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Identification of Soybean Plant Characteristics That Indicate the Timing of Drought Stress
Author(s) -
Desclaux Dominique,
Huynh TungThanh,
Roumet Pierre
Publication year - 2000
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/cropsci2000.403716x
Subject(s) - point of delivery , biology , cultivar , indeterminate , vegetative reproduction , agronomy , horticulture , dry matter , drought stress , greenhouse , crop , main stem , yield (engineering) , mathematics , pure mathematics , materials science , metallurgy
Low‐cost, phenotype‐based techniques are needed to help crop breeders interpret genotype × environment interactions. Our objective was to determine how drought stress imposed on soybean [ Glycine max (L.) Merr.] at various growth stages affected selected plant characteristics. Determinate (Spot) and indeterminate (Weber) soybean cultivars were grown under greenhouse conditions and subjected to two levels of drought stress (30 and 50% plant‐available water) during vegetative (V4–R1), flowering (R1–R3), pod lengthening (R3–R5), or seed‐filling (R5) stages. Mean internode length was the most drought sensitive factor during the vegetative and flowering stages. Significant height differences for the determinate cultivar accurately differentiated between stress periods, with shorter plants being associated with vegetative stress. The number of pods per vegetative dry matter unit was significantly affected by stress during pod lengthening. Early stress during seed fill reduced the number of seeds per pod, whereas late stress (after the abortion limit stage) decreased seed weight. These results suggest that precise periods of drought stress can be determined by measuring a posteriori several morphological factors and yield components of determinate and indeterminate soybean genotypes at physiological maturity.