Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 15, 2006
Publication Date: March 1, 2007
Citation: Campbell, B.T., Bauer, P.J. 2007. Genetic variation for yield and fiber quality response to supplemental irrigation within the Pee Dee Upland cotton germplasm collection. Crop Science 47:589-597. Interpretive Summary: An understanding of an individual cotton cultivar’s response to changes in water availability, conditions often present in the southeast USA, is an essential component of sustaining cotton production. In this study, thirteen germplasm lines were selected from the Pee Dee (PD) germplasm collection and evaluated under dryland and irrigated conditions to measure the effect of supplemental irrigation on lint yield, yield components, and fiber quality. All germplasm lines responded to supplemental irrigation for one or more yield component and/or fiber quality trait except for ‘PD-2’ and the commercial cultivar ‘FM-966’. Germplasm lines ‘PD5377’ and ‘PD93009’ showed a response to supplemental irrigation for five out of the twelve traits measured. These results indicate that variability exists for cultivar response to supplemental irrigation. A better understanding of variation for cultivar response to supplemental irrigation will allow for the development of cultivars with improved tolerance to changes in water availability.
Technical Abstract: Water availability is a major factor influencing the development of upland cotton (Gossypium hirsutum L.) cultivars and sustainable cotton production in the southeast USA because of endemic, intermittent drought events occurring in the region resulting from shallow, coarse textured soils and irregular rainfall patterns. An understanding of cotton cultivar yield and fiber quality response to supplemental irrigation, applied to lessen the effects of intermittent drought events, is essential to establishing a basis for sustainable cotton production. In this study, thirteen germplasm lines were selected from the Pee Dee (PD) germplasm collection and evaluated using split plot designs during 2004 and 2005 to measure the effect of supplemental irrigation on a number of agronomic and fiber quality traits important to cotton production systems. Overall, supplemental irrigation increased seed cotton yield, plant height, lint percent, lint yield, and bolls per square meter; while boll weight and seed index decreased. Significant variation was detected for seed cotton yield, lint percent, lint yield, seed index, bolls per square meter, micronaire, fiber length, fiber strength, and fiber uniformity. We detected six PD germplasm lines showing an increase to supplemental irrigation for plant height, three showing an increase for lint percent, six showing a decrease for boll weight, ten showing a decrease for seed index, two showing a decrease for fiber length, three showing a decrease for fiber strength, three showing a decrease for uniformity index, and four showing a decrease for micronaire. ‘PD-2’ and ‘FM-966’ did not show a significant response to supplemental irrigation for any of the traits measured based on our comparison. In contrast, ‘PD5377’ and ‘PD93009’ showed differential responses to supplemental irrigation for five out of the twelve traits measured. This study indicates the importance of comparing individual genotype response to supplemental irrigation for agronomic and fiber quality traits to efficiently target genotypes for irrigated or dryland production environments.