METHODS OF EXPERIMENTATION WITH COCKLEBUR 87 



Table 5-3. Check List for Writing Up Experiments 



1. Experiment number and title. The title should be a brief description 

 of the purpose of the experiment. 



2. The date on which plants are given the first long dark period. 



3. The size of the leaf left on trimmed plants. 



4. The day on which plants are trimmed. 



5. General weather conditions on the days preceding and following the 

 long dark period(s), and greenhouse temperatures. 



6. Number of days between the first inductive dark period and the time 

 plants are dissected. 



7. Age of the plants. 



8. Name of people who helped with the experiment. 



9. Experimental procedures including items such as: 



A. Length of the dark period(s), times of day when plants are put in 

 or removed from darkness. 



B. Times of light interruptions, application of chemicals, etc. 



C. Concentrations of chemicals, mixing procedures, and wetting 

 agents. 



D. Method of application of chemicals. 



E. Times, qualities, intensities, etc., of light interruptions. 



F. Any other pertinent data. Enough information should be given 

 so that the experiment could be repeated exactly. Actual times of 

 day should be listed, dark rooms used should be indicated, and 

 no pertinent point should be omitted. 



10. Flowering data: number of plants in each treatment with a given 

 Floral Stage (see below), average Floral Stage and % flowering by 

 treatments. 



IL Graphical representation of the data. 



becomes most acute when one is interested in the act of induction — 

 those processes taking place within the plant up to the time when the 

 shoot tip begins to develop into a flower. We have no way to study 

 the act of induction except by observing ultimate flowering. Thus 

 study of the act of induction is complicated by the intermediate 

 development of the flower, which may be strongly influenced by many 

 factors, including the overall rate of vegetative growth, which is in 

 turn influenced by many environmental factors. This is an important 

 and very significant complication in the overall question of how to 

 study flowering. 



2. Some Methods Used by Various Workers (3) 



Does flowering occur in response to a given treatment or doesn't 

 it? This is probably the simplest question that the investigator might 

 ask. He can wait until plants have reached an advanced stage of 

 maturity and record whether or not they have flowered. Very 



