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Carbon Dioxide and Temperature Effects on Pima Cotton Development
Author(s) -
Reddy K. Raja,
Hodges Harry F.,
McKinion James M.
Publication year - 1995
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1995.00021962008700050007x
Subject(s) - carbon dioxide , carbon dioxide in earth's atmosphere , gossypium barbadense , degree (music) , crop , malvaceae , horticulture , gossypium hirsutum , agronomy , botany , chemistry , environmental science , biology , ecology , physics , acoustics
Predicting plant responses to changing atmospheric CO 2 and to the possible global warming are important concerns. Effects of CO 2 on developmental events are poorly documented, as is the interaction of CO 2 and other major climate variables on crop development. The objective of this experiment was to determine the effects of an altered CO 2 environment and interactions of CO 2 and temperature on pima cotton developmental rates. Pima cotton ( Gossypium barbadense L. cv. S‐6) was grown from seed in sun‐lit plant growth chambers. Air temperatures were controlled from 20/12 to 40/32°C (day/night) in 5‐degree increments. Daytime CO 2 was maintained at 350 or 700 μL L −1 . In a second experiment, the temperature was maintained at 30/22°C day/night and the plants were grown in 350, 450, or 700 μL L −1 CO 2 . Days required to develop nodes on the mainstem, days from emergence to first square, number of vegetative and fruiting branches, number of fruiting sites produced, number of bolls and squares produced, and number of bolls and squares retained by the plants were determined. Rates of mainstem node formation and the time required to produce the first square and first flower were not sensitive to atmospheric CO 2 , but were very sensitive to temperature. Prefruiting branch nodal positions required longer to develop than nodes with fruiting branches. Carbon dioxide levels did not affect the time required to produce nodes. Number of branches produced was sensitive to both temperature and CO 2 . The larger number of bolls set on the lower branches of plants grown at high CO 2 provided a larger sink for photosynthate than plants grown at low CO 2 . This may be the reason for the observed reduction in number of fruit at the upper nodes of high‐CO 2 ‐grown plants. More bolls and squares were produced and retained on plants grown in high‐CO 2 environments, except that none were produced in either CO 2 environment at 40/32°C. Our results indicate that high‐temperature‐tolerant cotton cultivars would be more productive in the present‐day CO 2 world, and they would be essential in the future if global temperature increases.