Interrelation of Light and Darkness in Photoperiodic Induction

  title={Interrelation of Light and Darkness in Photoperiodic Induction},
  author={Karl C. Hamner},
  journal={Botanical Gazette},
  pages={658 - 687}
1. Experimental work has been presented on the effect of various cycles of light and darkness on photoperiodic induction of Biloxi soybean, Xanthium, dill, and beet. 2. Experimental evidence has indicated that in both the soybean and Xanthium photoperiodic induction is dependent in part upon responses which occur as the result of exposure to light. For purposes of discussion, these responses have been referred to as A. 3. Experimental evidence has indicated that in both Xanthium and soybean… 

Influence of Light and Darkness upon Carbon Dioxide Fixation.

It has long been accepted that some materials synthesized in a high intensity light process are utilized in the long dark period essential for flowering of short day plants, and this suggests that a study of C*02 fixation in light and darkness during the period of photoperiodic induction with the aid of Chromatographie and autoradiographic techniques may yield useful information regarding the biochemistry of the phot operiodic reactions.

Effect of Light and Temperature on Floral Initiation in Cocklebur and Biloxi Soybean

In cocklebur, the conditions brought about during the photoperiod may be diminished to such a point that plants fail to initiate floral primordia when subsequently subjected to a 12-hour dark period, and in Biloxi soybean the use of short alternating periods of darkness and light may be a more economical method of maintaining "short-day" plants in a vegetative condition.

Time measurement and the light period in flowering

Experiments with applied sucrose, as well as the general tenor of most of the experiments in this paper, indicate that the High Intensity Light Process is more than photosynthesis, and that the process is considerably slowed during dark periods which follow a very short light interruption.

A preliminary study of photoperiodic and formative processes in relation to metabolism, with special reference to the effect of night temperature

In long-day plants a short photoperiod in the middle of a long night induced flowering, and the photochemical reaction was closely related to a biochemical one, and no relation was found between flowering response and starch hydrolysis during darkness.

Mechanism of the photoperiodic response of Plantago lanceolata L., a long-day plant.

The initial experiments reported in this paper were performed to verify the photoperiodic response of English plantain and indicated that it would respond to long-day treatments.

Studies on the Nature of the Endogenous Rhythm Affecting Photoperiodic Response of Biloxi Soybean

The results obtained with Biloxi soybean support those obtained by Lockhart and Hamner with Xanthium in which a second dark period following a brief exposure to light partially nullified the effect of an inductive dark period.


The discovery by GARNER and ALLARD (3) that many plants have specific photoperiodic requirements for floral initiation has led to considerable research to determine the effect of light in the

Effects of some Environmental Factors on Photoperiodic Induction of Beet and Dill

Red light of wave lengths greater than 580 μ are capable of inducing the flowering response in dill when used as the sole source of illumination during the induction period, and continuous illumination with 900-1000 foot-candles of light from white fluorescent Mazda lamps, under conditions of only slight temperature fluctuation, was conducive to flowering in beet.

Biochemistry of the Photoperiodic Response the High-Intensity-Light Reaction

The high-intensity-light process appears to be concerned principally with the production of substrates for respiration and the other processes which take place during an inductive dark period.

Photoperiodic Flowering Response of Biloxi Soybean in 72-Hour Cycles.

Since Nanda and Hamner have demonstrated a periodic variation in floral response as a function of cycle durations, it was difficult to predict what results might be obtained with various photoperiods given in long cycles of standard duration.



Photoperiodic Induction as Influenced by Environmental Factors

Xanthium plants, when grafted to vegetative plants, continue to supply a stimulus for flower initiation when exposed to continuous long photoperiod, and soybeans exposed to an induction period of three or more consecutive long dark periods would not produce new primordia subsequently unless they were again exposed to another induction period.


Two types of experimental method have been employed by investigators in the field of photoperiodism. In the one case the experiments have been conducted during the long days of summer and the natural

Effect of Variation in Temperature During Photoperiodic Induction Upon Initiation of Flower Primordia in Biloxi Soybean

None of the temperature combinations used in these experiments brought about the initiation of flower primordia when photoperiods of 16 hours were used.

Photoperiodism in Relation to Hormones as Factors in Floral Initiation and Development

Evidence is presented that the floral initiation substance is not identical with any of the following known plant growth factors: vitamins B1, B2, and B6, ascorbic acid, nicotinic Acid, pantothenic acid), theelin, theelol, inositol, or indoleacetic acid.

Photoperiodic Responses of Dill, a Very Sensitive Long Day Plant

Vegetative plants transferred from conditions of short to those of long photoperiod were induced to flower after exposure to as few as four longphotoperiods, while seedlings from the commercial dill seed employed flowered soon after germination if grown on 9-hour photoper Period.

Photoperiodism in the Plant Kingdom

The fundamental fallacy lies in the study of photoperiodism as an isolated episode, without any reference to the preceding (including seed ripening) and subsequent periods in the life-history of the plants.

Influence of Photoperiods upon the Differentiation of Meristems and the Blossoming of Biloxi Soy Beans

Stimulation of two short photoperiods was sufficient to alter the course of development of the growing points in such a way that differentiation of flower primordia resulted, and the time of blossoming of young Biloxi soy beans was influenced.

Effect of Photoperiod on Development and Metabolism of the Biloxi Soy Bean

It was found that the longest photoperiod on which fruit formation occurred was 13 hours and the shortest one on which no flowering took place was 16 hours, and the amount of soluble carbohydrates in the transfer groups seems to be correlated with the length ofPhotoperiod.

Nitrogen Nutrition in Relation to Photoperiodism in Xanthium Pennsylvanicum

Plans of Xanthium pennsylvanicum were grown in sand cultures containing either an abundance of nitrogen or very little, and plants grown on a long photoperiod following an induction period with a low supply of nitrogen bore fruits and were larger than control plants growing on a similar longphotoperiod with no induction period but with a similar low nitrogen supply.

A Method of Measuring Respiration and Carbon Fixation of Plants Under Controlled Environmental Conditions

Of the sources tested, an Eveready carbon arc lamp, inclosed by a housing of window glass, was found to be the most suitable for maintaining plants under conditions of artificial light.