scispace - formally typeset
Search or ask a question
Author

Eugene V. Maas

Bio: Eugene V. Maas is an academic researcher from Agricultural Research Service. The author has contributed to research in topics: Salinity & Soil salinity. The author has an hindex of 34, co-authored 58 publications receiving 8186 citations. Previous affiliations of Eugene V. Maas include United States Department of Agriculture.


Papers
More filters
Journal ArticleDOI
TL;DR: An extensive literature review of all available salt tolerance data was undertaken to evaluate the current status of our knowledge of the salt tolerance of agricultural crops as mentioned in this paper, concluding that crops tolerate salinity up to a threshold level above which yields decrease approximately linearly as salt concentrations increase.
Abstract: An extensive literature review of all available salt tolerance data was undertaken to evaluate the current status of our knowledge of the salt tolerance of agricultural crops. In general, crops tolerate salinity up to a threshold level above which yields decrease approximately linearly as salt concentrations increase. Our best estimate of the threshold salinity level and yield decrease per unit salinity increase is presented for a large number of agricultural crops. The methods of measuring appropriate salinity and plant parameters to obtain meaningful salt tolerance data and the many plant, soil, water, and environmental factors influencing the plant's ability to tolerate salt are examined.

3,200 citations

Book ChapterDOI
01 Jan 1986
TL;DR: In this article, the salt-tolerance data as well as tolerance limits for boron, chloride, and sodium are presented for woody crops, which are also influenced by specific salt constituents.
Abstract: Many plant, soil, water, and environmental factors interact to influence the salt tolerance of a plant. This chapter presents the salt-tolerance data as well as tolerance limits for boron, chloride, and sodium. Plant tolerance to salinity is usually appraised in one of three ways: the ability of a plant to survive on saline soils, the absolute plant growth or yield, and the relative growth or yield on saline soil compared with that on nonsaline soil. Temperature, relative humidity, and air pollution are important climatic factors that influence plant response to salinity. The salt tolerance of woody crops is complicated because they are also influenced by specific salt constituents. Crops irrigated by sprinkler systems are subject to additional salt damage when the foliage is directly wetted by saline water. Boron is an essential plant element but it can become toxic to some plants when soil-water concentrations exceed only slightly that required for optimum plant growth.

1,061 citations

Book ChapterDOI
01 Jan 1999

486 citations

Journal ArticleDOI
TL;DR: The relative salt tolerance of two wheat species (Triticum aestivum L., cv. Aldura) at different stages of growth was determined in a greenhouse experiment.
Abstract: The relative salt tolerance of two wheat species (Triticum aestivum L., cv. Probred and Triticum turgidum L., Durum Group, cv. Aldura) at different stages of growth was determined in a greenhouse experiment. Plants were grown in sand cultures that were irrigated four times daily with modified Hoagland's solution. Salinization with NaCl and CaCl2 (2:1 molar ratio) provided seven treatment solutions with osmotic potentials (Ψ s ) ranging from −0.05 to −1.25 MPa (electrical conductivities of 1.4 to 28 dS/m). Salt stress was imposed for 45 days beginning at either 10, 56, or 101 days after planting. The three 45-day stages are referred to here as the vegetative, reproductive, and maturation stages although the first stage included spikelet differentiation. In a separate experiment, seedling growth was measured after 21 days of salt stress (Ψ s = −0.05 to −0.85 MPa) initiated at 0, 7, 11, and 16 days after planting. Salt stress (Ψ s = −0.65 MPa) delayed germination by 4 days for both wheats but full emergence occurred. Relative growth response curves of the seedlings were alike regardless of whether salt stress was imposed at planting or at the 1st, 2nd, or 3rd-leaf stage of growth. Salt stress also retarded leaf development and tillering but hastened plant maturity. Grain yields from plants stressed during either the vegetative, reproductive, or maturation stages indicated that both species became less sensitive to salinity the later plants were stressed. Grain yield was reduced 50% at Ψ s = −0.76, −1.53, and −1.58 MPa for Probred and −0.65, −1.08, and −1.34 MPa for Aldura when salinized during stages 1, 2, and 3, respectively. Salinity reduced grain yield by reducing seed number more than seed weight indicating that salt stress during stage 1 affected spikelet differentiation. Straw yield was significantly reduced by salt stress only during stage 1. Leaf mineral analyses revealed that Aldura readily accumulated Na whereas Probred did not. Both species accumulated Cl but the concentrations were much higher in Aldura. K uptake was severely inhibited by salt stress imposed during the first stage but not when imposed the second stage.

346 citations

Journal ArticleDOI
TL;DR: Differences in the response of citrus species to salt stress, the role of different rootstocks, the causes of salt injury, and the interactions of other environmental conditions or stresses with salinity are discussed.
Abstract: Soil salinity significantly limits citrus production in many areas worldwide. Although data on fruit yields in response to salinity are limited, they indicate that grapefruit, lemons, and oranges are among the most sensitive of all agricultural crops. Fruit yields decrease about 13% for each 1.0 dS m(-1) increase in electrical conductivity of the saturated-soil extract (EC(e)) once soil salinity exceeds a threshold EC(e) of 1.4 dS m(-1). Accumulation of excess Cl(-) and Na(+) can cause specific ion toxicities, but this problem can be minimized by selecting rootstocks that restrict the uptake of these ions. During the past two decades, numerous papers describing the agronomic and physiological responses of citrus to salinity have been published. This paper reviews these research reports and discusses differences in the response of citrus species to salt stress, the role of different rootstocks, the causes of salt injury, and the interactions of other environmental conditions or stresses with salinity.

298 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: It is important to avoid treatments that induce cell plasmolysis, and to design experiments that distinguish between tolerance of salt and tolerance of water stress, to understand the processes that give rise toolerance of salt, as distinct from tolerance of osmotic stress.
Abstract: Plant responses to salt and water stress have much in common. Salinity reduces the ability of plants to take up water, and this quickly causes reductions in growth rate, along with a suite of metabolic changes identical to those caused by water stress. The initial reduction in shoot growth is probably due to hormonal signals generated by the roots. There may be salt-specific effects that later have an impact on growth; if excessive amounts of salt enter the plant, salt will eventually rise to toxic levels in the older transpiring leaves, causing premature senescence, and reduce the photosynthetic leaf area of the plant to a level that cannot sustain growth. These effects take time to develop. Salttolerant plants differ from salt-sensitive ones in having a low rate of Na + and Cl ‐ transport to leaves, and the ability to compartmentalize these ions in vacuoles to prevent their build-up in cytoplasm or cell walls and thus avoid salt toxicity. In order to understand the processes that give rise to tolerance of salt, as distinct from tolerance of osmotic stress, and to identify genes that control the transport of salt across membranes, it is important to avoid treatments that induce cell plasmolysis, and to design experiments that distinguish between tolerance of salt and tolerance of water stress.

5,868 citations

Book
01 Jan 1976
TL;DR: Water quality for agriculture, water quality in agriculture for agriculture as mentioned in this paper, water quality of agriculture, Water quality of water for agriculture in agriculture, مرکز فناوری اطلاعات و اسلاز رسانی
Abstract: Water quality for agriculture , Water quality for agriculture , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

3,518 citations

Journal ArticleDOI
TL;DR: This new handbook has a better balance between whole-plant traits, leaf traits, root and stem traits and regenerative traits, and puts particular emphasis on traits important for predicting species’ effects on key ecosystem properties.
Abstract: Plant functional traits are the features (morphological, physiological, phenological) that represent ecological strategies and determine how plants respond to environmental factors, affect other trophic levels and influence ecosystem properties. Variation in plant functional traits, and trait syndromes, has proven useful for tackling many important ecological questions at a range of scales, giving rise to a demand for standardised ways to measure ecologically meaningful plant traits. This line of research has been among the most fruitful avenues for understanding ecological and evolutionary patterns and processes. It also has the potential both to build a predictive set of local, regional and global relationships between plants and environment and to quantify a wide range of natural and human-driven processes, including changes in biodiversity, the impacts of species invasions, alterations in biogeochemical processes and vegetation–atmosphere interactions. The importance of these topics dictates the urgent need for more and better data, and increases the value of standardised protocols for quantifying trait variation of different species, in particular for traits with power to predict plant- and ecosystem-level processes, and for traits that can be measured relatively easily. Updated and expanded from the widely used previous version, this handbook retains the focus on clearly presented, widely applicable, step-by-step recipes, with a minimum of text on theory, and not only includes updated methods for the traits previously covered, but also introduces many new protocols for further traits. This new handbook has a better balance between whole-plant traits, leaf traits, root and stem traits and regenerative traits, and puts particular emphasis on traits important for predicting species’ effects on key ecosystem properties. We hope this new handbook becomes a standard companion in local and global efforts to learn about the responses and impacts of different plant species with respect to environmental changes in the present, past and future.

2,744 citations

Journal ArticleDOI
TL;DR: Evaluation of claims in the literature that the transfer of a single or a few genes can increase the tolerance of plants to saline conditions reveals that, of the 68 papers produced between 1993 and early 2003, only 19 report quantitative estimates of plant growth.
Abstract: Salinity is an ever-present threat to crop yields, especially in countries where irrigation is an essential aid to agriculture. Although the tolerance of saline conditions by plants is variable, crop species are generally intolerant of one-third of the concentration of salts found in seawater. Attempts to improve the salt tolerance of crops through conventional breeding programmes have met with very limited success, due to the complexity of the trait: salt tolerance is complex genetically and physiologically. Tolerance often shows the characteristics of a multigenic trait, with quantitative trait loci (QTLs) associated with tolerance identified in barley, citrus, rice, and tomato and with ion transport under saline conditions in barley, citrus and rice. Physiologically salt tolerance is also complex, with halophytes and less tolerant plants showing a wide range of adaptations. Attempts to enhance tolerance have involved conventional breeding programmes, the use of in vitro selection, pooling physiological traits, interspecific hybridization, using halophytes as alternative crops, the use of marker-aided selection, and the use of transgenic plants. It is surprising that, in spite of the complexity of salt tolerance, there are commonly claims in the literature that the transfer of a single or a few genes can increase the tolerance of plants to saline conditions. Evaluation of such claims reveals that, of the 68 papers produced between 1993 and early 2003, only 19 report quantitative estimates of plant growth. Of these, four papers contain quantitative data on the response of transformants and wild-type of six species without and with salinity applied in an appropriate manner. About half of all the papers report data on experiments conducted under conditions where there is little or no transpiration: such experiments may provide insights into components of tolerance, but are not grounds for claims of enhanced tolerance at the whole plant level. Whether enhanced tolerance, where properly established, is due to the chance alteration of a factor that is limiting in a complex chain or an effect on signalling remains to be elucidated. After ten years of research using transgenic plants to alter salt tolerance, the value of this approach has yet to be established in the field.

1,979 citations

Journal ArticleDOI
TL;DR: It is concluded that although there are a number of promising selection criteria, the complex physiology of salt tolerance and the variation between species make it difficult to identify single criteria.

1,946 citations