جستجوی مقالات مرتبط با کلیدواژه « فاصله کاشت » در نشریات گروه « زراعت »

Saffron (Crocus sativus L.) belongs to the Iridaceae family, whose dry stigmas are the most expensive spices in the world and are widely used in food and pharmaceutical industries. Correct management of planting density is one of the most important factors in the formation of saffron yield. Choosing the appropriate planting density in saffron, while increasing the exploitation of this agriculture, increases the yield and reduces the period between planting and economic yield. On the other hand, gibberellins are classified as a diverse group of plant growth regulators that enhance some physiological and biochemical pathways in plants. Gibberellins are involved in many plant development processes and the improvement of some desirable traits such as increasing stem length, uniform flowering, reducing time to flowering, and increasing flower weight. Also, considering that the study of planting density factors and the simultaneous application of gibberellic acid hormone on the qualitative traits of the saffron medicinal plant has not been done, the purpose of this experiment is to investigate the effect of dense cultivation and gibberellic acid hormone on the antioxidant activity and effective substances of saffron.

To investigate the effects of gibberellic acid and plant density on the antioxidant activity and active ingredients of saffron, an experiment was conducted with a factorial arrangement based on a randomized complete block design at the Agricultural Research Station, University of Birjand during 2017-2018 growing season. Treatments consist of gibberellic acid (0 and 20 ppm) and plant density (100, 200, and 300 corms.m-2) with three replications. After the land preparation operation including initial plowing, disk, and land leveling, plots with dimensions of 1x2 meters were created. The distance between the plots was 50 cm and the distance between the blocks was 2 meters (including the irrigation ditches). Since it is important to choose a quality root for planting in order to create a high yield, healthy roots without wounds and scratches and free from any kind of disease were prepared and planted after weighing (the average weight of each root is 8 grams). Anthocyanin, phenol, antioxidant activity, safranal, crocin, picrocin, dry stigma yield, and photosynthetic pigments were measured. Data were analyzed using SAS 9.1 software and means were compared based on the Duncan test.  

The results showed that gibberellic acid had a significant effect on different traits (P<0.05). The highest amount of phenol (629.77 mg. 100 g dry weight-1) and antioxidant (39.53%) was obtained from the gibberellic acid treatment. Therefore, the effect of gibberellic acid at the level of one percent on stigma anthocyanin was also significant and the rate of this trait was 24% higher in the treatment of gibberellic acid application than the non-application treatment. Active ingredients of saffron are influenced by gibberellic acid treatments. The highest safranal (32.5 %), crocin (140.4 %), and picrocin (58.1%) obtained from the use of gibberellic acid, and the lowest safranal (28/3%), crocin (125.1 %), and picrocin (56.6 %) obtained from control. A planting density of 300 corms.m-2 had the highest dry stigma yield. Chlorophyll a and total were increased by application of 20 ppm of gibberellic acid by 14% and 12%, respectively, compared to the control. Plant density treatments were significantly affected only on some traits of active ingredients (safranal and picrocin) at the level of one percent and the highest these were obtained from plant density with 100 corms.m-2, but it had no significant effect on other traits. 

The current study's findings revealed that the use of 20 ppm gibberellic acid had positive effects on qualitative traits of saffron and low planting density (100 corms.m-2) affected only some traits of saffron active ingredients (safranal and picrocin) and high planting density (300 corms.m-2) affected the dry stigma yield.

Cotton Planting in rows of less than 40 cm is called ultra-narrow row (UNR). In this study, we compared the effect of narrow row spacing and prevalent row spacing on the bollworm pest population. The varieties studied in this study including Sahel, Sepid variety, and Golestan variety as the first factor and two methods of planting distance of 20×80 and 20×25 cm was considered as the second factor the experimental design was a randomized complete block design with 3 replications and was performed at Hashemabad Cotton Research Station, Gorgan. The results of the analysis of variance of data for two years of the experiment showed that the effect of varieties on crop row spacing was significantly different in terms of crop yield and population of cotton bollworm. The highest mean was obtained for Golestan variety with common cultivation distance (80×20 cm) at 3855 kg per hectare and the lowest average was obtained for Sahel variety with commonly cultivated row spacing with an average yield of 1052 kg per hectare was obtained. The results of the comparison of means on the effect of variety on cultivation distance on bollworm population density showed a significant effect on variety row spacing. The highest population density of this pest was related to Golestan variety with average cultivation distance, with average 0.65 is the number of growth stages per plant. Also, the lowest population density of this pest was related to Sahel variety with 20×80 and 20×25 cm varieties with mean of 0.25 and 0.23 growth stages per plant, respectively.

In future climatic conditions, rice yields depend on environmental conditions of the growing season, such as temperature and available radiation rate, which in unfavorable conditions can lead to yield loss in some rice producing countries (Welch et al., 2010). Achievement to the appropriate plant density per unit area is one of the methods in increasing crop yields through crop management that as a result, all environmental factors fully utilized, while intra- and inter-plant competitions be minimized and on the other hand, suitable plant density can provide sufficient space for agronomical operations and high quality access. In general, suitable rice density is a density that is not detrimental for proper crop development and high grain yield. As the density increased, the number of primary and secondary panicles and spikelet per panicle decreased and the number of panicles per m2 increased linearly and with decreasing density, stem thickness increased (Ebrahimi Rad et al, 2018). Knowing the heat indices, such as the accumulated heat unit, which in most sources are referred to as growing degree days (GDD), can provide basic principles for determining the appropriate phenological stages and planting dates. Evaluation of cumulative GDD for different development stages will allow adjustment of planting date for rice genotype with the aim of adapting the environmental conditions in the growth period. Choosing the appropriate planting date is one of the important factors in effective crop management which has a great role in production control by adapting physiological, morphological and phenological processes of the plant such as germination and emergence, vegetative growth, flowering and maturity with favorable climatic conditions. Management of planting time for optimal production of each cultivar is one of the main factors affecting production that can be easily managed by the farmer based on environmental conditions. Proper planting date will optimize the use of yield factors, while inappropriate planting date will disrupt the balance of yield components in the plant (Esmaeilzadeh et al., 2017). In order to determine proper transplanting date based on GDD and the best plant density in rice (Tisa cultivar), an experiment was conducted at Rice Research Institute of Iran, Tonekabon station during 2015 and 2016. This experiment was carried out as split plot in a randomized complete block design with three replications. The main plot was three transplanting dates with 10 days intervals (May 4, May 14 and May 24) and the sub plot was allocated to plant density at three levels (12×30, 15×30 and 18×30 cm). The results indicated that there was a significant difference between the years of experiment only for the panicle length. The effect of transplanting date was significant in the majority of the measured parameters. The highest grain yield (6573.6 kg/ha) was obtained on May 24 planting date, which did not show any significant difference with the transplanting date of May 14. Although plant density treatments had no significant effect on grain yield, 28 plants per m2 (30×12 cm) had the highest grain yield (6445.2 kg/ha). With delay in transplanting, GDD and number of days from transplanting to tillering stage as well as the time required for panicle emergence and complete maturity increased. The highest and the lowest growth degree-day (GDD) from transplanting to tillering, panicle emergence and full ripening stage were obtained on May 24 and May 4, respectively. According to the results of this research, it can be stated that the farmers of the region can transplant this cultivar between May 14 and May 24 with a plant distance of 12×30 cm (density of 28 plants per square meter).

The effects of application of humic acid and planting density on vegetative and reproductive characteristics of saffron were evaluated under field conditions. Treatments were four levels humic acid (0, 5, 10 and 15 kg.ha-1) and three density plantings (50, 75 and 100 corm.m-2). This experiment was carried out as a factorial based on randomized completely block design with three replications in the research farm of Birjand University, Iran, during the cropping year 2015-2016. The results showed that humic acid levels improved the corm vegetative indices (total weight of corm, fresh and dry weight of corm). The highest total weight of corm (23.09 g.plant-1) was obtained in with 5 kg.ha-1 humic acid. The results also showed that humic acid improved the saffron flower characteristics (flower number and fresh total yield, stigma fresh and dry yield) in the second year. The highest stigma fresh (1.35 g.m-2) and stigma dry (0.23 g.m-2) yield were obtained in plants treated with 10 kg.ha-1 humic acid while the lowest values were recorded in the control group. Application of different levels of planting density had a positive effect on flower number and fresh total yield, stigma fresh and dry yield in the second year of experiment. The highest of these characteristics were observed in planting density of 100 corm.m-2. Application of different levels of planting density and humic acid had a positive effect on the stigma length and stigma fresh yield. Thus, the results showed that 5 kg.ha-1 of humic acid and 75 corm.m-2 planting density have a significant impact on vegetative and reproductive characteristics of saffron.

Whole grain product is an important rich-protein source after cereals and also is the second most important food source for human. Bean in terms of area and economic importance has the first place in Iran. It has been reported that more distance between the plants caused by more space around the plants lead to each one get more light and could have better photosynthetic activity and therefore have better growth rather than which one are closer together. Nitrogen fertilizers play an important role in the plant production. Evaluation of its application for different herbal product is very important. The aim of the present research was to evaluate the effect of different planting distances and levels of nitrogen fertilizer on yield and yield components of beans in the north of Iran.
An experiment in complete randomized blocks with split plot arrangement in three replications performed in Roudsar city in 2014. The planting distance as main factor was in 3 levels (d1=30×10, d2= 40×10 and d3=50×10) and nitrogen fertilizer as second factor was in 4 levels (N1=control, N2=30, N3=60 and N4=90 nitrogen kg/ha).
The results showed that planting distance, different levels of nitrogen fertilizer and the interaction between planting distance and nitrogen fertilizer levels on number of pods per plant, number of seeds per plant, seed yield, plant dry weight, biological yield and harvest index were significant. Plant height was affected by different levels of nitrogen and planting distance but weight of 100 seeds was affected by different levels of nitrogen fertilizer. In different planting distances, the spacing between planting rows of 40 cm for plant height, seed yield, plant dry weight and spacing between row 40 and 50 cm for the number of pod per plant and number of seeds per plant were Significant, while the highest biological yield was obtained from the spacing of 30 cm row spacing. Application of 60 kg N ha-1 for plant height, 100 seed weight, seed yield and harvest index had a significant superiority to other nitrogen levels.

In order to determine the most suitable dwarf rootstock for apple cultivar 'Red Deliciou's and optimal planting distances under climatic conditions of Meshginshahr region, this research was conducted as a split plot with randomized complete block design in three replications during two years. The two planting distances of 2 × 4 and 3 × 4 meter were as the main plot and three rootstocks MM106, M9 and M26 were as sub-plots were included in the test. Analysis of variances showed significant differences between years in terms of yield and flowers density; between the planting distances in terms of yield, fruit size and soluble solids concentration and flowers density; between rootstocks in terms of yield, fruit size, flower density and dry matter; and significant differences in yields between interactions of the planting distances × rootstocks, year × planting distances × rootstocks at 5% and 1% possibility levels. Apple CV. 'Red Deliciou's grafted on M9 rootstock in planting distances of 2 × 4 meter with 9.367 tons per hectare had the highest yield and was placed in group. Analysis of average effect of rootstock in fruit production showed that 'Red Deliciou's on M9 rootstocks produced the biggest fruit and had the highest density. Fruit size, flower density on tree and soluble solids concentration in the planting at a distance of 3 × 4 m were greater than that in 2 × 4 meter. In this study, apple fire blight disease was not observed in the treatments.

The effects of applications of humic acid and planting density on antioxidant activities and components of saffron were evaluated under field conditions. Treatments were of four levels of humic acid (0, 5, 10 and 15 Kg.ha-1) and three densities of planting (50, 75 and 100 corms.m-2). The experiment was designed in randomized block design with three replications at the research station of the Faculty of Agriculture at the University of Birjand during the growing season of 2015. Petal antioxidant compounds (antioxidan, total phenol and Anthocyanins) and active ingredients of saffron (picrocin, safranal and crocin) were influenced by humic acid and planting density treatments. The highest antioxidant activity (69.7%) was obtained in plants treated with 5 kg.ha-1 humic acid with a planting density of 50 corms.m-2. However, no significant difference was found in phenol content under different treatments. The highest anthocyanin content (46.4 mg.100 g-1) was observed in 10 kg.ha-1 humic acid with a planting density of 75 corms.m-2. Picrocin content was influenced in response to humic acid planting density and the highest value (40.60%) was obtained from 15 kg.ha-1 humic acid with a planting density of 75 corms.m-2. The highest safranal (20.1%) and crocin (55.57%) were obtained in plants treated with10 kg.ha-1 acid humic, while the lowest values were recorded in the control (15.70%) and (43.12%) respectively. Thus, the results showed that humic acid and planting density have strong impacts on antioxidant compounds and active ingredients of saffron under field conditions.

In order to investigate the effect of planting density (50, 75 and 100 cm inter-row distance) and vermicompost (0, 5, 10 and 15 t.ha-1) on growth, qualitative and quantitative criteria of gooseberry (Physalis peruviana L., Solanaceae), an experiment was conducted as factorial based on complete randomized block design with three replications in University of Tehran, in 2013. Criteria such as leaf area, collar diameter, number of lateral branches per plant, plant height, fruit number and weight per plant, weight and diameter per fruit, calyx weight, total fruit yield, fruit marketable percentage, total marketable yield, plant dry weight and quality criteria such as pH, total soluble solids (TSS), titratable acidity (TA), vitamin C, antioxidant activity and fruit color indices were evaluated. Results showed that treatments significantly affected most measured growth and yield criteria in which application of 15 t.ha-1 vermicompost increased them compared to control (non-vermicompost application) in which fruit weight per plant, total fruit yield and marketable percentage were increased 37.31, 37.82 and 11.52 percent, respectively. Also, inter-row distance of 100 cm performed better for plant growth and yield criteria. Interaction effect of 100 cm planting density and 15 t.ha-1 vermicompost caused the highest number of fruit per plant and marketable yield. The highest amount of TA and antioxidant activity obtained by application of 15 and 10 t.ha-1 vermicompost, respectively and vitamin C, TA and TSS were increased in planting distance of 50, 75 and 75 cm inter-row distance, respectively.

In order to evaluate row spacing and microelements spraying on yield and some morphological traits of peppermint، a split plot experiment was conducted based on randomized complete block design with four replications in Sari Agricultural Sciences and Natural Resources University during 2010-20. Three levels of row spacing (50 × 10، 50 × 20 and 50 × 30 cm) and two levels of microelements (no spraying and spraying) were evaluated on peppermint at two harvesting time. The results showed that the first harvesting had significant effect on plant height، oil yield and dry matter. Maximum oil yield (19. 1 lit. ha1) and dry matter (1121. 3 kg. ha-1) was obtained in the first harvesting time. Microelements had significant effect on wet matter (3321. 3 kg. ha-1)، dry matter (987. 7 kg. ha-1) and oil yield (19. 63 lit. ha-1). Maximum dry matter (1015. 5 kg. ha-1) and oil yield (20. 31 lit. ha-1) was obtained in (50 × 20 cm) row spacing with spraying. 50 × 20 cm row spacing with spraying recommended، because of maximum oil yield in peppermint.

Castor bean Rininus Communis L. is one of the most important industrial plants in energy and medicine. In order to study the density and sulfur fertilizer effects on yield and yield components of four Iranian castor beans varieties for biofuel and medicine production an experiment was conducted in 2009 and 2010 in Eizeh city Farm. The experimental design was split split-plot based on randomized complete block with 3 replications. The Studied factors included four castor beans varieties as main plots (Taj bakhsh, Ebrahim, Mousavie and Ghobadian) and three planting distance on row as sub plots (50, 60 and 70 cm) and three levels of sulphor as sub-sub plots (0, 75 and 150kg net S per hectare). The results showed that traits such as grain yield and yield components were affected by experimental factors and they were different. According to the results of this experiment, the highest and the lowest grain yields were obtained from Mousavie (11735.28 kg/ha) and Ghobadian (7172.08 kg/ha) genotypes, 70 cm (10209.1 kg/ha) and 50 cm (8126.83 kg/ha) distance and 150kg (9868.38 kg/ha) and 0kg (7950.63 kg/ha) net S per hectare respectively.

The increasing of planting density of bulbous flowers is one of the most important step for more production of ornamental plants. One of the possible methods for increasing density, is cultivation of bulb plants in multiple rows pattern. In this research, the effect of one, two, and three row planting design bed were investigated on flowering and quality of Gladiolus (Gladiolus hybrida cv.Oscar) cut flower in climatic condition of Mollasani in Khuzestan province, located in south west of Iran on 1388 through 1389.. The treatments were the cultivation of corms in on row of 30 × 20 cm (control) and two and three-bed row (20 cm on row, 30 cm between main row and/or pattern with distance of 15, 20 and 25 cm between subordinate row). The results showed that cultivation of corm in three-row bed pattern with distance of 25 cm between subordinate row and/or cultivation of two-bed and three-bed row in distance between subordinate rows of 15 and 20 cm causes significant decreases on weight of cut flower, stem diameter and height of spike. Height of cut flower was not significantly different only in treatment of two-bed row with distance of 25 cm between subordinate rows when compared to control. The number of cormels were significantly decreased In treatment of three-bed cultivation pattern with distance of 25 cm between subordinate rows, as compared to control. The number of floret, only, in cultivation pattern of two-bed and three-bed row with distance of 15 cm between rows had significantly decreased when compared to control treatment. These treatments had no significant effect on diameter of cut flower, height of spike, diameter, width and weight of corms. The results indicated that the cultivation of gladiolus in pattern of multiple rows is possible but the decrease of distance between rows, reduce the quality of cut flower. It strongly suggested that more researches require to accomplish on various distances on subordinate rows.

To determine the suitable row spacing and rate of nitrogen fertilizer for rapeseed cv. Hayola 308, a factorial experiment based on randomized complete block design with three replications was carried out in paddy fields of Rice Research Institute of Iran, Rasht, Iran, in 2003-2004 and 2004-2005 growing seasons. Row spacing at three levels: 20, 25 and 30 cm and four nitrogen fertilizer rates, based on soil testing and Water and Soil Research Institute recommendations, including: 0.7R, 1.0R, 1.3R and 1.6R from urea source. The R factor was determined as 140 Kg urea ha-1. Some important agronomic characteristics such as number of secondary branches per plant, number of siliques per plant, number of seeds per silique, silique length, 1000-seed weight, grain yield, oil content and oil yield were measured and recorded. Combined analysis of variance showed no significant differences between row spacing for grain yield. However, row spacing of 20 cm with an average seed yield of 1947 kgha-1 was relatively superior to other row spacings. Among the nitrogen rates, the highest seed yield was obtained from fertilizer rates of 1.6 R with 2189 kg ha-1. No significant differences were observed among treatments for oil content. Increasing in nitrogen application didn’t decrease the oil content. Results clearly showed that row spacing of 20 cm with average of 887.4 kg ha-1 had the highest oil yield. Nitrogen rate of 1.6R showed maximum number of secondary branches per plant (4.3), number of siliques per plant (89.7), 1000-seed weight (4.719g) and oil yield (1001 kgha-1). Row spacing of 20 cm and nitrogen rate of 1.6R had the highest seed yield, oil content and oil yield. Since there was not significant differences between 1.3R and 1.6R nitrogen rates at 20 cm row spacing for seed and oil yields, the combination of 1.3R nitrogen fertilizer and 20 cm row spacing is recommended. This recommendation package would decrease application and leaching of nitrogen and is more environmental friendly.

To determine the critical period of weed control of two planting distances on canola yield, a factorial design with 3 replications was conducted using Hayola 401 variety, in paddy field of Rice Research Institute of Iran (RRII) in Rasht, during cropping season of 2006. Planting distances (15 and 30 cm) and hand weedings (12 treatments in two sets) were the two factors of the experiment. The hand weeding treatments were in two sets, the first set was weed free periods including cotyledon stage, 0, 2, 4, 8 leaf stages and flowering stage. The second set of hand weeding treatments was weed infested periods including cotyledon stage, 0, 2, 4, 8 leaf stages and flowering stage. The two sets of hand weeding treatments were fitted to Logistic and Gompertz functions to determine the critical period of weed control in this plant. Results showed that the effect of planting distances of canola, treatments of weeding, among weeded and unweeded treatments, and their interactions were significant on grain yield, biological yields, oil production and harvest index. There were significant differences between weed infested and weed free treatment in oil yield, grain and biological yields in each planting distances. The 30 cm planting distances had significantly higher grain yield (2502.4 kg/h) than 15 cm planting distances (2141 kg/h). The critical period of weed control for 15 cm distance was between 27 and 85 days after planting (DAP) (emergence to 10-leaf stage), and between 35 to 64 DAP (2-6 leaf stages), using 10 and 5% acceptable yield reduction, respectively. In 30 cm planting distances, these periods were between 32 and 95 DAP (2-10 leaf stages) and 50 to 77 DAP (4-8 leaf stages) using 10 and 5% acceptable yield reduction, respectively.

Crop genotype with high potential in weed competition is one of the main factors affecting competition against weeds. This experiment was conducted in a split– factorial plot design with four replications in base based on randomize complete block design in National Research Institute of Bean (Khomein) in 2004. The main plot comprised of with and without weed control and sub plot comprised of the plant densities (30, 40 and 50 plant /m2 or 60, 50 and 40 cm row spacing, respectively) and two lines of the white bean (KS41105 and KS41124). The evaluated characteristics were: plant height, branches number, pod number/plant, seed number/pod, seed number/plant, 100seed weight and grain yield. Results of the this experiment showed that decrease of row spacing caused increasing of the grain yield in both weed free and weed infest conditions. The maximum grain yield in KS41105 line with and without weed control obtained in 40 and 50 cm row spacing, respectively. In KS41124 line, maximum grain yield with and without weed control obtained in 50 and 40 cm row spacing, respectively. In two lines weed infested condition caused decreasing of the pod number/plant, seed number/plant and 100seed weight, but there were not any effect on seed number/pod.