Phytophthora cinnamomi is a major pathogen of Eucalyptus marginata (jarrah) in Western Australia (23). It can kill trees of all ages through infection of roots (10,27) or by girdling the trunks of 1to 7year-old trees in situations were the collar is ponded (12,19). Field observations have indicated that periods of waterlogging (low oxygen) can result in the rapid death of trees from P. cinnamom...

Waterlogging is a major abiotic stress that limits the growth of plants. The crucial role of Ca(2+) as a second messenger in response to abiotic and biotic stimuli has been widely recognized in plants. However, the physiological and molecular mechanisms of Ca(2+) distribution within specific cell types in different root zones under hypoxia is poorly understood. In this work, whole-plant physiol...

Like struggling swimmers trying to keep their heads above water, rosette plants lift up their leaves when faced with flooding. Instead of flailing arms and legs, plants use hyponastic petiole growth to improve their chances of keeping leaves in contact with the air. During this hyponastic growth, cells on the abaxial side of the petiole elongate more than those on the adaxial side, changing the...

The objective of this investigation was to study the effects of nitrogen on tolerance to water-stress in cotton (Gossypium hirsutum L.) seedlings. Growth chamber studies with pots of washed sand were carried out in Fayetteville, USA, and Nanjing, Chinawith three water conditions (well-watered, drought-stressed, and waterlogging), and three nitrogen rates, low nitrogen (16 mM, approximately 224 ...

Plants, like animals, are obligate aerobes, but due to their inability to move, have evolved adaptation mechanisms that enable them to survive short periods of low oxygen supply, such as those occurring after heavy rain or flooding. Crop plants are often grown on soils subject to waterlogging and many are sensitive to waterlogging of the root zone. The combination of unfavourable weather condit...

Tracer gas studies and oxygen uptake measurements have shown that pressurized gas transport improves oxygen supply to roots in the wetland tree species Taxodium distichum L. Rich. (Taxodiaceae), Betula pubescens J.F. Ehrh. (Betulaceae), and Populus tremula L. (Salicaceae), but not in Acer pseudoplatanus L. and Ilex aquifolium L., which are found in drier habitats. In the deciduous tree species ...

The present study aims to find out an optimum policy for pumping out the optimized volume of groundwater obtained from the authors' earlier Two Level Optimization Model [N.K. Garg, A. Ali, 1998. Two level optimization model for Lower Indus Basin. Agric. Water Manage. 36, 1±21] for the Dadu Canal Command of the Lower Indus Basin. It is shown that the tubewells in this canal command may be operat...

In the context of climatic change, more heavy precipitation and more frequent flooding and waterlogging events threaten the productivity of arable farmland. Furthermore, crops were not selected to cope with flooding- and waterlogging-induced oxygen limitation. In general, low oxygen stress, unlike other abiotic stresses (e.g., cold, high temperature, drought and saline stress), received little ...