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Water Relations of Tall and Short Cultivars of Winter Wheat 1
Author(s) -
Kirkham M. B.,
Smith E. L.
Publication year - 1978
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1978.0011183x001800020008x
Subject(s) - cultivar , biology , horticulture , agronomy , water stress
Water potential, osmotic potential, stomatal resistance, and leaf temperature were measured for 8 weeks in spring under field conditions, on the top and bottom green leaf of eight cultivars of winter wheat ( Triticum aestivum L.). Four cultivars were adapted for the Southern Great Plains (‘Payne,’ ‘Scout 66,’ ‘Sturdy,’ and ‘Turkey’) and four for Europe (‘Burgas 2,’ Bulgaria; ‘David,’ Austria; ‘F23‐71,’ Romania; ‘Odesskaya 51,’ U.S.S.R.). Four cultivars were tall (F23‐71, Odesskaya 51, Scout 66, and Turkey) and four were short (Burgas 2, David, Payne, Sturdy). Soil was moist and plants were not under moisture stress. Tall and short cultivars reached a maximum height of 114 and 84 cm, respectively. Water potential and osmotic potential of top leaves of tall cultivars averaged 4.8 and 3.3 bars less (more negative), respectively, than those of top leaves of short cultivars. Water potential and osmotic potential of bottom leaves of tall cultivars were similar to those of bottom leaves of short cultivars (about _7 and _16 bars for water and osmotic potentials, respectively). Stomatal resistance of the upper surfaces of top leaves of tall cultivars (5.8 sec/cm) was similar that of upper surfaces of the top leaves of short cultivars (5.3 sec/cm). Stomatal resistance of the upper surfaces of bottom leaves of tall cultivars (9.1 sec/cm) was less than that of upper surfaces of bottom leaves of short cultivars (13.2 sec/cm). Because plants were not water stressed, temperature of all leaves was always cooler than air temperature (0.4 to 0.9 C cooler than air). Average yields of short and tall cultivars were 3,260 and 2,950 kg/ha, respectively. The better yield of short cultivars appeared to be related, in part, to the lower tension with which water was held in the top leaf of the short plants compared to the top leaf of the tall plants.