, biological yield, plant height and protein content obtained from application of Azotobacter plus Pseudomonas. Grain yield, harvest index, biological, plant height were affected by interaction effects of chemical fertilizer and biological fertilizers. The highest and lowest grain yield belonged to the application of 180 kg ha-1 of chemical fertilizer and Azotobacter plus Pseudomonas and non- chemical fertilizer and non-inoculation, respectively, but the difference between 135 and 180 kg.ha-1 was not statistically different. Thus, it is cheaper to recommend use of 135 kg ha-1 of chemical fertilizer and Azotobacter plus Pseudomonas to get acceptable grain and biological yields.

In order to evaluate the effect of sugar beet sowing date, planting density and cultivar on solar radiation interception, a study was conducted in Kamal-Abad Agricultural Research Station of Sugar Beet Seed Institute (SBSI) in 2005 and 2006. The experimental design was split-split plots based on Randomized Complete Block Design (RCBD) with three replications with two sowing dates as the main plot (the earliest possible date including 04-April and 22-April in 2005 and 2006 and 40 days later including 23-May and 31-May in 2005 and 2006, respectively), four plant densities as the sub-plot (6.0, 7.5, 9.0 and 10.5 plants.m-2) and three sugar beet monogerm cultivars as the sub-sub-plot (Jolgah, Hybrid 428 and DS 4027). In terms of the effect of sowing date, it was shown that sugar beet sowing in Karadj at the earlist possible date (Mid-March) compared to the sowing date delayed for 40 days only led to an increase in intercepted radiation by 425 MJ.m-2; while radiation use efficiency (RUE) for producing dry matter which was in the range of 1.43-1.48 g.m-2 MJ-1 did not differ between the two sowing dates. The increase in plant density from 6.0 to 10.5 plants.m-2 led to a non-significant increase in intercepted radiation. RUE did not show a linear response to plant density, too; while the increase in plant density led to a decrease in radiation extinction coefficient and improvement of radiation distribution in canopy. The cultivar DS 4027 had better RUE than the cultivars Jolgah and Hybrid 428 (1.85 and 1.43 g.m-2.MJ-1, respectively). The main reason for this difference was the higher RUE of DS 4027 (1.54 g.m-2.MJ-1) in producing root system than the other two cultivars (1.10 g.m-2.MJ-1). In terms of RUE in producing shoot system, there was no significant difference between Jolgah and Hybrid 428 (0.34 g.m-2.MJ-1) and DS 4027 (0.32 g.m-2.MJ-1). According to the results, it can be conclude that improving the main drawback of domestic cultivars i.e. low R/S ratio should be given priority.

In order to evaluate the effects of sugar beet sowing date, planting density and cultivar on solar radiation interception, the present study was conducted in Kamal-Abad Agricultural Research Station of Sugar Beet Seed Institute (SBSI) in 2005 and 2006. The experiment arranged was in split-split plots based on Randomized Complete Block Design (RCBD) with three replications. The sowing date, planting density and cultivar were assigned to main, sub and sub-sub-plots, respectively. Results showed that the photosynthetically active radiation (PAR) rised from 8 MJ.m-2.day-1 during late April and after reaching the maximum amount (17.61-17.75 MJ.m-2.day-1) during June started to gradually decrease through growing season. Total intercepted PAR (iPAR) had significance differed significantly (P<0.01) between studied years and iPAR in 2005 (1817.04 MJ.m-2) was about 8.15% greater than that in 2004 (1680.22 MJ.m-2). The relationship between radiation interception (fi) and leaf area index (LAI) was significant in 2005 (r2=0.82**) and 2006 (r2=0.64**) indicating that increase in LAI caused the increase in iPAR. The highest fi was observed in mid-October and LAI equaled to 2.5-3.5 in Karaj. Sowing date had a significant effect (P<0.01) on fi and sowing the sugar beet in the earliest possible date increased the iPAR by 29.67%. The effect of planting density on fi was non-significant and linear correlation coefficient was positive and non-significant. Average radiation extinction coefficient (K) was estimated to be 0.605. The effect of sowng date on K was not significant. The increase in planting density from 6.0 plants.m-2 (K=0.717) to 7.5, 9.0 and 10.5 plants.m-2 reduced the K by 11.2, 18.6 and 32.9%, respectively. The significant effect of cultivar on K in 2006 showed that the K of cultivar 428 (0.373) was less than that of cultivars Jolgeh and DS4027 by 54.1 and 72.9%, respectively.

In order to investigate the best planting time and rice cultivars for the conditions in Khuzestan Province, seven high quality cultivars of rice namely Domsiah, Binam, Ramasanali Tarom, Sang Tarom, Hasansarai, Tarom Mahalli, Daylamani and Anboori were selected and studied in 4 planting dates starting in Mid-May, with intervals of 15 days. The experiment was conducted as a split plot design in randomized complete blocks with 3 replications for 2 years from 1995 in Shavoor Agricultural Research Station. Main plots were planting dates and subplots were allocated to cultivars. Results of this experiment showed that significant differences existed among planting dates on grain yield only in the second year. Grain yields were different among cultivars in the two years of study. Simple and combined analyses indicated that there were significant interactive effects between planting dates and cultivars. Tiller number was different between planting date and cultivars in the first year. Interactive effect between planting date and cultivars on tiller number was not significant. Maximum grain number in spike obtained early June planting date (76 grains per spike) and lowest grain number in spike obtained early May planting date (28 grains). Among cultivars, Anboori with 152 and Daylamani with 17 grains had maximum and minimum grain numbers in spike, respectively. One-thousand grain weight was maximum in the early June planting date. Among cultivars, Binam and Daylamani had maximum and minimum grain weights, respectively. Highest fertility percentage was obtained in early June planting date compared to other planting dates. Fertility percentage of cultivars depended on temperature at growth stages before and at anthesis, which was early June for all cultivars. Among environmental factors affecting plant growth, temperature was relatively more important than other factors, particularly than the photoperiod. Even under Khuzestan conditions, there is a wide range of temperature levels for rice planting (from early March to early November) however, even this wide temperature range may not be enough to provide favourable conditions for planting all the cultivars.

Effects of different levels of nitrogen fertilizer and cutting time of forage on grain and forage yield of barley (Hordeum vulgare L.) Karoon cultivar was studied during 1995-1996 at Ramin Agricultural Research and Educational Center, University of Shahid Chamran, Ahwas, by using a split plot design in randomized complete block with 4 replications. Main plots were assigned to five levels of N fertilizer (45, 90, 135, 180 and 225 kg N/ha) as urea fertilizer and subplots to three cutting times (no cutting, cutting forage at early stem elongation without removing reproductive meristem and cutting forage in the middle of stem elongation with cut reproductive meristem). The effects of N rates and cutting time on grain yield were significant. Maximum yield was obtained with 281.6 g/m2 when crop plants received 90 kg N/ha and cutting time at early stem elongation and minimum yield was obtained (158.2 g/m2) with 45 kg N/ha and cutting forage in the middle of stem elongation. Interactive effect of levels of N and cutting time on spike number per m2, grain number in spike and grain weight were significant. Among yield components, spike number and grain weight showed the highest sensitivity to both. Different levels of N increased forage protein concentration and protein yield significantly, but delay in cutting time decreased protein concentration and increased protein yield. Results indicated that high levels of N could not compensate for the delay in cutting time of forage for grain yield. It was concluded that application of 90 kg N/ha and cutting time in early stem elongation was preferable for grain and forage production as compared to other treatments.

Effects of different levels of nitrogen fertilizer and cutting time of forage on grain and forage yield of barley (Hordeum vulgare L.) Karoon cultivar was studied during 1995-1996 at Ramin Agricultural Research and Educational Center, University of Shahid Chamran, Ahwas, by using a split plot design in randomized complete block with 4 replications. Main plots were assigned to five levels of N fertilizer (45, 90, 135, 180 and 225 kg N/ha) as urea fertilizer and subplots to three cutting times (no cutting, cutting forage at early stem elongation without removing reproductive meristem and cutting forage in the middle of stem elongation with cut reproductive meristem). The effects of N rates and cutting time on grain yield were significant. Maximum yield was obtained with 281.6 g/m2 when crop plants received 90 kg N/ha and cutting time at early stem elongation and minimum yield was obtained (158.2 g/m2) with 45 kg N/ha and cutting forage in the middle of stem elongation. Interactive effect of levels of N and cutting time on spike number per m2, grain number in spike and grain weight were significant. Among yield components, spike number and grain weight showed the highest sensitivity to both. Different levels of N increased forage protein concentration and protein yield significantly, but delay in cutting time decreased protein concentration and increased protein yield. Results indicated that high levels of N could not compensate for the delay in cutting time of forage for grain yield. It was concluded that application of 90 kg N/ha and cutting time in early stem elongation was preferable for grain and forage production as compared to other treatments.