Today, drought stress is one of the limiting factors for the development of green space. One of the solutions to reduce the effects of drought stress for plants is foliar spraying with potassium silicate. In order to investigate the reduction of the adverse effects of low irrigation with the application of potassium silicate on ligustrum vulgare L. in the research greenhouse of Ferdowsi University of Mashhad, a factorial experiment was conducted in the form of a completely randomized design in 4 replications in 1400-1401. Experiment in the form of pot cultivation in 3 levels of low irrigation (control (100% crop capacity), 50% crop capacity (SDI), 50% crop capacity with PRD technique and 3 levels of foliar spraying with potassium silicate (0, 2 and 4%) It was done in 4 repetitions. According to the results, the highest plant height related to the treatment of no drought stress and foliar spraying with 4% potassium silicate (68.5 cm) and the lowest plant height in the drought stress of 50 PRD and without foliar spraying (29 cm) ) was the highest antioxidant activity in the treatments of drought stress 50% + potassium silicate 2% foliar spraying (67%), also in PRD 50 and without potassium silicate foliar spraying (69%) and in potassium silicate foliar spraying 4% (72%) . total phenol was the highest in PRD 50 and 4% potassium silicate foliar treatments (11.16 mg/gfw). Total carbohydrates in 50% drought stress and 4% potassium silicate foliar treatments (0.93 mg/g fw) in plants and proline in treatments of drought stress PRD 50 and without foliar spraying of potassium silicate (4.06 mg/g fw) was higher than other treatments. The results showed that drought stress with 50% FC + PRD technique compared to drought stress with 50% Crop capacity has disturbed the optimal growth of the plant, but in combination with potassium silicate foliar application, the growth and survival of the plant improved. Based on the results of this experiment, in the irrigation treatment with 50% crop capacity, the condition of the plant improved with potassium silicate foliar application.

In order to study the effect of different amounts of potassium silicate and potassium sulfate on growth traits of pistachio seedlings cv. Badami-E-Riz Kerman, an experiment was done as factorial with three factors, including two levels of salinity as source of NaCl (0 and 90 mM), three levels of silicon as source of potassium silicate (0, 50 and 100 mgL-1) and three levels of potassium as source of potassium sulfate (0, 1 and 2%), in compeletely randomized design with three replications. 45 days after the emergence of seeds, seedlings were exposed to salt stress foliar application of potassium silicate and potassium sulfate, both a week before and after starting salinity stress. The results showed that salinity decreased leaf relative water content, water use efficiency, leaf total soluble protein and increased electrolytes leakage, proline, soluble sugars, phenolic compounds in leaf and glycine betaine in leaf and root. Foliar application of potassium silicate and potassium sulfate increased leaf relative water content, water use efficiency, leaf total soluble protein, proline, soluble sugars, phenolic compounds and glycine betaine in leaf and roots, and reduced electrolytes leakage under salinity conditions. The most effective treatments were 50 mgL-1 potassium silicate and 2% potassium sulfate.

In the recent years, Lilium cut flower production has become very important among ornamental plant growers in Iran. Proper fertilization is a major factors affecting Lilium flower quality. In this study, the effect of different concentrations of potassium silicate, nanosilicon and calcium chloride were investigated on the quantitative and qualitative characteristics of Asiatic lily ‘Brunello’. This experiment was conducted randomized complete block design with 9 treatments and 3 replications. Treatments included drench of potassium silicate in three concentrations (25, 50 and 75 mg l-1), spray of potassium silicate in concentration of 25 mg l-1, spray of calcium chloride in two concentrations (25 and 50 mg l-1) and spray of nano-silicon in two concentrations (12.5 and 25 mg l-1) and control. Quantitative and qualitative characteristics and flower postharvest longevity were measured. Results showed significant differences between treatments. Calcium chloride compared to potassium silicate and nano-silicon, significantly increased fresh weight of flower stem at harvest time and drench of potassium silicate at 25 mg l-1 resulted in maximum number of florets 5.27). Maximum flower vase - life was related to spray of potassium silicate at 25 mg l-1. Spray of potassium silicate significantly increased flower vase - life than drench, for one extra day. The results showed that in general, the effect of potassium silicate was more effective than calcium chloride and nano-silicon on improving the measured characteristics particularly floret number and vase - life.

Mazandran province is ranked the second in production strawberry in Iran so it is considered as an important pole production of this popular small fruit. So in this research, the using of rice husk as an organic source of silicon (Si) along with foliar application of 50 and 100 mg Si/lit sodium and potassium silicate in strawberry cultivation was evaluated. The results showed that plants treated with sodium silicate 100 has more chlorophyll a in comparison with other silicon treatments. Potassium and calcium concentration of strawberry leaf in medium without rice husk (MWRH) was more than medium contained rice husk (MCRH) significantly. Among applied treatments, potassium silicate 100 was the only treatment that has more leaf silicon in comparison with other treatments at 1% probability level. Total flavonoid content in the MWRH with potassium silicate 100 treatment was significantly more than other treatments except MCRH with sodium silicate 50. Totally, MWRH with potassium silicate

This study was conducted to investigate the effect of silicon on wheat yield and water use efficiency (WUE) in water stress conditions. The study site was Research Farm of Soil and Water Research Institute in Karaj. The experiment was conducted as a randomized complete block design with split plots, in 2018-219 season. The main factor was irrigation at two levels of full irrigation and stress (40% less than wheat water requirement), and the secondary factor including foliar application of potassium silicate at three levels (zero, 2.5 and 5 kg/ha) at three growth stages (shooting, flowering, and grain filling) and soil application of potassium silicate (zero and 20 kg/ha). The results showed that soil and foliar application of potassium silicate increased grain yield, thousand-grain weight, number of seeds per spike, spike length, and height of wheat plant. Reducing irrigation from 100% to 60% of wheat water requirement caused a decrease in grain yield by 8.3%, but the application of potassium silicate compensated for this decrease, such that under drought stress, wheat grain yield with application of 0.005 potassium silicate increased by 30.6% compared to the non-application of silicon. The highest WUE was obtained under water stress conditions and application of 5‰ potassium silicate increased the WUE by 31% compared to non-application. Therefore, in the conditions of water stress, compared to the farmers' practices, foliar application of potassium silicate with a concentration of 5‰ can be recommended during the growth stages of wheat.

Production of many cut flowers، such as lilium، is very common in Iran. Flower quality has special importance in lilium flower production process، and proper nutrition is one of the major effective factors. This research was conducted to investigate the effect of different concentrations of potassium silicate، nano-silicon and calcium chloride on concentration of potassium، calcium and magnesium، chlorophyll index and number of florets of Asiatic lily ''Brunello''. The experiment was carried out based on randomized complete blocks design with 9 treatments and 3 replications (each replication included 5 pots)، in Educational/Research Greenhouses of Isfahan University of Technology، Isfahan، Iran. Treatments included drench of potassium silicate at three concentrations (25، 50 and 75 mg/L)، spraying of 25 mg/L potassium silicate، spraying of calcium chloride at two concentrations (25 and 50 mg/L)، spraying of nano-silicon at two concentrations (12. 5 and 25 mg/L) and control (no treatment). Number of florets، chlorophyll index and concentrations of calcium، magnesium and potassium in stem and leaves were measured. Results showed significant differences between treatments in stem and leaf calcium and magnesium، leaf potassium، chlorophyll index at harvest time and number of florets. Drench of 25 mg/L potassium silicate had maximum number of florets per plant (5. 27) and stem magnesium. Spraying 50 mg/L calcium chloride showed maximum leaf calcium، magnesium and potassium، respectively، with 4. 38، 15. 75 and 16. 43 percent increase as compared to control. Spraying of 25 mg/L calcium chloride، with 38. 9 percent increase as compared to control، had maximum stem calcium. Maximum chlorophyll index at harvesting time was related to spraying 25 mg/L potassium silicate. In general، if the goal is production of more florets، then drench of 25 mg/L potassium silicate is an appropriate treatment.

In this paper, artificially prepared sand-bentonite samples with different bentonite contents were employed to investigate the role of the clay content in the swelling potential, swelling pressure and oedometric behavior of expansive clays. Specimens were also dynamically compacted utilizing an identical compaction effort at various initial water contents to study the effect of the initial fabric of the soil on its volume change behavior and also to find the moisture content corresponding to the minimum drying-wetting induced swell and shrinkage of the material. Furthermore, commercially available Potassium Silicate is evaluated as a potential stabilizer in improving the volume change features of the sand-bentonite mixtures. Three dosage levels of the Potassium Silicate solutions were utilized to stabilize the expansive clayey soil. Free swelling, drying-wetting and consolidation tests were conducted on the stabilized soil samples. The results indicate that the swelling potential of the improved soil specimens are much lower than those of the non-stabilized soils. Also, Potassium Silicate eliminates the shrinkage behavior of the expansive clay. Besides, the mechanical oedometric behavior of the stabilized and non-stabilized soils is similar and Potassium Silicate does not change the response of the soil samples to the mechanical loading.

Salinity is one of the rising problems causing tremendous crop productivity losses in different parts of the globe. Silicon can be regarded as multi-talented quasi-essential element due to its versatile role in providing several benefits for plant growth particularly under stress conditions. The present investigation deals with the impact of potassium silicate on the germination and biochemical parameters of tomato under salt stress. Maximum seed germination of tomato seeds 98% was observed with potassium silicate. The seed germination and other growth characteristics followed the order: PS > C > NaCl (1mM)+PS > NaCl (1.5 mM)+PS > NaCl (2mM)+PS > NaCl. Application of potassium silicate significantly increased biochemical components such as pigment content, sugar, proline, protein and total antioxidant contents in tomato seedlings. Maximum total antioxidant content 55% was observed in NaCl (2mM)+PS treatment. The results revealed that potassium silicate acts as a plant growth promoter and it can be used as fertilizer for tomato under salt stress.

Effect of potassium-silicate, calcium chloride and nano-silicate spray was investigated on yield, yield components and some physiological properties of sweet corn under irrigation regimes in a split plot experiment based on a complete block design with three replications in 2017. Experimental treatments were irrigation regimes as optimal irrigation, moderate and severe water deficit stresses, irrigation after 35%, 55% and 75% depletion of available water in the root zone as the main factor and foliar applications of 1000 and 2000 ppm potassium silicate and calcium chloride , 1000 ppm  nano-silica, pure water and without foliar application as sub plots. The highest grain (6588 kg ha-1), biomass (36050 kg ha-1) and dry forage (30417 kg ha-1) yields were obtained from the main effect of foliar application of 1000 ppm potassium silicate. In water deficit conditions, application of potassium silicate significantly increased grain yield, so that potassium silicate in optimal irrigation conditions, moderate and severe irrigation increased grain yield 7, 25 and 49% compared to non-foliar application, respectively. In intensive irrigation regime the conditions, these increases were -9.29 and 9.82%, for calcium chloride and nano-silica, compared to the control (without foliar). Therefore, according to the results of this study, it can be stated that foliar application of potassium silicate was more efficient in deficit irrigation conditions in sweet corn.

Broccoli is a one of the vegetables that has a very high nutritional value and it is cultivated in many countries all around the world. Due to the intensification of climate change, sudden drops in temperature during the winter in northern countries pose a serious threat to some vegetable species, including broccoli. In this study, an experiment was conducted to investigate the effect of sucrose, potassium silicate, and Bordeaux mixture on increasing the tolerance of broccoli seedlings to sudden cold stress. 

The experiment was conducted in a completely randomized design with eight treatments, three replications, and three samples per each replication. The treatments included: control, sucrose1%, potassium silicate 0.2%, Bordeaux mixture 0.2%, sucrose + potassium silicate, sucrose + Bordeaux mixture, potassium silicate + Bordeaux mixture, and sucrose + potassium silicate + Bordeaux mixture. 

The effect of the treatments on the growth of broccoli seedlings one week after exposure to low temperature stress, including stem height, leaf number, shoot dry weight, root fresh weight, and root dry weight, was not statistically significant. The highest concentration of chlorophyll b (1.647 mg/g fresh weight) was obtained in the Bordeaux mixture treatment which along with the combined treatment of sucrose + potassium silicate + Bordeaux mixture were the only treatments that showed a significant superiority compared to the control. The highest transpiration rate among the tested treatments was observed in the sucrose + Bordeaux mixture treatment, which did not show a significant difference compared to the three-component treatment of sucrose + potassium silicate+ Bordeaux mixture, but showed a significant superiority compared to the other treatments. The foliar application of Bordeaux mixture caused a higher stomatal conductance compared to the control after a temperature stress of -2 °C, but the other treatments did not show a significant difference compared to the control. In terms of the non-photochemical quenching (Y(NPQ)), the highest Y(NPQ), was observed in the control and potassium silicate treatments, which was significantly higher than all other treatments. Meanwhile, the lowest level of this index was observed in the potassium silicate+ Bordeaux mixture treatment, which did not show a significant difference compared to the sucrose + potassium silicate, sucrose + potassium, and silicate+ Bordeaux mixture treatments. The highest level of antioxidant activity was observed only in the sucrose treatment and the sucrose + potassium silicate and Bordeaux mixture treatments, which were superior to all other treatments without any significant difference among them. In terms of total phenolic content, only the sucrose+ Bordeaux mixture treatment showed a significant superiority compared to the control, and the other treatments did not show a significant difference from the control. In the trait of soluble sugar content, the sole potassium silicate and the three-component treatments were better than the control, and the other treatments did not show a significant difference compared to the control. The highest ion leakage was observed in the sucrose + Bordeaux mixture treatment, which was higher than the control and all other treatments. The lowest ion leakage was also observed in the sucrose + potassium silicate and potassium silicate+ Bordeaux mixture treatments, although the difference between them and the control and potassium silicate-only treatments was not significant. The highest level of proline was observed in the sucrose+potassium silicate treatment, which was significantly superior to all other treatments. 

Sucrose+potassium silicate treatment improved the defense system of the plant against sudden cold stress by increasing the amount of carotenoid and proline, and as a result of these activities, the antioxidant of the whole plant and higher chlorophyll also increased. Also, this treatment showed low ion leakage and low non-photochemical quenching, which can show higher sudden cold tolerance. Another favorable treatment was potassium silicate + bordeaux mixture which produced a higher assimilation rate, although this photosynthetic production did not affect the biomass, but since the ion leakage was low and caused the lowest Y(NPQ), it can be said that the plant in this treatment receive lower stress. Overall, considering all the evaluated traits, the top-performing treatment in this experiment was the potassium silicate+ Bordeaux mixture treatment, followed by the sucrose + potassium silicate treatment.