scholarly journals Physiological Factors and their Relationship with the Productivity of Processing Tomato under Different Water Supplies

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 586 ◽  
Author(s):  
Eszter Nemeskéri ◽  
András Neményi ◽  
András Bőcs ◽  
Zoltán Pék ◽  
Lajos Helyes
Keyword(s):  
Stomatal Conductance ◽  
Significant Influence ◽  
Water Status ◽  
Canopy Temperature ◽  
Irrigation Scheduling ◽  
Fruit Weight ◽  
Processing Tomato ◽  
Spad Value ◽  
Yield And Quality ◽  
Fruit Setting

Measurement of physiological traits can be used to monitor plant water status, for irrigation scheduling or to predict the expected yield in open-field production of vegetables. This study evaluates the changes in stomatal conductance, chlorophyll fluorescence (Fv/Fm), relative chlorophyll content (SPAD), and canopy temperature at different stages of development of processing tomato to show their relationships with the yield and quality under well-irrigated, deficit irrigated, and non-irrigated conditions. Under non-irrigated conditions, during flowering with fruit setting and early fruit development the highest canopy temperature, lowest stomatal conductance, and Fv/Fm were measured, while the SPAD value was the highest. Under this condition, the correlation between the SPAD value, fruit weight, and marketing yield was positive, but it was negative with the total soluble solid (°Brix). During flowering with fruit setting, under deficit irrigation conditions a close significant positive correlation was found between the SPAD value and the fruit weight, marketing yield, and vitamin C content of fruits. During this period, under regularly irrigated conditions, the SPAD, Fv/Fm, and canopy temperature related to stomatal conductance. Stomatal conductance had significant influence on yield and quality under non-irrigated and well-irrigated conditions while the SPAD value and canopy temperature had significant influence on under deficit irrigated conditions.

Assessing canopy temperature-based water stress indices for soybeans under subhumid conditions

2020 ◽  
Author(s):  
Angela Morales Santos ◽  
Reinhard Nolz
Keyword(s):  
Water Stress ◽  
Soil Water ◽  
Water Status ◽  
Canopy Temperature ◽  
Irrigation Scheduling ◽  
Stress Index ◽  
Crop Water ◽  
Stress Indices ◽  
Soil Water Status ◽  
Crop Water Stress

<p>Sustainable irrigation water management is expected to accurately meet crop water requirements in order to avoid stress and, consequently, yield reduction, and at the same time avoid losses of water and nutrients due to deep percolation and leaching. Sensors to monitor soil water status and plant water status (in terms of canopy temperature) can help planning irrigation with respect to time and amounts accordingly. The presented study aimed at quantifying and comparing crop water stress of soybeans irrigated by means of different irrigation systems under subhumid conditions.</p><p>The study site was located in Obersiebenbrunn, Lower Austria, about 30 km east of Vienna. The region is characterized by a mean temperature of 10.5°C with increasing trend due to climate change and mean annual precipitation of 550 mm. The investigations covered the vegetation period of soybean in 2018, from planting in April to harvest in September. Measurement data included precipitation, air temperature, relative humidity and wind velocity. The experimental field of 120x120 m<sup>2</sup> has been divided into four sub-areas: a plot of 14x120 m<sup>2</sup> with drip irrigation (DI), 14x120 m<sup>2</sup> without irrigation (NI), 36x120 m<sup>2</sup> with sprinkler irrigation (SI), and 56x120 m<sup>2</sup> irrigated with a hose reel boom with nozzles (BI). A total of 128, 187 and 114 mm of water were applied in three irrigation events in the plots DI, SI and BI, respectively. Soil water content was monitored in 10 cm depth (HydraProbe, Stevens Water) and matric potential was monitored in 20, 40 and 60 cm depth (Watermark, Irrometer). Canopy temperature was measured every 15 minutes using infrared thermometers (IRT; SI-411, Apogee Instruments). The IRTs were installed with an inclination of 45° at 1.8 m height above ground. Canopy temperature-based water stress indices for irrigation scheduling have been successfully applied in arid environments, but their use is limited in humid areas due to low vapor pressure deficit (VPD). To quantify stress in our study, the Crop Water Stress Index (CWSI) was calculated for each plot and compared to the index resulting from the Degrees Above Canopy Threshold (DACT) method. Unlike the CWSI, the DACT method does not consider VPD to provide a stress index nor requires clear sky conditions. The purpose of the comparison was to revise an alternative method to the CWSI that can be applied in a humid environment.</p><p>CWSI behaved similar for the four sub-areas. As expected, CWSI ≥ 1 during dry periods (representing severe stress) and it decreased considerably after precipitation or irrigation (representing no stress). The plot with overall lower stress was BI, producing the highest yield of the four plots. Results show that DACT may be a more suitable index since all it requires is canopy temperature values and has strong relationship with soil water measurements. Nevertheless, attention must be paid when defining canopy temperature thresholds. Further investigations include the development and test of a decision support system for irrigation scheduling combining both, plant-based and soil water status indicators for water use efficiency analysis.</p>

scholarly journals Use of Thermal Imaging to Assess Water Status in Citrus Plants in Greenhouses

Horticulturae ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 249
Author(s):  
Gustavo Haddad Souza Vieira ◽  
Rhuanito Soranz Ferrarezi
Keyword(s):  
Thermal Imaging ◽  
Sweet Orange ◽  
Water Status ◽  
Irrigation Management ◽  
Canopy Temperature ◽  
Irrigation Scheduling ◽  
Water Levels ◽  
Automated System ◽  
Thermal Images ◽  
One Year

The direct examination of plant canopy temperature can assist in optimizing citrus irrigation management in greenhouses. This study aimed to develop a method to measure canopy temperature using thermal imaging in one-year-old citrus plants in a greenhouse to identify plants with water stress and verify its potential to be used as a tool to assess citrus water status. The experiment was conducted for 48 days (27 November 2019 to 13 January 2020). We evaluated the influence of five levels of irrigation on two citrus species (‘Red Ruby’ grapefruit (Citrus paradisi) and ‘Valencia’ sweet orange (Citrus sinensis (L.) Osbeck)). Images were taken using a portable thermal camera and analyzed using open-source software. We determined canopy temperature, leaf photosynthesis and transpiration, and plant biomass. The results indicated a positive relationship between the amount of water applied and the temperature response of plants exposed to different water levels. Grapefruit and sweet orange plants that received less water and were submitted to water restrictions showed higher canopy temperatures than the air (up to 6 °C). The thermal images easily identified water-stressed plants. Our proof-of-concept study allowed quickly obtaining the canopy temperature using readily available equipment and can be used as a tool to assess citrus water status in one-year-old citrus plants in greenhouses and perhaps in commercial operations with mature trees in the field after specific experimentation. This technique, coupled with an automated system, can be used for irrigation scheduling. Thus, setting up a limit temperature is necessary to start the irrigation system and set the irrigation time based on the soil water content. To use this process on a large scale, it is necessary to apply an automation routine to process the thermal images in real time and remove the weeds from the background to determine the canopy temperature.

scholarly journals THE EFFECT OF IRRIGATION STRATEGIES ON PEACH FRUIT GROWTH AND FINAL SIZE

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 572e-572
Author(s):  
R. Scott Johnson ◽  
Claude Phene ◽  
Charles Medawar
Keyword(s):  
Growth Stage ◽  
Water Status ◽  
Fruit Size ◽  
Canopy Temperature ◽  
Fruit Weight ◽  
Fruit Growth ◽  
Final Size ◽  
Peach Fruit ◽  
Early Stages ◽  
Peach Trees

Six irrigation strategies were imposed on a block of O'Henry peach trees irrigated by fanjets. Treatments received different percentages of ET during the various stages of fruit growth and postharvest. ET was estimated by a large weighing lysimeter containing 2 trees and located in the center of the block. Fruit diameters were measured weekly and final fruit weights were determined at harvest. Adjusted fruit weights were estimated by statistically adjusting each treatment to the same fruit load. Adjusted fruit weight correlated well with soil water content during the month before harvest but not during early stages of fruit growth. Treatments which applied 50% ET during early stages of fruit growth showed reduced fruit size at that time. However, with applications of 150% ET during the final fruit growth stage, fruit size recovered. Adjusted fruit weight also correlated with measures of tree water status including midday leaf water potential and canopy temperature.

scholarly journals Effect of Plant density and Fertilizer Application Rates on Growth, Fruit Yield and Quality of Tomato (Solanum lycopersicum L.) in Greenhouse Condition

2021 ◽  
pp. 22-31
Author(s):  
Mai Hai Chau ◽  
Ngo Xuan Chinh
Keyword(s):  
Solanum Lycopersicum ◽  
Plant Density ◽  
Fruit Weight ◽  
Fruit Yield ◽  
Fertilizer Rate ◽  
Tomato Cultivar ◽  
Solanum Lycopersicum L ◽  
Yield And Quality ◽  
Fruit Setting ◽  
Marketable Fruit

Plant density and fertilization are key practices for improving the fruit quality and yield of vegetables grown in greenhouses. The experiment was performed to investigate the effects of density and fertilization on the fruit yield and quality, economic efficiency of Solanum lycopersicum L. at Duc Trong district of Lam Dong province. The density (50,000; 33,000; 25.000 plants ha-1) and the fertilizer rates (240N – 100P2O5 – 275K2O; 300N – 125P2O5 – 344K2O; 360N – 150P2O5 – 413K2O kg and 420N – 175P2O5 – 482K2O kg ha-1) were studied in a completely randomised split plot design with three blocks. The fertilizer rate (420N – 175P2O5 – 482K2O kg ha-1) was produced the highest height (562.39 cm), fruit setting rate (69.87%), number of fruit per plant (95.65 fruits), average fruit weight (106.37 g), fruit yield (441.11 tons ha-1) and marketable fruit yield (204.31 tons ha-1). The density (25,000 plants ha-1) gave the highest fruit setting rate (75.35%), number of fruit per plant (94.84 fruits), average fruit weight (113.24 g), individual fruit yield (10.02 kg per plant) and fruit yield (501.17 tons ha-1). The combination of density (25,000 plants ha-1) and fertilizer rate (420N – 175P2O5 – 482K2O kg ha-1) have the highest fruit yield (613.5 tons ha-1), marketable fruit yield (223.91 tons ha-1) and rate of return (2.44). In addition, this combination was the best density and fertilizer level management strategy for greenhouse-grown Lahay 334 tomato cultivar in Lam Dong province, Vietnam.

scholarly journals Effect of water supply on canopy temperature, stomatal conductance and yield quantity of processing tomato (Lycopersicon esculentum Mill.)

2010 ◽  
Vol 16 (5) ◽  
Author(s):  
L. Helyes ◽  
A. Bőcs ◽  
Z. Pék
Keyword(s):  
Stomatal Conductance ◽  
Lycopersicon Esculentum ◽  
Water Supply ◽  
Canopy Temperature ◽  
Tomato Plants ◽  
Horticultural Crops ◽  
Processing Tomato ◽  
Lycopersicon Esculentum Mill ◽  
Plant Stand ◽  
Positive Effect

Tomato (Lycopersicon esculentum Mill.) is one of the most extensively cultivated horticultural crops in the world.Water supply is important for yield quantity and quality. The aims of the present study were 1) to evaluate the canopy temperature and the stomatal conductance on processing tomato substances with different water supply, 2) to investigate the effect of different water supply on yield quantity. There were two irrigated treatments, one of them was the reguralry irrigated plant stand which got 333 mm water during investigated period, including the precipitation and the other was the cut off substance which means the irrigation (drip) was stopped at the beginning of the ripening process and there was a control as well which got 189 mm precipitation. The canopy temperature was measured row by row with a Raytek MX 4 type infrared remote thermometer. The stomatal conductance was measured by Delta-T AP4 type porometer. There were significant differences between the control and irrigated plants according to the water supply which was formulated the canopy values. The plants with a deficient water supply were decreased the transpiration rate, therefore its cooling effect didn’t show up. The regularly irrigated tomato plants’ yield exceeded the unirrigated ones more than twice. It is emerged from the study that the irrigation has a positive effect on the amount of the harvestable yield in this year type.

Agronomic and physiological assessments of genotypic variation for drought resistance in sorghum

1989 ◽  
Vol 40 (1) ◽  
pp. 49 ◽  
Author(s):  
A Blum ◽  
J Mayer ◽  
G Golan
Keyword(s):  
Stomatal Conductance ◽  
Drought Resistance ◽  
Water Status ◽  
Genotypic Variation ◽  
Relative Yield ◽  
Canopy Temperature ◽  
Total Biomass ◽  
Leaf Rolling ◽  
Growth Duration ◽  
Drought Resistant

This study was designed to assess genotypic variability for drought resistance in sorghum (Sorghum bicolor [L.] Moench) and to conclude on the possible physiological differences between drought resistant and drought susceptible genotypes.Grain yield under drought stress ranged from 184 to 943 g m-2 and relative yield ranged from 35.8 to 103.5% among genotypes. Yield (but not relative yield) under stress was decreased (r= -0.89**) with a longer growth duration of gentoypes. Both stover yield and total biomass under stress increased (r = 0.69** and r = 0.72**, respectively), while harvest index decreased (r = 0.80**) with longer growth duration. Genotypes differed significantly in leaf water potential (LWP), canopy temperature, leaf rolling, leaf carbon exchange rate (CER), stomatal conductance and osmotic adjustment. These data were averaged for the four best ('drought resistant'-R) and the two poorest ('drought susceptible'-S) genotypes in terms of their absolute and relative yields under stress. Compared with S, the R genotypes were earlier in heading and had higher LWP, lower canopy temperature and higher stomatal conductance. While leaf rolling was similar in R and S genotypes, it was found to increase as LWP decreased across all genotypes. Under these stress conditions variations in CER among genotypes on given dates appeared to be affected more by phenology than by plant water status.

scholarly journals Leaf Water Relations in Lime Trees Grown under Shade Netting and Open-Air

Plants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 510 ◽  
Author(s):  
Ana Belén Mira-García ◽  
Wenceslao Conejero ◽  
Juan Vera ◽  
María Carmen Ruiz-Sánchez
Keyword(s):  
Gas Exchange ◽  
Leaf Gas Exchange ◽  
Water Status ◽  
Canopy Temperature ◽  
Net Photosynthesis ◽  
Irrigation Scheduling ◽  
Plant Water Status ◽  
Plant Water ◽  
Stem Water Potential ◽  
Thermal Index

Physiological plant water status indicators are useful for managing precision irrigation in regions with limited water resources. The aim of this work was to evaluate the effect of shade netting on the diurnal and seasonal variations of several plant water status indicators in young lime trees (Citrus latifolia Tan., cv. Bearss), grown at the CEBAS-CSIC experimental station in Murcia, Spain. Stem water potential (Ψstem), leaf gas exchange (net photosynthesis (Pn) and stomatal conductance (gs)), and canopy temperature (Tc) were measured on representative days of winter and summer. The Ψstem daily pattern was quite similar in both seasons under both conditions. However, the circadian rhythm of leaf gas exchange was affected by shade conditions, especially in summer, when shaded leaves showed maximum gs values for a longer time, allowing higher net photosynthesis (37%). Canopy temperature behaved similarly in both conditions, nevertheless, lower values were recorded in open-air than in shaded trees in the two seasons. The canopy-to-air temperature difference (Tc − Ta), however, was lower in shaded trees during the daylight hours, indicating the higher degree of leaf cooling that was facilitated by high gs values. The possibility of continuously recording Tc makes it (or the proposed canopy thermal index, CTI) a promising index for precise irrigation scheduling. Shade netting was seen to favour gas exchange, suggesting that it may be considered alternative to open-air for use in semi-arid areas threatened by climate change.

Vapour pressure deficit aids the interpretation of cotton canopy temperature response to water deficit

2014 ◽  
Vol 41 (5) ◽  
pp. 535 ◽  
Author(s):  
Warren C. Conaty ◽  
James R. Mahan ◽  
James E. Neilsen ◽  
Greg A. Constable
Keyword(s):  
Water Stress ◽  
Soil Water ◽  
Vapour Pressure ◽  
Water Status ◽  
Canopy Temperature ◽  
Vapour Pressure Deficit ◽  
Irrigation Scheduling ◽  
Plant Water ◽  
Stress Detection ◽  
Water Fraction

Crop canopy temperature (Tc) is coupled with transpiration, which is a function of soil and atmospheric conditions and plant water status. Thus, Tc has been identified as a real-time, plant-based tool for crop water stress detection. Such plant-based methods theoretically integrate the water status of both the plant and its environment. However, previous studies have highlighted the limitations and difficulty of interpreting the Tc response to plant and soil water stress. This study investigates the links between cotton Tc, established measures of plant water relations and atmospheric vapour pressure deficit (VPDa). Concurrent measures of carbon assimilation (A), stomatal conductance (gs), leaf water potential (Ψl), soil water (fraction of transpirable soil water (FTSW)) and Tc were conducted in surface drip irrigated cotton over two growing seasons. Associations between A, gs, Ψl, FTSW and Tc are presented, which are significantly improved with the inclusion of VPDa. It was concluded that utilising the strong associations between Ψl, VPDa and Tc, an adjustment of 1.8°C for each unit of VPDa should be made to the critical Tc for irrigation. This will improve the precision of irrigation in Tc based irrigation scheduling protocols. Improved accuracy in water stress detection with Tc, and an understanding of the interaction the environment plays in this response, can potentially improve the efficiency of irrigation.

scholarly journals Assessing the Water-Stress Baselines by Thermal Imaging for Irrigation Management in Almond Plantations under Water Scarcity Conditions

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1298
Author(s):  
Saray Gutiérrez-Gordillo ◽  
Iván Francisco García-Tejero ◽  
Víctor Hugo Durán Zuazo ◽  
Amelia García Escalera ◽  
Fernando Ferrera Gil ◽  
...  
Keyword(s):  
Water Stress ◽  
Thermal Imaging ◽  
Water Status ◽  
Irrigation Management ◽  
Irrigation Treatment ◽  
Canopy Temperature ◽  
Irrigation Scheduling ◽  
Stress Index ◽  
Crop Water ◽  
Crop Water Stress Index

This work examines the use of thermal imaging to determine the crop water status in young almond trees under sustained deficit irrigation strategies (SDIs). The research was carried out during two seasons (2018–2019) in three cultivars (Prunus dulcis Mill., cvs. Guara, Lauranne, and Marta) subjected to three irrigation treatments: a full irrigation treatment (FI) at 100% of irrigation requirements (IR), and two SDIs that received 75% and 65% of the IR, respectively. Crop water monitoring was done by measurements of canopy temperature, leaf water potential (Ψleaf), and stomatal conductance. Thermal readings were used to define the non-water-stress baselines (NWSB) and water-stress baselines (WSB) for each treatment and cultivar. According to our findings, Ψleaf was the most responsive parameter to reflect differences in almond water status. In addition, NWSB and WSB allowed the determination of the crop water-stress index (CWSI) and the increment of canopy temperature (ITC) for each SDI treatment, obtaining threshold values of CWSI (0.12–0.15) and ITC (~1 °C) that would ensure maximum water savings by minimizing the effects on yield. The findings highlight the importance of determining the different NWSB and WSB for different almond cultivars and its potential use for proper irrigation scheduling.

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