RELATIONSHIP BETWEEN TRUNK DIAMETER FLUCTUATIONS, STEM WATER POTENTIAL AND FRUIT GROWTH RATE IN POTTED ADULT APPLE TREES

2000 ◽  
pp. 43-50 ◽  
Author(s):  
J. Bonany ◽  
F. Camps ◽  
J. Salvia ◽  
M. Cohen
Keyword(s):  
Growth Rate ◽  
Water Potential ◽  
Fruit Growth ◽  
Stem Water Potential ◽  
Apple Trees ◽  
Trunk Diameter ◽  
Stem Water ◽  
Trunk Diameter Fluctuations

scholarly journals Deficit Irrigation to Control Vegetative Growth in Apple and Monitoring Fruit Growth to Schedule Irrigation

HortScience ◽  
1995 ◽  
Vol 30 (6) ◽  
pp. 1229-1232 ◽  
Author(s):  
Robert C. Ebel ◽  
Edward L. Proebsting ◽  
Robert G. Evans
Keyword(s):  
Growth Rate ◽  
Stomatal Conductance ◽  
Water Potential ◽  
Vegetative Growth ◽  
Deficit Irrigation ◽  
Irrigation Treatment ◽  
Fruit Growth ◽  
Stem Water Potential ◽  
Stem Water ◽  
Soil Volume

A standard fruit growth curve, used commercially as an aid to hand thinning, was compared to periodic volume measurements of apple fruit (Malus domestica Borkh. `Delicious') subjected to early season regulated deficit irrigation (RDI) to determine when to end RDI, which is used to control vegetative growth and save water. RDI suppressed stem water potential, stomatal conductance, and fruit growth rate compared to the trickle- and furrow-irrigated controls, which wetted about one-half and the entire soil volume, respectively. Full irrigation was restored to RDI trees by trickle and microsprinklers, which wetted about one-half and the entire soil volume, respectively, after terminal buds set. Stem water potential, stomatal conductance, and fruit growth rate of RDI trees increased to that of the controls, except for RDI/trickle trees, which had 80% the stomatal conductance of the other treatments. Fruit weight at harvest was affected by an interaction of irrigation treatment and cropload. RDI trees had similar or less vegetative growth and similar or higher yield efficiency than the controls. We recommend ending RDI before fruit growth declines below the standard curve.

scholarly journals Relationship of stem water potential and leaf conductance to vegetative growth of young olive trees in a hedgerow orchard

2008 ◽  
Vol 59 (3) ◽  
pp. 270 ◽  
Author(s):  
María Gómez-del-Campo ◽  
A. Leal ◽  
C. Pezuela
Keyword(s):  
Water Stress ◽  
Water Potential ◽  
Soil Water ◽  
Vegetative Growth ◽  
Shoot Growth ◽  
Irrigation Treatment ◽  
Leaf Conductance ◽  
Stem Water Potential ◽  
Trunk Diameter ◽  
Stem Water

In 2005, four irrigation treatments were applied to a 3-year-old cv. Cornicabra orchard. In T1, wetted soil volume was maintained close to field capacity by irrigating when soil sensors indicated that soil water potential in the root zone had fallen to –0.03 MPa and 0.06 MPa from spring until 15 August and from 15 August until September, respectively. On those days, 8, 6, 4, and 2 h of irrigation was applied to T1, T2, T3, and T4, so that over the season they received 106, 81, 76 and 31 mm of irrigation, respectively. The high value for T3 was the result of a valve failure on 13 June. Measurements were maintained throughout the experimental period of relative extractable water (REW) to 1 m depth at the wetted volume (0.30 m from a drip emitter), shoot length, trunk diameter, stem water potential (Ψstem) and leaf conductance (gl). The irrigation treatment significantly affected REW (P < 0.10), Ψstem, gl and vegetative growth (P < 0.05). Ψstem, and trunk diameter were the least variable parameters and Ψstem and shoot growth were the most sensitive to water stress. Although T1 received 24% more water than T2, no significant differences were detected in vegetative growth. T2 should be considered the optimum irrigation value. The mean monthly Kc for T2 was 0.086. The failure of the valve in T3 simulated a wet spring followed by limited irrigation. Irrigation applied was similar to T2 but shoot growth stopped one month earlier and lower values of Ψstem and gl were observed after mid August. REW was highly related to vegetative growth, 66% of maximum being achieved at REW 0.53 and 50% at 0.45. gl was independant of plant or soil water status and did not determine vegetative growth. A strong relationship established Ψstem as a good indicator of vegetative growth and hence of water stress. Shoot growth was 66% of maximum at Ψstem –1.5 MPa and 50% at –1.8 MPa.

scholarly journals Sensitivity and Variability of Maximum Trunk Shrinkage, Midday Stem Water Potential, and Transpiration Rate in Response to Withholding Irrigation from Field-grown Apple Trees

HortScience ◽  
2003 ◽  
Vol 38 (4) ◽  
pp. 547-551 ◽  
Author(s):  
A. Naor ◽  
S. Cohen
Keyword(s):  
Water Stress ◽  
Water Potential ◽  
Transpiration Rate ◽  
Water Status ◽  
Stem Water Potential ◽  
Apple Trees ◽  
Stress Indicators ◽  
Moisture Availability ◽  
Stem Water ◽  
Daily Transpiration

The sensitivity of water stress indicators to changing moisture availability, and their variability, determine the number of measurements that should be taken in order to represent properly plant water status in a certain orchard. In the present study we examined the sensitivity and variability of maximum daily trunk shrinkage, midday stem water potential, and daily transpiration rate in their responses to withholding irrigation from field-grown drip-irrigated `Golden delicious' apple trees in a commercial orchard. Irrigation was withheld from the stressed trees for 17 days starting in mid-July, and the control trees were irrigated daily at 100% of the “Class A” pan evaporation rate. The courses of daily transpiration rate, maximum trunk shrinkage, and midday stem water potential before and 10 days after the drying period were similar in the control and the stressed trees. Highly significant differences between the stressed and the control trees in their midday stem water potentials were apparent from the early stages of the stress period. Daily transpiration rate and maximum daily shrinkage were more variable than midday stem water potential, and differences between treatments became significant only after measurements were expressed relative to the initial values before irrigation was witheld. Differences between treatments (as percentages of the values obtained for the control trees) increased after irrigation stopped where these differences were greatest for maximum daily shrinkage, which reached 90%; moderate for stem water potential (60%); and least for daily transpiration rate, for which the differences remained below 20%. Our data show that the choice of a certain water stress indicator should be based on both the sensitivity to changing moisture availability and the degree of variability. Possible reasons for the different sensitivity to moisture availability and the different variability between the water stress indicators under study are discussed.

scholarly journals 756 PB 152 DIURNAL PATTERNS OF SHOOT EXTENSION GROWTH IN FIELD-GROWN PEACH

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 541d-541
Author(s):  
Matt E. Berman ◽  
Theodore M. DeJong
Keyword(s):  
Growth Rate ◽  
Water Potential ◽  
Fold Increase ◽  
Early Morning ◽  
Extension Growth ◽  
Extension Rate ◽  
Stem Water Potential ◽  
Daily Growth ◽  
Late Night ◽  
Stem Water

The primary period of shoot extension growth on field-grown peach trees occurs in the evening. Field measurements indicate a 2-3 fold increase in growth rate occurs in the late afternoon and lasts for about 2 hours. The daily growth pattern is correlated with trends in temperature, water potential and carbohydrate concentrations. Early morning and late night growth rates are apparently limited by low temperatures. Heating shoot tips at these times causes extension rate to increase greatly above that of controls at ambient temperature. The afternoon surge in extension growth rate is correlated with recovering stem water potentials. Artificially increasing stem water potential at mid-day by reducing transpiration causes extension rates to dramatically increase 2-3 fold. Starch is accumulated in the shoot extension zone during the day and depleted during the evening surge in growth.

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