University of California

Responses of rice to photoperiod


D. P. Ormrod
W. A. Bunter
D. C. Finfrock
J. R. Thysell

Authors Affiliations

D. P. Ormrod is Junior Agronomist, University of California, Davis; W. A. Bunter, Jr. is Laboratory Assistant, University of California, Davis; D. C. Finfrock is Associate Specialist in Agronomy, Biggs Rice Experiment Station, University of California; J. R. Thysell is Research Agronomist, ARS, USDA, Rice Experiment Station, Biggs.

Publication Information

Hilgardia 14(5):6-7. DOI:10.3733/ca.v014n05p6. May 1960.

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Experiments indicate that photoperiod, or daylength, is of great importance in the heading of rice plants and that maturity of rice varieties can be classified in the field by their sensitivity to above-optimum daylength. Early varieties such as Colusa are less sensitive and will head in the field under the longer days of midsummer, while Caloro, a midseason variety, is more sensitive and heads in the field later in the summer after the photoperiod has shortened considerably. A very late variety such as Texas Patna 49 is highly sensitive to photoperiod and does not head until the days have become much shorter in the fall.

Ormrod D, Bunter W, Finfrock D, Thysell J. 1960. Responses of rice to photoperiod. Hilgardia 14(5):6-7. DOI:10.3733/ca.v014n05p6
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