Premium
Canopy Temperature, Seed Yield, and Vapor Pressure Deficit Relationship in Soybean
Author(s) -
McKinney N. V.,
Schapaugh W. T.,
Kanemasu E. T.
Publication year - 1989
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/cropsci1989.0011183x002900040043x
Subject(s) - loam , vapour pressure deficit , canopy , agronomy , yield (engineering) , silt , soil water , environmental science , biology , botany , transpiration , soil science , materials science , photosynthesis , paleontology , metallurgy
Drought stress frequently limits soybean production. Thirty soybean [ Glycine max (L.) Merr.] lines in a field trial in 1982 were tested for canopy temperatures and response to vapor pressure deficit (VPD) as criteria for yield and drought tolerance. Lines were monitored for canopy temperature differential (Td = canopy temperature — air temperature), and wet and dry bulb temperatures determined the VPD of the air. The five warmest and five coolest lines based on seasonal mean Td, orTd ¯ , were monitored forTd ¯in 1983 and 1984 under irrigated and nonirrigated environments. Soil type was (Umucic Hapiustoll) a Muir silt loam (fine‐silty, mixed, mesic in 1982 and 1984) and a Eodora silt loam soil (coarse‐silty, mixed, mesic) Fluventic Hapludoll) in 1983. Differences forTd ¯among the lines were negatively correlated with seed yield. Warm genotypes were not more productive under dryland conditions, nor was the ratio of dryland yield to irrigated yield (yield stability) greater than for cool genotypes. NeitherTd ¯nor the ratio of drylandTd ¯to irrigatedTd ¯( Td ¯stability) was significantly correlated with yield stability. Lines did not differ significantly in their Td response to VPD (measared as the Td — VPD regression slope) on a seasonal basis. On 5 d with maximum VPD greater than 3 kPa, however, Td response to VPD differed significantly in the irrigated environment. These differences were not related toTd ¯ , yield, or yield stability. Indirect selection for yield using canopy temperature may be effective; however, warm genotypes are not more drought tolerant or yield stable than cooler selections.