Potato Top Growth as Influenced by Day-Night Temperature Differences1
- G. R. Benoit,
- W. J. Grant and
- O. J. Devine2
Past work has considered plant growth as a function of average or constant temperatures and has not evaluated the affect of diurnal temperature variations on growth. This study was conducted to evaluate the growth response of potato plant tops (Solanum tuberosum L.) to exposure to 72-h controlled-temperature treatments consisting of 14 different day-night temperature combinations. Day-night temperature differences ranged from 0 to 30°C with no night temperature ever exceeding a given day temperature. Ten potato plants were grown in individual pots in a greenhouse for each treatment with the treatment accomplished by inserting the plants into a growth chamber for 72 h at two stages of vegetative growth. Plants were maintained under “nonlimiting” soil moisture conditions. Growth was measured as increase in plant height and leaf area during the treatment period. Developed equations (all significant at P<0.01) express plant growth (plant height and leaf area) as a function of the combined influence of maximum and minimum temperatures at both growth stages. The data suggest that each maximum daytime temperature has an optimum night temperature for growth. In general, the difference in temperature between the maximum temperature and its optimum minimum temperature increases as the maximum temperature increases. Plant growth models should incorporate functions that include day-night temperature effects on growth.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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