JOURNAL OF CROPS IMPROVEMENT (JOURNAL OF AGRICULTURE)
Year:2019 | Volume:21 | Issue:1 |Papers Count:8

In order to study the effect of row spacing and plant density on agronomic traits of dual-purpose sunflower, cultivar Lakomka, a two-year study has been carried out in Khoy from 2014, which is a factorial experiment based on RCB design, with four replicates. The treatments of this experiment include row spacing at two levels (60 and 75 cm) along with five plant densities (30, 45, 60, 75, and 90 thousand plants. ha-1). According to the results, there is no significant difference between 60 and 75 cm row spacing for any of the studied traits; however, plant density has a considerable effect on all these traits. As plants get denser, the phenological stages accelerate and head diameter decrease, even though plant height and oil content ascend. Also, seed weight is decreased from 115 g to 84 g, while oil content is increased from 36% to 39% as plant density rises from 30 to 90000 plants. ha-1. The highest seed and oil yields (4132 and 1611 kg ha-1) have been observed in plant density of 75000 plants. ha-1. The regression analyses reveal that oil content, plant height, and seed number are the most effective traits to estimate oil yield. Results from this study indicate that plant densities of 75 and 45000 plants. ha-1 are optimum densities for production of cultivar Lakomka with the highest oil yield as well as confectionary usage in the city of Khoy, West Azarbaijan Province, Iran.

In order to investigate the effect of drought stress and inoculation with mycorrhizal fungi and rhizobium bacteria on quality and quantity of soybean yield, an experiment has been conducted as a split-plot factorial in a RCBD with three replications at research farm of Agricultural Highschool of Urmia during 2017 cropping season. The main plot has been drought stress, including optimum irrigation, and moderate and severe drought stress, while the sub plots include mycorrhizal fungi in three levels (without mycorrhiza and inoculation with Glomus mosseae and G. intraradices) as well as Rhizobium japonicum in two levels (without inoculation and inoculation with R. japonicum). In response to moderate drought stress, protein percentage has increased, though raising the severity of drought stress reduces protein and oil percentage. Irrigation along with inoculation with mycorhizal fungi, especially G. mosseae, enhances the number of seeds per plant, protein percentage, and protein yield. Under three irrigation conditions, inoculation with bacteria, in comparison with non-inoculation, boosts seed, oil, and protein yield, with inoculation with bacteria and mycorhizal fungi increasing seed and oil yield. Study of correlation coefficient shows that there is a positive and significant correlation between seed yield with 1000-seed weight, number of seeds per plant, and oil and protein yield. According to the results of this research, using mycorrhiza G. mosseae and inoculation with R. japonicum can have a positive effect on the quantitative and qualitative traits of soybeans.

In order to study the effect of irrigation levels and application of methanol and nano iron oxide on yield and grain filling components of sunflower (Helianthus annuus L. ), a factorial experiment has been conducted based on randomized complete block design with three replications at the research farm of Islamic Azad University, Ardabil Branch, within 2017. The experimental factors include application of methanol (foliar application with water as control along with 20 and 30 volume percentage), nano iron oxide (foliar application with water as control as well as application of 0. 3, 0. 6, and 0. 9 g. L-1), and irrigation levels (full irrigation as control, irrigation withholding at flowering stage, and irrigation withholding at grain filling period). Results show that the highest grain yield (2952 kg/ha), number of filled grains per head (1121 grains per head), 1000-grain weight (50 g), rate and grain filling period, effective grain filling period (i. e., 0. 00239 g/day, 42, and 33 days, respectively), and chlorophyll index (56) have been obtained in full irrigation and high levels of methanol and nano iron oxide, with maximum proline and soluble sugars content (11. 1 μ g/g FW and 72 mg/g FW) belonging to irrigation withholding at flowering stage and application of high rates of methanol and nano iron oxide. The minimum rates of these have also been obtained in full irrigation without any application of methanol and nano iron oxide.

In order to study the effect of sugar beet (Beta vulgaris) seed coating with organic fertilizer of Teprosyn, Kadostim and Zagroot on the emergence and seedling growth characteristics, a greenhouse experiment has been conducted at the Faculty of Agriculture and Natural Resources of Mohaghegh Ardabili University within 2015. There, the treatments are arranged in a factorial experiment, based on completely randomized block design with three replications, with the experiment factors including seed washing (washing and without washing), hybrids (Shokoufa and Pars), and seed coating with different amounts of organic fertilizers of Teprosyn, Kadostim, and Zagroot, not to mention the control and adhesive treatments. Results show that seed washing treatment has increased the percentage of emergence, velocity of emergence, and the percentage of plant establishment, and decreased the time to 10% and 90% of the emergence. The percentage of seedling emergence have been superior in seed coating treatments with Zagroot (20 ml per kg of seed) responsible for 95% of emergence and seed coating with Zagroot (30 ml per kg seed) for 94. 16%, compared to other treatments. The percentage of plant establishment has been higher in the Pars hybrid than the Shokoufa. Among different treatments of seed coating, seed treatment with Zagroot has had the highest leaf area and root and leaf dry weight. In general, seed coating with Teprosyn and Zagroot has improved seedling growth and increased plant establishment in this research.

The present study deals with the effect of different levels of Trichoderma fungus on some morpho-physiological, flowering, and biochemical traits of tuberose flower under drought stress conditions, for which it has conducted an experiment in a factorial based on completely randomized design with three replications at Research Greenhouses of Ferdowsi University of Mashhad during the year 2016. Drought stress treatments of this experiment include irrigation at 100%, 50%, and 25% of field capacity with fungal treatments being composed of three levels of 20%, 10%, and 0% of fungus. Results show that drought stress has increased the amount of antioxidant, total chlorophyll, and proline. In addition, it has had a negative significant effect on fresh and dry weights of root and biomass, relative water content of leaves, floret diameter, and number of open floret, but Trichoderma has largely moderated these negative effects. The highest amounts of total chlorophyll (1. 04 mg/g leaf fresh weight) and relative humidity of leaf water (85. 2%) belong to 10% level of fungus, which has not differed significantly from the ones at 20% level of fungus. As for the rest of the traits, the highest levels have been found at 20% level of fungus. Since Trichoderma fungus, along with reducing the effects of drought stress, increases vegetative growth and raises the number of open florets (considered an important factor in its marketability) of tuberose flower, its use is quite suggested as a biological factor to increase the quality of tuberose flower in similar conditions.

In order to investigate the effects of different intercropping ratios of fenugreek and savory on their yield and essential oil, an experiment has been conducted, based on a randomized complete block design (RCBD) with three replications in Ahar Faculty of Agriculture and Natural Resources. The treatments include different row intercropping ratios, 50% savory + 50% fenugreek (1+1), 33% savory + 67% fenugreek (1+2), 67% savory + 33% fenugreek (2+1), 50% savory + 50% fenugreek (2+2), 25% savory + 75% fenugreek (1+3), 75% savory + 25% fenugreek (3+1), and sole cropping fenugreek and savory. The study measures yield, essential oil percentage and essential oil yield of fenugreek and savory, biomass of savory, land equivalent ratio, actual yield loss or gain, relative crowding coefficient, intercropping advantage, competitive ratio, relative value total, and system productivity index. Results reveal that fenugreek yield in sole cropping are significantly higher than other intercropping ratios, with the highest percentage of seed protein of fenugreek and dry weight, essential oil percentage and essential oil yield of savory, obtained in 1 row savory + 1 row fenugreek. The highest fenugreek essential oil yield is achieved in sole cropping and 1 row savory + 3 rows fenugreek. Among the used intercropping treatments, the highest intercropping advantage (IA) (1. 29) belongs to 1 row savory + 3 rows fenugreek, with the maximum land equivalent ratio (LER) values (1. 94) obtained in 1 row savory + 1 row fenugreek, indicating yield improvement in intercropping systems by 94%, as compared with sole cropping. System productivity index in 1 row savory + 1 row fenugreek (1860. 3) has been more than other intercropping treatments. According to the yield and agronomic and economic benefits, it seems that 1 row savory + 1 row fenugreek is suitable for increasing the yield, the income, and land use efficiency.

Almond is highly sensitive to salt stress and one way to reduce the negative effects of this type of stress is to select a tolerant rootstock/scion. Keeping these in mind, the present experiment investigates the effects of salinity stress on some morphological, physiological, and nutritional traits of almond rootstocks with the help of a factorial experiment, conducted at Horticultural Research Institute in 2017, which was based on a completely randomized design with two factors (eight levels of rootstock/scion compositions and five levels of salinity) and in three replications. Results show that by increasing salinity from zero to eight ds/m, the highest and lowest amount of reduction in root dry weight can be observed in ‘ Shahrood 12’ /Tetra (37. 8%) and GN15 (14. 5%), respectively. Also, the lowest and highest dry weight loss in the main branch can be seen in bitter almond seedling (38. 2%) and ‘ Shahrood 12’ / GN15 (47. 9%), respectively, with the highest amount of necrosis, observed in bitter almond seedling (28. 98%) and the lowest value in ‘ Shahrood 12’ /GF677 (9. 9%). Based on the experiment, the lowest and highest changes in electrolyte leakage occurred at the rootstock of GF677 (30. 74%) and GN15 (42. 93%) with the lowest and the highest changes in sodium belonging to ‘ Shahrood 12’ /GF677 (51. 2%) as well as bitter almond seedling (82%), respectively. The results also show that by increasing salinity stress, the amount of root and leaf nutrient elements ascends initially, then to drop as salinity levels are increased further. Based on the results, ‘ Shahrood 12’ /GF677 is the most tolerable combination and ‘ Shahrood12’ , grafted on bitter almond seedling, is the most sensitive to salt stress.

The present study aims at producing healthy primary pear plants for propagation and establishing a high health maternal orchard, for which an experiment was conducted in 2014 at Agriculture Biotechnology Research Institute of Iran (ABRII), trying to evaluate the effectiveness of chemotherapy treatments (Ribavirin 0, 20, 40, and 80 mg/l) as well as the sizes of apical meristems culturing (below 0. 2 mm, between 0. 2 and 0. 7 mm, and above 0. 7 mm) on eradication of some virus strains (ACLSV, ASPV, ASGV) from seven pear cultivars ("Abate Fetel", "Beiruti", "Coscia", "Dargazi", "Louise Bonne", "Mellina", and "Spadona"). Initially, the maternal samples are tested for ACLSV, ASGV, and ASPV by RT-PCR and all explants are infected with all three viruses, with the exception of Abate Fetel and Beirut which have been free from ASPV. The chemotherapy treatments and meristems cultivation take place in vitro, with the regenerated shoots from meristem tested by RT-PCR for all three viruses. Results show that increasing the concentration of ribavirin and reducing the size of cultivated meristem are effective on elimination of all three viruses from the explants. Also, the responses from the studied cultivars and virus varieties have varied among this experiment's treatments. Samples, diagnosed as virus free by means of RT-PCR, are then proliferated, rooted, and transferred into pots to be used for later propagation along with establishment of the maternal orchard.