Ornamental plants
T. Oraee; M. Shoor; A. Tehranifar; S.H. Nemati; A. Oraee
Abstract
Introduction Climate change predictions indicate that drought and extreme heatwaves will become more frequent and extreme in many regions. Drought is the main abiotic stress that severely reduces plant yield across the globe. Thus, this may have negative consequences for the agricultural soils, ...
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Introduction Climate change predictions indicate that drought and extreme heatwaves will become more frequent and extreme in many regions. Drought is the main abiotic stress that severely reduces plant yield across the globe. Thus, this may have negative consequences for the agricultural soils, as it limits the availability of water and nutrients to soil microorganisms and plants that develop on these soils. To cope with this situation, the use of organic amendments is the best option. Recent studies have shown that the application of organic fertilizers can affect soil moisture and thus, mitigate the negative effect of climate change on that parameter. Organic amendments increase soil organic matter content thus improving soil physical, chemical, and biological properties, and therefore, can confer drought resistance to soils. The application of organic residues has been presented as a great strategy against soil degradation in semiarid environments. However, the interactions between organic amendments and drought in hollyhock plants are not fully known. Here, we evaluate whether the organic amendment influences the physiological traits of hollyhocks and soil properties under drought conditions. Materials and Methods The experiment was conducted in the research field at Ferdowsi University of Mashhad, Iran. The experiment consisted of three factors (cultivars, organic amendments, and drought) with organic amendments and drought having four and three levels, respectively. Drought treatments were controlled by a TDR at 80, 60, and 40% FC. The three sources of organic amendments were used cow manure, rice hull and wheat straw. Seeds were planted in cocopeat, perlite, and peat mixture trays in the greenhouse with an average temperature of 20 °C and under a photoperiod of 14 hours of light and 10 hours of darkness with a light intensity of 400 μmol-1 m2. In the 5-6 leaf stage, seedlings were transferred in pots (18 cm high and 8 cm in diameter) containing field soil. The plants were transferred to the field with four different substrates (field soil, field soil + manure, field soil + rice hull, and field soil + wheat straw) and were exposed to drought stress for one month during the flowering stage. This analysis examined both the physical and chemical properties of the soil, including changes in the macroelements nitrogen, phosphorus, and potassium. Results and Discussion Soil nitrogen changes were significantly affected by the interactions of ecotype with drought, ecotype with the medium, and drought stress with medium. The highest nitrogen changes were recorded in Mashhad ecotype under 80% FC. Nitrogen content in amended soil had an increasing trend during the experiment, but the amount of nitrogen had a decreasing trend in soil. In all media under stress, the amount of soil phosphorus was increased and the highest amount of phosphorus was observed in soil + manure at all irrigation regimes. The highest amount of potassium in both ecotypes was observed in soil + manure. The amount of potassium in amended soils under stress significantly increased, but in all organic amendments with increasing drought stress from 80 to 40% FC, the potassium content decreased. In both ecotypes, soil salinity was increased in all culture media. Han et al. (2016) stated that the amount of nitrogen, phosphorus, and potassium in the amended soil was higher than the substrates containing chemical fertilizer. The medium EC was alkaline at the end of the experiment and the salinity of the culture medium increased compared to the control. This study revealed a negative correlation between electrolyte leakage and dry weight in hollyhock plants. Furthermore, all measured physiological and growth parameters were significantly affected by the treatments. Notably, the Mashhad ecotype grown in soil supplemented with animal manure at 80% field capacity (FC) exhibited the highest levels of physiological traits (SPAD and relative water content) and growth index (dry weight).The application of manure + soil by providing macro elements reduces the negative effects of drought stress. Conclusion The type of crops grown in arid and semi-arid regions should be reconsidered. Also, some plants with high water requirements should be replaced with plants with low and unexpected water requirements. Because hollyhocks are low-expected plants that grow well in drought areas, so they can be considered as suitable species for cultivation in low-input systems and can tolerate drought situations by 40% FC in amended soil.
M. Naseri; hossein arouiee; M. Mohammadi
Abstract
Introduction: Spinacia olerace is the most important leaf vegetable of the Chenopodiacea family, which has a special place in human nutrition because of its variety of minerals and vitamins. Cultivation of this plant in Iran is several thousand years old and accordingly Iran is considered as the main ...
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Introduction: Spinacia olerace is the most important leaf vegetable of the Chenopodiacea family, which has a special place in human nutrition because of its variety of minerals and vitamins. Cultivation of this plant in Iran is several thousand years old and accordingly Iran is considered as the main place and a source of spinach in the world. Growth of plants is affected by genetics, environmental conditions, growing season, nutrients, and soil, harvesting method, temperature, intensity and quality of light. Among these factors, soil nutrients have a significant influence on plant growth and yield. Nowadays, the consumption of organic matter as fertilizer due to its high cost and limited availability is not sufficient and the major nutritional needs of plants are met by chemical fertilizers, which can lead to environmental problems and, over time, reduced yields. In this connection humic acid is a naturally occurring organic compound and contains 2% to 5% organic matter. Humic acid can be used to seedling nutrition and improve its quality and quantity. Given the recent use of organic acids such as humic acid to improve crops and horticulture, but little research has been done on transplant birth, this experiment was conducted to investigate the application of different levels of humic acid in irrigation water at the time of irrigation. Different effects and their effects on growth indices and spinach production were investigated.
Material and Methods: The present experiment was conducted to investigate the application of different concentrations of humic acid at different times and its effects on quantitative and qualitative indices of spinach in a factorial completely randomized design with three replications in research greenhouse at Torbat Heydariyeh University. Treatments consisted of three concentrations of humic acid (0, 3 and 6 ml/L) at two application times (one-week and two-week). The mean daily greenhouse temperature at the time of plant growth was 25°C and the mean nighttime temperature was 18°C, the average relative humidity was 60%. After seedlings were planted in the main pots at four-leaf stage, they were irrigated with humic acid (0, 3 and 6 ml/L) at different intervals once a week, twice weekly. The humic fertilizer used belonged to Green Seed Company, containing 24% humic acid and 3% folic acid and 2% potassium. Five weeks after treatment, the traits were measured. Transplant growth indices including number of leaves (by counting the number of shoots per plant), leaf length and width, leaf area, canopy, height, chlorophyll index, chlorophyll a, b, carotenoid and dry weight of each plant were determined.
Results and Discussion: Based on the results of this experiment, the effect of humic acid concentration on morphological and physiological traits of spinach transplant was significant. The highest leaf number (4.6) at 3 ml concentration and the lowest number (3.5) were at zero concentration. These traits were subjected to humic acid titer, but the increase in concentration had no significant effect on these traits. The increased number of leaves and traits mentioned in the early stages of transplant growth is probably due to the rapid expansion of the root system of the plant at high concentrations of humic acid, which in turn leads to increased nutrient uptake, better plant growth and subsequent growth. Leaf number and other traits become leaf dependent. The results showed that the highest chlorophyll a (1.8 ml/g fresh leaf), chlorophyll b (2.5 ml/ml fresh leaf), carotenoids (7.1 ml/ml). Fresh leaf g) and biomass (150 mg) at 3 ml concentration and the lowest at zero concentration. The highest chlorophyll index (74.1 ml/ml fresh leaf g) was also found in the concentration of 6 ml and the lowest was obtained from zero concentration. Humic acid increased spinach transplant biomass by increasing the amount of photosynthetic pigments and leaf area or the same photosynthetic capacity. In most of the traits, the two-week application time was higher than the one-week, so that spinach transplant biomass increased by 110% over the two-week application period. So that spinach transplant biomass was 156 at the two-week application and 74 mg at the one-week application. Based on the results of this experiment, humic acid application can improve the quantitative and qualitative traits of spinach transplant and its production.
Conclusion: Production of vegetable seedlings have an important role in the production and olericulture economy. Specializing in different activities in the vegetable production process will simplify the production process and increase efficiency. This means that the best conditions for seedling growth should be provided during transplanting. Application of humic acid organic fertilizer instead of chemical fertilizer can reduce environmental pollution in line with sustainable agriculture and healthy eating with vegetables to prevent the accumulation of chemicals in the human body to be effective. In this regard, the results of this study showed that using low humic acid as organic fertilizer can improve morphophysiological traits of spinach transplant.
H. Shirzad
Abstract
The use of natural compounds to control plant pathogens lead to reduction in using fungicides. Chitosan with duble effects, control pathogenic microorganisms and activate inducing defence responses, has been shown to be a reliable nontoxic material in the plant-pathogen interaction. The aim of this research ...
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The use of natural compounds to control plant pathogens lead to reduction in using fungicides. Chitosan with duble effects, control pathogenic microorganisms and activate inducing defence responses, has been shown to be a reliable nontoxic material in the plant-pathogen interaction. The aim of this research was to consider the effects of chitosan and calcium chloride on decay and quality attributes of sweet cherry cv. Siah mashhad. This experiment was conducted factorially in the figure of completely randomized design with five replications. Treatments were included of chitosan (0, %0.5 and %1) and Calcium Chloride (0, %1 and %2) and time (20 and 40 days). Measuring factors was included total soluble solids (TSS), titrable acidity (TA), partability index (PI), pH, weight loss, fruit decay. The results showed that application of chitosan %0.5 alone lead to stabilize soluble solids, organic acid, pH and fruit weight, also partability index and fruit rot was decreased. In short time storage (20 days) CaCl2 stabilize organic acids and fruit weight and caused partability index, pH, fruit decay to be decreased but fruit soluble solids increased. In total simple treatment of calcium chloride and chitosn showed better results compared to combination treatments on measured parameters.
