To determine the possible protective and enhancer role of selenium foliar application on oil yield, fatty acid composition and glucosinolate content of rapeseed cultivars under late-season thermal stress, a factorial split-plot experiment based on randomized complete block design with three replications was carried out in Karaj, Iran during the two growing seasons 2014–2015 and 2015–2016. Three sowing dates (Oct. 7 as normal planting date), (Oct. 17 as semi-late planting date), (Oct. 27 as late planting date) and two selenium foliar application (non-application as control and sodium selenate as foliar application) were factorially randomized to main plots, and rapeseed cultivars were allocated to sub-plots. Plant materials were six cultivars including three hybrids and three Iranian open pollinated varieties. Late-season thermal stress caused by late planting date reduced oil yield, oil content, oleic acid, linoleic acid, palmitic acid and increased linolenic acid, erucic acid and glucosinolate content of investigated cultivars. The results of this study demonstrated that the highest amount of oil yield, oil content, oleic acid, linoleic acid, palmitic acid and the lowest amount of erucic acid and glucosinolate content were observed in L72 cultivar in both control and selenium application treatments. This study provided new important findings about the supportive and enhancer role of selenium in the form of sodium selenate on quantity and quality of oil in rapeseed plant.

This study was conducted to compare the effects of nano and chemical fertilizers on physiological efficiency and essential oil yield of Borago officinalis L. during 2013 and 2014 crop years. The different levels of fertilizers were used as main factors in 11 levels including iron-sulphate and nanoiron, zinc and nano-zinc, urea and nano-urea, potassium sulphate and nano-potassium, micro-complete and micro-complete nanosuper and control. The application methods of fertilizers were considered as secondary factor (soil application, foliar application and combined application). Physiological efficiency of nitrogen, phosphorous, potassium, zinc and iron, dry and fresh weight of aerial parts, number of secondary branches, chlorophyll content, 100 grains and essence yield were evaluated. Our findings showed that chemical fertilizers had no beneficial effects in comparison to nano fertilizers (P > 0.05). In addition, nano-urea and urea fertilizers increased essential oil yield because of increased wet and dry weight of aerial parts and number of secondary branches. In conclusion, nano-fertilizers can be used in order to improve the essence production and also as environmentally friendly fertilizers.

The high vulnerability of sweet corn (Zea mays L. var. saccharata) to weed competition and the urgent reduction of the dependence on chemical herbicides are major challenges facing the agricultural community. To investigate the effects of plastic mulches on weed control and yields in sweet corn under different sowing dates, a 2-year experiment was conducted at Varamin, Iran, in 2010 and 2011. The mulch treatments included black plastic mulch, semitransparent biodegradable mulch, an unmulched weeded control, and an unmulched unweeded control. The sowing dates were 5 June, 20 June, and 6 July. Results revealed that delayed sowing (6 July) reduced weed dry weight by 51% and 41% compared with the 5 June sowing date in 2010 and 2011, respectively, without reducing crop yield. The black plastic mulch treatment had the lowest weed biomass. The sowing date × mulch interactions on kernel number per ear, length of ear, percentage of unfilled ear tip, and yield of sweet corn were statistically significant (P < 0.01) in both years. The maximum kernel number per ear (535) and the highest fresh ear yield (24,684 kg·ha−1) in 2010 were obtained on the 6 July sowing date under biodegradable mulch. The plants sown on 6 July produced the highest fresh kernel yield with the black plastic mulch (12,893 kg·ha−1) and unmulched weeded control (11,777 kg·ha−1) in 2010 and 2011, respectively. The highest percentage of unfilled ear tips in both years was observed in the unmulched unweeded plots sown on 5 June. According to our findings, to suppress the weeds and avoid the sweet corn yield loss in such a hot summer that we had, using the black plastic mulch and delayed sowing are recommended.

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In order to evaluate the effects of organic, chemical and integrated nutrition systems on morpho-physiological traits of oregano (Origanum vulgare L.), an experiment was carried out at the experimental farm of the Agricultural and Natural Resources Research Center, Urmia, Iran, during 2016-2017 growing season. The experimental design was a completely randomized block design with three replications. The experimental treatments included NPK, two organic (vermicompost and biochar), two biological (nitroxin and bio super phosphate) fertilizers and their all twin combinations and control (non-fertilized). Our results showed that the application of organic fertilizers caused a significant increase in yield and essential oil content in oregano. On the other hand, integrated nutrition treatments had the most effect on increasing the traits in compared with the individual treatments. The highest essential oil yield was obtained from Nitroxin treatment (871.27 kg ha-1) in the second year. Whereas, the lowest value of essential oil yield was found in control (non-fertilized) (25.92 kg ha-1) in the first year. The present study clearly indicated that chemical fertilizers could be replaced by biofertilizers resulted in similar oil yield.

No abstract

Response of forage quality in Persian clover upon coinoculation with native Rhizobium leguminosarum symbiovar (sv.) trifoli RTB 3 and plant-growth promoting Pseudomonas florescence 11168 under different levels of chemical fertilizers

Evaluation of genetic diversity is the key principal for plant breeding, providing an opportunity to discover novel characters and alleles for breeders. In the present study, 69 durum wheat genotypes were investigated for genetic diversity using several CAAT box-derived polymorphism (CBDP) and inter-simple sequence repeat (ISSR) markers. Twelve CBDP and sixteen ISSR primers amplified a total of 115 and 160 polymorphic fragments with a mean of 9.58 and 10 fragments per primer, respectively. CBDP primers showed the higher mean values for informativeness parameters such as polymorphic information content (PIC), resolving power (Rp) and marker index (MI) in comparison with ISSR primers. The results of analysis of molecular variance (AMOVA) indicated that the highest proportion of genetic variance referred within populations. Furthermore, CBDP primers indicated high values for all genetic parameters. Besides, the highest values of genetic parameters including number of observed (Na) and effective alleles (Ne), Shannon?s information index (I) and Nei?s gene diversity (He) were estimated for Iranian durum wheat landraces. Cluster analysis based on each molecular technique classified all durum wheat genotypes into three main groups, so that the results of principal coordinate analysis (PCoA) supported the grouping patterns. As a result, the grouping pattern observed by ISSR primers was clearer than CBDP primers and grouped all samples based on their origins. However, Mantel?s coefficient correlation test illustrated the higher positive correlation (0.54) between both marker techniques. Hence, the use of these markers in combination with each other to evaluate the genetic diversity is recommended.