Increasing ambient temperature is a major climatic factor that negatively affects plant growth and development, and causes significant losses in soybean crop yield worldwide. Thus, high temperatures (HT) result in less seed germination, which leads to pathogenic infection, and decreases the economic yield of soybean. In addition, the efficiency of photosynthesis and transpiration of plants are affected by high temperatures, which have negative impact on the physio-biochemical process in the plant system, finally deteriorate the yield and quality of the affected crop. However, plants have several mechanisms of specific cellular detection of HT stress that help in the transduction of signals, producing the activation of transcription factors and genes to counteract the harmful effects caused by the stressful condition. Among the contributors to help the plant in re-establishing cellular homeostasis are the applications of organic stimulants (antioxidants, osmoprotectants, and hormones), which enhance the productivity and quality of soybean against HT stress. In this chapter, we summarized the physiological and biochemical mechanisms of soybean plants at various growth stages under HT. Furthermore, it also depicts the mitigation strategies to overcome the adverse effects of HT on soybean using exogenous applications of bioregulators. These studies intend to increase the understanding of exogenous biochemical compounds that could reduce the adverse effects of HT on the growth, yield, and quality of soybean.

Salinity is a global problem that threatens chickpea (Cicer arietinum L.) cultivation in all stages from germination to maturity. Also, salt-affected areas in the World are increasing by the day. Germination is one of the primary stages affecting plant growth and seed yield. Thus, germination performance of seeds has a vital role in vegetative and productive stages. Seed priming, a cheap and easily applicable technique, improves the germination performance by regulating enzymatic reactions and controlling water intake. Seed priming is controlled hydration of seeds soaked in a solution that has low osmotic potential to start the germination metabolism without elongation of radical. The aim of the study was to investigate the effects of different priming treatments on germination traits of chickpea under saline conditions. Three levels of salinity (control, 50 mM and 100 mM NaCl) and 5 priming treatments (non-primed, hydro-priming, 0.1 mM, 0.2 mM and 0.3 mM salicylic acid) were used in the study. Germination percentage (GP), mean germination time (MGT), germination rate (GR), germination index (GI) and coefficient of uniformity of germination (CUG) were varied between 80.7-98.3%, 1.40-2.67 day, 38.1-75.7, 37.5-72.5 and 0.3-0.7, respectively. Although all treatments caused significant positive effects, the 0.2 mM SA mostly improved the germination traits in the study. Also, it was determined that 0.2 mM salicylic acid priming is the threshold for chickpea and higher concentrations have inhibitory effects on the germination process.

To deal with increasing salinization, plants show an array of responses such as root system architecture remodelling, thereby enhancing stress tolerance. Although various chemical, molecular and genetic techniques such that generally expensive and difficult applications are used to enhance stress tolerance, out of them, seed priming with suitable substrates is an easy-applicable and cost-effective treatment. The experiment aimed to evaluate the effects of salicylic acid (SA), silicon (Si), and sodium chloride (NaCl) priming on lentil seed germination parameters, seedling development, and root system architecture. In 2022, the experiment was carried out in the Field Crops Department laboratory at Siirt University in Turkey. Petri and pot investigations were part of the two stages of the experiment. Three concentrations of NaCl and priming treatments were utilized. Germination characteristics were impeded by rising saline levels. But seed priming, which boosted uniformity of germination by 50% as compared to unprimed seeds under saline stress, enhanced germination characteristics. A pot experiment revealed that the dry matter accumulation in roots was reduced by 24.6% due to salt stress. Si priming increased number of lateral roots by 32.6% compared to control seeds, whereas salt stress lowered it by 22.8%. The total length of lateral roots (TLLR) and mean length of lateral roots (MLLR) were inhibited by salinity stress by 75% and 63, respectively. Total root area was reduced by salinity stress by almost 70%, although seed priming increased it by as much as 29.3%. The SA and Si priming treatments improved germination stage and induced seedling growth by reducing salinity stress via more effective shoot development and root system architecture. In conclusion, seed priming with SA and Si is an affordable and sustainable method for reducing salt stress in lentil farming.

Although legumes can meet nitrogen requirements via symbiotic nitrogen fixation, they must acquire phosphorus from the rhizosphere through their roots. Additionally, the fixation of phosphorus with various cations in soils reduces its availability, thereby decreasing its effectiveness and increasing production costs. This study was conducted during the 2021-22 and 2022-23 growing seasons to investigate the effects of seed pre-treatment (priming) and phosphorus doses on plant growth, yield attributes, and seed chemical composition in lentil at Siirt, Türkiye. Six seed priming treatments and four phosphorus doses were used in the study. The research was laid out in split-plot randomized complete block design with four replications. According to the results, phosphorus fertilizer increased seed yield, but there was no statistical difference between 15 and 60 kg P₂O₅ ha^− 1. Seed priming had a synergistic effect, allowing for higher seed yield when combined with phosphorus fertilizer, especially silicon priming resulting in high seed yield even at low phosphorus fertilizer doses. This result also indicated that seed priming improved phosphorus efficiency. The highest seed yield and net income were obtained by 6 kg P₂O₅ ha^− 1 with silicon priming treatment. Moreover, seed priming with salicylic acid, beneficial bacteria and silicon boosted growth and yield attributes, and seed chemical composition. Silicon priming increased the total antioxidant content in seeds while salicylic acid priming provided opportunities for both the increase of total antioxidants and phenolics. In conclusion, seed priming is an easy-to-implement and economical method for reducing phosphorus fertilizer and an effective way for higher profitability in lentil cultivation.

Drought stress spearheads the main factors threatening food security. Although many strategies might use for stress management, microbial inoculation with plant growth promoting bacterias (PGPBs) which have ACC deaminase activity and biochar amendment which is an effective way to increase soil carbon stock, improve soil physiological and biological properties are sustainable and easyapplicable methods. The experiment was laid out in a 3x10 factorial design with three replications under controlled conditions in 2020. The aim of this study was to evaluate the efficiency of microbial inoculation (MI: TV24C + TV126C + TV61C) and biochar amendments (1%BC, 2%BC and 4%BC) on growth of wheat seedlings under different irrigation levels (IL1: 80%, IL2: %50 and IL3: 25%). While biochar applications and microbial inoculation backed up to plants to alleviate drought stress, most effective results were obtained with combined applications of them. The combined application of 4% biochar+microbial inoculation increased plant height, shoot fresh weight, shoot dry weight, root fresh weight and root dry weight up to 28.3%, 56.8%, 72.2%, 141.3% and 112.8% compared with control plants while it improved them up to 4.9%, 10.3%, 16.6%, 21.1% and 40.3% compared with optimum synthetic fertilizer under drought conditions, respectively. In conclusion, biochar applications with microbial inoculations can be considered as an effective method to cope with the destructive effects of drought.

Background: The importance of organic fertilizers in agricultural production has increased due to the negative effects of intensive chemical fertilizer use on soil, the environment and human health. Vermicompost, as a rich organic fertilizer and soil amendment material, maybe a viable alternative to chemical fertilizers. While a low concentration of vermicompost has a promotive effect on growth, it may lead to inhibition of germination and seedling growth. Therefore, this study aimed to find appropriate dose ranges for vermicompost application. Methods: The study was carried out as a factorial experiment with a completely randomized design with three replications. The experiment was conducted in a growth chamber as a pot study with four doses of vermicompost (control, 10, 20 and 30%). Eight cultivars from four different species were used. The response of germination and seedling traits to increased vermicompost concentration was investigated. Result: In general, while 10% and 20% of vermicompost showed a promotive effect depending on species, higher dose inhibited the germination and dry matter accumulation. As a result, the promotive effect of low dose and inhibitory effect of higher doses are thought to be caused by the complex chemical composition of vermicompost and increasing medium pH. Therefore, the concentration of the vermicompost that will cause pH changes should be carefully considered and the pH range in which the plant species show optimum growth should be well determined.