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Reproductive Response of Soybeans to Night Interruption 1
Author(s) -
Lawrence B. K.,
Fehr W. R.
Publication year - 1981
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/cropsci1981.0011183x002100050031x
Subject(s) - photoperiodism , sunset , cultivar , sunrise , biology , long day , light intensity , dusk , horticulture , zoology , meteorology , ecology , physics , astronomy , optics
Artificial lights may be used to delay flowering of soybean [ Glycine max (L.) Merr.] cultivars. Previous research has suggested that night interruption imposed every other night would delay flowering as much as every‐night interruption. Our objective was to evaluate the reproductive development of cultivars when exposed to night interruption every night compared with exposure every other night. One cultivar of each Maturity Group 00 through V was grown in the field at Ames, Iowa during 1978 and 1979. The four light treatments imposed every night or every other night included illumination with incandescent light from sunset to sunrise, 2300 to 0030 hours, 0030 to 0200 hours, or 0200 to 0330 hours. Control plots were not exposed to artificial light. The average number of days that reproductive development was delayed beyond the control was twice as great for the every‐night treatments as for the every‐other‐night treatments. Illumination from sunset to sunrise delayed reproductive development significantly more than the treatments of night interruption for 1.5 hours. Night interruption near the end of the dark period (0200 to 0330 hours) delayed reproductive development more than the earlier interruptions. The results did not support the hypothesis that light treatments every other night would delay reproductive development as much as every‐night interruptions. The lighting regime needed to delay reproductive development will depend on the photoperiod requirements of the cultivars and duration of the delay that is desired.