The Role of Mycorrhiza in Drought Tolerance of Marigold (Calendula officinalis L.)

To study the effect of mycorrhizal symbiosis and drought stress on marigold, a factorial experiment in a completely randomized design with three replications was conducted at the Plant Research Laboratory of Islamic Azad University, Neyshabur branch in 2014. The first factor consisted of application and non-application of mycorrhiza (Glomus intraradices) and the second factor consisted of drought stress with three levels (irrigation based on 100%, 75% and 50% of field capacity). The results showed that growth parameters like plant height, leaf number, leaf area, root, shoot dry/fresh weight, Chla and Chlb content were significantly decreased by drought stress in both mycorrhizal and non-mycorrhizal plants. However, inoculation of plants by mycorrhizal fungus increased growth parameters and photosynthetic pigments as compared with non-mycorrhizal ones. Traits like RWC, potassium and phosphorus in response to drought stress were decreased. Inoculation of plant roots with Mycorrhizal fungi increased significantly RWC, potassium and phosphorus content of the plants under drought conditions as compared with non-inoculated plants. The results also showed the mycorrhizal symbiosis by Glomus intraradices improved drought tolerance of marigold through enhancing the absorption of water and mineral ions

Growth and biochemical changes of sorghum genotypes in response to carbon dioxide and salinity interactions

In this study, the interactive effects of atmospheric CO2 concentration and salinity were evaluated on the growth of four sorghum genotypes (SG1, SG3, SG14, and SG28). For this purpose, sorghum plants were exposed to ambient (380±50 µmol mol−1) and elevated (700±50 µmol mol−1) CO2 concentrations under two salinity levels (1.55 and 10.55 dS m−1). Elevated CO2 increased shoot (10–25%) and root (9–26%) dry weights, the concentrations of chlorophyll a, chlorophyll b, carotenoids, and K+, and the activities of catalase, ascorbate peroxides, and superoxide dismutase but decreased those of Na+ and water-soluble carbohydrate. Increases of 14.9 and 8.6% in shoot dry weights, 14.4 and 9.6% in root dry weights were observed under the non-saline and saline conditions, respectively. While all genotypes showed increased biomass production in response to elevated CO2 under non-saline treatment, only two genotypes were positively afected by the elevated CO2 under saline condition. Moreover, the scales of increases in plant biomass were greater under the non-saline treatment. The results of this experiment showed that the response of sorghum to elevated CO2 depended on both salinity level and genotype

بهینه‌سازی عملیات پالایش آفلاین روغن هیدرولیک دروگر نیشکر دوره10 شماره1 سال1399

The purpose of this study was to model and optimize the offline refinement operations of sugarcane harvester hydraulic oil using RSM. For this purpose, the effects of independent variables of operating hours (250, 500 and 750 hours), Twin Dip Filter Mesh (7, 9 and 11 microns) and hydraulic oil refining times (0, 1 and 2) on variables of water contamination, uncleanness level (NAS), silicon (Si), viscosity (Vis) and oil acid number (TAN) were evaluated. The results indicated that all models were suitable for water contamination, uncleanness level (NAS), silicon (Si), viscosity (Vis) and oil acid number (TAN) for describing experimental data. In addition, the desirability function showed that the optimum conditions for the offline refinement operations of the hydraulic oil of the sugar cane harvester included 728.61 operating hours, the 7-micron filter mesh, and the two refining times of the oil. Under this condition, the amount of water contamination, the uncleanness level (particles 5 to 15 micrometers), Vis, Si, and TAN were equal to 187.63 ppm, 234000, 5.91 ppm, 66.34 centistokes and 0.65 (mg KOH g-1), respectively.روش سطح پاسخ (RSM)، مجموعه‌ای از تکنیک‌های آماری و ریاضی برای طراحی آزمایش‌ها، مدل‌سازی، بهبود دادن و بهینه‌سازی فرآیندها می‌باشد. هدف از مطالعه حاضر مدل‌سازی و بهینه‌سازی عملیات پالایش آفلاین روغن هیدرولیک دروگر نیشکر به روش RSM بود. بدین‌منظور، اثرات متغیرهای مستقل ساعات کارکرد (250، 500 و 750 ساعت)، مش فیلتر مکشی دوقلو (7، 9 و 11 میکرون) و دفعات تصفیه روغن هیدرولیک (0، 1 و 2) روی متغیرهای وابسته آلودگی آب، سطح عدم تمیزی (NAS)، سیلیسیوم (Si)، ویسکوزیته (Vis) و عدد اسیدی روغن (TAN) ارزیابی شد. نتایج نشان داد که همه‌ی مدل‌های به‌دست آمده برای آلودگی آب، سطح عدم تمیزی (NAS)، سیلیسیوم (Si)، ویسکوزیته (Vis) و عدد اسیدی روغن (TAN) برای توصیف داده‌های آزمایشی مناسب بودند. علاوه‌بر این تابع مطلوبیت نشان داد که شرایط بهینه عملیات پالایش آفلاین روغن هیدرولیک دروگر نیشکر شامل ساعت کارکرد 61/728 ساعت، مش فیلتر 7 میکرون و دفعات تصفیه روغن 2 بود. تحت این شرایط، مقدار پارامترهای آلودگی آب، سطح عدم تمیزی (تعداد ذرات 5 تا 15 میکرومتر)، Si، Vis و TAN به‌ترتیب برابر با ppm 63/187، 234000، ppm 91/5، 34/66 سانتی استوک و mg KOH/g 65/0 به‌دست آمد

Economical Assessment of Replacing and Refining Methods of Hydraulic Oil of Sugarcane Harvesters in Sugarcane Cultivation Industry of Khuzestan

Contamination due to hydraulic fluids exerts deleterious effects after a long time, however this factor is often ignored or its consecutive breakdowns and system failures are considered due to other factors. Therefore, in order to prevent the likelihood of occurring such problems, the following two strategies are presented: using oil change method to replace all of the hydraulic fluids from the discharge system with the new oil and using offline hydraulic oil filtration system for the removal of contaminated oil particles. In this regard, the present study aimed to investigate the economic status of cane sugar harvesting machines with an emphasis on hydraulic oil filtration process in seven units of sugarcane developmental company and affiliated industries in Khuzestan province, Iran. To perform this study, all statistics and data of the sugarcane and affiliated industries in seven companies during the crop year 2011-2016 were collected and classified. The results indicated that the application of the hydraulic filtration method led to the oil consumption saving (per liter) and in price (Iranian Rial) during the three crop-years of 2014-2016, as following: Imam Khomeini: 25500 L and 2882154363 Rials, Amir Kabir: 49000 L and 5847389466 Rials, Hakim Farabi: 82000 L and 9534396744 Rials, Dabal Khazaee: 73400 L and 6808230362 Rials, Dehkhoda: 31680 L and 3421979639 Rials, Salman Farsi: 73500 L and 7606675370 Rials and Mirza Koochak Khan: 75934 L and 8083068395 Rial