جستجوی مقالات مرتبط با کلیدواژه « اسیدهای چرب » در نشریات گروه « اکولوژی »

Fertilizer management and irrigation are important factors in camellia cultivation at water deficit stress condition. The purpose of this experiment is to obtain the best fertilizer composition for increase yield, forage quality, and fatty acid of camellia seed at different irrigation levels for sustainable agriculture.

This 2-years experiment were performed in 2017-2018 and 2018-2019 as a split-plot based on RCBD with four replications. The main plots included: rainfed, once irrigation, and twice irrigation. The sub-plots included: chemical fertilizers, bio-organic and control (without fertilizer). In this experiment, quantitative and qualitative characteristics of forage and camellia seeds and the amount of fatty acids of camellina seed were determined.

The application of bio-organic and chemical fertilizers significantly increased dry matter digestibility, crude fat, and forage ash. The highest yield of dry forage (2122.4 and 2018.5 kg ha-1) was obtained from chemical fertilizer and bio-organic treatments respectively, and the highest grain yield (2018.9 kg ha-1) was obtained from twice irrigation treatments and the use of chemical fertilizer. The use of bio-organic fertilizers increased camelina yield by 25.49% in rainfed conditions. Bio-organic fertilizers at all levels of irrigation had the greatest effect on palmitic acid, stearic acid, eicosadienoic acid compared to the chemical fertilizers.

Although use of chemical fertilizers under twice irrigation showed the highest effect on camellina traits, but use of bio-organic fertilizers under rainfed or low irrigation conditions can be recommended due to a significant increase in grain yield, forage quality and fatty acid composition.

This study was conducted to evaluate some qualitative traits (fatty acids, canopy temperature and stomatal resistance) of new rapeseed genotypes in response to irrigation cut-off and zinc application in Karaj. 

This experiment was performed as a factorial split-plot in a randomized complete block design with three replications for two cropping years (2014-2015 and 2015-2016) in Karaj. In this study, irrigation at three levels including normal or controlled irrigation, cessation of irrigation from flowering stage onwards and cessation of irrigation from pod stage onwards, zinc in two levels including normal water (no zinc application), and foliar application with zinc 30 g.L-1 zinc and rapeseed cultivars including Danob, HW113, KR2, L155, HL2012 were placed in sub-plots. 

The results of analysis of variance showed that the interaction effect of irrigation × genotype on 1000-seed weight, seed yield, seed oil percentage, stomata resistance, linoleic acid, linoleic acid, erotic acid was significant at the level of one percent. Also, the interaction effect of irrigation × on × genotype on grain yield, oleic acid, and linoleic acid at 1% level and canopy temperature, palmitic acid, and linoleic acid at 5% level were significant. Zinc reduced the adverse effects of dehydration stress on the tested genotypes so that under normal zinc application and irrigation conditions, L155 genotype with 6310 kg/ha grain yield and the highest percentage of oleic acid (67.3%). Besides, in terms of zinc application and irrigation interruption from the plowing stage onwards, HL2012 and L155 genotypes with grain yield of 5032 and 4826 kg.ha-1, respectively, and the highest percentage of oleic acid (65.8% and 65.7%, respectively) produced. Also, in case of cessation of irrigation from flowering stage onwards, HL2012 and L155 genotypes with 3679 and 3606 kg.ha-1 grain yield, respectively, had the highest percentage of oleic acid (64.3% and 64.2%, respectively). 

In general, the positive effect of zinc application on traits such as seed oil percentage (0.9 %) increased with increasing drought stress intensity and L155 genotype for all water conditions and HL2012 genotype for end-of-season drought stress conditions are recommended for planting in cold temperate regions with a semi-arid climate.

In the production of medicinal plants, it is a global approach toward sustainable agricultural systems and use of agricultural practices such as intercropping, application of biofertilizer and mulch to enhance the quantitative and qualitative performance of medicinal plants. Thus, two experiments were conducted with factorial arrangement based on randomized complete block design (RCBD) with three replications at the Research Farm of University of Tabriz in 2015 and 2016. The first factor was included sole cropping of purslane, sole cropping of dragon’s head, additive intercropping of dragon’s head + purslane (20, 40, 60 +100 %), and the mulch application as second factor including wheat straw mulch and no mulch; two types of fertilization including application of 100% chemical fertilizer and 50% chemical + biological fertilizers as third factor. Results revealed that the highest values of oil content and unsaturated fatty acids were observed in D20 + P100 intercropped plants, while the highly saturated fatty acid of palmitic content was observed in sole cropped. Mulch application had the highest yield and growth traits. Also, quantity and quality of dragon’s head was not significantly affected by replacing biofertilizers with chemical fertilizer. In other words, it can be used 50% chemical + biological fertilizers. The highest land equivalent ratio and relative crowding coefficient were obtained from dragon’s head with purslane intercropping (D40 + P100), wheat straw mulch application, and combinative application of chemical and biological fertilizers in second year. It seems that intercropping system (D40 + P100) and application of biofertilizers and mulch can be suggested as an appropriate agricultural method to reduce the consumption of chemical inputs and increase yield of dragon’s head.