Interactive Effects of Water-Stress, CO2 and O3 on Upland Cotton II. Yield and Yield Components

Mohamed I. Zakaria, Charles L. Mulchi, and Edward H. Lee


Two cultivars Deltapins 50 and 90 (G. hirsutum, L.) grown under field conditions in open-top chambers were subjected to chronic combinations (2 levels each) of climatic factors soil moisture (-0.05 and -0.1 MPa), CO2 (ambient and 500 µmol CO2 mol-1), and O3 [carbon-filtered (CF) and non-filtered (NF) air]. The average NF air (45.3 nmol O3 mol-1) concentration during the growing season showed no visible O3-injury. The combinations of O3 and CO2 treatment interactive effects indicated that NF+350 µmol CO2 mol-1 and CF+500 µmol CO2 mol-1 had higher seedcotton and lint yield (20 to 30%) under both W and D conditions. Positive effects of CO2 enrichment on physiological and morphological characteristics appeared to have no effect on yield, except for plants treated with CF air under both soil moisture levels had improved yield. The results suggest that treatments inducing higher photosynthesis, morphological growth, and biomass accumulation do not necessarily result in higher yields. DP50 showed 20 - 34% higher yield than DP90, which could be attributed to its superior physiological, morphological and reproductive characteristics.

Reprinted from Proceedings of the 1994 Beltwide Cotton Conferences pp. 1452 - 1454
©National Cotton Council, Memphis TN

[Main TOC] | [TOC] | [TOC by Section] | [Search] | [Help]
Previous Page [Previous] [Next] Next Page
Document last modified Sunday, Dec 6 1998