Termination of vase life for cut flowers is characterized by wilting associated with an imbalance developing between water uptake through xylem conduits in stems and water loss through stomata and other structures on leaves and other organs. To
Peitao Lü, Xinmin Huang, Hongmei Li, Jiping Liu, Shenggen He, Daryl C. Joyce, and Zhaoqi Zhang
Ronald B. Sorensen and Tim L. Jones
Soil depth for water uptake in pecan trees [Carya illinoensis (Wangenh.) C. Koch `Western Schley'] is considered to be <100 cm (3.2 ft) for sites that have high water tables. The objective of this research was to determine the water uptake pattern of pecan trees grown on sites with a deep water table [>30 m (100 ft)] and irrigated at 50 kPa (0.5 bar). Trees (15- to 20-year-old trunks) were transplanted into laser-leveled terraces in 1986. Two terraces (T) were selected and irrigated (1994 and 1995) at 50 kPa (T5) and farmer controlled [T6, weekly at ≈30 kPa (0.3 bar)]. Soil water content was measured on a 1.3 by 1.3 m (4 ft by 4 ft) grid for one tree in each terrace using a neutron probe. In 1994, the average soil depth for water uptake was 75 (2.5 ft) and 62 cm (2.0 ft) for T5 and T6 respectively. In 1995, the average soil depth for water uptake was 150 cm (5 ft) on T5 and 130 cm (4 ft) on T6. The total quantity of water removed below 140 cm (4.6 ft) soil depth was minor (<15%) when compared with the total water removed between 0 and 140 cm depth. T5 showed a deeper (260 cm; 8.5 ft) and wider (3.0 to 5.0 m; 10 to 16 ft) water uptake pattern compared with T6. Thus, pecan trees growing on these coarse soils with a deep water table and irrigated at 50 kPa have an effective root zone of ≈140 to 150 cm (4.6 to 5.0 ft).
Gretchen B. North and Evan A. Baker
For desert succulents, and for several other plant species, older roots play a more active role in water uptake than is generally acknowledged. We suggest that older roots of most plants can and do take up water, and we discuss in more detail the
Kristof Vermeulen, Kathy Steppe, Katrien Janssen, Peter Bleyaert, Jan Dekock, Jean-Marie Aerts, Daniel Berckmans, and Raoul Lemeur
an important objective in current horticultural research programs ( Ehret et al., 2001 ). One of the techniques to determine water uptake directly is by using a lysimeter or an electronic balance. This device is commonly used in the scientific
Donna A. Marshall, James M. Spiers, and Kenneth J. Curry
plants (19.90%). Yet some splits apparently occurred from uptake of water by the roots that is transported to the fruit by the xylem. Susceptibility to splitting in cherries appears to be related to the rate and quantity of water uptake by the fruit
Andreas Winkler, Stefanie Peschel, Kathleen Kohrs, and Moritz Knoche
assumes the flesh of the berry to be held under compression by an elastically strained skin. Upon water uptake, the pressure in the fruit rises. When the fruit pressure (synonymous with fruit turgor and with flesh turgor) exceeds some critical threshold; i
M.S. Albahou and J.L. Green
It has been shown that container medium volume affects plant growth and development in conventional production methods. The objective of this study was to investigate the effect of media volume on the growth and yield of the determinate tomato genotype `Pik Red' in the closed, insulated pallet system (CIPS). The CIPS contains media pouches with wicks extended down into a water reservoir. Three root media volumes were investigated: 3, 6, and 9 L (3L, 6L, and 9L). The root media were placed in pouches that varied in diameter but had constant depth. The surface area of the wicks in contact with the bottom of all pouch sizes remained constant at 110 cm2. It was hypothesized that increasing the volume of root media would allow sufficient water replenishment during the dark period to meet the plant's need the next day, and thus allow greater growth and fruit yield. Daily water uptake for each individual plant was measured by the principle of atmospheric pressure and water replacement technique. Media volume had no significant effect on water uptake during early stage of plant growth. After 45 days after planting (DAP), water uptake and plant growth were less in 3L media volume. Water uptake was similar in the 6L and 9L treatments between 45–60 DAP. Total water uptake from day 60 to 125 was greatest in the 9L, intermediate for 6L, and least in the 3L treatments. The water uptake from 1–60 DAP was reflected in the fresh shoot weight, and the water uptake was reflected in the fruit weight. Average fruit sizes and the total fruit weights for the 3L were 67.7% and 60.4% those of the 9L treatment, respectively. The 6L treatment fruit yield and fruit size were intermediate between the 3L and 9L.
Kelly T. Morgan, Smita Barkataky, Davie Kadyampakeni, Robert Ebel, and Fritz Roka
yields. However, water uptake increased after harvest when irrigation resumed. These observations are in agreement with those of several researchers who reported recovery of sweet orange trees in less than 1 week after resuming irrigation ( Fereres et al
Ursula K. Schuch, Anita N. Miller, and Leslie H. Fuchigami
Dormant coffee (Coffea arabica L.) flower buds require water stress to stimulate regrowth. A xylem specific watersoluble dye, azosulfamide, was used to quantify the uptake of water by buds after their release from dormancy by withholding water. In non-stressed flower buds, the rate of water uptake was generally slower and variable. In stressed flower buds, the rate of uptake tripled from one day to 3 days after rewatering and preceded the doubling of fresh and dry weight of buds. Free, ester, and amide IAA levels of developing flower buds were measured by GCMS-SIM using an isotope dilution technique with [13C6] IAA as an internal standard. Throughout development, the majority of IAA was present in a conjugated form and the dominant form was amide IAA. The proportions of amide and free IAA changed rapidly after plants were water stressed until day 3, and preceded the doubling of fresh and dry weight. Correlation coefficients of 0.9, 0.7, and 0.7 (p<0.l) were found between auxin content and fresh weight, dry weight, and rate of water uptake, respectively.
Tina Wilson, Robert Geneve, and Brent Rowell
One possible influence film-coating may have on seeds is modifying water uptake and electrolyte leaking during imibibition. Film-coating is a seed treatment that can improve sweet corn germination, especially under cold soil conditions. Two shrunken-2 sweet corn varieties (`Even Sweeter' and `Sugar Bowl') were treated with a polymer film-coating and evaluated for water uptake patterns during imibibition. `Even Sweeter' is a low-vigor sweet corn, while `Sugar Bowl' is a high-vigor variety. Standard germination tests were performed according to AOSA rules and suggest film-coated seeds germinated at a slower rate than untreated seeds. After 4 days of imibibition, `Sugar Bowl' film-coated seeds had 5% germination, while untreated seeds had ≈20% germination. However, after 7 days, film-coated seeds had 94% germination with untreated seeds at 80% germination. Results were similar for `Even Sweeter'. Bulk electrical conductivity readings were taken over 24 h to determine the amount of electrolyte leakage during imibibition. Low-vigor `Even Sweeter' had 92% higher overall leakage than high-vigor `Sugar Bowl'. Additional conductivity readings were taken for both seed lots every 2 h for 12 h. Film-treated seeds leaked 15% less than untreated seeds for `Sugar Bowl'. However, `Even Sweeter' film-coated seeds actually leaked 17% more than the untreated seeds. In both cases, 70% of electrolyte leakage occurred within the first 12 h of imibibition. An imibibition curve was established for the two seed lots comparing untreated and film-coated seeds. During the first 6 h of water uptake, film-treated seeds weighed ≈50% more than the untreated seeds for both `Even Sweeter' and `Sugar Bowl'. Pathways for water uptake as influenced by film-coating shrunken-2 seeds will also be presented.