Survival of Plants under Prolonged Flooded Conditions1

Barley (Hordeum vulgare L.), corn (Zea mays L.), sunflower (Helianthus annus L.), tomato (Lycopersicum esculentum L.), and ‘Pato’ and ‘Inia’ varieties of wheat (Triticum vulgare L.) were grown in Krilium‐stabilized Yolo loam in pot culture under greenhouse conditions until the root systems were well established. The plants were then subjected to full‐flooded, half‐flooded, and temporarily‐flooded treatments. Observations of plant growth rates under treatments were made by periodically measuring top and root length. Plants were harvested after 2 to 4 weeks of treatment and the air‐filled root porosity was measured for each root system. Reduction in growth rates and dry weights for all plants was observed in full‐flooded as compared to nonflooded treatments. Damage caused by full‐flooding was less severe in corn, sunflower and Pato wheat, and was associated with a more porous root system of these plant species as compared to the other species studied. Root porosities of these three plants were greatly increased in full‐flooded as compared to non‐flooded conditions. These results suggest that tolerance to excess moisture was related to plant internal aeration which might be achieved by increases in root porosity. Reduction in weight and growth rates was significant in full‐flooded but not signification half‐flooded conditions when compared to control.