salicylic acid

Guar (Cyamopsis tetragonoloba) is an annual and tropical plant of the legume family that is suitable for seed production in arid and semi-arid regions due to its resistance to drought.

Methods & Materials: 

Therefore for studying the effects of salicylic acid on morphological, physiological characteristics, yield and yield components of Guar under at three levels of field capacity (drought stress), a split plot experiment based on randomized complete block design with four replicates was conducted in Jiroft in Kerman province, Iran. The experimental treatments were included three levels of irrigation (45, 65 and 85% of field capacity as main factor) and four concentrations of salicylic acid (0, 0.5, 1 and 2 mM as the sub factor). Foliar application of salicylic acid was carried out in three five-leaf, flowering and pod stages.

Results showed that by reducing soil moisture (from 85 to 45% FC) significantly decreased all traits except grain protein. The effect of salicylic acid was also significant on all traits except for 1000-grain weight. Foliar application of 1mM salicylic acid at 85% and 65% of field capacity resulted in the highest grain yield.

There was no statistically significant difference between 2 and 1 mM concentrations in most of the studied traits, so, it can be concluded that foliar application of salicylic acid at a 1 mM concentration can reduce the negative effects of decreasing soil moisture, Finally 65% of field capacity it can be introduced as superior level for irrigation of Guar.

This study aimed to investigate the effect of salicylic acid and fulvic acid foli-ar use on some growth responses and essential oil content of thyme.

A factorial experiment as completely randomized design with three replications was conducted. The first and second factors included: fulvic acid (0,1,1.5,2 mg/l) and salicylic acid (0,10,50,100 µM). After spray-ing and harvesting, the following factors were evaluated; fresh and dry weight, photosynthetic pigments, flavonoids, total antioxidants activity, and essential oil content of the aerial parts.

Foliar treatments significantly influenced plant height, fresh and dry weight biomass as well as chlorophyll b content. Also, salicylic acid had a significant effect on yield traits such as fresh weight, total antioxidant activity, flavonoids and essential oil content. The interactions of salicylic acid and fulvic acid on fresh and dry weight also showed a significant effect. The highest total antioxidants activity and flavo-noids were obtained at 100 µM salicylic acid. The highest essential oil content was obtained at of 50 µM salicylic acid.

In order to produce the highest yield of the plant, the application of 50 μM concentrations of salicylic acid and fulvic acid with a concentration of 1.5 mg/l seems appropriate. Also, to achieve the highest essential oil content of shoots and leaves, a concentration of 50 μM salicylic acid is recommend-ed.

Water stress is one of the most important factors in reducing the yield of agricultural products worldwide. If the stress is intensive and continuous, plant growth and productivity are severely diminished. Water superabsorbent polymer can absorb and retain extremely large amounts of a liquid relative to its own mass. They have a wide range of applications because of their high water absorbing capacity, biodegradability and low cost.Humic acid is an organic compound that is derived from the decomposition of organic matter and contains carbon, hydrogen, oxygen and nitrogen. This acid plays a key role in increasing the fertility of the soil and feeding the plant when added to the plant, in helps to increase its growth through its effect to photosynthesis, respiration, increase the plants resistance to harsh environmental conditions and stimulates many of the vital interactions within the plant.Salicylic acid, a naturally occurring plant hormone, acts as an important signaling molecule and enhances tolerance of treated plants against biotic stresses. Salicylic acid also has a vital role in plant growth, ion uptake, and nutrient transport within the plant.Factor analysis is a technique that is used to reduce a large number of variables into fewer numbers of factors. This technique extracts maximum common variance from all variables and puts them into a common score.

In order to evaluate the effects of different irrigation levels and nutritional treatments and determining factors affecting water use efficiency of maize (Zea mays L.), a split plots experiment based on RCBD design with three replications was conducted during 2015-16 growing season, at Research Field of Ferdowsi University of Mashhad, Iran. Irrigation levels in two levels (50 and 100% of water requirement) and nutritional treatments in five levels (1- Nitrogen+Superabsorbent, 2- Superabsorbent+Humic acid+Salicylic acid, 3- Humic acid+Salicylic acid+Nitrogen, 4- Humic acid+ Salicylic acid+Nitrogen+Superabsorbent and 5- Control) assigned to main and sub plots, respectively.

The results showed that all of the nutritional treatments affected water use efficiency, but in both conditions of 50 and 100% of water requirement, the highest water use efficiency were obtained in treatment of Humic acid+Salicylic acid+Nitrogen+Superabsorbent. The highest seed yield (17542 kg.ha-1) observed in treatment of nitrogen+superabsorbent+humic acid+Salicylic acid and supply 100% of water requirement and the lowest seed yield (12515 kg.ha-1) obtained in treatment of control and supply 50% of water requirement. Factor analysis results showed that variables analyzed to two factors. First factor included 51% of variables variance, respectively. First factor included variables of seed yield, biological yield, plant height, leaf area index, crop growth rate and soil nitrogen, phosphorous and pH and variables of seed weight per plant, soil EC and water use efficiency were in second factor. In first factor, important variables such as soil nitrogen, phosphorous were included, so this factor describe soil conditions and second factor which had the highest impact on water use efficiency was called as water use efficiency factor. In a research reported that application of water superabsorbent increased seed yield of maize compared to control. In another research, the highest seed yield of maize obtained in treatment of simultaneous application of 120 kg.ha-1 water superabsorbent and 8 kg.ha-1 humic acid. Application of salicylic acid and humic acid enhanced seed yield of maize 24.5 and 24.2% compared to control, respectively.

In general, based on results of this research, it seems simultaneous application of nitrogen and ecological inputs can improve yield, growth characteristics and water use efficiency. Factor analysis and high correlation among variables in same group showed that with change of variables that are in same group of water use efficiency, can increased water use efficiency and decreased damages of drought stress.

The effect of foliar application of potassium, salicylic acid and gamma aminobutyric acid on morphophysiological traits and nutrient uptake of bread wheat genotypes under soil salinity stress was studied as a research conducted in agricultural research station in Miandoab, West Azerbaijan during the two cropping years 1396-97 and 1397-98. The experiment was performed as a split plot in a randomized complete block design with three replications under soil salinity (0 and 8 dS / m). Main plots included foliar application with growth stimulants: potassium, GABA, SA, control and subplots included seven genotypes ( Orum, Zare, Mihan, Heydari, MS-89-12, MS -89-13 and MS-91-14). The analysis of variance showed that the simple effects of salinity stress on grain yield and foliar application treatments on all studied traits were significant. Also, the simple effects of different genotypes on all measured traits were significant. The interactions of three factors of salinity, foliar application and genotype had a significant effect on all measured traits. Based on the results, comparison of the means showed that GABA foliar application under non-stress conditions with an average of 11366.7 kg / ha in Mihan cultivar produced the highest grain yield, while GABA foliar application under salinity stress conditions with the average of 1876.7 kg / ha produced the lowest grain yield in Orum cultivar. The overall results showed that most of the traits were reduced due to salinity stress. Foliar application of all the compounds in most traits caused an increase compared to the control conditions.

Capper (Capparis spinosa) is a resistant plant with remarkable sustainability to adverse environmental conditions. It has special importance from the side of soil conservation and it’s a suitable species for bio-restoration in arid and semi-arid regions. Weak germination and seed dormancy in capper is an obstacle to inclusive use in restoration projects. In the current study, with the aim of investigating the effects of chemical, mechanical, and biological priming on germination and primary growth in plants, an exam was designed. The experiment performed in two conditions: 1) In a petri dish, 2) Seedling tray both under completely randomized design. Chemical priming included Salicylic Acid and Giberlic Acid in three levels of 1000, 2000, and 3000 ppm. The 24 kHz wavelength of the ultrasonic device was applied as mechanical priming for 5 minutes. Bio-priming Included Azotobacter chroococcum, Flavobacterium F-40, Azospirillum lipoferum, Bacillus megaterium, and Pseudomonas fluorescens. Results showed a significant level (p <0.01) on seed germination percentage, root and shoot length, seedling growth, root and shoot fresh weight, and root and shoot dry weight in petri dish test. In seedling tray test, root length, shoot length, root length to shoot length ratio, seedling growth, root dry weight, fresh and dry weight of shoot and leaf and leaf number at 1%, and root fresh weight at 5 percent were significant. In the Petri dish test, ultrasonic treatment increased shoot length compared to control treatment. Bacillus megaterium and GA3 (Gibberellic Acid 3000ppm) in Petri dish test and GA1 and GA2 in seedling tray test had a more positive effect on germination characteristics than other treatments. Bacillus megaterium had a 25 percent positive effect on germination percentage in comparision with control treatment. Using bio-priming, several waves of ultrasonic treatment, and different Gibberellic Acid concentrations could be a proper solution to solve the problem and develop C. spinosa implantation.

There are many methods to deal with salinity, one of which is less costly and more practical seed priming. Seed prime with different methods with mycorrhiza fungi can be used to improve the deposition of seeds and ultimately yield in saline lands. According to available reports, priming seeds are better placed in environmental stress conditions, such as salinity, and produce higher plantings. Priming increases rooting and increases the yield in corn by 14%. The seedling growth rate was seven days earlier than the non-prime. Plants that are inoculated with mycorrhiza will increase growth and yield and maintain the osmotic potential and ionic balance to a normal level and cause resistance to stress conditions.

This research was carried out during two years 2014 and 2015 in two locations in the province of Khouzestan, Gotvand city, with an altitude of 76 meters above sea level and the coordinates of 32 degrees north latitude and 48 degrees east longitude. The experimental design was factorial based on randomized complete block design with three replications on maize hybrid NS64. The concentration of salicylic acid 0.5 mM within 14 hours, osmopriming with NaCl solution at a concentration of 2 dS.m-1 within 22 hours, tap water within 18 hours were selected as the best combination of on-farm seed priming. The mycorrhiza fungus was taken in strips under the seeds of 20 g.m-2 . Analysis of variance was done using the PROC GLM procedure of the SAS 9.1 (SAS Institute, Cary, NC, USA).

Results showed that all traits in both years and places inoculation with mycorrhiza and priming with salicylic acid, tap water and NaCl solution to the non-inoculate and non-prime increasing significantly and between inoculation with mycorrhiza and Prime treatments, inoculation with mycorrhiza and prime with salicylic acid in both place have better condition. Inoculated with mycorrhiza and priming with salicylic acid in saline place increases the leaf area index in the Tasseling, number of seeds per ear, 1000-kernal weight, yield, biological yield, harvest index, the amount of 26.5, 42, 15.5, 62.5, 49.2, 9.3 percent than non- inoculation with mycorrhiza and not prime. The difference between inoculation with mycorrhiza and salicylic acid treatment and non- inoculation with mycorrhiza and non-prime in saline place compared to non-saline place in all traits was higher.

The results showed that application of inoculation with mycorrhiza to non-inoculation and seed priming compared to control (Non-primed) in all measured traits under both saline and non-saline environments were superior in both years. Priming of maize seeds with salicylic acid (0.5 mM for 14 hours) was superior to other pretreatments. Under salinity without prime application and  inoculum  mycorrhiza (Control) the amount of  number of seeds per ear (212), 1000 grain weight (210 g), grain yield (2826 kg.ha-1) were measured, that application of priming  increased all traits and the highest increase was observed in salicylic acid treatment, which increased  grain number in ear (34.4%), 1000 grain weight (10.9%), grain yield (48.7%) compared with not used prime and inoculation with mycorrhiza (control). Inoculation with mycorrhiza increased the number of seeds per ear (19.8%), 1000 grain weight (4.2%), grain yield (23.9%) compared with lack of prime application and inoculation with mycorrhiza (control). Interaction of seed priming and inoculation with mycorrhiza increased all traits. The highest increase was observed in salicylic acid priming treatments and inoculation with mycorrhiza that increased number of seeds per ear (42.4% ), 1000 grain weight (15.7%), grain yield (62.9%) than lack of prime and inoculation with mycorrhiza (Control). In the first year, in comparison to the second year, all measured traits increased due to the favorable temperature and number of sunny hours for growing and inoculation of flowers and filling of grain. Consequently, in both saline and non-saline environment, inoculation with mycorrhiza and prime with salicylic acid is suggested as a method for improving crop cultivation of the NS640 cultivar.