Water Potential and Stomatal Resistance of Sunflower and Soybean Subjected to Water Stress during Various Growth Stages 1

AUTOR(ES)

Sionit, Nasser

RESUMO

Plants of two varieties of soybean (Glycine max (L.) Merr.) and two varieties of sunflower (Helianthus annuus L.) were grown in controlled environments and subjected to water stress at various stages of growth. Leaf resistances and leaf water potentials were measured as stress developed. In soybeans the upper leaf surface had a higher resistance than the lower surface at all leaf water potentials and growth stages. Resistance of the upper surface began to increase at a higher water potential and increased more than the resistance of the lower surface. Resistances returned to prestress values 4 days after rewatering. In sunflowers upper and lower leaf surfaces had similar resistances at all water potentials and growth stages. Leaf resistances were higher in sunflower plants stressed before flowering than in those stressed later. Sunflower plants stressed to −16 bars recovered their prestress leaf resistance and water potential a few days after rewatering, but leaves of sunflower plants stressed to −23 bars died. Leaves of soybean and sunflower plants stressed before flowering suffered less injury than those of older plants and sunflowers stressed after flowering suffered more injury than soybeans.

Documentos Relacionados

• Leaf Water Potential, Stomatal Resistance, and Photosynthetic Response to Water Stress in Peach Seedlings 1
• Response of Leaf Water Potential, Stomatal Resistance, and Leaf Rolling to Water Stress
• Gas exchange and growth of sunflower subjected to saline stress and mineral and organic fertilization
• Leaf Enlargement and Metabolic Rates in Corn, Soybean, and Sunflower at Various Leaf Water Potentials 1
• Gas exchange and growth of zucchini crop subjected to salt and water stress