M. Goldani; E. Keshmiri
Abstract
Introduction: Salinity has been recognized as one of the major abiotic factors affecting crop yields in arid and semi-arid irrigated areas of the world and efforts for breeding salt-resistant crop plants have been made. Approximately one-third of the world irrigated soils and a large proportion of soils ...
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Introduction: Salinity has been recognized as one of the major abiotic factors affecting crop yields in arid and semi-arid irrigated areas of the world and efforts for breeding salt-resistant crop plants have been made. Approximately one-third of the world irrigated soils and a large proportion of soils in dry land are saline. Two major effects have been identified as the probable causes of high salt toxicity in crop plant i.e., the ionic effect and the osmotic effect. The ionic effect results in alterations in enzymatic processes, disturbances in accumulation and transport of different ions or a combination of all these factors. As a result, shoot and root growing reduce and uptake of nutrient elements by plants is adversely affected. While excess Na accumulated in plants under salinity stress conditions hinders K uptake; Cl hinders NO3 uptake by plants and destroys ionic balance in plants. Evening primrose is a plant which belongs to Onagraceae. Its seed oil has a special arrangement in Glycerol molecule, so it has been used a lot in medical treatments and also feeding. Researchers showed that using the best techniques and methods in farming can increase the amount of oil in the seeds of this plant. The wrong method of agricultural activities in Iran caused increasing salt in the soil, so growing plants in this situation isn’t possible. For confronting with this phenomenon knowing and choosing kinds of plants that can resist the situation of salt is really a necessary.
Materials and Methods: This study was conducted as a factorial experiment based on completely randomized design with three replicates was performed with five levels of NaCl salinity on Oenothera macrocarpa (0, 30, 60, 90 and 120 mM) and potassium chloride levels (zero and 15.02 mM) and three times in the Faculty of Agriculture, Ferdowsi University of Mashhad in 1390. Salt treatment to prevent osmotic shock was applied to four-leaf stage and treated with potassium was gradually simultaneously with irrigation water applied. 6 weeks after the treatments, the rate of photosynthesis, chlorophyll relative content and stomata conductance was measured. The analysis of variance was estimated using SAS software. The statistical comparison was done by Duncan's multiple range tests. Charts were drawn using Excel software.
Results and Discussion: According to the result of the analysis of variance, increasing the density of sodium chloride in the planting areas had a special effect on the size of the leaves and the weight of dried plant and the weight of each leaf and dried root. This effect showed a meaningful variation between the weight of dried leaves and its dried root and shoots. The salty areas have a lot of negative ions like Magnesium, Chlorine, sodium and sulfate. These materials are harmful by themselves or cause effective disorder in the plants metabolism. Salinity treatments applied to significant influence (01/0> p) on the characteristics of photosynthesis, stomata conductance and numbers were read out by spade. For example, sodium and potassium competition and competition between chlorine and nitrate impairs the absorption of nutrients. The result of this reaction is that the plant needs more energy for producing organic matter so it loses most of its energy to resist against salt. This situation of the plant causes a low activity of the root and the growing of the shoot consequently reduce. At this situation the weight and length of the plant reduce too. For example existing potassium in salty lands cause the reduction of sodium in the shoot of the plants. This research was done in a pot with the same amount of salt. Potassium causes the reduction of Toxicity effects of sodium. Research has shown that the potassium in regulating osmotic pressure and permeability of plant cell membranes is effective and cause Increase plant tolerance to salinity.
Conclusion: Some biological indexes of evening primrose plant were negatively affected by increasing rates of NaCl and KCl applications. In salty condition, increasing the amount of sodium causes the reduction of potassium, comparing with sodium. As a matter of fact, this kind of reaction causes the reduction of potassium comparing with sodium. We know that potassium causes a suitable osmotic pressure and reduce the destructive effect of oxidation. So having more potassium than sodium in salty lands is known as the standard resistance. NaCl and KCl compounds should be applied in a precise amount to evening primrose. Otherwise, quantity and quality of evening primrose plant will be decreased.
Mohammad Kafi; E. Keshmiri
Abstract
Abstract
Cumin (Cuminum cyminum) is one of the most important medicinal plants in Iranian dry region. In order to study the effects of irrigation times and salinity stress on yield and yield components of cumin, an experiment was conducted at the Research Farm Ferdowsi University of Mashhad in 2009. ...
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Abstract
Cumin (Cuminum cyminum) is one of the most important medicinal plants in Iranian dry region. In order to study the effects of irrigation times and salinity stress on yield and yield components of cumin, an experiment was conducted at the Research Farm Ferdowsi University of Mashhad in 2009. Factors including irrigation times (1: one time irrigation, 2: two times irrigation 3: three times irrigation and 4: four times irrigation (control)) with two levels of salinity stress (irrigation with normal water and saline water of 5 dS/m) and two Cumin cultivars (Sarayan, Indian cultivar RZ 19) were compared in a split plot based on randomized complete block design with three replications per treatment. The results showed that two and three time irrigation with normal water produced the highest biological and seed yield and there was no significant difference at these traits. One time irrigation and two times irrigation treatments with saline water had lowest seed yield, biological yield and seed number per umber and umbers per plant. Salinity stress decreased significantly all parameters of cumin cultivars such as seed yield, biological yield, number of umbers per plant, number of seeds per umber, 1000 seeds weight. The Indian cultivar was less reduced on seed yield than Sarayan cultivar under salinity stress and also Sarayan cultivar was less affected on seed yield in drought stress than Indian cultivar, however, in overall, Sarayan cultivar had higher seed yield than Indian cultivar in all treatments. Based on the results of this experiment (two times irrigation with normal water for Cumin in Mashhad area) will be achieved as desirable seed yield. However, yield reduction of cumin under irrigation with saline water of 5 dS/m was less than 20% compared with control.
Keywords: Irrigation, Salinity stress, Cumin, Yield, Yield component
