scholarly journals Crop load affects assimilation rate, stomatal conductance, stem water potential and water relations of field-grown Sauvignon blanc grapevines

1997 ◽  
Vol 48 (9) ◽  
pp. 1675-1680 ◽  
Author(s):  
A. Naor ◽  
Y. Gal ◽  
B. Bravdo
Keyword(s):  
Stomatal Conductance ◽  
Water Potential ◽  
Water Relations ◽  
Assimilation Rate ◽  
Stem Water Potential ◽  
Crop Load ◽  
Sauvignon Blanc ◽  
Stem Water

scholarly journals Variation in scion water relations mediated by two newly released Geneva series rootstocks

2021 ◽  
Author(s):  
Erica Casagrande Biasuz ◽  
Lee Kalcsits
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Water Potential ◽  
Water Relations ◽  
Isotope Composition ◽  
Water Status ◽  
Physiological Traits ◽  
Stem Water Potential ◽  
Carbon And Oxygen Isotope ◽  
Stem Water

Dwarfing rootstocks are used to control tree vigor allowing for increased densities that increase apple production. Although there is considerable variation among rootstocks in dwarfing capacity, the mechanisms by which rootstocks affect vigor in apple scions remains unclear. Here, Honeycrisp apple growth and water relations were compared among three rootstocks; M-9 as the industry standard and two less studied Geneva series rootstocks; G.87 and G. 814 in Washington, USA. Trees were acquired from a commercial nursery and planted in 2017. In 2018 and 2019, scion physiological, isotopic and morphological traits were measured to better understand the link between rootstock-driven vigor and physiological traits. Rootstock affected scion shoot growth (P <0.001), stomatal conductance (P< 0.01) and stem water potential (P <0.001). Rootstocks with low vegetative vigor like M.9 also had lower stomatal conductance and enriched leaf δ13C and δ18O isotope composition. Plant growth was positively correlated with stomatal conductance and stem water potential. Rootstocks also affected plant water status and net gas exchange. Here, we report an association between rootstock-induced vigor and scion physiological traits such as gas exchange, stem water potential, and leaf carbon and oxygen isotope composition. This research has implications for the understanding of the mechanisms of dwarfing by rootstocks in apple.

scholarly journals Irrigation and Crop Load Influence Fruit Size and Water Relations in Field-grown `Spadona' Pear

2001 ◽  
Vol 126 (2) ◽  
pp. 252-255 ◽  
Author(s):  
Amos Naor
Keyword(s):  
Stomatal Conductance ◽  
Water Potential ◽  
Soil Water ◽  
Fruit Size ◽  
Leaf Water ◽  
Stem Water Potential ◽  
Crop Load ◽  
Water Potentials ◽  
Stem Water ◽  
Highly Correlated

Interrelations between water potential and fruit size, crop load, and stomatal conductance were studied in drip-irrigated `Spadona' pear (Pyrus communis L) grafted on quince C (Cydonia oblonga L.) rootstock and growing in a semi-arid zone. Five irrigation rates were applied in the main fruit growth phase: rates of 0.25, 0.40, 0.60, 0.80, and 1.00 of “Class A” pan evaporation rate. The crop in each irrigation treatment was adjusted to four levels (200 to 1200 fruit per tree) by hand thinning at the beginning of June 1999. The crop was harvested on 1 Aug. 1999, and fruit size was determined by means of a commercial sorting machine. Soil, stem, and leaf water potentials and stomatal conductance were measured during the season. Crop yield was highly correlated with stem and soil water potentials. The highest midday stem water potential was lower than values commonly reported for nonstressed trees, and was accompanied by high soil water potential, indicating that the maximal water absorption rate of the root system under those particular soil conditions was limited. Stomatal conductance was highly correlated with leaf water potential (r2 = 0.54), but a much better correlation was found with stem water potential (r2 = 0.80). Stomatal conductance decreased at stem water potentials less than -2.1 MPa. Both stem water potential and stomatal conductance were unaffected by crop load under a wide range of irrigation rates.

scholarly journals Assessing the growth response of Vitis vinifera L. cv. Xynisteri, Maratheftiko, Shiraz and Sauvignon Blanc to different irrigation regimes.

2022 ◽  
Author(s):  
Alexander Willem Copper ◽  
Stefanos Koundouras ◽  
Susan E. P. Bastian ◽  
Trent Johnson ◽  
Cassandra Collins
Keyword(s):  
Stomatal Conductance ◽  
Water Potential ◽  
Chlorophyll Content ◽  
Field Trial ◽  
Composition Analysis ◽  
Stem Water Potential ◽  
Sauvignon Blanc ◽  
Fruit Composition ◽  
Irrigation Regimes ◽  
Stem Water

Abstract The world’s changing climate is placing great pressure on the resources for sustainable viticulture. With this, it has become necessary to investigate grape varieties that are well adapted to hot climates. The aims of this study were to (1) assess the response of Xynisteri to different irrigation regimes, and (2) compare the performance of Xynisteri, Maratheftiko, Shiraz and Sauvignon Blanc grown in pots with different irrigation regimes. Trial one was established in a commercial Xynisteri vineyard in Cyprus under three different irrigation regimes - full, 50% and no irrigation in 2019. Trial two compared three irrigation regimes - full, 50% and 25% in a potted trial of Xynisteri and Sauvignon Blanc conducted in Cyprus in 2019. Trial three was a potted trial of Xynisteri, Sauvignon Blanc, Maratheftiko and Shiraz with the same three irrigation regimes conducted in Australia in 2020/21. Vine performance and physiology measurements were taken in both trials. Fruit composition analysis, yield (field trial only), shoot, trunk and root mass measurements were performed at the end of the season. Few differences between measures were found between irrigation regimes in the field trial. Fruit composition analysis revealed fructose to be lowest in the full irrigation group compared to deficit and no irrigation treatments. The potted trial in 2019 demonstrated that for all three irrigation regimes, Xynisteri had higher stem water potential, stomatal conductance and chlorophyll content than Sauvignon Blanc. Xynisteri produced greater end of season root, shoot and leaf mass than Sauvignon Blanc under all irrigation regimes. In 2020/21, Xynisteri had greater end of season root, shoot and leaf mass than Maratheftiko and Sauvignon Blanc with Shiraz the lowest. Few significant differences in stem water potential were observed in the early stages of the trial. However, toward the end of the trial and with reduced irrigation, Xynisteri and Maratheftiko had higher stem water potential than Shiraz and Sauvignon Blanc. Xynisteri had higher stomatal conductance and chlorophyll content than Maratheftiko and both were higher than Sauvignon Blanc and Shiraz. These results indicate that Xynisteri in particular may possess better cultivar specific growth traits than Shiraz and Sauvignon Blanc when grown under the same environmental conditions and in turn may be a more appropriate choice in areas where water is limited.

scholarly journals Stem Water Potential and Apple Size

1995 ◽  
Vol 120 (4) ◽  
pp. 577-582 ◽  
Author(s):  
Amos Naor ◽  
Isaac Klein ◽  
Israel Doron
Keyword(s):  
Water Stress ◽  
Stomatal Conductance ◽  
Water Potential ◽  
Fruit Size ◽  
Plant Water ◽  
Stem Water Potential ◽  
Plant Water Stress ◽  
Stem Water ◽  
Irrigation Treatments ◽  
Highly Correlated

The sensitivity of leaf (ψleaf) and stem (ψstem) water potential and stomatal conductance (gs) to soil moisture availability in apple (Malus domestics Borkh.) trees and their correlation with yield components were studied in a field experiment. Two drip irrigation treatments, 440 mm (H) and 210 mm (L), were applied to a `Golden Delicious' apple orchard during cell enlargement stage (55-173 days after full bloom). Data collected included ψstem, y leaf, gs, and soil water potential at 25 (ψsoil-25) and 50 cm (ψsoil-50). No differences in midday ψleaf's were found between irrigation treatments. Stem water potential was higher in the H treatment than in the L treatment in diurnal measurements, and at midday throughout the season. Stomatal conductance of the H treatment was higher than the L treatment throughout the day. Stomatal conductance between 0930 and 1530 hr were highly correlated with ψstem. The H treatment increased the percentage of fruit >65 mm, and increased the proportion of earlier harvested fruit reaching marketable size compared to the L treatment. Fruit size in the first harvest and the total yield were highly correlated with ψstem. The degree of correlation between plant water stress indicators and yield component decreased in the following order: ψstem>ψsoil-25,>ψsoil-50>ψleaf. The data suggest that midday ψstem may serve as a preferable plant water stress indicator with respect to fruit size.

Water stress and reduced fruit size in micro-irrigated pear trees under deficit partial rootzone drying

2007 ◽  
Vol 58 (7) ◽  
pp. 670 ◽  
Author(s):  
Mark G. O'Connell ◽  
Ian Goodwin
Keyword(s):  
Water Stress ◽  
Water Potential ◽  
Water Relations ◽  
Fruit Size ◽  
Leaf Conductance ◽  
Stem Water Potential ◽  
Crop Water ◽  
Reproductive Growth ◽  
Stem Water ◽  
Partial Rootzone Drying

Crop water relations, vegetative and reproductive growth, and soil water status were studied during 2 seasons to determine the effectiveness of partial rootzone drying (PRD) in a mature micro-irrigated pear orchard in the Goulburn Valley, Australia. PRD treatments were 50% (PRD50) and 100% (PRD100) of predicted crop water requirement (ETc) applied on one side of the tree alternated on a 14-day cycle compared with a Control treatment, which received 100% of ETc irrigated on both sides of the tree. Irrigation was applied daily by micro-jets to replace ETc estimated using reference crop evapotranspiration (ETo) and a FAO-56 crop coefficient of 1.15 adjusted for tree size. The PRD50 regime applied 174–250 mm for the season v. 347–470 mm for both the Control and PRD100 treatments. Irrigation maintained a well watered rootzone under the emitter compared with the drying profiles of the alternated wet/dry irrigated zones of the PRD treatments. There was no significant benefit of PRD100 compared with the Control irrigation regime. Similar vegetative growth (canopy radiation interception), reproductive growth (fruit growth rate, final fruit size, yield), fruit quality (total soluble solids, flesh firmness), and crop water relations (midday leaf conductance, midday leaf and stem water potential) were measured between the Control and PRD100. Trees under the PRD50 regime showed symptoms of severe water stress, that being greater fruit drop, reduced fruit size, lower yield, reduced leaf conductance, and lower leaf and stem water potential. The 50% water saving afforded by PRD50 led to a yield penalty of 16–28% compared with the Control and PRD100. PRD50 fruit failed to meet commercial cannery requirements due to poor fruit size. We conclude from an agronomic basis that deficit PRD irrigation management is not recommended for micro-irrigated pear orchards on fine-textured soils in the Goulburn Valley, Australia.

The effect of irrigation and crop load on stem water potential and apple fruit size

1997 ◽  
Vol 72 (5) ◽  
pp. 765-771 ◽  
Author(s):  
A. Naor ◽  
I. Klein ◽  
I. Doron ◽  
Y. Gal ◽  
Z. Ben-David ◽  
...  
Keyword(s):  
Water Potential ◽  
Fruit Size ◽  
Apple Fruit ◽  
Stem Water Potential ◽  
Crop Load ◽  
Stem Water

scholarly journals Physiological Response of Carambola Trees to Soil Water Depletion in Krome Soils

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 857B-857
Author(s):  
Rashid Al-Yahyai* ◽  
Bruce Schaffer ◽  
Frederick S. Davies
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Water Potential ◽  
Soil Water ◽  
Leaf Gas Exchange ◽  
Stem Water Potential ◽  
Soil Water Depletion ◽  
Water Depletion ◽  
Loam Soil ◽  
Stem Water

The effect of soil water depletion on plant water potential and leaf gas exchange of carambola (Averrhoa carambola L. cv. Arkin) in Krome very gravelly loam soil was studied in an orchard and in containers in the field and in a greenhouse. The rate of soil water depletion was determined by continuously monitoring soil water content with multi-sensor capacitance probes. Stem water potential and leaf gas exchange of carambola in containers were reduced when the soil water depletion level fell below 50% (where field capacity = 100%). Although there was a decrease in the rate of soil water depletion in the orchard as the soil dried, soil water depletion did not go below an average of 70%. This was presumably due to sufficient rainfall and capillary movement of water in the soil. Therefore, soil water content did not decline sufficiently to affect leaf gas exchange and leaf and stem water potential of orchard trees. A decline in soil water depletion below 40% resulted in a concomitant decline in stem water potential of the container trees in the field and greenhouse to below -1.0 MPa. Stomatal conductance, net CO2 assimilation, and transpiration declined significantly when stem water potential was below -1.0 MPa. The reduction of net CO2 assimilation and transpiration was proportional to the decline in stomatal conductance of container trees in the field and greenhouse. Thus, soil water depletion in Krome very gravelly loam soil must be less than 50% before water potential or leaf gas exchange of carambola is affected. Based on these results, irrigation scheduling should be based on physiological variables such as stem water potential and stomatal conductance or the amount rather than the rate of soil water depletion.

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