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Showing 32 results for Yield Components

N. Dadashi, M. R. Khajehpour,
Volume 8, Issue 3 (10-2004)
Abstract

Although safflower is known to be a cool-season crop, it is usually planted as a summer crop in Isfahan. Thus, an experiment was conducted in 2000 at the Agricultural Research Station, Isfahan University of Technology, to study the effects of date of planting on growth, yield components, and seed yield of safflower. Five planting dates (March 12, April 12, May 10, June 8, and July 12) and four safflower genotypes (Arak 2811, local variety Koseh, Nebraska 10, and Veramin 295) were evaluated using a randomized complete block design with split-plot layout in three replications. Date of planting was considered as the main plot and cultivars were randomized in sub-plots. Delay in planting from March 12 to may 10 reduced plant dry weight per unit area, number of heads per plant, number of seeds per head, seed yield per unit area, harvest index and petal yield. The above traits increased as planting was further delayed from May 10 to June 8. Highest seed oil and lowest seed protein contents were also obtained for this planting date. Plants of July 12 planting date did not reach physiological maturity. Among the genotypes evaluated and over planting dates, the highest and lowest number of heads per plant, 1000-seed weight, and seed yield were produced byArak 2811 and Veramin 295 (mean of the first and second planting dates), respectively. Highest seed yield (4512 kg ha

-1) was produced by local variety Koseh in June 8 planting date. It might be concluded that this variety has adapted to the summer planting conditions of Isfahan by natural selection.
H. Sabori, A. Rezai, S. A. M. Mirmohammady Maibody, M. Esfahani,
Volume 9, Issue 1 (4-2005)
Abstract

An experiment was conducted at Rasht Rice Research Institute, in 2001 to study trait relationships and to determine the direct and indirect effects of different characteristics on grain yield of rice (Orgza sativa L.). A 9x2 factorial experiment in complete randomized block design with 3 replications was used. The two factors were 9 cultivars, namely: Hashemi, Ali Kazemi, Binam, Sepeedroud, Nemat, Khazar, Taichung, Chanto, and Usen, and 2 planting patterns (15x15 cm and 30x30 cm). Significant differences were detected among cultivars, between planting patterns, and their interaction effects. The direct effect of the number of panicles/m2 on grain yield was positive and significant in both planting patterns and their combined analysis. Heading date had a positive and significant direct effect on the number of panicles/m2 in both planting patterns and their combined analysis. Only in 30x30 cm planting pattern, a positive correlation was found between biomass at heading date and the number of panicles/m2. Grain weight per plant had a direct and positive effect on panicle weight in the 3 cases studied. Also, in all the cases studied, flag leaf area had positive direct effects on grain weight per plant. Grain filling rate and effective grain filling period increased in 30x30 cm planting pattern. Native cultivars demonstrated longer latent period. Grain filling rate and effective grain filling period showed positive direct effects on grain yield in both plantings. According to the results obtained, an increase in the number of panicles/m2, rate of grain filling, and effective grain filling period would enhance grain yield. Selection for heading date, grain yield per plant, and flag leaf area would also indirectly increase grain yield.
M . Hassani, G. Saeidi, A . Rezai,
Volume 9, Issue 1 (4-2005)
Abstract

A diallel analysis of eight bread wheat (Ttriticum aestivum L.) cultivars was conducted to determine genetic parameters and the type of genetic control for yield and yield components. The parents and their F1 hybrids were evaluated in a randomized complete block design with 3 replications. General and specific combining ability effects were estimated by the method 2 of the Griffings model I, and the genetic parameters were estimated by the Jinks-Hayman method. According to the analysis of variance, the variances of parents and crosses were significant for all of the traits, except for the fertile tillers per plant in parents and harvest index in crosses. The variance of GCA was significant for almost all of the traits. GCA to SCA ratio indicated a large additive effects for all the traits, except for the number of fertile tillers, grain yield per plant and biological yield. Darab and Chamran cultivars were the excellent general combiners for days to heading. However, Falat for plant height, Arvand for number of fertile tillers, spike length and grain weight per spike, Qods and Arvand for spikeletes per spike, Falat and Arvand for grain yield per plant and Qods and Arvand cultivars for biological yield were the best general combiners. Based upon the Jinks-Hayman method, the average degree of dominance for grain weight per spike, 1000- grain weight, grain yield per plant and biological yield indicated that these traits might be controlled by over dominance effects and other traits by partial dominance. The correlation between Yr and (Wr + Vr) for the flag leaf length, spikeletes per spike, grains per spike and 1000-grain weight indicated that recessive allels enhanced these traits. But dominant allels had their contribution to enhance other traits. The narrow-sense heritability for grain yield per plant (4%) and biological yield (14%) and harvest index (37%) was lower. However, for other traits it was more than 50%. Therefore, it can be inferred that indirect selection of grain yield through selection for yield components such as spikeletes per spike, grains per spike and grain weight per spike with high heritability and correlation with grain yield can be more effective.
M. Aghaalikhani, A. Ghalavand, A. Ala,
Volume 9, Issue 4 (1-2006)
Abstract

In order to evaluate the effects of plant densities (10, 13, 20 and 40 plant/m2 ) on the yield and yield components of two cultivars (Partow, Gohar) and a line (VC-1973A) of mungbean [Vigna radiata (L.) Wilczek] a field experiment was conducted at the Seed and Plant Improvement Institute (SPII) of Karaj in Summer 1998. This research carried out in a factorial experiment based on Randomized Complete Block Design (RCBD) with 4 replications. The results indicated that VC-1973A line had the highest grain yield. This line has superiority to other cultivars, due to the early and uniformity of seed maturity and easy mechanized harvest. Plant density has a significant effect (p<0.01) on the grain yield, in such a way that the densities of 20 and 10 plant/m2 outyielded the highest (2221 kg/ha) and lowest (1650 kg/ha) grain yield respectively. Among the yield components, only the number of pods per plant indicated a significant difference due to the plant density. Correlation coefficient between attributes indicated that the plant height and height of first pod internode had a positive correlation with the plant density, while the correlation of the plant density with harvest index (HI), branch number and pod number per plant was negative. More over it seems that the pod number per plant is the most important components of mungbean’s yield, because it has a high (r = 0.88) and significant (p<0.01) correlation with the grain yield.
F A. Frouzandeh Shahraky, M. R. Khajehpour,
Volume 9, Issue 4 (1-2006)
Abstract

Under irrigation and in double-cropping system, a large amount of plant residue remains after harvest that along with the limited time for residue decomposition and complete seedbed preparation, necessitates reduced tillage and special residue management. In the present study, the effects of various seedbed preparation methods on vegetative growth, yield components and seed and oil yields of sunflower (Euroflor hybrid) were studied in a barley-sunflower cropping system during 2001 at the Agricultural Research Station, Isfahan University of Technology. Three residue management treatments (standing, partly removed and burned) along with five tillage systems (moldboard + disk chisel + disk disk moldboard and furrower as the minimum tillage) were laid out in a split-block design with three replications. Burning residue treatment significantly increased plant dry weight at various developmental stages and also head diameter. Number of seeds per head, 1000 seed weight, harvest index, and oil yield were non-significantly higher in the burned residue treatment. Seed yield was significantly higher in the burned and partly removed residue treatments. Moldboard + disk and chisel + disk treatments significantly produced higher plant dry weight at various developmental stages, head diameter and seed yield. Number of seeds per head, 1000 seed weight, harvest index, and oil yield were non-significantly higher in these treatments. Minimum tillage ranked the lowest for these traits. The results of this experiment indicate that chisel + disk treatment with the partly removed residues might be an appropriate seedbed preparation method in a barley-sunflower double planting under conditions similar to this experiment.
A. Abouzari Gazafrodi, R. Honarnegad, M. H. Fotokian, A. Alami,
Volume 10, Issue 2 (7-2006)
Abstract

In order to investigate path analysis and study correlations among 16 agronomic traits, 49 Iranian and foreign rice entries were evaluated in a simple lattice square as experimental design with 2 replications at research farm of Tonekabon agricultural college in 2001. Analysis of variance showed significant difference among genotypes for all the studied traits (p<0.05). Phenotypic and genotypic correlation analysis showed positive and significant correlation between grain yield and the number of productive tiller, total tillers and number of grain per panicle. Based on path analysis of the traits, the number of productive tillers had the highest direct effect on the grain yield. Furthermore, the number of grain per panicle and 100-grain weight had a high direct effect on the yield. Overall, the results are suggestive of the direct selection for grain yield in these genotypes through above - mentioned traits.
Gh. Mohammadi, K. Ghasemi Golezani, A. Javanshir, M. Moghaddam,
Volume 10, Issue 2 (7-2006)
Abstract

In order to investigate the effect of different irrigation regimes on some agronomic and physiological characters of three chickpea cultivars (Jam, 301 and Pirooz), a field experiment was conducted in 1998 at the Agricultural Research Farm of Tabriz University, Tabriz, Iran. A split plot experiment based on a randomized complete block design with three replications was used, in which irrigation treatments (full irrigation, irrigation at only branching or flowering and or pod formation stage) were in the main plots and chickpea cultivars were in the sub plots. Under limited irrigation conditions there were no significant differences among irrigation regimes for green cover percentage and the number of pods per plant while rate and duration of grain filling, grain weight and grain yield were significantly higher for irrigation at pod formation than for irrigation at branching or flowering stage. The mean of all the traits, except for the number of seeds per pod were significantly higher for full irrigation than for limited irrigation treatments. Rate of grain filling, maximum grain weight and grain yield were significantly higher for irrigation at flowering than for irrigation at branching stage. While, other characters were not significantly different between these two treatments. Although, green cover percentage and seeds per pod in 301 were higher than those in Jam, but in other cases their response to water limitation was almost similar. All traits, except the number pods per plant, were noticeably lower for Pirooz compared to Jam and 301 cultivars. Green cover percentage showed the highest correlation with the grain yield. This study revealed that among phenological stages of chickpea, pod formation is the most sensitive to water deficit, and that under water limitation conditions chickpea yield could be improved by irrigation at this stage.
H. R. Ali Abbasi, M. Esfahani, B. Rabiei, M. Kavousi,
Volume 10, Issue 4 (1-2007)
Abstract

Effect of nitrogen (N) fertilizer levels and its split applications on yield and yield components of rice (Oryza sativa L.) Cv. Khazar was investigated in a completely randomized block design with 3 replications in a paddy light soil at Guilan province, Iran, 2003. In this experiment, six treatments including: T1-control (no N fertilizer) T2- 40 kg/ha N (at transplanting time) T3- 80 kg/ha N (at transplanting, and tillering times) T4- 80 kg/ha N (at transplanting, tillering, and panicle initiation times) T5- 120 kg/ha N (at transplanting, and tillering times) and T6- 120 kg/ha N (at transplanting, tillering, and panicle initiation times) were compared. Results showed that the highest fertile tiller number was obtained in the fifth and sixth treatments with double and triple split applications of 120 kg/h N (236 and 248 m-2). The highest fertile filled spikelets percentage (84.8%), 1000-grain weight (26.1 g) and grain yield (4.83 t/ha) belonged to the sixth treatment, but grain yield and 1000-grain weight were not significantly differerent in the fourth and sixth treatments with three fertilizing times. This finding may have resulted from the third topdressing application of nitrogen fertilizer in panicle initiation and higher leaf area (44.8 and 45.5 Cm2), leaf greenness (39.4 and 39.9) and leaf nitrogen concentration (31.2 and 33.6 g/kg) during grain filling in the fourth and sixth treatments. Regression analysis also showed that flag leaf greenness (SPAD values at 5 days after flowering) and flag leaf area accounted for about 75% and 78% changes in yield, respectively. In conclusion, triple split application of 80 kgN/ha could be suggested for rice Cv. Khazar in these regions since the yield would be the same as the application of 120Kg/ha N.
G. Saeidi, M. Khodambashi,
Volume 10, Issue 4 (1-2007)
Abstract

This study was carried out to evaluate the yield potential and other agronomic traits of nine genotypes of flax at two different spring planting dates: April 4 and May 5, 2003 and 2004, using a randomized complete block design with three replications at the Research Farm of Shahrekord University. The results showed that the effects of planting date and genotypes were significant on all of the traits, and the genotypes had a great genetic variation. On average, the range of number of seedlings/m2, maturity, plant height, yield/plant, seed yield and seed oil content of genotypes were 306 to 464, 93.3 to 105.1 days, 28.8 to 58.2cm, 0.274 to 0.569g, 995 to 1423 kg/ha and 32.88 to 34.83%, respectively. The lowest mean of plant height and the highest mean of seed yield/ha were observed for Kordestan local population. Late planting significantly decreased the number of seedlings/m2, days to maturity, plant height, yield/plant and seed yield/ha, while this increased seed oil content. Average of seed yield/plant and seed yield/ha in the first and second planting dates were, respectively 0.506 and 0.414g, and 1598 and 811 kg/ha. Significant interaction of genotype by planting date for seed yield/ha and seed oil content was mostly due to the variation in the reduction of seed yield and increasing or decreasing of seed oil content in some genotypes in the second planting date. The genotypes had a variation of 1358 to 1784 and 632 to 1088 kg/ha for seed yield in the first and second planting dates, respectively. The local population of Kordestan had the highest mean of seed yield in both years. The results of regression analysis and also the correlation coefficients showed that the number of seedlings/m2 and seed yield/plant had the most contribution to the seed yield variation. The trait of number of seeds/capsule and number of capsules/plant were the main and most important yield components affected on seed yield/plant and due to can be used as selection criteria in selection programs to improve seed yield.
M. R. Tadayon, Y. Emam,
Volume 11, Issue 1 (4-2007)
Abstract

In order to study the physiological responses of two barley cultivars to salinity stress, a 4-replicate CRD greenhouse experiment was conducted during at the College of Agriculture, Shiraz University, Iran2003-2004. The treatments consisted of two barley cultivars: Afzal and Reyhan and five salinity levels: 0, 4, 8, 12 and 14 dS/m. Seedling emergence, number of tillers and leaves per plant, leaf area and dry matter decreased with increasing salinity levels. The reductions were lower in Afzal (salt tolerant) than Reyhan (salt sensitive). A lower Na+ and higher K+Na+ in Afzal compared to Reyhan were observed under high level of salinity. The results of the present experiment also showed that the tolerance to salinity was associated with a greater stomatal conductivity, as well as transpiration and photosynthesis rate. Sub-stomatal CO2 concentration in both cultivars decreased with an increase in salinity, with the exception of 12dS/m, where it led to an increase in sub-stomatal CO2 concentration. Leaf temperature increased with an increase in salinity level in both cultivars, whereas a more pronounced decrease for number of fertile tillers, ears per plant, kernels per ear, thousand grain weight and harvest index was observed in Reyhan compared to Afzal .Since a higher tolerance to salinity in Afzal was apparently associated with a lower concentration of Na+ and a higher K+/Na+ ratio of the shoots, this trait could probably be used for yield improvement of barley cultivars under saline conditions.
M. R. Jazayeri Nooshabadi, A. M . Rezai,
Volume 11, Issue 1 (4-2007)
Abstract

This research was conducted at Research Farm of Isfahan University of Technology to examine the relations among phonologic, morphologic and physiologic traits and their effects on grain yield of 20 oat (Avena sativa L.) genotypes. A randomized complete block design with three replications was used in each irrigation treatment (i.e. irrigation after 70±3, and 130±3 mm evaporation from class A pan). Grain yield had significant and positive correlations with harvest index and relative water content (RWC) in both irrigation treatments and with plant height at maturity in non-stress condition. Also, grain yield had significant and negative correlation with days to heading. Factor analyses resulted in three factors in each condition, which were named yield factor, phenologic factor and sink factor in both conditions. Based on stepwise regression, harvest index was the first character which entered the grain yield model in both conditions. At the next step, RWC and plant height entered the model, with harvest index explaining 66% and 64% of yield variation in stress and non-stress conditions, respectively. The results of path analysis in both conditions showed that harvest index had the highest positive direct effect on grain yield. The highest indirect negative effects through number of grain per panicle were obtained for the harvest index and panicle m-2 in stress and non-stress conditions, respectively.
M. Salehi, A. Haghnazari, F. Shekari, H. Baleseni,
Volume 11, Issue 41 (10-2007)
Abstract

In order to evaluate relationship between Different traits in lentils (lens culinaris Medik), a field study was conducted as an RCBD based design with 3 replications on Zanjan University Research Farm during spring of the year 2004. ANOVA analysis revealed significant differences for all characters except for the number of primery branches. Correlation analysis indicated positive and significant correlation between seed yield and harvest index, number of primery branches, pods/plant and biological yield, and grian yield. The result of the factor analysis also showed that the second factor including number of primery branches, pods/plant, grian yield, canopy width and seeds/plant was an important trait involved in the grian yield in lentil. In addition, cluster analysis helped divide the genotypes into four distance groups of large, medium, semi medium and low yields.
P. Sharifi, M. Tajbakhsh,
Volume 11, Issue 41 (10-2007)
Abstract

To evaluate the effect of plant density and detopping on grain yield, protein content biological yield harvest index, growth indices, number of cob in each plant, No. of row per ear, No. of grain in each row, thousand seed weight of corn (Zea mays L. ar. SC 704), an experiment was conducted at the experimental statues of Research Center of Uremia Agricultural College in 2004. The Treatment design was split plot in randomized complete block design with four replications. The main plots included plant density at three levels (53000, 66000, and 88000 Plants/ha) and the subplets comprised three levels: (1) no detopping (control) (2) removing canopy only and (3) removing canopy and three leaves above the node. Analysis of Variance of data showed that both detopping treatment and plant density influenced the number of kernel per ear ,1000 grain weight, ear weight, total dry weight of biomass, seed yield and harvest index. Canopy detopping led to a marked increase in photo assimilateion import grains. The highest plant density evaluated, 88000 plants per hectare with detopping of three above leaves had the highest number of cobs per square meter. In plant density of 53000 plants per hectare and canopy detopping treatment, the number of grain per ear was greater than other densities. The efficiency of harvest index increased under corn detopping compared with control, and this increase with an increase in photosynthesis contributed to grain yield. It was concluded that major increase in grain yield under high plants density and tassel detopping was due to improvement of physiological indices.
P. Heydaryzadeh , M.r. Khajehpour,
Volume 11, Issue 42 (1-2008)
Abstract

  During the past years, safflower genotypes have been selected from local variety of Isfahan, named Kouseh. The response of these genotypes to planting date might be different. To determine this, performances of several genotypes selected from Kouseh plus Arak 2811 ) as check ( were studied at the Agricultural Research Station, Isfahan University of Technology in 2002-2004. The experiment was conducted using a split-plot arrangement within a randomized complete block design with three replications. Planting dates were considered as the main plots and subplots consisted of 22 genotypes of safflower. Number of days from planting to emergence was highest (18.0 days) in early spring planting and lowest (10.3 days) in late spring planting. Days from planting to head visible, flowering and physiological maturity were decreased with delay in planting from autumn to late spring. Days from planting to emergence, head visible and physiological maturity were not influenced by genotype. Genotypes C116 and DP29 had the highest (145.0) and genotype ISF28 the lowest (140.2) days from planting to flowering. Plant height, number of first and second degree branches, number of heads per first and second degree branches, number of seeds per head, 1000-seed weight and seed weight per plant reduced significantly with delay in planting from autumn to late spring. Genotypes C128 and DP7 had the highest (120.0 and 120.5 cm, respectively) and genotype DP9 the lowest (104.2 cm) plant height. Genotypes DP6 and DP9 had the highest (12.8) and the lowest (6.7) first degree branches per plant, respectively. Arak-2811 had the highest (16.9) and genotypes DP9 and DP5 the lowest (7.2 and 7.1, respectively) second degree branches per plant. Number of heads per first degree branches was not significantly affected by genotype. Arak-2811 and genotype C114 had the highest (12.8 and 12.2, respectively) and genotype DP9 the lowest (5.1) number of heads per second degree branches. Genotype DP7 had the highest (45.9) and genotype C111 had the lowest (28.0) number of seeds per head. Genotypes DP3 and C128 had the highest (34.2 g) and lowest (22.0 g) 1000-seed weight, respectively. Genotype DP25 had the highest (20.5 g) and genotypes DP29 and DP9 the lowest (9.9 and 10.0 g) seed weight per plant. Harvest index was not affected by planting date and genotype. The result of this study showed that safflower may yield more in fall planting under conditions similar to this experiment. Genotype DP25 might be recommended for this planting date, genotypes ISF66 and DP25 for early spring planting and genotypes DP7 and ISF14 for summer planting.


M Noruzi, A Jalalian, Sh Ayoubi, H Khademi,
Volume 12, Issue 46 (1-2009)
Abstract

Crop yield, soil properties and erosion are strongly affected by terrain parameters. Therefore, knowledge about the effects of terrain parameters on strategic crops such as wheat production will help us with sustainable management of landscape. This study was conducted in 900ha, of Ardal district, Charmahal and Bakhtiari Province to develop regression models on wheat yield components vs. terrain parameters. Wheat yield and its components were measured in 100 points. Points were distributed randomly in stratified geomorphic surfaces. Yield components were measured by harvesting of 1 m2 plots. Terrain parameters were calculated by a 3×3 m spacing from digital elevation model. The result of descriptive statistics showed that all variables followed a normal distribution. The highest and lowest coefficient of variance (CV) was related to grain yield (0.36) and thousand seeds weight (0.13), respectively. Multiple regression models were established between yield components and terrain parameters attributes. The predictive models were validated using validation data set (20% of all data). The regression analysis revealed that wetness index and curvature were the most important attributes which explained about 45-78% of total yield components variability within the study area. The overall results indicated that topographic attributes may control a significant variability of rain-fed wheat yield. The result of validation analysis confirmed the above-stated conclusion with low RMSE and ME measures.
F Valimohamadi, M Tajbakhsh, A Saeed,
Volume 12, Issue 46 (1-2009)
Abstract

In order to evaluate effect of planting date and plant density on grain yield, yield components and some quality and morphological traits of chickpea (Cicer arietinum L.), an experiment was conducted at the research center of agricultural and natural resources of west Azerbaijan in Urmia rain-fed research farm during 2005-2006 growing season in a split plot arrangement, based on a completely randomized block design with four replications. The cultivar of chickpea (Qazvin local mass) was planted in three sowing dates (mid November, mid March and mid April) in main plots, and four plant densities (intra row space: 7.5, 10, 15 and 20 cm) representing (45, 34, 23 and 17 plant/m2) in sub plots. Yield, number of pod per plant, seed protein content, plant height, number of secondary branches and 100 seed weight were evaluated. Results indicated that date of sowing had a significant effect on the yield, number of pod per plant and seed protein content but was not significant for plant height, secondary branches and 100 seed weight. Highest number of pod per plant was obtained in mid November sowing (37.69) and high protein content (22.63) in mid March. Different plant density effects were also not significant on yield, plant height, secondary branches and 100 seed weight but the effect of density on the number of pod per plant and seed protein content was significant. Highest number of pod per plant was obtained in the third density (31.5), and highest protein content in the first density (22.31). The results of study indicated that between mid March planting in the density (45 plant/m2) had highest yield (1042.08kg/ha) and protein content compared with the other planting dates.
H Miri,
Volume 12, Issue 46 (1-2009)
Abstract

In order to study changes in morphophysiological traits of wheat cultivars released from 1940 to 2000 in Iran and to determine the association of these traits with grain yield, an RCBD experiment was conducted with 15 wheat cultivars released during past 60 years in Arsanjan (Fars province) in 2006 and 2007. Results indicated that grain yield increased significantly during these 60 years (r=0.912, P<0.01). HI and BY increased significantly with increasing grain yield. The changes in photosynthesis rate were not significant during this period, but transpiration rate and stomotal conductance in recent cultivars increased significantly. Chlorophyll index also increased in new cultivars. Among yield components, grain number per ear increased significantly, but increase in ear number was not significant. Plant height decreased significantly in new cultivars. The results showed that during wheat breeding in Iran, increasing HI, grain number per ear, transpiration rate, stomatal conductance and decreasing plant height had the highest role in wheat yield increase. The role of BY and ear number per area were lower in grain yield increase. It seems that present HI values are near the highest possible value, but the opportunity for increasing grain yield by mean of HI is still possible.
M Modares Sanavi, M Amini Dehagh, M Gholamhoseni, M Panj Tan Dost,
Volume 13, Issue 48 (7-2009)
Abstract

In order to study the effect of air and root-zone temperature on yield, yield components, nodulation and nitrogen fixation of three annual medics, an experiment was conducted in controlled environment (growth chamber) at the Faculty of Agriculture, Tarbiat Modares University in 2006. The experiment was performed as a spilt split plot with the layout of completely randomized design with three replications. Air temperature at three levels including 15/10, 20/15 and 25/20ºC day/night, four levels of root-zone temperatures including 5, 10, 15 and 20ºC and three annual medics (Medicago polymorpha, M. radiata and M. rigidula) were randomized to main plot, sub plot and sub sub plot units, respectively. The results showed that there were significant differences among annual medics for dry matter production, yield components and nitrogen fixation. M. rigidula produced more leaves, stems and root dry matter, leaf and stem to root ratio, leaf number and area and forage yield than other annual medics. Also, three annual medics at 25/20ºC day/night air temperature (the highest one) produced more nodulation dry matter (8.85 mg/pot) and nitrogen fixation (7.7 mg/g dry matter) than other temperatures. Plants at the former temperature produced 8 and 2 times more nodulation and nitrogen fixation than 15/10ºC day/night air temperature (the lowest one), respectively. Low root-zone temperature up to 5ºC had severely negative effect on yield and nitrogen fixation in the three studied annual medics. Interaction among annual medics, air and root-zone temperatures showed that M. rigidula was better than other annual medics for yield, nodulation and nitrogen fixation at 25ºC air temperature and 15ºC root-zone temperature . The result showed that M. rigidula had normal growth and development compared with other annual medics at low root-zone temperatures. Thus, M. rigidula may be a better annual medic for cultivation in cold and moderate regions. Therefore, in the zones where soil temperature is lower than 5ºC during the season, cultivation of annual medics is not successful, but in the zones where soil temperature is greater than 10ºC, annual medics have normal growth and produce average yield due to better nitrogen fixation.
J. Hamzei, M. Seyedi,
Volume 18, Issue 70 (3-2015)
Abstract

This experiment was carried out at the Agricultural Research Station of Bu-Ali Sina University to study the effect of different tillage methods on bulk density, yield, and yield components of barley (Hordeum vulgare) cultivars under rainfed conditions. Three levels of tillage (CT: conventional tillage, MT: minimum tillage and NT: no tillage) and five barely cultivars (V1: Local V2: AbidarV3: Valfagr V4: Bahman and V5: Makouei) were evaluated in a factorial arrangement in a completely randomized block design with three replications in the growing season of 2010-11. Traits of bulk density plant height, grain yield, yield components, biological yield, and harvest index (HI) were evaluated. The results showed that maximum value of bulk density (1.09, 1.26 and 1.29 g cm-3 for 0-10, 10-20 and 20-30 cm of sampling depth, respectively) was observed at MT treatment. But, there was no significant difference between MT and NT treatments for this trait. In comparison of cultivars, maximum bulk density was achieved with Valfagr cultivar. Using chisel plow (MT treatment) produced maximum plant height (70 cm) and yield components (513 numbers of spike m-2 and 19.2 grain spik-1). Also, among cultivars maximum plant height (72.7 cm) and grain number spike-1 (23.2 grain spike-1) belonged to Valfagr cultivar. Also, results showed that V3×MT treatment had the highest grain yield (3100 kg ha-1). Therefore, the findings of the study recommend using chisel plow (MT treatment) and Valfagr cultivar.


M. Shahsavari Gugharغ, A. Rezaei Estakhroieh, M. Irandost, A. Neshat,
Volume 22, Issue 1 (6-2018)
Abstract

With the increase of population, the optimal use of water resources is necessary. This study was carried out to evaluate the impact of different levels of irrigation on the yield, yield components and water productivity of corn using single and double row drip irrigation systems (Tubes type). . The experiment was conducted in a split plot design based on the randomized complete block design (RCBD) with three replications in 2012 in Hajiabad, Hormozgan Province. The treatments were comprised of three levels of irrigation as the main plot (100, 80 and 60% water requirement) and two patterns of irrigating water pipe installation (normal and every other row) as a sub-plot of the design. The results showed that irrigating with the 80 percent water requirement, in comparison with full irrigation, increased the total yield by 1.4%, the seed weight by 1.8%, the number of seeds per row by 8.7%, and the number of seed row per maize by 13%. In spite of yield superiority in the pattern of normally irrigating water pipe installation (10055.56 kg ha-1), against every other row installation (9366.67 kg ha-1), water productivity was more in every other row installation (1.089 kg m-3). Therefore, partial root-zone drying   was recommended by the irrigation of    the 80% plant water requirement for the maize in the region.


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