Fungal diseases on tomato plant under greenhouse condition

The cultivation of crops in the greenhouse is the most intensive form of horticultural production. Greenhouse climatic conditions provide an ideal condition for the development of many foliar, stem and soil-borne plant diseases. Diseases are a major limiting factor for vegetable that cause serious yield reduction leading to severe economic losses. Fungi enter plants through natural openings such as stomata and through wounds caused by pruning, harvesting, hail, insects, other diseases, and mechanical damage. This chapter provides an overview of the most important diseases of tomato plants. Some of the diseases that will cover in this chapter are the follow: Early blight late, Septoria leaf spot, Late blight, Fusarium wilt, Verticillium wilt, Anthracnose, Buckeye rot, and Southern blight. For each disease, main symptoms and disease development are described. This review is based on combined information derived from available literature and expertise knowledge. DOI: http://dx.doi.org/10.5281/zenodo.101116

The Role of Shared Leadership and Communication in Promoting Strategic Consensus and Performance

The current study aims to investigate the effect of strategic consensus among managers on organizational performance, with an emphasis on shared leadership and communications in Iranian knowledge-intensive firms. Since Iran has its unique cultural characteristics with favoring a more authoritarian attribute, and leadership in knowledge-intensive firms has a more shared style, the context of the study is more appealing to such relationships. Data were collected from 115 randomly selected knowledge-intensive firms and analyzed using structural equation modeling by LISREL. Findings show that shared leadership positively influences strategic consensus of the management team, but it does not have a direct effect on performance. Also, communication among managers increases their strategic consensus which in turn positively affects firm performance. The findings act as a guideline for managers and suggest them to broaden the scope and the content of consensus and also for more effective decision-making and improved performance

Salinity Effect on Horticultural Crops: Morphological, Physiological, and Biomolecular Elements of Salinity Stress Response

Among abiotic stresses, high salinity stress is the most severe environmental stress. High salinity exerts its negative impact mainly by disrupting the ionic and osmotic equilibrium of the cell. In saline soils, high levels of sodium ions lead to plant growth inhibition and even death. Salt tolerance in plants is a multifarious phenomenon involving a variety of changes at molecular, organelle, cellular, tissue as well as whole plant level. In addition, salt tolerant plants show a range of adaptations not only in morphological or structural features but also in metabolic and physiological processes that enable them to survive under extreme saline environments. The main objectives of my dissertation were understanding the main physiological and biomolecular features of plant responses to salinity in different genotypes of horticultural crops that are belonging to different families Solanaceae (tomato) and Cucurbitaceae (melon) and Brassicaceae (cabbage and radish). Several aspects of crop responses to salinity have been addressed with the final aim of combining elements of functional stress response in plants by using several ways for the assessment of plant stress perception that ranging from destructive measurements (eg. leaf area, relative growth rate, leaf area index, and total plant fresh and dry weight), to physiological determinations (eg. stomatal conductance, leaf gas exchanges, water use efficiency, and leaf water relation), to the determination of metabolite accumulation in plant tissue (eg. Proline and protein) as well as evaluation the role of enzymatic antioxidant capacity assay in scavenging reactive oxygen species that have been generated under salinized condition, and finally assessing the gene induction and up-down regulation upon salinization (eg. SOS pathway)

Morphological and Physiological Plant Responses to Drought Stress in Thymus citriodorus

Water availability is considered as a determinant factor that affects plant growth. The commercial medicinal values of an aromatic plant rely on the presence of secondary metabolites that are affected under water shortage. Two-year-old Thymus citriodorus plants were subjected to different polyethylene glycol (PEG-6000) levels (0, 2%, and 4%) under greenhouse condition. PEG treatment lasted for 15 days. Thyme plant showed a morphological drought avoidance mechanism by maintaining the root system development through shoot fresh weight reduction resulting in promoted root absorption capacity and sustained plant growth. Moreover, stressed plants were able to maintain water use efficiency and root: shoot ratio suggesting a strong relation between root water uptake and water use saving strategies. Furthermore, thyme plants reduced tissue dehydration through stomatal closure and improved root water uptake. Content of volatile oil constituents of geraniol and diisobutyl phthalate increased upon drought stress while pseudophytol was reduced. Unexpectedly, thymol was not reported as a main oil element under either control or mild stress condition, while it was increased upon high drought stress in measure of 4.4%. Finally, carvacrol significantly accumulated under high drought stress (+31.7%) as compared to control plants

Using salinity to improve nutritional and market value of strawberries

Plants respond to salinity by producing antioxidants and osmolytes; some of these are nutritionally useful to humans (e.g. phenolics), or may improve the sensory quality of produce (e.g. sugars). For the current study, strawberries were irrigated with 0, 10, 20 or 40 mM NaCl, and the responses in antioxidants, phenolics, and flavour attributes were measured. A linear positive relationship was observed between salt stress and antioxidant concentrations, and the DPPH antioxidant assay responded more clearly than the FRAP assay. Phenolics were increased with statistical significance by salinity at all treatment levels, although trends differed between total phenolics and the subclasses anthocyanins and total flavonoids. It was seen that mild salinity (10 mM) with a low impact on yield could be used to increase antioxidants (6-10% above control) and total phenolics (11-16% above control). However differences between cultivars outweighed differences due to salinity in treatments below 20 mM NaCl. We found that sugars in strawberries (unlike other fruits) weren’t increased by salinity treatment. The lack of sugar increase can be explained by suggesting that organic acids are more important osmolytes than sugars for strawberries under salinity. However it was also determined that the failure of strawberries to increase their soluble sugars during salt stress can be explained by the lean nutrient regimes used by researchers, which don’t represent commercial production practices. Practically, mild salinity (≤20 mM) can be used to increase strawberry fruit value, but should be combined with an appropriate nutrient regime to avoid harm to flavour quality. The varieties Elsanta and Elsinore are both suitable for salt treatment, but Elsanta is better for antioxidant and phenolic production, as well as being more salt tolerant

Effect of Absorptive Capacity on Strategic Flexibility and Supply Chain Agility: Implications for Performance in Fast-Moving Consumer Goods

This paper develops a model to examine the relationships between absorptive capacity (ACAP), strategic flexibility (SF), supply chain agility (SCA), and firm performance (FP) based on the resource-based view (RBV) and the dynamic capabilities view (DCV). Using structured questionnaire, a sample of 186 randomly selected firms in fast-moving consumer goods (FMCG) industry from both Turkey and Iran as two developing countries is used to test the hypotheses. Variance-based structural equation modeling (SEM) was the primary data analysis method. The results show that absorptive capacity has direct and indirect effects on performance with the mediator variables of supply chain agility and strategic flexibility. Moreover, increased absorptive capacity leads to increased supply chain agility that in turn improves performance. The effect of absorptive capacity on strategic flexibility, and also, the overall proposed conceptual model, especially in the FMCG industry are the original features of the current study which was conducted in two developing countries. Efforts to promote absorptive capacity can improve both strategic flexibility and supply chain agility which are effective factors for enhancing performance in the fast-changing environment of FMCG industry

Morphological and Physiological Plant Responses to Drought Stress in Thymus citriodorus

Water availability is considered as a determinant factor that affects plant growth. The commercial medicinal values of an aromatic plant rely on the presence of secondary metabolites that are affected under water shortage. Two-year-old Thymus citriodorus plants were subjected to different polyethylene glycol (PEG-6000) levels (0, 2%, and 4%) under greenhouse condition. PEG treatment lasted for 15 days. Thyme plant showed a morphological drought avoidance mechanism by maintaining the root system development through shoot fresh weight reduction resulting in promoted root absorption capacity and sustained plant growth. Moreover, stressed plants were able to maintain water use efficiency and root : shoot ratio suggesting a strong relation between root water uptake and water use saving strategies. Furthermore, thyme plants reduced tissue dehydration through stomatal closure and improved root water uptake. Content of volatile oil constituents of geraniol and diisobutyl phthalate increased upon drought stress while pseudophytol was reduced. Unexpectedly, thymol was not reported as a main oil element under either control or mild stress condition, while it was increased upon high drought stress in measure of 4.4%. Finally, carvacrol significantly accumulated under high drought stress (+31.7%) as compared to control plants

Temporal and Spatial Considerations in Maintenance Planning

Maintenance spending is well-known to constitute a substantial part of total production and service costs. We focus on optimal planning of maintenance activities in several novel settings. In each setting, we formulate a mathematical optimization model using stochastic modeling techniques and establish the structural properties of the optimal policy through theoretical derivations. We provide additional policy insights using numerical observations and develop easy-to-implement and high-performing heuristic policies. Specifically, we first study an age-replacement setting (with minimal repair) in which the maintenance worker may be unpunctual. That is, the actual preventive replacement times may deviate from the prescribed replacement times in a probabilistic manner. We formulate a long-run expected cost-rate minimization model and compare the optimal solution and its performance to those when the unpunctual behavior is assumed to be either absent or independent of the prescribed replacement time. Next, we consider an age-replacement setting (without minimal repair) in which replacement costs are non-decreasing in system age. This assumption is motivated by factors such as decreasing salvage value or increasing costs associated with obtaining spare parts. We formulate a long-run expected cost-rate minimization model that captures this dependency and compare the optimal solution and its performance to those for the case in which replacement costs are assumed to be constant. Finally, we consider the problem of performing condition-based maintenance on a set of geographically distributed assets via a single maintenance resource that travels between the assets' locations. We use a graph representation to model possible geographical locations of the resource, including idling and asset locations and the links between them. We formulate a Markov decision process to dynamically obtain the optimal positioning of the maintenance resource and the optimal timing of the interventions that the resource performs

Using Gray Relation Analysis and Entropy Methods in Ranking Corporates’ Social Responsibility: Evidence from Iranian Pharmaceutical Companies

Analyzing corporate social responsibility (CSR) is a multi-criteria problem. This paper firstly introduces gray relation and entropy weighting methods in order to find a solution to analyze and rank corporations from this point of view. The proposed technique that conducted through combining these two methods, will become more reliable decision making criterion. Furthermore, since in literature there are different dimensions suggested for CSR, entropy method is used to determine the relative importance of each dimension. Awareness-raising questionnaire prepared by the social responsibility unit of European Commission was used to measure corporate responsibility. By applying these methods, 10 active pharmaceutical material and products manufacturing corporations were investigated and in terms of paying attention to social responsibilities, Pars Daro corporation placed first. This technique not only helps corporations to diagnose their weaknesses and strengths, but also helps them to know their position against competitors and make better decisions to promote corporate rank in social responsibility

Ionic partitioning and stomatal regulation: Dissecting functional elements of the genotypic basis of salt stress adaptation in grafted melon.

Vegetable grafting is commonly claimed to improve crop\u2019s tolerance to biotic and abiotic stresses, including salinity. Although the use of inter-specific graftings is relatively common, whether the improved salt tolerance should be attributed to the genotypic background rather than the grafting per se is a matter of discussion among scientists. It is clear that most of published research has to date overlooked the issue, with the mutual presence of self-grafted and non-grafted controls resulting to be quite rare within experimental evidences. It was recently demonstrated that the genotype of the rootstock and grafting per se are responsible respectively for the differential ion accumulation and partitioning as well as to the stomatal adaptation to the stress. The present paper contributes to the ongoing discussion with further data on the differences associated to salinity response in a range of grafted melon combinations