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Showing 5 results for Harvest Index
Mr Yaqub Yazdani Chamheidary, Dr Mahmoud Ramroudi, Dr Mohammad R. Asgharipour,
Volume 1, Issue 3 (10-2014)
Abstract
This experiment was conducted to evaluate the effects of Fe and Zn foliar spraying on yield, yield components and essential oil quality of cumin under drought condition based on split plot arrangement in randomized complete block design with three replications at Zabol University Research Farm in 2012. Drought stress as a main factor included three irrigation intervals of 5, 10 and 15 days and micro-nutrients spraying as a sub factor included 4 levels of non-spraying (control), Fe spraying, Zn spraying and their combination. The results indicated that increasing drought stress reduced plant height, number of umbels per plant, 1000 seed weight, seed and biological yield. The effects of micro-nutrients spraying on plant height, number of umbels per plant, number of seeds per umbels, seed and biological yield, harvest index and essential oil yield and percentage was significant and the greatest seed yield (833.8 kg/ha) was obtained at plant sprayed with Zn. Interaction of micro-nutrients spraying and drought stress was significant on number of seeds per umbels, 1000 seed weight and biological yield and the greatest biological yield was obtained at 5 days irrigation intervals and Zn spraying.
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Volume 3, Issue 1 (9-2016)
Abstract
The present study was conducted to evaluate the effects of planting date and plant density on yield and yield components of safflower cv. Local Esfahan. Therefore, a factorial experiment based on randomized complete blocks design with four replications was carried out in research farm of Vali-e-Asr University of Rafsanjan in 2012. Factors were included planting dates (5 April, 25 April and 18 May) and plant density (15, 40, 65 and 90 plant/m2). The trend of changes in plant head number and head seed number in the first and second planting dates was described by means of power equation. Results showed plant head number decreased with slope of 0.79 and 0.78 in the first and second planting dates. Also, head seed number decreased with the slope of 0.30 and 0.26 in the first and second planting dates. In the third planting date, these yield components decreased linearly with the slopes of 0.03 and 0.15, respectively. In the first planting date, seed yield per unit area decreased linearly with slope of 1.03. In the second and third planting dates, trend of yield variation was described by a quadratic equation. Regarding these equations, optimum plant density to obtain maximum seed yield was estimated 55.8 plant/m2 for the second planting date and 56.6 plant/m2 for the third planting date.
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Volume 3, Issue 1 (9-2016)
Abstract
In order to study yield and yield components of wheat under the influence of genotypes and planting date under rainfed conditions, an experiment was carried out in the Agricultural Research Station of Gonbad-e-Kavous in 2010-2011. The experiment was arranged in a factorial design based on randomized complete block design with five genotypes (Zagross, Koohdasht, Morvarid, Lain 17 and N-80-19) and four planting dates (17 Des. 2010, 3 Jan. 2011, 20 Jan. 2011, and 6 Feb. 2011) with three replications. The results revealed that biological yield, grain yield and yield components (except for seed weight) decreased with a delay in planting, but harvest index increased. The highest (480.9 g/m2) and lowest (337.6 g/m2) grain yield was produced at the first and late planting date, respectively in such a way that in every day delay in planting date, the yield was decreased (2.81 g/m2) i.e. 0.58 percent. Koohdasht and N-80-19 produced the highest and lowest grain yield and biological yield, respectively. There was a positive and significant correlation between grain yield and biological yield (r=0.94**) but it did not have any significant correlation with harvest index. Generally, yield reduction happened not only due to the decrease of the number of seed per spikes and the number of spikes/m2, as a result of delaying in planting date but also due to the reduction of growth period.
Hadiseh Faramarzi Kohsar, Hossein Sabouri,
Volume 7, Issue 13 (9-2023)
Abstract
Introduction: In order to select their breeding goals among different physiological traits, plant breeders need to categorize the limitations as well as the capabilities of plants. This issue has led to the emergence of a concept called ideal type. Achieving the ideal type of agricultural plants requires the use of appropriate statistical methods. The aim of this study is to introduce the method of using regression modeling to determine the ideal type of crop plants on the rice plant. In breeding programs, it is very important to estimate the amount of yield based on the change in effective plant traits, which can be identified using regression modeling. In plant breeding, correlation between traits is of special importance, because it determines the amount and type of relationship between two or more traits. In plant breeding, correlation between traits is of particular importance, because it determines the degree and type of relationship between two or more traits. Correlation between different traits can help researchers in indirect selection using traits that are easier to measure in order to achieve self-sufficiency.
Materials and methods: For this purpose, a study on 124 lines of the ninth generation of two varieties of rice (Ahlomi Tarom and Dorfak) was conducted at Gonbad Kavous University, Iran, using a randomized complete block design with three replications in two growing seasons of 2015 and 2016. Irrigation was done until the maximum stage of tillering in stress-free conditions (flooding). From this stage until the end of the growth period, irrigation was completely stopped. Among the measured traits, using stepwise regression, four traits of plant weight, panicle weight, 100-seed weight, and harvest index were identified that had the greatest role in increasing yield. Then the correlation between the selected traits and the rate of increase in performance was evaluated and the rate of increase in performance (percentage) resulting from that trait in relation to the total increase in performance was calculated. Regarding negative correlation between the harvest index and plant weight, three hypotheses were evaluated, that in each assumption the amount of increase in yield was estimated. Data analysis was carried out using SAS software.
Results: The results indicate that if the correlation between the harvest index and plant weight, is not breakable, ideotype yield variation would have an increasing of 1125.5 kg/ha. If with increasing plant weight, harvest index stay at moderate level, it would be an increasing of 850.78 kg/ha and if correlation between plant weight and harvest index is breakable, it would be an increasing of 148.5 kg/ha. The method used in this study, due to the fact that the genetic differences between the lines are noticeable, can be a way for the breeders to move towards yield increasing in rice cultivars.
Conclusion: The purpose of this article is to introduce the method of using regression modeling in determining the ideal type of rice crop plant, and considering the negative correlation between the two attributes of harvest index and plant weight, three hypotheses were proposed. The results showed that if a change is made in relation to the selected traits, it will increase performance.
Mohammad Mirzakhani, Ailreza Dadian,
Volume 7, Issue 14 (3-2024)
Abstract
Introduction: One of the most strategic crops in our country is wheat providing 45% of the protein and 55% calories necessary for the nutrition of our country’s population need. Nitrogen plays a vital role in boosting the yield of wheat and its lack is noticeable compared with other chemical components. Nowadays most cultivatable soils need nitrogen. Generally, the farmers use nitrogen fertilizers more than the recommended amounts to obtain higher yields.
Materials and methods: To evaluate the effect of time, rate, and method of nitrogen application on yield and yield components of winter wheat, this study was carried out in the field of Payaam Nour Arak University in Markazi province in 2019. A factorial arrangement of treatment in a randomized complete block design with three replications was used. Time of nitrogen application (50% of nitrogen in planting date + 50% of nitrogen in tillering stage, 50% of nitrogen in tillering stage + 50% of nitrogen in stem elongation, and 50% of nitrogen in stem elongation + 50% of nitrogen in heading stage), rate of nitrogen application (150 kg/ha urea and 300 kg/ha urea) and method of nitrogen application (mix with soil, using by irrigation and foliar application) were assigned in plots. Each subplot consisted of 4 rows, 5 m long.
Results: Results indicated that the effect of using time treatment on characteristics such as plant height, number of spikelets per spike, number of grain per spike, number of grain per spikelet, spike density, biological yield, harvest index, and grain yield were significant. The effect of nitrogen rate treatment on plant height, root length, number of spikelets per spike, spike density, biological yield, harvest index, 1000 grain weight, and grain yield was significant, too. Results indicated that treatment (using of 50% urea in planting date + using 50% urea in tillering stage) with an average grain yield (3219 kg/ha) and treatment (using 50% urea in stem elongation + using 50% urea in heading stage) with an average of grain yield (2797 kg/ha) was significantly superior to the other treatments.
Conclusion: The results of the recent experiment have shown that delaying the application of nitrogen fertilizers can significantly decrease the yield of seeds, by up to 13%. This delay indicates a postponement in the physiological step of the plant growth process. Nitrogen plays a crucial role in the growth and development of wheat, which is why it's important to carefully manage its application time, the method of application, and the amount applied.
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