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
Xiaohui Lin, Hongbo Li, Shenggen He, Zhenpei Pang, Shuqin Lin, and Hongmei Li
flowers, including carnations, are the result of stomatal water loss that gradually exceeds the rate of water uptake through the xylem vessels in the cut-stem ends ( Mattos et al., 2017 ; van Doorn, 2012 ). The stomata of higher plants occur mainly on the
Youssef Rouphael, Giampaolo Raimondi, Rosanna Caputo, and Stefania De Pascale
al., 2005 ). This makes necessary the discharge of the nutrient solution resulting in water and nutrient loss ( Massa et al., 2011 ), therefore the term “semiclosed” is used for such cultivation systems ( Carmassi et al., 2007 ). Several scientists
H. C. Kohl and D. L. Rundle
Abscisic acid (ABA) concn as low as 1 ppm, when added to the vase water, effective by reduced water loss of cut roses.
D. J. Cotter
One of paired tomato plants was sprayed with 100 ppm phenylmurcuric acetate (PMA). Transpiration rates were measured gravimetrically. During the initial daylight periods, PMA treatment reduced water losses in 2 tests. Conversely, night water losses were higher for the PMA treated plants in both tests. When moisture stress symptoms occurred, water losses by the treated plant were higher. The results indicate that PMA closes the stomates at some small aperature. This reduces transpiration when plants are not stressed for water. Relative increased water losses occur, however, when untreated plant losses would be minimal (dark, wilted).
Jeff B. Million and Thomas H. Yeager
Outdoor production of plants in containers requires frequent irrigation to compensate for the limited water storage capacity of confined substrate volumes ( Beeson, 2007 ; Warren and Bilderback, 2005 ). Frequent irrigation of container-grown plants
Chris Wilson, Joseph Albano, Miguel Mozdzen, and Catherine Riiska
water into N-limited aquatic ecosystems may stimulate many undesirable changes associated with eutrophication, resulting in the loss of desirable aquatic habitats and changes to natural ecosystems. In fact, the USEPA and many state governments are
Albert C. Purvis, G. Eldon Brown, and Robert D. Carter
Freeze-damaged ‘Marsh’ grapefruit (Citrus paradisi Macf.) and ‘Pineapple’ orange [Citrus sinensis (L.) Osbeck] fruit were sealed in polyethylene shrink film and stored for 6 weeks at 15°C in an attempt to prevent segment dehydration. Although the film greatly restricted water loss from the fruit, segment dehydration was similar to that observed for waxed fruit. During dehydration of freeze-damaged segments of ‘Valencia’ orange fruit, the relative water content of the adjacent mesocarp tissue increased. However, no differences were found in the soluble carbohydrate levels in mesocarp tissue adjacent to damaged and undamaged segments. The results indicate that the mesocarp tissue is not only in the pathway of water loss from free-damaged citrus fruit, but also accumulates water from damaged tissues. Furthermore, segment tissue membranes and walls appear to be differentially permeable to sugars and water.
Margaret Landrigan, Stephen C. Morris, and Barry W. McGlasson
Rambutan (Nephelium lappaceum L.) rapidly lose their attractive appearance after harvest due to a superficial pericarp browning. Storage at high humidity minimizes fruit desiccation and may, therefore, delay browning onset. This paper examines the effect of reduced water loss rate on browning that may occur with time. Rambutan fruit pericarp browning beyond a commercially saleable level occurred at a weight loss of 25% to 40%. This depended on duration and storage relative humidity (RH). Skin browning was 50% greater on the red (R 134) than the yellow (R 156) cultivar at 60% RH. There was a storage time × RH interaction in the development of browning such that browning was observed earlier at lower RHs. Skin browning and spintern (soft spine) browning developed independently. Cracks appeared on the surface of fruit with increased weight loss. Browning occurrence was consistent with increased total phenolic compound levels in the pericarp. Water loss precedes browning occurrence and, over time, water loss is related to browning. Water stress appeared to affect rambutan pericarp tissue in much the same manner as senescence.
N.K Lownds, M.G. White, and R.D. Berghage
Previous work has shown that container grown landscape plants use, and likely need, much less water than is typically applied. Therefore, studies were conducted to quantify the relationships between water loss and water stress responses using several drought tolerant (Cassia corymbosa, Leucophyllum frutescens, Salvia greggii) and traditional landscape plants (Euonymus japonicus, Pyracantha coccinea). Water stress was induced by withholding water and water loss measured gravimetrically. The shape of the water loss curve was similar for all species being, Y = a + bx + cx2 (r2 > 0.95). The rate of ethylene production began to increase 24 hr after irrigation, reaching a maximum 36-48 hr after irrigation and then decreasing. Maximum ethylene production occured at 35-47% water loss irrespective of species or rate of water loss. Stress symptoms (wilting leaf discoloration and abscission) followed a similar pattern. The potential for monitoring gravimetric water loss to schedule container irrigation will be discussed.