Growth, boll development, agronomic performance, and fiber quality of Gossypium barbadense L. in the southeastern U.S. Coastal Plain

Abstract

AbstractPima (Gossypium barbadense L.) cotton is currently grown commercially in the western United States and has exceptional fiber quality, which provides an economic value almost two times greater than Upland (Gossypium hirsutum L.) cotton. Due to limited experience with Pima production in the southeastern United States, our primary objective was to compare the growth, development, agronomic performance, and fiber quality of four Pima genotypes with a high‐yielding high fiber quality commercial Upland cultivar under irrigated and dryland conditions at different planting dates. Lint yields of all Pima genotypes were ∼50% less and had lower lint percentages (38.0–42.4%) than the Upland genotype (45.7%); however, the Pima genotypes had consistently lower micronaire values and increased fiber strength, length, and uniformity. Although irrigation did not significantly impact agronomic and fiber quality performance, plants grown under supplemental irrigation developed 10% more bolls throughout the season, mostly occurring on monopodial branches and at mainstem nodal positions above 15. Bolls on Pima genotypes were 13–34% smaller than the Upland genotype and developed at more distal and higher nodal positions in the plant canopy. The highest net returns were found in 2019 at the early planting date, displaying the importance of timely planting of Pima genotypes when grown in the southeastern United States. Results suggest that irrigation may not be required for Pima production in the southeast, early planting is preferred to obtain maximum yields, and increasing lint percent, boll number, or earliness through breeding may improve Pima yields in the southeastern United States.