Soil physical properties, nitrogen uptake and grain quality of maize (Zea mays L.) as affected by tillage systems and nitrogen application

Soil compaction is a global issue pertaining to agricultural lands. The frequent use of farm machinery and field operations at the same depth are the major causes of soil compaction. The gradual increase in soil compaction deteriorates maize grain quality due to reduced nitrogen (N) uptake. Quality food production by reducing soil compaction is the need of time, which can be achieved through deep tillage and N management. In this study, three tillage systems viz. conventional tillage (using cultivator), tillage with mould board plough +2-cultivations (MBP), and tillage with chisel plough +2-cultivations (CP); and three nitrogen levels viz. 100, 150 and 200 kg ha–1 were used to evaluate their effect on soil properties, N uptake and grain quality in maize. Lower bulk density (1.41 Mg m–3), higher total porosity (0.47 m3 m–3) and higher nitrogen uptake (96.01 kg ha–1) was recorded under chisel plough (CP) compared with other tillage systems. Different N levels had significant effect on grain and total N uptake and grain quality, while soil properties remains unaffected. Higher N uptake was recorded with 200 kg ha–1 N application than other treatments. Similarly, 8.51% and 8.57% more grain protein contents were recorded with 200 kg ha–1 N during first and second year respectively. Unlike grain protein, starch and oil contents were negatively affected by N application being higher starch (71.7%) and oil contents (3.41%) with less N supply (100 kg ha–1). However, interaction effect of tillage and nitrogen levels was found non-significant for all studied parameters except for oil contents. Higher oil contents were recorded with MBP along with 100 kg ha–1 N application. Overall study indicated that deep ploughing with CP is important for maize to explore more soil area for nutrient uptake and N is also important for improving grain quality especially protein contents an important food constituent

Foliar application of putrescine alleviates terminal drought stress by modulating water status, membrane stability, and yield- related traits in wheat (Triticum aestivum L.)

Drought stress is one of the major limitations to the growth and yield productivity of cereal crops. It severely impairs the early growing and grain -filling stages of wheat. Therefore, cost- effective and eco-friendly approaches for alleviating drought stress in cereal crops are in high demand. Polyamines, such as putrescine, have a significant effect on improving crop yield under drought- stress conditions. Therefore, the current study was executed with the aim of exploring the significance of putrescine in alleviating drought stress and improving yield- related traits in wheat. Two distinct wheat cultivars (Fakhar-e-Bhakkar and Anaj-2017) were treated with the foliar application of different concentrations (control, 0.5, 1.0, and 1.5 PPM) of putrescine (put) under two moisture conditions (well- watered and terminal drought stress). The results demonstrate that the imposition of terminal drought stress significantly reduces different physiological and yield- related traits of both wheat cultivars. The reduction of relative water content (RWC%), membrane stability index (MSI), leaf area, tillers per plant, biomass yield, number of spikelets per spike, 100-grain weight, grain yield per plant, and straw yield was greater in Anaj-2017 than in Fakhar-e-Bhakkar cultivar. The results further explain that the foliar application of increased concentrations of putrescine from 0.0 to 1.0 PPM gradually improved physiological and yield traits, whereas these traits declined with the application of putrescine at the highest dose (1.5 PPM). The exogenous application of 1.0 PPM putrescine improved the relative water content (19.76%), specific leaf area (41.47%), and leaf area ratio (35.84%) compared with the controlled treatment. A higher grain yield (28.0 g plant-1) and 100-grain weight (3.8 g) were obtained with the foliar application of 1.0 PPM putrescine compared with controlled treatments. The findings of this study confirm the protective role of putrescine against terminal drought stress. It is therefore recommended to use putrescine at a concentration of 1.0 PPM, which could help alleviate terminal drought stress and attain better wheat yield

Consequences and Mitigation Strategies of Heat Stress for Sustainability of Soybean (<em>Glycine max</em> L. Merr.) Production under the Changing Climate

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

Potential Role of Plant Growth Regulators in Administering Crucial Processes Against Abiotic Stresses

Plant growth regulators are naturally biosynthesized chemicals in plants that influence physiological processes. Their synthetic analogous trigger numerous biochemical and physiological processes involved in the growth and development of plants. Nowadays, due to changing climatic scenario, numerous biotic and abiotic stresses hamper seed germination, seedling growth, and plant development leading to a decline in biological and economic yields. However, plant growth regulators (PGRs) can potentially play a fundamental role in regulating plant responses to various abiotic stresses and hence, contribute to plant adaptation under adverse environments. The major effects of abiotic stresses are growth and yield disturbance, and both these effects are directly overseen by the PGRs. Different types of PGRs such as abscisic acid (ABA), salicylic acid (SA), ethylene (ET), and jasmonates (JAs) are connected to boosting the response of plants to multiple stresses. In contrast, PGRs including cytokinins (CKs), gibberellins (GAs), auxin, and relatively novel PGRs such as strigolactones (SLs), and brassinosteroids (BRs) are involved in plant growth and development under normal and stressful environmental conditions. Besides, polyamines and nitric oxide (NO), although not considered as phytohormones, have been included in the current review due to their involvement in the regulation of several plant processes and stress responses. These PGRs are crucial for regulating stress adaptation through the modulates physiological, biochemical, and molecular processes and activation of the defense system, upregulating of transcript levels, transcription factors, metabolism genes, and stress proteins at cellular levels. The current review presents an acumen of the recent progress made on different PGRs to improve plant tolerance to abiotic stress such as heat, drought, salinity, and flood. Moreover, it highlights the research gaps on underlying mechanisms of PGRs biosynthesis under stressed conditions and their potential roles in imparting tolerance against adverse effects of suboptimal growth conditions.Fil: Sabagh, Ayman EL. Kafrelsheikh University; EgiptoFil: Mbarki, Sonia. National Institute Of Research In Rural Engineering; TúnezFil: Hossain, Akbar. Bangladesh Agricultural Research Institute; BangladeshFil: Iqbal, Muhammad Aamir. University Of Poonch Rawalakot; PakistánFil: Islam, Mohammad Sohidul. Hajee Mohammad Danesh And Technology University; BangladeshFil: Raza, Ali. Fujian Agriculture And Forestry University; ChinaFil: Llanes, Analia Susana. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquimicas y Naturales. Instituto de Investigaciones Agrobiotecnologicas. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Investigaciones Agrobiotecnologicas.; ArgentinaFil: Reginato, Mariana Andrea. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquimicas y Naturales. Instituto de Investigaciones Agrobiotecnologicas. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Investigaciones Agrobiotecnologicas.; ArgentinaFil: Rahman, Md Atikur. Grassland And Forage Division National Institute; Corea del SurFil: Mahboob, Wajid. Nuclear Institute Of Agriculture,; PakistánFil: Singhal, Rajesh Kumar. Indian Council Of Agricultural Research; IndiaFil: Kumari, Arpna. Guru Nanak Dev University; IndiaFil: Rajendran, Arvind. Vellore Institute Of Technology; IndiaFil: Wasaya, Allah. Bahauddin Zakariya University; PakistánFil: Javed, Talha. Fujian Agriculture And Forestry University; JapónFil: Shabbir, Rubab. University Of Poonch Rawalakot; PakistánFil: Rahim, Junaid. University Of Çukurova; PakistánFil: Barutçular, Celaleddin. Institute Of Crop Science And Resource Conservation; AlemaniaFil: Habib Ur Rahman, Muhammad. Sichuan Agricultural University; ChinaFil: Raza, Muhammad Ali. Sichuan Agricultural University; ChinaFil: Ratnasekera, Disna. University Of Ruhuna; Sri LankaFil: Konuskan l, Ömer. Mustafa Kemal University; TurquíaFil: Hossain, Mohammad Anwar. Bangladesh Agricultural Research Institute; BangladeshFil: Meena, Vijay Singh. Indian Council Of Agricultural Research; IndiaFil: Ahmed, Sharif. Bangladesh Agricultural Research Institute; BangladeshFil: Ahmad, Zahoor. Bangladesh Wheat And Maize Research Institute; BangladeshFil: Mubeen, Muhammad. Sichuan Agricultural University; ChinaFil: Singh, Kulvir. Punjab Agricultural University; IndiaFil: Skalicky, Milan. Czech University Of Life Sciences Prague; República ChecaFil: Brestic, Marian. Slovak University Of Agriculture; EslovaquiaFil: Sytar, Oksana. Slovak University Of Agriculture; EsloveniaFil: Karademir, Emine. Siirt University; TurquíaFil: Karademir, Cetin. Siirt University; TurquíaFil: Erman, Murat. Siirt University; TurquíaFil: Farooq, Muhammad. College Of Agricultural And Marine Sciences Sultan; Omá

Maize Adaptability to Heat Stress under Changing Climate

The rapidly increasing human population is an alarming issue and would need more food production under changing climate. Abiotic stresses like heat stress and temperature fluctuation are becoming key issues to be addressed for boosting crop production. Maize growth and productivity are sensitive to temperature fluctuations. Grain yield losses in maize from heat stress are expected to increase owing to higher temperatures during the growing season. This situation demands the development of maize hybrids tolerant to heat and drought stresses without compromising grain yield under stress conditions. The chapter aimed to assess the updates on the influence of high-temperature stress (HTS) on the physio-biochemical processes in plants and to draw an association between yield components and heat stress on maize. Moreover, exogenous applications of protectants, antioxidants, and signaling molecules induce HTS tolerance in maize plants and could help the plants cope with HTS by scavenging reactive oxygen species, upregulation of antioxidant enzymes, and protection of cellular membranes by the accrual of compatible osmolytes. It is expected that a better thought of the physiological basis of HTS tolerance in maize plants will help to develop HTS maize cultivars. Developing HTS-tolerant maize varieties may ensure crops production sustainability along with promoting food and feed security under changing climate

Root Phenotyping for Drought Tolerance: A Review

Plant roots play a significant role in plant growth by exploiting soil resources via the uptake of water and nutrients. Root traits such as fine root diameter, specific root length, specific root area, root angle, and root length density are considered useful traits for improving plant productivity under drought conditions. Therefore, understanding interactions between roots and their surrounding soil environment is important, which can be improved through root phenotyping. With the advancement in technologies, many tools have been developed for root phenotyping. Canopy temperature depression (CTD) has been considered a good technique for field phenotyping of crops under drought and is used to estimate crop yield as well as root traits in relation to drought tolerance. Both laboratory and field-based methods for phenotyping root traits have been developed including soil sampling, mini-rhizotron, rhizotrons, thermography and non-soil techniques. Recently, a non-invasive approach of X-ray computed tomography (CT) has provided a break-through to study the root architecture in three dimensions (3-D). This review summarizes methods for root phenotyping. On the basis of this review, it can be concluded that root traits are useful characters to be included in future breeding programs and for selecting better cultivars to increase crop yield under water-limited environments

Determinants of frozen food purchase intentions: insights from a developing country

This study highlighted the role of knowledge about frozen foods and focused on what traits will change consumers' intentions toward frozen food purchases. Further, it analysed how consumer attitudes toward frozen food acted as a mediator and family structure acted as a moderator in the relationships between knowledge of frozen food products, change seeking traits, and frozen food purchase intentions. Data was collected through a questionnaire based on adopted scales, and the sample consisted of 279 frozen food customers of branded and non-branded stores in Multan District, Pakistan. Exploratory factor analysis, confirmatory factor analysis, and multi-group moderation were conducted to provide statistical evidence for hypotheses. Knowledge about frozen foods and change seeking traits were found significant in predicting frozen food purchase intentions directly and through mediation. Additionally, family structure was found to be a significant moderator of the hypothesized path between attitude towards frozen food and frozen food purchase intentions. This study is the only one of its kind and helps to demystify frozen food purchase behaviour of consumers in a developing country like Pakistan, especially, in light of a changing social phenomenon, that is, shifting of joint family systems to nuclear family structures

The influence of norms on tourist behavioural intentions

This article examines how various norms affect customer loyalty behaviours, including revisiting intentions and positive word of mouth (WOM). Subjective norms were modelled as independent variables, while personal and cultural norms were used as mediators. The rationale for these proposed relationships is provided in the article. The normative conduct theory and the theory of planned behaviour were utilized in the development of this integrated model. Data were collected from 668 tourists at five different tourist locations in districts in the northern province of Pakistan. The results demonstrate that injunctive norms were significant predictors of tourists' revisit intentions and positive WOM intentions. Descriptive norms were also significant in predicting revisit intentions. Surprisingly, these norms appeared insignificant in terms of a direct relationship with positive WOM. Nevertheless, personal and cultural norms significantly mediated the proposed relationships. The current study extends the existing empirical and theoretical body of evidence regarding tourists' subjective, cultural and social norms, and their effects on tourists’ behavioural intentions. The findings also yield useful insights for marketers and governmental bodies that will aid in future decision-making

Drivers of customer loyalty and word of mouth intentions: moderating role of interactional justice

This paper proposes a conceptual model of the antecedents of customer loyalty and word of mouth (WOM) intentions with the moderating influence of interactional justice. Using data from 500 tourist respondents at six different tourist locations in the districts of the northern province of Pakistan, the study reported here extends the theoretical and empirical body of evidence regarding customers’ perceptions of the quality and value of hotel services and their impact on customer loyalty and WOM intentions. The moderating role of interactional justice perceptions is also studied. The results show that service quality and relationship quality are significant predictors of customer loyalty and WOM intentions. Perceived service value also significantly mediated all the conceptualized relationships. Interactional justice moderated the mediated relationships. Surprisingly, the image of hotels appeared insignificant and did not mediate the most of the relationships. The findings demonstrate that hotel marketers should not assume that all customers’ perceptions represent similar underlying value in developing loyalty and WOM intentions