HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Bittman, S. Articles by Simpson, G. M. Search for Related Content PubMed Articles by Bittman, S. Articles by Simpson, G. M. Agricola Articles by Bittman, S. Articles by Simpson, G. M.

Drought Effect on Leaf Conductance and Leaf Rolling in Forage Grasses

Agriculture Canada, present address Agriculture Canada, Research Station, Agassiz, British Columbia, VOM 1A0
Dep. of Crop Science and Plant Ecology, Univ. of Saskatchewan, Saskatoon, Saskatchewan, Canada, S7N 0W0

^* Corresponding author.

Control of water loss is essential for plants growing in the northern Great Plains. The objectives of this study were to examine seasonal changes in leaf conductance (g₁) of three forage grasses, smooth bromegrass (Bromus inermis Leyss.) Altai wildrye [Leymus angustus (Trin.) Pilger], and crested wheatgrass [Agropyron cristatus (L.) Beauv. ssp. pectinatum (Bieb.) Tzvel.] growing under contrasting water regimes to relate changes in g_L to leaf water status, and to examine the relationship between leaf rolling response and leaf water status in crested wheatgras (CWg). The study was conducted on deep black soil (Melfort silty clay, Typic Cryoboroll) at Melfort, Saskatchewan. Rainout shelters and irrigation were used to impose two contrasting water regimes. Altai wildrye (AWr) generally had higher g_L than the other species, while smooth bromegrass (Br) had low g_L early in the season when its leaf water potential (_L) was high. Under favorable moisture, CW₈ had lowest proportion of conductance from abaxial surface among the species, although abaxial conductance in Br and AWr declined more rapidly than adaxial conductance under drought. Much of the variation in g_L was not accounted for by _L in all three species. Leaf conductance also changed gradually with leaf pressure potential (_p) over a wide range of _p values, particularly in the mornings. In contrast, leaf rolling in CWg was strongly related to both, _L and _p. The data suggest that other factors such as the rate of leaf water loss affect stomatal response to tissue water loss.

Received for publication March 1, 1988.