Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/4/2008
Publication Date: 4/10/2008
Citation: Baumhardt, R.L., Staggenborg, S., Gowda, P., Colaizzi, P.D., Howell, T.A. 2008. Simulating the effects of growing season length and irrigation practices on cotton growth and yield [abstract]. 38th Biological Systems Simulation Conference, April 8-10, 2008, Temple, Texas. p. 20-21.
Technical Abstract: Cotton [Gossypium hirsutum (L.)] is grown under both dryland and irrigated conditions because of its drought tolerance. Rising irrigation costs have encouraged farmers in Kansas and the Texas Panhandle to consider cotton as an alternate crop to reduce irrigation but maintain profitability. The risk of producing cotton in those areas comes from shorter growing seasons. Our objective was to compare simulated cotton lint yield and water use with varying irrigation capacity and duration at four locations with progressively shorter growing seasons. Using GOSSYM and long-term (>30yr) weather records, we simulated growth and lint yields for a stripper cotton cultivar grown in rows 0.76 m apart and with 13 plants m**-2 for local soils at Bushland and Stratford, Texas; and Tribune and Colby, KS. Four irrigation levels (0.0, 2.5, 3.75, and 5.0 mm d**-1), applied every 7 days, four durations (4, 6, 8, and 10 weeks beginning 37 days after emergence), and three emergence dates (145, 152, 159) were evaluated. Treatments were compared using the SAS general linear model procedures according to a factorial arrangement of a completely randomized design. Cotton yield generally increased as irrigation capacity increased and with earlier emergence dates, ranging from 580 kg ha**-1 for day 145 to 400 kg ha**-1 for day 159. Lint yield ranged from 520 kg ha**-1 at Bushland to 310 kg ha**-1 at Colby, decreasing due to growing season limitations. Locations in Kansas with short growing seasons suffered more severe yield reductions with delayed emergence and did not benefit from irrigation periods extending longer than 4 to 6 weeks. Both Texas sites benefited from irrigation periods of 6 to 8 weeks depending on the earliness of the emergence date. Based on these simulations, we concluded cotton production in Kansas, while possible and well suited to deficit irrigation, is sensitive to planting/emergence delays. Simulated cotton yields at Bushland were less sensitive to emergence delay.