A Review on Potential Plant-Based Water Stress Indicators for Vegetable Crops

Abstract

Area under vegetable cultivation is expanding in arid and semi-arid regions of the world to meet the nutritional requirements of an ever-growing population. However, water scarcity in these areas is limiting vegetable productivity. New water-conserving irrigation management practices are being implemented in these areas. Under these irrigation management practices, crops are frequently exposed to some extent of water stress. Vegetables are highly sensitive to water stress. For the successful implementation of new irrigation practices in vegetable crops, it is of immense importance to determine the threshold water deficit level which will not have a detrimental effect on plant growth and yield. Along with this, plant response and adaptation mechanisms to new irrigation practices need to be understood for the successful implementation of new irrigation practices. To understand this, water stress indicators that are highly responsive to water stress; and that can help in early detection of water stress need to be identified for vegetable crops. Plant-based water stress indicators are quite effective in determining the water stress level in plants because they take into account the cumulative effect of water stress due to declining soil moisture status and increased evaporative demand of the atmosphere while determining the water stress level in plant. Water stress quantification using plant-based approaches involves direct measurements of several aspects of plant water status and indirect measurements of plant processes which are highly sensitive to water deficit. In this article, a number of plant-based water stress indicators were critically reviewed for (1) their efficacy to determine the level of water stress, (2) their potential to predict the yield of a crop as affected by different water-deficit levels and (3) their suitability for irrigation scheduling in vegetable crops.

Leaf Monoterpene Emission Limits Photosynthetic Downregulation under Heat Stress in Field-Grown Grapevine

“…The fact that the monoterpene emitter INRA809 maintained higher F v /F m for a similar leaf temperature to SMA130 may further confirm an induced thermotolerance of the emitter clone. Consistent with this work, F v /F m declined much less in isoprene-emitting tobacco plants subjected to environmental stress [15,40]. However, data collected on the 23 July 2019 highlighted a much higher increase in leaf temperature for identical environmental conditions in SMA130 than INRA809.…”

“…Temperature response of two grapevine clones (INRA809 and SMA130) for CO 2 assimilation (A, A), stomatal conductance (g s , B), intrinsic water-use efficiency ( i WUE, C) and the ratio between ETR and A (ETR/A, D). Data were collected with a Licor6400 and at increasing leaf temperatures(25,30,35,40 • C). Data are means (n = 5) ± standard error of the means (SEM).…”

Biochemical and Genetic Responses of Tea (Camellia sinensis (L.) Kuntze) Microplants under Mannitol-Induced Osmotic Stress In Vitro

“…Our results are consistent with some other results in jackfruit and sugar apple plants under drought stress [ 37 ]. Nevertheless, most of the published studies showed decreasing pigment contents in plants under the effect of osmotic stress [ 38 ]. In the previous studies, this was attributed to the inhibition of chlorophyll synthesis, together with the activation of its degradation by chlorophyllase [ 39 ].…”

Can Organic Amendments Improve Soil Physical Characteristics and Increase Maize Performances in Contrasting Soil Water Regimes?

“…Water stress has a negative impact on metabolic processes, the most sensitive being cellular expansion and development, resulting in specific morphological traits, i.e., reduced leaf elongation, reduced leaf area and stem diameter, among others [47]. By comparing the morphological characteristics of plants grown at the same moment and in the same location, but with different soil water conditions, a diagnosis of the occurrence of a water stress and its intensity can be made [48]. The reduced growth and development in the dry treatment compared to the wet treatment (Figure 3) confirmed the higher plant stress in the dry treatment, and consequently validated our technique of managing the timing and amount of irrigation by controlling Ψm, as well as validating the threshold Ψm of −500 hPa to impose a slight water stress and −150 hPa for negligible stress.…”