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ARS Home » Research » Publications at this Location » Publication #72632
Title: EFFECT OF LATE SEASON COOL NIGHT TEMPERATURES ON PHOTOSYNTHESIS AND YIELD OF SOYBEANS

Author
item Cooper, Richard
item STREETER, JOHN - OSU/OARDC, WOOSTER, OH

Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 9/15/1996
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Published and unpublished research results have suggested that late season cool nights (35 to 40 degF) can cause a marked, irreversible reduction of photosynthesis in soybean leaves. The occurrence of these cool night temperatures in late August and early September, in the Midwestern states, would significantly reduce photosynthate production of soybeans late in the reproductive cycle which could potentially significantly reduce yield. Research was conducted both in the field and in the greenhouse, over a 3-year period, artificially simulating cool nights, to test this hypothesis. Results from this research indicated cool nights significantly reduced photosynthesis in soybean leaves and that this effect was enhanced as moisture stress was increased. However, in these studies, this effect was reversible and photosynthesis returned to normal within 24 to 48 hours. As a result, there was no significant effect of the cool night treatment on seed yield.