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Showing 14 results for Biological Yield

A. Hayati , M. Ramroudi , M. Galavi ,
Volume 1, Issue 2 (5-2011)
Abstract

The research on reducing the water consumption in conventional cropping system is one of the important strategies to improve the water use efficiency in agriculture. In order to investigate the effect of time of potassium application under different irrigation regimes on millet grain yield and protein percent, a field experiment was carried out in Agricultural Research Center of Yasuj, Iran, in 2009. The experiment was conducted as split plot design in a randomized complete blocks design with 3 replications. Irrigation regime included 7, 14 and 21-day intervals as main factor and sub-plots included time of potassium fertilizer application in four stages: planting, tillering, stem development and flowering. The results showed that the effect of irrigation interval was significant on 1000-seed weight, grain and biological yield, number of grains per spike, harvest index, protein content, and chlorophyll a, b and total of leaves. By increasing the irrigation interval, all the above-mentioned traits decreased, except the protein percent that increased. The 1000-seed weight, grain and biological yield, harvest index and protein content were affected significantly by the time of potassium application. Maximum grain yield was obtained by interaction of 7- day irrigation interval and potassium application at the stem development stage. Maximum grain protein content was measured in potassium application at flowering stage. In general, increasing the irrigation interval, and subsequent water stress, reduced plant growth and yield components. Application of potassium fertilizer at early growth stages increased yield and yield components, while in reproductive stages increased seed quality.
J. Rabbani , Y. Emam,
Volume 1, Issue 2 (5-2011)
Abstract

Drought stress is the most important limiting factor in crop plants including maize (Zea mays L.), which is the third important world crop after wheat and rice. Water deficiency at different growth stages affects maize yield differently. To examine the response of four maize hybrids to drought stress at different growth stages, a field experiment was carried out as a split plot based on completely randomized block design at Research Farm of College of Agriculture, Shiraz University, during 2009 and 2010 growing seasons. The main plots composed of four drought stress levels including optimum irrigation, withholding irrigation at vegetative growth stage (8-leaf to flowering), flowering and kernel filling. Four maize hybrids including Zola, BC666, Maxima and SC704 were allocated into sub-plots. Data analysis showed that the effect of year was not significant on measured characters thus, the data of both years were combined. Drought stress affected all measured characters except number of kernels per ear. The most significant effect of drought stress at vegetative growth phase was on reduction of plant height (10.2%). Drought stress at flowering reduced ear length (12.6%), kernel per ear (17.8%), yield (29.1%) and harvest index (20.4%). The 1000-kernel weight was significantly reduced (10.3%) when drought stress occurred at kernel filling stage. SC704 hybrid had the highest height (281.07 cm), kernel per ear (710.62), ear length (19.45 cm), 1000-kernel weight (316.49 gr), biological yield (25368 kg/ha) and kernel weight (11291 kg/ha). The highest harvest index (46.99%) was achieved in Maxima hybrid. It appears that flowering stage was the most sensitive stage to drought. Although drought stress at all growth stages reduced maize yield, but in dry areas, it might be possible to accept a small reduction in maize yield and save an irrigation in favor of other crops, simultaneously grown with maize. According to the results of this 2-year experiment, Maxima hybrid appeared to be suitable for drought-prone areas, while SC704 is better for normal conditions.
I. Niroomand Tomaj, M. Jami Al-Ahmadi, Gh. Zamani1, A. Riasi,
Volume 2, Issue 3 (6-2012)
Abstract

Grass pea (Lathyrus sativus L.) is a crop which could substitute soybean in poultry ration in arid and semi-arid regions. To investigate the effects of sowing date and plant density on yield and yield components of grass pea, a factorial experiment based on randomized complete blocks design with four replications was conducted at Research Farm of Faculty of Agriculture, University of Birjand in 2008. Treatments included three sowing dates (March 5, March 21 and April 4) and four plant densities (30, 40, 50 and 60 plants per m2). Number of pods per plant, number of seeds per pod, number of seeds per plant, 100-seed weight, seed yield, biological yield and harvest index were measured. Results showed that by delaying the planting date, number of pods per plant, number of seeds per plant, seed yield and biological yield were decreased significantly. Maximum seed yield (2524 kg/ha) was achieved at the early sowing date (5th of March). These traits were increased with increasing plant density up to 50 plants per m2. But, increasing the plant density to 60 plants per m2 caused a decrease of these characteristics. Different planting dates and densities did not show any significant changes in number of seeds per pod, 100-seed weight and harvest index. Based on these results and the fact that Birjand is overwhelmed by an arid climate, planting grass pea at the first possible date at the end of winter with a moderate planting density (50 plants per m2) can lead to a reasonable seed yield.
M. Roshdi, D. Boyaghchi , S. Rezadoust,
Volume 2, Issue 5 (12-2012)
Abstract

To study the effect of micronutrients and irrigation cutback at different development stages on vegetative characteristics and yield of pinto bean (Talash cultivar), an experiment was carried out at Agricultural Research Station of Khoy in 2009. This experiment was performed as strip split plots based on randomized complete blocks design with 3 replications. Treatments included irrigation as the main factor at 3 levels (conventional irrigation (control), irrigation cutback at podding stage, irrigation cutback at seed-filling stage), and application of micronutrients (boron, zinc and manganese) as sub factor at 4 levels (soil treatment, one foliar application, two foliar applications, and control (no micronutrients application)). According to the results, irrigation levels had significant effects on height of the first branch above the ground, stem diameter, seed yield, biological yield and protein content of the seeds. By irrigation cutback at podding and seed-filling stages, the seed yield decreased from 2647 kg/ha to 1269 and 1920 kg/ha, respectively. Micronutrients treatments had also significant effects on number of branches per plant, height of the first branch above the ground, stem diameter, seed yield, biological yield and protein percent. The highest seed yield (2379 kg/ha) was in two foliar applications, which was 893 kg/ha more than control (no micronutrients application). The highest protien content (26.8%) belonged to irrigation at control level and two foliar applications of micronutrients. The general result of this research shows that due to high sensitivity of pinto bean to water deficiency, irrigation at conventional level with two foliar applications of micronutrients is recommendable to improve its growth.
M. Pourebrahimi, M. Zavareh, S. M. R. Ehteshami,
Volume 3, Issue 10 (2-2014)
Abstract

In order to investigate the effect of Pseudomonas fluorescence strain 93 bacteria and Glomus esculentum fungus on quantitative and qualitative yield of two forage corn cultivars, an RCBD based factorial field experiment with three replications was conducted at the Agricultural Research Station of the University of Guilan in 2008. Treatments were considered as phosphorus chemical fertilizer, seed inoculation with Glomus esculentum mycorrhiza fungus, seed inoculation with Pseudomonas fluorescence strain 93 bacteria, seed inoculation with Pseudomonas fluorescence strain 93 bacteria and Glomus esculentum mycorrhiza fungus, and two corn cultivars (SC704 and SC647). No application of chemical fertilizer and microorganisms was considered as control. Results of ANOVA showed that plant height and leaf area, plant SPAD value, and plant biological yield were affected by cultivar × fertilizer interaction, significantly. The highest plant height (249.30 cm), SPAD value (52.30), and biological yield (251.51 g/plant) were related to cultivar SC704 which treated with chemical phosphorous fertilizer or inoculated with bacteria-fungus combination. The maximum plant leaf area was achieved in chemical phosphorous fertilizer followed by application of both bacteria and fungus treatments. Inoculation with both bacteria and fungus also resulted to highest dry matter digestibility (77.37 %) and crude protein (12.61 %). However, the highest (54.41 %) and lowest (34.38 %) crude fiber was related to control and bacteria-fungus combination treatments, respectively. Among two cultivars used in the experiment, SC704 was superior according to examine crop traits. Therefore, it could be expected that inoculating the seeds of SC704 corn cultivar with Pseudomonas fluorescence- Glomus esculentum combination resulted to reduce the use of phosphorus fertilizers and increase in the quality and quantity of forage corn.
M. E. Sedaghat, Y. Emam,
Volume 6, Issue 21 (12-2016)
Abstract

Plant growth regulators (PGRs) are used to prevent reduction in wheat grain yield under limited moisture conditions. The effect of 3 PGRs including cycocel, salicylic acid and brassinoestroeid on yield and yield components of  four wheat cultivars (Chamran, Shiroudi, Pishtaz and Sirvan) under well watered and water stress (withheld irrigation after flowering) was examined. The experiment was carried out as a factorial split plot in a completely randomized block design with three replicates at research farm of Sarvestan, Fars province in 2014-15 growing season. The results showed that drought stress reduced ear weight, grains per ear, grain weight per ear, thousand grain weight, harvest index, biological yield and grain yield, significantly. Albeit, the extent of the decrease varied, i.e. the smallest and greatest decreases were found in thousand grain weight (7%) and number of grains per ear (13%), respectively. Furthermore, application of PGRs especially cycocel, could increase ear weight, grains per spike, harvest index, thousand grain weight and consequently, grain yield. Among cultivars, Sirvan had the highest and Shiroudi had the lowest yield under both moisture regimes. According to our results although drought stress suppresses wheat yield and yield components, PGRs could be harnessed to compensate some parts of drought stress. Therefore, use of PGRs could be recommended to alleviate the drought stress effect on bread wheat.


Dr Iraj Tahmasebi, Miss Narges Dolatmand Shahri,
Volume 7, Issue 1 (6-2017)
Abstract

This study was conducted to evaluate the effects of nitrogen fertilizer and plant density on the capacity of photosynthesis (leaf area index, the number of leaves and the chlorophyll contents), yield components and yield of maize. The experiment laid out as split plot based on a randomized complete block design with three replications in 2011 summer planting at research station of Kurdistan University. Nitrogen fertilizer on three levels (115, 184 and 253 kg ha-1) assigned to main plots and plant density on four levels (8, 10, 12 and 14 plants m-2) to subplots. Results showed that Increasing the nitrogen fertilizer and plant density did not affect the number of leaves, but increased leaf area and the content of the chlorophyll. Thus, Biological yield, yield components and seed yield was consequently increased. The highest grain yield (6927 kg ha-1) was obtained from 184 kg ha-1 nitrogen and 12 plants m-2. Increasing the nitrogen and plant density more than mentioned amounts did not increase the seed yield significantly. therefore, more nitrogen and plant density in trail location and other locations with similar conditions is not recommended in order to save production costs and avoid environmental pollutions.


Sh. Sepahvand, A. Koochekzadeh, A. Moshatati, A. Siahpoosh,
Volume 9, Issue 4 (1-2020)
Abstract

Among soil and agronomic factors affecting growth, nutrition and plant density have a great effect on the growth and yield of crops such as Flax (Linum usitatissimum L.). In order to study the effect of different levels of nitrogen and plant density on yield and yield components, oil percentage and yield of Flax, a split plot experiment was conducted in a randomized complete block design with four replicates at the Research Farm of Agricultural Sciences and Natural Resources University of Khuzestan, Iran in 2016-2017. Experimental factors included different levels of nitrogen (0, 75, 150 and 225 kg/ha) in main plots and four plant densities (50, 100, 150 and 200 plants/m2) in sub plots. Analysis of variance showed that nitrogen, plant density and their interaction effect was significant on all measured traits. The highest grain and oil yields were obtained in 150 kg/ha nitrogen level and the density of 200 plants/m2. The mean comparison of interaction effect showed that the highest grain yield (1348 kg/ha) and oil yield (349 kg/ha) were achieved in 150 kg/ha nitrogen level and the density of 200 plants/m2. The lowest grain yield (570 kg/ha) and oil yields (188 kg/ha) were observed in 0 kg/ha nitrogen level and the density of 150 plants/m2.
Meysam Karami, Seyed Abdolreza Kazemeini, Mehdi Zarei, Mozhgan Alinia,
Volume 9, Issue 4 (1-2020)
Abstract

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

M. Amiryousefi, M. R. Tadayon, R. Ebrahimi,
Volume 10, Issue 2 (7-2020)
Abstract

In order to investigate the effects of solitary and combined application of chemical and biological fertilizers on the yield and yield components of quinoa plant, a factorial experiment was conducted based on randomized complete block design with three replications in Dastgerd (Borkhar), Isfahan, central Iran, during the 2017-2018 growing season. Experimental factors included four levels of Chemical fertilizers [control, urea, triple superphosphate (TSP), and combined urea + TSP fertilizers] and bio-fertilizers at four levels (no inoculation, and inoculations with nitroxin, bio-phosphorus, and combined nitroxin + biophosphorus). Results showed that the interaction effects of chemical and biological fertilizers on leaf area index, grain yield, and yield components (including number of panicles per m2, number of grains per panicle, and 1000-grain weight) of quinoa plant were significant at 1% probability level. Combined application of urea and TSP fertilizers had the highest impact on the biological yield. Overall, the results showed that plant height, chlorophyll content and the number of panicles per m2 were significantly influenced by nitrogen sources of fertilizers used in this study. The phosphorus fertilizer sources had the highest effects on leaf area index, number of grains per panicle, 1000-grain weight, grain yield, and biological yield, which can be attributed to the greater impact of nitrogen on the increase of prolific panicles and to the marked role of phosphorus in both flower and grain formation. The integrated application of biofertilizers and all of the examined chemical fertilizers treatments increased the yield of quinoa plant compared to the control. Therefore, the application of biofertilizers as supplements can be introduced as a practical approach for optimal and balanced use of chemical fertilizers in order to achieve sustainable agriculture goals in quinoa cultivation.

F. Hajiabadi, F. Hassanpour, M. Yaghoobzadeh, H. Hammami, S. M. Seyyedi,
Volume 11, Issue 2 (8-2021)
Abstract

Today, maintaining the quantity and quality of irrigation water are the most critical challenges in the agriculture system, especially in arid and semi-arid regions of the world. Accordingly, to evaluate the growth and yield responses of bread wheat (Sirvan cultivar) to different levels of deficit irrigation and water salinity, a factorial experiment was conducted in a randomized complete block design with three replications in the Research Field of Agriculture Faculty of the University of Birjand, at Birjand (east of Iran) during the growing seasons of 2016-2017 and 2017-2018. The experimental treatments included irrigation at five levels (125, 100, 75, and 50% of wheat water requirement and rain-fed with two supplementary irrigation at the first growing season) and saline water at two levels (1.6 dS/m and 6 dS/m). The results showed that growth characteristics, yield components, biological yield, and grain yield were affected by deficit irrigation water and saline water. These treatments significantly reduced all of the measured traits. The lowest leaf area was observed in rain-fed with 6 dS/m saline water treatment, which suppressed this trait by 61% compared to 125% water requirement with 1.6 dS/m saline water treatment. The highest and the lowest biological yield and grain yield were observed in 125% water requirement with 1.6 dS/m saline water and rain-fed with 6 dS/m saline water treatments, respectively. Non-significant differences were observed in biological and grain yield between 125% water requirement with 1.6 dS/m saline water and 100% water requirement with 1.6 dS/m saline water treatments. Biological yield and grain yield were decreased in rain-fed with 6 dS/m saline water treatment compared to 125% water requirement with 1.6 dS/m salinity treatment by 72% and 88%, respectively. Results of this study showed that although the greatest amounts of yield attributes were obtained upon using the 125% water requirement treatment, but these attributes were not significantly greater than the 100% water requirement treatment. Consequently, in areas with scarce water and saline water (6 dS/m), reliance on the 75% water requirement with 6 dS/m saline water and 100% water requirement with 1.6 dS/m saline water treatments may suffice to achieve an acceptable grain yield and to save water under saline water condition.

K. Eskandarizanjani, M. Goldani, A. Nezami, A. H. Shirani Rad, F. Shekari,
Volume 11, Issue 3 (11-2021)
Abstract

In order to investigate the effect of salicylic acid application on reducing the effects of cold stress due to delayed planting in rapeseed genotypes, this experiment was conducted as a factorial-split plot during the 2014 and 2015 growing seasons in the Faculty of Agriculture, University of Zanjan, Iran. Interaction of the sowing date (11th September and 7th October) and salicylic acid (control (spray with distilled water), 250 µM and 500 µM) were as the main-plot and rapeseed genotypes (Karaj-3, L14, Okapi, Zarfam) were assigned to subplots. The effect of planting date* salicylic acid* genotype on winter survival percentage, grain yield and its components, harvest index, and biomass was significant. Delayed planting reduced survival percentage of all rapeseed genotypes; but the severity of reduction varied depending on the genotype. It was also found that the decrease in survival percentage due to delay in planting can be partially compensated for by the use of salicylic acid, which varied depending on the salicylic acid concentration and genotype. Delayed planting date reduced grain yield in all genotypes and salicylic acid application had the opposite effect and increased grain yield. Karaj-3 had the highest grain yield on 7th October planting date and 500 µM salicylic acid, while Zarfam had the lowest grain yield on 11 September and 0 µM salicylic acid. Application of salicylic acid compensated for part of the reduction in yield due to delay in planting, so that the lack of application of salicylic acid and the use of 250 and 500 μM salicylic acid in planting on 7 October caused grain yield reduction in Karaj-3 genotype by 36, 31 and 18% respectively, compared to 11 September, while grain yield in L14 genotype showed 26, 21 and 8% reduction respectively, compared to 11 September planting date. The grain yield of Zarfam genotype at delayed planting date decreased by 9% and 5% and increased by 13%, respectively, in conditions of non-application and application of 250 and 500 μM salicylic acid compared to the 11 September planting date. There was a positive significant correlation between grain yield components and winter survival percentage. Although delayed planting reduced grain yield, yeld components, harvest index, and biomass in all genotypes, the severity of the decrease varied among the genotypes. Consumption of salicylic acid moderated the effect of delay in planting and this modulatory effect was higher in the application of salicylic acid with a concentration of 500 μM than 250 μM. In general, the results showed that in both planting dates, the Karaj-3 genotype had the highest grain yield in all salicylic acid levels, so it is recommended for planting in areas with similar conditions.

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.
J. Shafagh-Kolvanagh, S. Zehtab-Salmasi, K. Ghassemi-Golezani, M. Amani, B. Shokati Amrollah,
Volume 15, Issue 1 (2-2025)
Abstract

Extended Abstract
Introduction: Intercropping is a vital strategy in sustainable agriculture; it enhances production sustainability by improving both the yield and quality of crop plants. This strategy increases biodiversity and capitalizes on the interactions among different plant species, including their morphological and ecophysiological differences. Such diversity can lead to more efficient use of resources, reduced production costs, and ultimately, an increase in net farm income. The integration of legumes in intercropping systems is particularly beneficial, as these species have the ability to fix atmospheric nitrogen, enriching the soil and supporting the growth of neighboring plants from a different crop species like dill (Anethum graveolens L.). This study aims to identify the optimal mixed treatment combinations for dill, focusing on both grain yield and essential oil yield in intercropping versus monoculture systems. By systematically evaluating various intercropping treatments, the research seeks to uncover the most effective plant combinations that enhance the performance of dill as an edible vegetable. The findings will not only contribute to the understanding of sustainable agricultural practices but provide also practical recommendations for farmers, promoting the adoption of intercropping systems that can lead to improved ecological benefits and economic viability in farming.
Materials and Methods: In order to achieve the most appropriate planting combination in terms of spatial arrangement and to investigate its effects on yield, yield components, as well as the percentage and efficiency of essential oil, an experiment was conducted using a randomized complete block design with seven treatments and three replications at the Research Farm of the Faculty of Agriculture, University of Tabriz, Tabbriz, northwest Iran. The different cultivation patterns included a pure stand and six mixed cultivation patterns of the two plants, comprising three additive ratio patterns (1:20, 1:40, and 1:60) and three replacement ratio patterns (1:1, 1:2, and 1:3).
Results and Discussion: The results of the study revealed that dill plants cultivated in various mixed cropping patterns exhibited remarkable performance, particularly in the 1:20 and 1:60 planting ratios. These specific intercropping arrangements resulted in the highest inflorescences/plant, indicating a strong reproductive capacity that is essential for maximizing seed production. Additionally, these ratios also led to an increased grains/plant, which is a critical factor for final grain yield. The biological yield, which encompasses the total biomass produced, was also significantly enhanced in these mixed cropping patterns, suggesting that the synergistic interactions between the crops in these ratios contributed positively to growth and productivity. Moreover, the study found that the percentage and yield of essential oil were significantly influenced by the different mixed cropping patterns. The 1:20 and 1:60 ratios not only yielded the highest essential oil content but consistently performed well also across all three stages of oil extraction: flowering, milky, and maturity. This finding underscores the importance of selecting appropriate intercropping ratios to optimize essential oil production. Among the three stages of oil extraction, the milky stage emerged as the most productive, yielding the highest essential oil quantity. This stage is characterized by the plant’s investment in the grain constituents, which likely enhances the biosynthesis of essential oil compounds. These insights suggest that schedueling the harvest to coincide with the milky stage can significantly benefit essential oil yield, providing valuable information for farmers aiming to maximize both grain and oil production in dill cultivation. Taken to gether, the findings highlight the advantages of utilizing specific mixed cropping patterns, particularly the 1:20 and 1:60 ratios, to enhance the agronomic and economic viability of dill as an edible and aromatic crop. This research not only contributes to the understanding of intercropping benefits but offers also practical recommendations for farmers seeking to improve their production practices through sustainable agricultural methods.
Conclusions:Our findings suggest that intercropping can significantly enhance dry matter accumulation and improve the overall quality of dill products. This strategy can result in a more efficient use of land and resources, ultimately contributing to higher yields compared to monoculture systems. The specific observation that the 1:1 treatment and sole cropping demonstrated favorable performance in dry matter accumulation indicates that there is a potential for both mixed and single cropping systems to be effective. The 1:1 ratio suggests a balanced competition between the two species, allowing them to complement each other’s growth requirements. In this scenario, both dill and fenugreek can benefit from shared resources while minimizing competition, leading to enhanced growth and productivity.
 


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