scholarly journals Monitoring of Emerging Water Stress Situations by Thermal and Vegetation Indices in Different Almond Cultivars

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1419
Author(s):  
Saray Gutiérrez-Gordillo ◽  
Javier de la Gala González-Santiago ◽  
Emiliano Trigo-Córdoba ◽  
Alfredo Emilio Rubio-Casal ◽  
Iván Francisco García-Tejero ◽  
...  
Keyword(s):  
Water Stress ◽  
Deficit Irrigation ◽  
Water Status ◽  
Stress Conditions ◽  
Irrigation Season ◽  
Stem Water Potential ◽  
Crop Water ◽  
Regulated Deficit Irrigation ◽  
Sensitive Periods ◽  
Mild Water Stress

In recent years, the area dedicated to modern irrigated almond plantations has increased significantly in Spain. However, the legal irrigation allocations are lower than the maximum water requirements of the crop in most cases. Therefore, almond growers are forced to implement regulated deficit irrigation strategies on their farms, applying water stress in certain resistant phenological periods and avoiding it in sensitive periods. Given the need to monitor the water status of the crop, especially in the most sensitive periods to water stress, the objective of this work was to evaluate the sensitivity of two UAV-based crop water status indicators to detect early water stress conditions in four almond cultivars. The field trial was conducted during 2020 in an experimental almond orchard, where two irrigation strategies were established: full irrigation (FI), which received 100% of irrigation requirements (IR), and regulated deficit irrigation (RDI), which received 70% of IR during the whole irrigation period except during the kernel-filling stage when received 40% IR. The UAV flights were performed on four selected dates of the irrigation season. The Crop Water Status Index (CWSI) and the Normalized Difference Vegetation Index (NDVI) were derived from thermal and multispectral images, respectively, and compared to classical water status indicators, i.e., stem water potential (Ψstem), stomatal conductance (gs), and photosynthetic rate (AN). Of the four flights performed, three corresponded to mild water stress conditions and a single flight was performed under moderate water stress conditions. Under mild water stress, CWSI was not able to capture the differences between FI and RDI trees that were observed with Ψstem. Under moderate stress conditions, CWSI was sensitive to the water deficit reached in the trees and showed significant differences among both irrigation treatments. No differences were observed in the CWSI and NVDI response to water stress among cultivars. Although NDVI and CWSI were sensitive to water stress, the low signal intensity observed in NDVI makes this index less robust than CWSI to monitor crop water stress. It can be concluded that UAV-based CWSI measurements are reliable to monitor almond water status, although for early (mild) levels of water stress, Ψstem seems to be the preferred option.

Linking canopy temperature and trunk diameter fluctuations with other physiological water status tools for water stress management in citrus orchards

2011 ◽  
Vol 38 (2) ◽  
pp. 106 ◽  
Author(s):  
Iván F. García-Tejero ◽  
Víctor H. Durán-Zuazo ◽  
José L. Muriel-Fernández ◽  
Juan A. Jiménez-Bocanegra
Keyword(s):  
Water Stress ◽  
Deficit Irrigation ◽  
Water Status ◽  
Irrigation Treatment ◽  
Canopy Temperature ◽  
Control Treatment ◽  
Stem Water Potential ◽  
Crop Water ◽  
Trunk Diameter ◽  
Trunk Diameter Fluctuations

The continuous monitoring of crop water status is key to the sustainable management of water stress situations. Two deficit irrigation (DI) treatments were studied during the maximum evapotranspirative demand period in an orange orchard (Citrus sinensis (L.) Osb. cv. Navelina): sustained deficit irrigation irrigated at 55% crop evapotranspiration (ETC), and low-frequency deficit irrigation treatment, in which the plants were irrigated according to stem water potential at midday (Ψstem). Additionally, a control treatment irrigated at 100% of ETC was established. The daily canopy temperature (TC) was measured with an infrared thermometer camera together with measurements of trunk diameter fluctuations (TDF), Ψstem and stomatal conductance (gS). The time course of all physiological parameters and their relationships were analysed, confirming that canopy air temperature differential (TC – Ta) variations and TDF are suitable approaches for determining the water stress. In addition, the maximum daily shrinkage (MDS) and TC – Ta showed high sensitivity to water stress in comparison to Ψstem and gS. Significant relationships were found among MDS and TC – Ta with Ψstem and gS, for monitoring the crop water status by means of MDS vs Ψstem and TC – Ta vs Ψstem. Thus, the combination of these techniques would be useful for making scheduling decisions on irrigation in orchards with high variability in plant water stress.

scholarly journals Absence of Yield Reduction after Controlled Water Stress during Prehaverst Period in Table OliveTrees

Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 258 ◽  
Author(s):  
María Martín-Palomo ◽  
Mireia Corell ◽  
Ignacio Girón ◽  
Luis Andreu ◽  
Alejandro Galindo ◽  
...  
Keyword(s):  
Water Stress ◽  
Deficit Irrigation ◽  
Water Status ◽  
Block Design ◽  
Irrigation Scheduling ◽  
Yield Reduction ◽  
Irrigation Season ◽  
Stem Water Potential ◽  
Olive Trees ◽  
Effect On Yield

Deficit irrigation scheduling is becoming increasingly important under commercial conditions. Water status measurement is a useful tool in these conditions. However, the information about water stress levels for olive trees is scarce. The aim of this experiment was to evaluate the effect on yield of a moderate controlled water stress level at the end of the irrigation season. The experiment was conducted in the experimental farm of La Hampa (Coria del Río, Seville, Spain) during three years. A completely randomized block design was performed using three different irrigation treatments. Deficit irrigation was applied several (4 or 2) weeks before harvest. Irrigation was controlled using the midday stem water potential, with a threshold value of −2 MPa and compared with a full irrigated treatment. This water stress did not reduced gas exchange during the deficit period. The effect on yield was not significant in any of the three seasons. In the high-fruit load season, fruit volume was slightly affected (around 10%), but this was not significant at harvest. Results suggest an early affection of fruit growth with water stress, but with a slow rate of decrease. Moderate water stress could be useful for the management of deficit irrigation in table olive trees.

scholarly journals Physiological mechanism contributing to efficient use of water in field tomato under different irrigation

2009 ◽  
Vol 55 (No. 3) ◽  
pp. 128-133 ◽  
Author(s):  
S. Lei ◽  
Q. Yunzhou ◽  
J. Fengchao ◽  
S. Changhai ◽  
Y. Chao ◽  
...  
Keyword(s):  
Water Stress ◽  
Water Use ◽  
Deficit Irrigation ◽  
Water Status ◽  
Physiological Mechanism ◽  
Regulated Deficit Irrigation ◽  
Normal Water ◽  
Use Efficiency ◽  
Antioxidant Enzymes Activities ◽  
Partial Root Drying

An open field experiment was conducted under furrow irrigation with 3 treatments: CK (control), PRD (partial root drying) and RDI (regulated deficit irrigation). The results showed that water potential, water content of the leaf and growth were decreased under PRD and RDI and the plants met stronger water stress under RDI than under PRD regime. The water use efficiency (WUE) based on fruit yield reached to 10.95 kg/m<SUP>3</SUP> and 15.33 kg/m<SUP>3</SUP>, i.e. 17.1% and 63.9% increase over CK under RDI and PRD, respectively. The transpiration efficiency in RDI was kept at the same level as CK, whereas it was promoted by 32.4% under PRD condition. CAT, SOD and POD activities were more active under RDI and especially under PRD than under CK. Therefore, following conclusions could be made: moderate water stress induced osmotic regulation under PRD conditions, leading to normal water status, higher antioxidant enzymes activities, the same level of biomass and lower water use, thus providing some part of mechanism to higher WUE under PRD condition.

scholarly journals Impacts of water stress, environment and rootstock on the diurnal behaviour of stem water potential and leaf conductance in pistachio (Pistacia vera L.)

2016 ◽  
Vol 14 (2) ◽  
pp. e0804 ◽  
Author(s):  
Houssem Memmi ◽  
Jose F. Couceiro ◽  
Carmen Gijón ◽  
David Pérez-López
Keyword(s):  
Water Stress ◽  
Water Potential ◽  
Water Status ◽  
Irrigation Scheduling ◽  
Leaf Conductance ◽  
Irrigation Season ◽  
Stem Water Potential ◽  
Stem Water ◽  
Diurnal Behaviour ◽  
Pistachio Trees

Little information is available on the diurnal behaviour of water potential and leaf conductance on pistachio trees despite their relevance to fine tune irrigation strategies. Mature pistachio trees were subject to simultaneous measurements of stem water potential (Ψx) and leaf conductance (gl) during the day, at three important periods of the irrigation season. Trees were grown on three different rootstocks and water regimes. An initial baseline relating Ψx to air vapor pressure deficit (VPD) is presented for irrigation scheduling in pistachio. Ψx was closely correlated with VPD but with a different fit according to the degree of water stress. No evidence of the variation of Ψx in relation to the phenology of the tree was observed. Furthermore, midday Ψx showed more accuracy to indicate a situation of water stress than predawn water potential. Under well irrigated conditions, gl was positively correlated with VPD during stage II of growth reaching its peak when VPD reached its maximum value (around 4 kPa). This behaviour changed during stage III of fruit growth suggesting a reliance of stomatal behaviour to the phenological stage independently to the tree water status. The levels of water stress reached were translated in a slow recovery of tree water status and leaf conductance (more than 40 days). Regarding rootstocks, P. integerrima showed little adaptation to water shortage compared to the two other rootstocks under the studied conditions.

Monitoring Crop Water Status and Irrigation Needs Using Multispectral Airborne Sensors

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 905D-905
Author(s):  
Thomas R. Clarke ◽  
M. Susan Moran
Keyword(s):  
Water Stress ◽  
Near Infrared ◽  
Water Status ◽  
Canopy Cover ◽  
Stress Index ◽  
Crop Water ◽  
Vegetative Cover ◽  
Crop Water Stress Index ◽  
Water Stress Index ◽  
Subsurface Drip

Water application efficiency can be improved by directly monitoring plant water status rather than depending on soil moisture measurements or modeled ET estimates. Plants receiving sufficient water through their roots have cooler leaves than those that are water-stressed, leading to the development of the Crop Water Stress Index based on hand-held infrared thermometry. Substantial error can occur in partial canopies, however, as exposed hot soil contributes to deceptively warm temperature readings. Mathematically comparing red and near-infrared reflectances provides a measure of vegetative cover, and this information was combined with thermal radiance to give a two-dimensional index capable of detecting water stress even with a low percentage of canopy cover. Thermal, red, and near-infrared images acquired over subsurface drip-irrigated cantaloupe fields demonstrated the method's ability to detect areas with clogged emitters, insufficient irrigation rate, and system water leaks.

scholarly journals Potential of UAS-Based Remote Sensing for Estimating Tree Water Status and Yield in Sweet Cherry Trees

2020 ◽  
Vol 12 (15) ◽  
pp. 2359
Author(s):  
Víctor Blanco ◽  
Pedro José Blaya-Ros ◽  
Cristina Castillo ◽  
Fulgencio Soto-Vallés ◽  
Roque Torres-Sánchez ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Deficit Irrigation ◽  
Vegetation Index ◽  
Sweet Cherry ◽  
Prunus Avium ◽  
Water Status ◽  
Control Treatment ◽  
Stem Water Potential ◽  
Irrigation Treatments ◽  
Cherry Trees

The present work aims to assess the usefulness of five vegetation indices (VI) derived from multispectral UAS imagery to capture the effects of deficit irrigation on the canopy structure of sweet cherry trees (Prunus avium L.) in southeastern Spain. Three irrigation treatments were assayed, a control treatment and two regulated deficit irrigation treatments. Four airborne flights were carried out during two consecutive seasons; to compare the results of the remote sensing VI, the conventional and continuous water status indicators commonly used to manage sweet cherry tree irrigation were measured, including midday stem water potential (Ψs) and maximum daily shrinkage (MDS). Simple regression between individual VIs and Ψs or MDS found stronger relationships in postharvest than in preharvest. Thus, the normalized difference vegetation index (NDVI), resulted in the strongest relationship with Ψs (r2 = 0.67) and MDS (r2 = 0.45), followed by the normalized difference red edge (NDRE). The sensitivity analysis identified the optimal soil adjusted vegetation index (OSAVI) as the VI with the highest coefficient of variation in postharvest and the difference vegetation index (DVI) in preharvest. A new index is proposed, the transformed red range vegetation index (TRRVI), which was the only VI able to statistically identify a slight water deficit applied in preharvest. The combination of the VIs studied was used in two machine learning models, decision tree and artificial neural networks, to estimate the extra labor needed for harvesting and the sweet cherry yield.

Using saline reclaimed water on almond grown in Mediterranean conditions: deficit irrigation strategies and salinity effects

2019 ◽  
Vol 19 (5) ◽  
pp. 1413-1421 ◽  
Author(s):  
Gaetano Alessandro Vivaldi ◽  
Salvatore Camposeo ◽  
Giuseppe Lopriore ◽  
Cristina Romero-Trigueros ◽  
Francisco Pedrero Salcedo
Keyword(s):  
Tree Growth ◽  
Deficit Irrigation ◽  
Management Practices ◽  
Water Productivity ◽  
Maximum Yield ◽  
Control Treatment ◽  
Irrigation Season ◽  
Regulated Deficit Irrigation ◽  
Trunk Diameter ◽  
Almond Trees

Abstract The main objective of this study was to acquire agronomic knowledge about the effects of irrigation with saline reclaimed (RW) and desalinated DESERT (DW) water and different irrigation strategies: control full irrigation (FI) and regulated deficit irrigation (RDI) on leaf nutrients, tree growth and fruit quality and yield of almond trees in pots. Our results showed that RW had the highest concentration of some valuable agronomic nutrients such as N, but also of phytotoxic elements (Na and Cl−). Na leaf concentration on RW treatments reached toxic levels, especially under RDI, and toxicity symptoms were shown. Regarding tree growth, cumulate trunk diameter on RW-RDI was significantly lower than on the control treatment and shoot growth was reduced from the beginning of the irrigation season in RW treatments. Maximum yield was reached on RW-FI, 18% higher than the control treatment. However, RDI strategies influenced negatively on yield, being 23% less in RW and 7% less in DW although water productivity was not significantly reduced by water stress. These findings manifest that the combination of RW and RDI can be a promising future practice for almond irrigation, but long-term studies to establish suitable management practices must be developed.

Sign in / Sign up

Export Citation Format

Share Document