Factors Affecting the Development of Flue-Cured Tobacco Grown in Artificial Environments. III. Morphological Behavior of Leaves in Simulated Temperature, Light-Duration, and Nutrition Progressions During Growth1
- C. D. Raper2
The growth environment of a plant determines the ultimate expression of many characteristics of development. Among other environmental variables, a plant growing in the field encounters seasonal progressions of temperature, daylength, and nutrient supply. To determine if these natural, seasonal progressions are essential for reproducing “normal” field growth of flue-cured tobacco (Nicotiana tabacurn L. ‘Coker 319’) in controlled-enviromnent facilities, simplified simulations of temperature, light-duration, and nitrogen and potassium nutrition were established in controlled-enviromnent rooms. Regression-descriptors plots of regression equations with leaLstalk position as the independent variable) of size, shape, and specific weight of mature leaves from plants grown under combinations of these simulated progressions and constant temperature, light-duration, and nutrition regimes were evalualed relative to characteristic regression-descriptors derived from field grown plants.
A seasonal progression of temperature and progressive reductions of nitrogen and potassimn supply are critically involved in determining the physical attributes of leaves characteristic of “normal”, field-grown tobacco. Combined with a continuous daily light-duration of 9 hours, the simulated progressions of temperature and nutrition most nearly facsimilated a “normal” leaf-size ordering and resulted in the least disruption of “normal” variations of leaf shape and specific leaf weight due to stalk position.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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