جستجوی مقالات مرتبط با کلیدواژه "seedling establishment" در نشریات گروه "منابع طبیعی"

This study evaluated different methods of improving seed germination in tamarind (Tamarindus indica L.). The experiment was laid out in a completely randomized design and each treatment was replicated four times. Treatments were consisting of distilled water for 24 h at ambient temperature, hot water 80 Ċ for 5 min, potassium nitrate (KNO3) at 1 and 2% for 24 h, sulphuric acid (98% H2SO4) for 5 min, sulphuric acid (50% H2SO4) for 10 min and control (seeds were not treated). Results showed that the greatest percentage and speed germination and was observed in treatment of sulphuric acid (98% H2SO4) for 5 min. The lowest Mean time to germination was obtained in sulphuric acid (98% H2SO4) for 5 min followed by potassium nitrate at 1% . Maximum seed vigour index was observed in sulphuric acid (98% H2SO4) for 5 min that had no had no significant difference with sulphuric acid (50% H2SO4) for 10 min and potassium nitrate (1 and 2%) for 24h. pre-treatment of distilled water and hot water were not effective in improving seed germination of tamarind. The highest number leaf, length of shoot and root, fresh and dry weight of stem and root was observed in potassium nitrate at 1% for 24h followed by potassium nitrate at 2%. Therefore, the results showed that pre-treatment of seed with potassium nitrate 1% for 24h is effective way to improve seed germination and early growth of tamarind.

This study evaluated different methods of improving seed germination in date palm (Phoenix dactylifera L.) of Medjool cultivar. The experiment was laid out in a completely randomized design and each treatment was replicated four times. Treatments were consisting of distilled water for 24 h at ambient temperature, potassium nitrate (KNO3) at 0.5 and 1% for 24 h, sulphuric acid (50% H2SO4) for 3 min, sulphuric acid (98% H2SO4) for 3, 5 and 10 min, boiling water for 5 and 10 min and control(seeds were not treated). The best seed germination and seedling growth were obtained in seed soaking treatments in distilled water and potassium nitrate. The greatest percentage and speed germination was observed in treatment of potassium nitrate (KNO3) at 0.5 % for 24 h. The seeds treated with boiling water for 5 and 10 min and sulphuric acid (98% H2SO4) for 3, 5 and 10 min, did not germinate at all. The lowest Mean time to germination was obtained in distilled water for 24h that had no significant difference with distilled water for 48h, potassium nitrate (0.5 and 1%) for 24h. The highest fresh and dry weight of stem was observed in distilled water for 48 h treatment. The greatest root length was related to control, distilled water (48h) and potassium nitrate (1%) treatments. There was no significant difference between the treatments in shoot height. Therefore, pre-treatment of seeds with distilled water or potassium nitrate effective way to improve seed germination of date palm.

Percentage and rate of seed germination in laboratory are usually different from field, especially under rainfed conditions. Therefore, to assessment of standard germination test to predict seedling emergence and establishment of lentil, two separate experiments were conducted under laboratory and farm conditions. Eight lentil seed lots (includes four cultivars Kimia, Bilesavar, Qazvin and Local with different storage periods) were evaluated by the standard germination test and the rainfed farm and some indices related to seedling emergence (includes seedling emergence rate, mean time to emergence, mean daily emergence and final emergence percentage) were measured. The results of the laboratory and the farm tests showed that the seed lots were different significantly in terms of seed and seedling vigor characteristics. The correlation coefficients illustrated that the final germination percentage, the normal seedling percentage and the seed storage usage in laboratory test had positive correlations with the seedling emergence percentage in the farm experiment. The mean daily germination and the germination rate in the laboratory test had the positive correlations with the seedling emergence rate in the farm test. So it seems that, the above mentioned traits in standard germination test can use to predict seedling emergence of lentil in rainfed farm.

To study the effects of artificial seed ageing on germination indices in the laboratory condition and seedling establishment and yield of two red kidney bean genotypes in the field condition, an experiment was carried out at Research Field of Faculty of Agriculture, University of Tehran, Karaj, Iran in 2011. The two experiment design, were as factorial with four replications arranged in randomized complete blocks design (RCBD) and complete randomized design (CRD) for field and laboratory condition, respectively. The experimental treatments consisted of four levels of seed ageing – 0 (control), 2, 4 and 6 days seed ageing – and two red bean genotypes (Akhtar and Sayyad). Results showed that germination percentage, germination rate, normal seedling and seedling vigor index significantly decreased by seed ageing treatment in standard germination test. Also, seed ageing significantly decreased germination percentage, germination rate, seedling length and dry weight, normal seedling and seedling vigor index in accelerated ageing test. Studied genotypes was different in terms of germination percentage, germination rate, normal seedling, seedling length, seedling vigor index and electrical conductivity test. In the electrical conductivity test, seed leakage increased by increment of seed ageing level and is sever in Akhtar compared to Sayyad. In the field condition, seedling emergence and grain yield significantly affected by genotype and seed ageing. Seedling emergence index, seedling establishment percentage and grain yield decreased by seed ageing treatment that was severe in Akhtar than that of Sayyad genotype.

In order to investigate and determine the best laboratory test for predicting seedling emergence of canola (Brassica napus L.) in field conditions, two experiments were conducted using three canola cultivars (RG003, Sarigol and Zarfam). In the first experiment, different laboratory tests including standard germination (SG), germination rate (GR), seedling dry weight (SDW), seedling length (SL), accelerated aging (AA) and electrical conductivity (EC) were conducted as a factorial experiment in a completely randomized design with three replications. In the second experiment a randomized complete block design with three replications was used in field conditions. The results indicated that there was not any significant differences between cultivars in terms of SG and GR. Similarly, there was not significant differences between cultivars in terms of SDW, SL and EC after AA for 24 hours at 41 °C. But, GR, EC, SL and SG after AA for 24 and 48 hours at 41 °C showed significant differences among the cultivars. Generally, the results of this study indicated that EC, SG and AA for 24 and 48 at 41 °C can well predict the percentage of canola seedling emergence in field conditions. Therefore, these tests can be suggested for prediction of canola seedling emergence

In order to evaluate the role of seed osmopriming on the emergence, seedling establishment, grain yield and yield components of three soybean cultivars a factorial experiment was conducted on the basis of randomized complete blocks design with three replications at research farm of Tarbiat Modares University on summer 2010. Experimental materials were threesoybeancultivars (Telar, DPX and 032) producedunderdifferent levels ofwaterdeficit (irrigation after 50, 100 and 150 mm evaporation from evaporation pan class A) in the field of Seed and Plant Improvement Institute, Karaj in previous years. Seed osmopriming in five levels includes osmotic potentials -5, -10, -15 and -20 bar created by PEG6000 andnonpriming(control). Results showed that water deficit stress on mother plant decreased field emergence percentage and field emergence rate. However seed osmopriming improved emergence percentage, emergence rate and grain yield of seeds produced in diffrent irrigation conditions so that in seeds exposed to mild and sever stress condition, osmopriming with solution -20 bar increased the traitsmeasured incomparisonwithcontrol. The most grain yield and pod number.plant-1 was observed in seed osmopriming by -15 bar potential. It seems that the use of osmopriming is appropriate for compensation water deficit stress and improvement field emergence and grain yield