Showing 25 results for Haghighi
E. Rowghani Haghighi Fard,
Volume 4, Issue 4 (winter 2001)
Abstract
Whole corn plant was ensiled in 70 gr minisilos for 60 days to evaluate the effects of addition of two levels of Cellulomonas uda bacteria (0, 1.2×105 and 2.4×105 cfu per gr of fresh forage) on fermentation and chemical composition of silage. The experiment was arranged as a completely randomized design. The silos were opened after 3 and 6 days of fermentation. The criteria measured included dry matter (DM), pH, organic matter, water soluble carbohydrates, crude protein, cell wall (NDF), acid detergent fiber (ADF), hemicellulose, cellulose, and ammonia-N contents.
Both levels of bacteria significantly decreased the pH of silages after 3 days (P<0.05). The final pH of silage with the higher level of bacteria was significantly lower, indicative of a greater fermentation of cellulose in this silage. Addition of bacteria resulted in a non-significant increase in the level of final residual water soluble carbohydrates. Final silage ammonia-N concentration was less than 0.8% of dry matter in all silages and was not affected by bacterial treatment. The ADF content was decreased by 11.9% in the silage containing the lower level of bacteria and by 1.8% in the silage which contained the higher level of bacteria. The NDF content increased in the control silage and that with the lower level of bacteria but decreased by 3.6 gr Kg DM-1 in the silage with the higher bacterial level. Hemicellulose contents increased in all silages but cellulose contents decreased by 9.38% (control), 17.37% (low bacteria) and 12.49% (high bacteria) in the control and bacteria-treated silages, respectively. The results indicated that the addition of 12×105 cfu Cellulomonas uda per gr of whole fresh corn plant was effective in increasing residual water soluble carbohydrates, reducing NDF and hydrolyzing cellulose of whole corn plant.
E. Rowghani Haghighi Fard, M.j. Zamiri,
Volume 5, Issue 3 (fall 2001)
Abstract
Three levels of urea (0, 0.5 and 0.75% on fresh weight basis) were added to whole corn plants to investigate their effects on the chemical composition, and digestibility in 16 Ghezel male lambs using a completely randomized design. Rumen degradability and nutritive values were also evaluated.
pH, total nitrogen and ammonia-N concentration of silages increased (P<0.05) with the addition of urea. Total nitrogen apparent digestibility was higher (P<0.05) with the urea addition. Nitrogen balance in ruminal fluid increased (P<0.05) with the addition of 0.5% urea. pH and ammonia-N concentration increased (P<0.05) with the addition of urea until 1.5 hr post feeding. Blood serum urea nitrogen concentration was higher (P<0.05) with the addition of urea until 6 hr post feeding. Potential degradability of dry matter and organic matter was higher at 0.5% urea level. Average daily gain increased with the urea addition and was highest (212.88 gr) at 0.75% urea. Subcutaneous fat depth was significantly (P<0.0l) lower for the sheep fed with 0.5% urea-treated silage as compared to other treatments. The results indicated that feed efficiency may be improved by urea addition and that the addition of urea (0.5% on fresh weight basis) may be recommended in order to increase the feeding value of whole corn plants.
V. Karimi, A.a. Kamkar-Haghighi, A.r. Sepaskhah, D. Khalili,
Volume 5, Issue 4 (winter 2002)
Abstract
Drought can occur at such times when variables such as rainfall depth, run-off, soil moisture, etc. show a deficiency, or variables such as temperature show an increase, or when ground water level shows a decrease in comparison with the average level. Therefore, drought can be evaluated with respect to agricultural, meteorological, or hydrological variability. In this research, considering the meteorological aspects, the method by Herbst et al., later modified by Mohan and Rangacharia, was applied in drought evaluation in Fars Province, Iran. Monthly rainfall measurements over a period of 21 years for 51 stations obtained from Fars Regional Water Board, were used in the analysis. Maps showing lines of iso-duration and iso-intensity lines were developed for the province. Based on the results, northeast, southeast, south, and southwestern parts of the province have the highest potential for being affected by drought events.
E. Rowghani Haghighi Fard,
Volume 6, Issue 2 (summer 2002)
Abstract
This experiment was carried out to study the effects of Lactic Acid Bacteria (LAB) and urea on chemical composition, nutritive value and rumen fermentation characteristics of whole-crop barley. In a completely randomized design with cross over arrangement, 4 Suffolk male lambs were used. Whole-crop barley was either treated with LAB solution (35% dry matter) at the rate of 2 L/ton herbage fresh weight or urea (55% dry matter) at the rate of 40 Kg/ton dry matter herbage and ensiled for 60 days. Low dry matter silages had lower pH and higher residual water soluble carbohydrates, ammonia-N, lactic acid and ethanol and higher lactate:acetate ratios. LAB resulted in higher lactic acid content and lactate:acetate ratios. DM (P<0.001), OM (P<0.01), NDF (P<0.05), ADF (P<0.01) and total nitrogen (TN) digestibility increased with additives. Mean rumen ammonia-N concentration and pH significantly (P<0.05) increased with urea-treated silages. Rumen propionate concentration was significantly (P<0.01) higher with LAB-treated silages than with urea-treated ones. The results indicated that the addition of LAB at the rate of 2 L/ton fresh weight to whole-crop barley at 35% dry matter enhanced fermentation and nutritive value.
N. Pirmoradian, A. A. Kamgar Haghighi, A. R. Sepaskhah,
Volume 6, Issue 3 (fall 2002)
Abstract
This research was conducted in Kooshkak Farm Research Station of Shiraz University in 1997 and 1998 in order to determine crop coefficient and water requirements of rice, using lysimeter. The variety used was Champa-Kamfiroozi which is an early mature variety and is grown by most farmers in the area. Results showed that potential evapotranspiration varied from 3.76 to 9.34 mm/day. Penman FAO method was used in calculating reference evapotranspiration. Crop coefficient was 0.97 in the initial growth stage, 1.25 in the mid-season growth stage, and 1.09 at the time of harvest. Total crop evapotranspiration rates in 1996 and 1997 were 560 and 757 mm, respectively. Average deep percolation rates in the growing season was 3.4 and 3.5 mm/day in 1996 and 1997, respectively. Finally the total water requirements of rice in 1996 and 1997 were 1983 and 2361 mm, respectively.
E. Rowghani Haghighi Fard, M. J. Zamiri,
Volume 6, Issue 4 (winter 2003)
Abstract
The effect of adding two urea levels (0.5 and 0.75% on fresh basis) to whole-crop barley (WCB) on chemical compositon and digestibility in Ghezel rams was studied. The effect of including these silages in the ration of fattening Ghezel and Mehraban rams was also investigated.
Urea supplementation of WCB silage resulted in an increase in pH, total nitrogen level, and ammonia-nitrogen concentrations (P<0.05). Apparent digestibility coefficients of dry matter, organic matter, acid detergent fiber, and neutral detergent fiber of WCB silage were not affected by urea treatment (P>0.05), but apparent digestibility coefficient of total nitrogen was higher for 0.5% urea-WCB silage. Apparent digestibility coefficients of total nitrogen and nitrogen balance were higher for 0.5% urea-WCB silage than for 0.75% urea-WCB silage, but the differences were not significant. Ruminal fluid pH at 2.5 h, and ammonia-nitrogen concentration at 4 h post-feeding were higher for 0.75% urea-WCB silage than for 0.5% urea-WCB silage (P<0.05). BUN levels (<20 mg per dl) in sheep fed with a mixture of alfalfa hay and silages were not affected by the treatment. The potential and effective degradabilities of dry matter and crude protein were higher for 0.75% urea-WCB silage. Feed performance and carcass characteristics were not significantly different amongst diets. The results showed that urea supplementation at 0.75% fresh basis, at the time of ensiling, may have a beneficial effect on feeding value of WCB silage.
S.m.a. Jalali Hajiabadi, S.a.h. Abolghasemi, A.r. Jafari Sayadi, M. Rostaei Alimehr, M. Haghighian Roudsari,
Volume 8, Issue 4 (winter 2005)
Abstract
Two hundred Arian broiler chicks were used to investigate the effect of contents of dietary glucosinolates on performance of broiler chicks during starter (0-21 days of age) and grower periods (22-42 days of age) in a completely randomized design. The dietary glucosinolates contents in the starter period were 0 (S1), 7.5 (S2), 15 (S3), 22.5 (S4), 30 (S5) µmol/g and in the grower period they were 0 (G1), 5.7 (G2), 11.4 (G3), 17.1 (G4), 22.8 (G5) µmol/g. Feed intake during the grower period was affected (P<0.05) by different levels of glucosinolates in the diets and the lowest feed intake was observed in the G5 treatment. The lowest body weight gains were observed in the S5 and G5 treatments during the starter and grower periods, respectively (P<0.05). The feed conversion ratio (FCR) in the S5 treatment for the starter and the G5 treatment for the grower period were significantly different (P<0.05) from other treatments. The correlation between the body weight gain and level of dietary glucosinolates or glucosinolate consumption was high during the starter (r = -95.3% and -94.7%, respectively) and relatively high (r = -69.5% and -72.4%, respectively) during the grower period. This experiment showed that the amount of glucosinolates in the diets of broiler chicks for the periods of starter and grower feeding system should not be more than 11.36 and 8.11µmol/g diet, respectively. Also during the starter and grower feeding periods, the highest level of rapeseed meal could be used in the broiler diets are 13 and 8 percent, respectively.
A. A. Azizi Zehan, A. A. Kamgar-Haghighi, A. R. Sepaskhah,
Volume 10, Issue 1 (spring 2006)
Abstract
Iran with a cultivation area of 45000 ha and production of 150 ton/year is the number one saffron producer in the world. Planting of large size corms will increase flowering, but production of corms (number and size) may be affected by irrigation method or frequency. In this research which is performed in the farm of College of Agriculture, Shiraz University, the effects of method and frequency of irrigation on corm production, and the effect of produced corms on flowering were evaluated in two consecutive years. Two irrigation methods (basin and furrow) with four levels of irrigation frequencies (12, 24 and 36 days and dryland farming) were applied. In August of 2000 sample corm was taken from every plot, and the effect of applied treatment from previous growing period on corm production and the effect of produced corms on future flowering were evaluated and analyzed. Based on the results, in furrow irrigation, total number of corms and total number of corms smaller than 4 gr is significantly higher than basin irrigation. In all of the above cases, irrigation frequencies did not show a meaningful difference between themselves or in comparison with dryland farming treatment. Total weight of corms and number and weight of corms larger than 8 gr in basin irrigation were more than furrow irrigation. This is to the extent that it is considered as the main reason for the difference in the flowering of corms, and has caused the flowering of basin irrigation to be significantly higher than furrow irrigation. In basin irrigation, irrigation frequencies of 12 and 24 days had the highest amount of flowering. No significant difference was observed on average corm production between the treatments in the two irrigation methods. However, irrigation treatments in both irrigation methods showed significant differences when compared with dryland farming treatment. So, basin irrigation with irrigation frequency of 24 days is preferred over furrow irrigation due to lower water consumption and production of larger size corms which is effective in flowering.
V. Khaksari, S. A. A. Moosavi, S. A. M. Cheraghi, A. A. Kamgar Haghighi, Sh. Zand Parsa,
Volume 10, Issue 2 (summer 2006)
Abstract
Since performing field experiments for determining the optimum amount of water for soil desalinization is costly and time consuming, use of computer models in leaching studies has received more attention. However, the accuracy of the results of these models should be evaluated by comparison with the results of the field experiments. In this study SWAP and LEACHC models were used for the simulation of soil moisture profile and salinity, and the results were compared with those of a field leaching experiment. The SWAP model gave better results in simulating soil moisture movement and profile, compared to LEACHC model, but statistical indexes showed that both models produced satisfactory results in predicting soil moisture profile. LEACHC model gave better results in comparison to SWAP model for the prediction of soil salinity profile at different time, possibly because it takes into account different solute transport mechanisms such as advection, diffusion, dispersion and also chemical interactions such as adsorption, precipitation and dissolution. In spite of the differences between predicted and measured values of salinity in the initial stages of leaching process, both models were able to predict the trend of leaching process with an acceptable accuracy.
A. R. Ziaee, A. A. Kamgar-Haghighi, A. R. Sepaskhah, S. Ranjbar,
Volume 10, Issue 3 (fall 2006)
Abstract
In the present research, for the development of Fars province minimum temperature atlas, minimum daily temperature data of 20 evaporative stations of Fars Regional Water Organization and five synoptic stations of Fars Meteorological Organization were used. At first, two starting times were selected for all of the stations. The first was the first day of Farvardin for analyzing the spring frost and the secend was the first day of Mehr for analyzing the autumn and winter frost. Also, the temperature range of 0 to –1.5 was classified as mild frost or freeze, the temperature range of -1.5 to –3 as the moderate frost or freeze and temperature below –3 as severe frost or freeze. The data of minimum temperatures, the first and the last days in which the three temperature ranges occurred and the day of the lowest temperature based on the two starting times were recorded. The selected number of days (dates) were fitted to the distribution functions by SMADA software and the best distribution function was identified using the statistical parameter Root Mean Square. The best fitted distribution functions were Pearson type III and log Pearson type III. Then, based on the fitted distribution function, the number of days for the occurrence of the first and last frost and number of days for the occurrence of the first lowest temperature were determined at 50 and 70% probability levels. Finally, each of these occurrence dates was plotted with Surfer software using the geographical positions of each station (longitude and latitude) for Fars province. Based on these plotted maps, the best days of planting and harvesting of the crops can be determined throughout the Fars province.
A. Majnooni-Heris, Sh. Zand-Parsa, A. R. Sepaskhah, A. A. Kamgar-Haghighi,
Volume 10, Issue 3 (fall 2006)
Abstract
Agricultural investigations use computer models for simulation of crop growth and field water management. By using these models, the effects of plant growth parameters on crop yields are simulated, hence, the experimental costs are reduced. In this paper, the model of MSM (Maize Simulation Model) was calibrated and validated for the prediction of maize forage production at Agricultural College, Shiraz University in 1382 and 1383 by using maize forage yield under furrow irrigation with four irrigation and three nitrogen treatments. Irrigation treatments were I4, I3, I2, and I1, with the depth of water 20% greater than, equal to, 20% and 40% less than potential crop water requirements, respectively. Nitrogen treatments were N3, N2, and N1, with the application of N as urea equal to 300, 150, and 0 kg N ha-1, respectively. After calibration and validation of MSM, it was used to estimate suitable planting dates, forage yield and net requirement of water discharge for planting at different dates. The results indicated that the net requirement of water discharge was reduced by gradual planting at different planting dates. By considering different planting dates for maize, from Ordibehest 20th to Tir 10th, the planting area might be increased 17.9%, compared with single planting date on Ordibehesht 30th under a given farm water discharge and full irrigation.
A. Majnooni-Heris, Sh. Zand - Parsa, A. R. Sepaskhah, A. A. Kamgar-Haghighi,
Volume 11, Issue 41 (fall 2007)
Abstract
Optimal crop water requirement is needed for precise irrigation scheduling. Prediction of crop water requirements is a basic factor to achieve this goal. In this study, maize potential evapotranspiration (ETp) was prediced by maize simulation model (MSM). Then, it was evaluated and validated using experimental field data obtained in Agricultural Research Station of Shiraz University (Bajghah, Fars province) during 2003 and 2004. Comparison of measured volumetric soil water content with predicted values by MSM model in 2003 and 2004 indicated that this subroutine (prediction of maize evapotranspiration) did not need modification. Also, daily potential evapotranspiration of maize was estimated by using Penman-Monteith equation considering single and dual crop coefficients. Comparison between the results of predicted ETp by MSM model, calculated ETp by Penman-Monteith, and measured irrigation water and soil water content indicated that the prediction of ETp by MSM model was satisfactory. Model prediction of seasonal ETp, potential transpiration (Tp) and soil evaporation (E) were 831, 536 and 329 mm, respectively, in 2003, and 832, 518 and 314 mm, respectively, in 2004. The values of ETp, Tp and E calculated by Penman-Monteith method using dual crop coefficients were 693, 489 and 205 mm, respectively, in 2003, and 700, 487 and 213, respectively in 2004. Maximum rate of predicted potential ETp, Tp and E were 11.1, 8.2 and 5.1 mm d-1, respectively in 2003 and 13.0, 9.0 and 4.0 mm d-1, respectively in 2004. The values of calculated seasonal ETp by Penman-Monteith method using single crop coefficient were 615 and 632 mm in 2003, and 2004, respectively. Comparison between the results of predicted ETp by MSM model, calculated ETp by Penman-Monteith equation with single and dual crop coefficients (FAO-56) and measured values of irrigation water and soil water contents of root depth indicated that FAO-56 methods underestimated the ETp.
S. H. Sanaienejad, A. R. Shah Tahmasbi, R. Sadr Abadi Haghighi, K. Kelarestani,
Volume 12, Issue 45 (fall 2008)
Abstract
Remote sensing science and satellite data are widely used by researchers for agricultural studies. Vegetation spectral reflections recorded by satellite sensors have been used extensively for identifying plant types, plant cover, health community of plants and predicting yield. The TERRA satellite, with 5 sensors, provides an opportunity to observe land, atmosphere and ocean characteristics. The Moderate Resolution Imaging Spectroradiometer (MODIS) is
on–board TERRA satellite. This sensor with 36 bands by 250m, 500m, and 1000m spatial resolution help us to study our environment. The MODIS vegetation indices are used to monitor photosynthetic activity radiation, change detection in plant communities, planted area estimation and plant health. A statistical analysis was done to analyze Near Infra Red (NIR) (841-876 nm) and Red (R) (620-670 nm) bands of MODIS images for a 16 day period. The images have been used for winter wheat in Mashhad (North East of IRAN) during agricultural season of 2004-05.Some image processing techniques were used to extract the related digital numbers (DN), showing the electromagnetic spectrum reflection for all of the pixels. The analysis shows a positive correlation between R and NIR spectrum (0.70 and 0.69) and decrease in NDVI (0.18 and 0.24) in the first and late wheat growth season. However, there is not such a good correlation in the middle of the season and NDVI increased very much. In spite of having wheat cover in the field, NIR reflection decreased very much in the late wheat growth season (0.5). Therefore the correlation relation between R and NIR band along with NDVI could be used effectively in precision agriculture management such as predicting of phonological stage, wheat yield estimation and wheat health condition.
M. Majidian, A. Ghalavand, N. Karimian, A. A. Kamgar Haghighi,
Volume 12, Issue 45 (fall 2008)
Abstract
In order to investigate the effects of moisture stress, nitrogen fertilizer, manure and integrated nitrogen and manure fertilizer on yield, yield components and water use efficiency of SC 704 corn (late maturing, non-prolific and dent). In 2005, a field study was conducted in agricultural experiment station of the college of agriculture, Tarbiat Modares University. The type of design was randomized complete block with factorial arrangement and three replications. For the study, four levels of nitrogen fertilizer (0, 92, 184 and 276 kg N ha-1), integrated fertilizer (46 kg N ha-1 + 2/5 ton ha-1 FYM, 92 kg N ha-1 + 5 ton ha-1 FYM and 138 kg N ha-1 +7/5 ton ha-1 FYM ) and organic Farm Yard Manure (5, 10 and 15 ton ha-1 FYM ) along with three levels of irrigation (optimum irrigation (control), water stress 75% optimum irrigation and water stress 50% optimum irrigation) were used as treatments. The results showed maximum seed yield was produced with 92 kg N ha-1 + 5 ton ha-1 FYM and average of seed yield was 7976 kg ha-1. Maximum corn seed yield resulted when optimum irrigation water was applied and average seed yield was 7041 kg ha-1. When water stress was imposed in 50% and 75% of optimum irrigation, seed yield was decreased by 33 and 12%, respectively. The best seed yield was obtained with interaction of 5 ton ha-1 FYM and optimum irrigation. Also, maximum water use efficiency was obtained in using 50% of optimum irrigation. Maximum water use efficiency was obtained with interaction of 92 kg N ha-1 + 5 ton ha-1 FYM and imposition of water stress in 50% optimum irrigation. Results showed that adequate nitrogen fertilizer slightly increased corn seed yield under stress, and integrated (nitrogen and manure) fertilizer increased corn seed yield under stress. But seed yield greatly increased with optimum irrigation. Integrated fertilizer application increased seed yield even with severe moisture stress. Application of integrated chemical fertilizers and manure produced better seed yield and also decreased the amount of chemical fertilizers and improved soil physical and chemical characteristics.
S. A. Kazemeini, H. Ghadiri, N. Karimian, A. A. Kamgar Haghighi, M. Kheradnam,
Volume 12, Issue 45 (fall 2008)
Abstract
In order to evaluate the interaction effects of nitrogen and organic matter on growth and yield of dryland wheat, an experiment was conducted at the research station of the College of Agriculture, Shiraz University at Bajgah in 2005 and 2006. The experimental design was split plot in which three levels of nitrogen (0, 40, and 80 kg N ha -1) were main factors and additive organic matters including liquorice root residue at 15 and 30 Mg ha -1, municipal waste compost at 10 and 20 Mg ha -1, and wheat residues at 750 and 1500 kg ha -1 (all rates equivalent to 50 and 100%) were sub factors. A check treatment (no additive materials) was also included in the experiment. Results indicated that with increasing nitrogen level from zero to 40 and 40 to 80 kg ha-1, wheat yield increased significantly. Among yield components, number of seeds per spike increased significantly with zero to 40 and 40 to 80 kg nitrogen ha-1, but number of spikes m-2 increased significantly only when nitrogen level was increased from zero to 80 kg ha-1. Compared to check (no additive materials), maximum wheat grain yield (32%) was obtained from 100% compost application. Results of nitrogen and organic matters interaction effects indicated that 100% compost application and increasing nitrogen level from 40 to 80 kg ha -1 had no significant effect on dryland wheat yield. This showed the positive impact of compost application on the reduction of nitrogen fertilizer. Thus, it appears that 50% of the required nitrogen fertilizer could be replaced by compost. Applying organic matter increased soil water in both years, however, among organic matters, compost had a more pronounced effect on increasing soil water.
N Rouhani, H Yang, S Amin Sichani, M Afyuni, S.f Mousavi, A.a Kamgar Haghighi,
Volume 12, Issue 46 (1-2009)
Abstract
Iran, with an average annual precipitation of about 252 mm (413 BCM) and renewable freshwater resources of 130 BCM, has irregular distribution of water resources. With a high population growth rate, agriculture remains the greatest water user in Iran but its production still does not meet the total food demand of the country. Due to unreliable water availability, the competition for water from other sectors and the increasing demand for food and better diets, Iran will experience water stress. In this study, virtual water trade in relation to water resources availability has been assessed as a way of relaxing water stress in Iran. The results showed that from the 21 food products, cereals, pulses, nuts and oilseeds are water-intensive crops according to their estimated virtual water content, while fruits, vegetables and industrial crops are not water-intensive. Considering the volume of virtual water entering the country through food imports, more water will be available for other essential uses. However, the virtual water trade has been developed rather unconsciously regarding water use and crop water productivity during the past two decades. For instance, wheat with a share of 58.5% in the virtual water import to Iran, was the dominant imported crop during 1983-2003. By importing 10.4 Mt of wheat, 11.6 BCM of water has been saved within the country during 1999-2003. However, Iran became self-sufficient in wheat production in early 2005. Consequently, this latest drive for self-sufficiency in the production of wheat, as a water-intensive crop, put tremendous pressure on domestic water resources. The trend in crop trade in terms of quantity and virtual water for other groups of crops has also been shown in the study. Seemingly, crop production and import have been greatly influenced by the weather conditions. With the increasing water scarcity, the role of virtual water in food security is expected to rise continuously in Iran. Thus, conscious virtual water trade as a policy measure in water management and judicious adjustment in agricultural structure will ensure sustainable food security and water availability in Iran.
M Kafi, M Haghighi, A Tehrani Far, Gholamhoseein Davari Nrjad, H Nemati,
Volume 13, Issue 47 (4-2009)
Abstract
Turfgrass is important in urban landscape and by considering that organic matter has a important roll in improving physical and chemical soil characteristics using an organic matter instead of manure and MSW seems necessary .in this research the possibility of using new method of culture such as hydromulching (i.e. mixing seed, organic matter, water, and fertilizer and then distributing it) spent mushroom compost (SMC) has done .for these reason we use two level of SMC 6- month old and one –year old .in two time ,spring and autumn .the experiment design as a factorial Randomized Complete Block Design with 3 replications .Germination ,establishment ,uniformity ,density ,color was measured .results showed that SMC is better than manure especially 6-month old SMC as it is than one-year old SMC .in the spring establishment and germination is better . So using hydromulching by 6-month compost in spring is recommended.
A Shaabani, A Kamgar Haghighi, A Spaskhah, Y Emami, T Honar,
Volume 13, Issue 49 (Water and Soil Science 2009)
Abstract
Oil seed rape (Brasica napus) is an important crop, which is cultivated in Iran for oil production. As a management practice deficit irrigation strategy is applied to cope with water shortages, especially during drought periods. This research was conducted to study the effect of water stress on physiological parameter of oil seed rape in the experimental research field of Collage of Agriculture (of shiraz university) during 2004- 2005 and 2005- 2006. Licord cultivar of oil seed rape was planted and experimental design was random block with five treatments and four replications. Treatments were full irrigation in all growth stages, water stress in vegetative stage in early spring, water stress in flowering and podding stages, water stress in grain filling stage and dry land treatment with supplemental irrigation in time of planting. Water stress caused decrease in water potential of plant, an increase in canopy temperature, and decrease in plant height especially in dry land treatment. Leaf area index decreased as water stress increased. The decrease in leaf area index was more severe in vegetative stage water stress treatment. At the end of water stress period leaf area index increased again. Rate of decrease in leaf area index at the end of the growing season was higher in grain filling stage of water stress treatment.
H.r. Memari, E. Tafazoli, A. Kamgar-Haghighi, A. Hassanpour, N. Yarami,
Volume 15, Issue 55 (spring 2011)
Abstract
Many experiments have been carried out to decrease the negative effect of drought stress and obtain suitable growth under water deficit conditions. Application of plant growth regulators (especially growth retardants) is one of the proposed methods. This study was conducted to investigate the effect of Cycocel application on growth of two olive cultivars (Shengeh and Roghani) under water stress condition. The design of experiment was completely randomized with six replications (Factorial arrangement). Treatments included irrigation intervals (2, 4, 6, 8 weeks) and Cycocel concentrations (0, 500,1000,2000,4000 mg per litter). Some indices such as height, chlorophyll, leaf area, root, and shoot weight (fresh and dry) were measured. Results indicated that interaction of C.C.C treatment and irrigation intervals on height of olive cultivars was not significant, probably due to the response of these cultivars to concentrations of C.C.C. Although drought stress decreased the number of leaves in both cultivars, the application of CCC (500 mg per litter) thwarted the adverse effects of drought stress. Cycocel increased chlorophyll content significantly (500 mg per litter in Roghani and Shengeh and 6 weeks irrigation interval). Cycocel application decreased leaf area, but in Shengeh cultivar increased leaf area in 6 week irrigation interval. Overall, the results indicated that the application of Cycocel with concentration of 500 mg per litter in 6 week irrigation intervals in both cultivars (Roghani and Shengeh) was the best treatment for controlling the adverse effects of drought. Also, results indicated that such changes were dependent on Cycocel concentration and drought level.
T. Honar, A. Sabet-Sarvestani, A. Sepaskhah, A. A. Kamgar-Haghighi1, Sh. Shams,
Volume 16, Issue 59 (spring 2012)
Abstract
In recent years, simulatiom modelling of yield has been the focus of attention for many researchers. Because, while reducing adminestrative costs, it can easily provide simulation models of different situations. In this study, while a subroutine on simulation of canola was added to CRPSM model, effect of different water treatments on canola was also investigated. In this research, canola (Talaye) under 5 irrigation treatments (full irrigation treatment during the growing period, water stress treatment at the spring re-growth stage, the flowering stage and pod formation, the grain formation stage and dry land treatment) was sown in complete randomized block designs at the college of Agriculture, Shiraz University during 2007-2008, and then the model was calibrated based on available information (soil-location -plant-water). Review of statistical indicators between simulated and measured yield show high accuracy in the estimation of crop yield (R2=0.98) and soil water content. The result of model validation with independent data series also showed that the result of soil water content is desirable except in dry treatment, and the corrolation coeficient between simulated and measured crop yield (R2=0.98) was acceptable.
