Pima (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.

中文翻译：

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美国东南沿海平原Gossypium barbadense L.的生长、棉铃发育、农艺性能和纤维品质

皮马 ( Gossypium barbadense L.) 棉目前在美国西部进行商业种植，具有卓越的纤维质量，其经济价值几乎是陆地棉 ( Gossypium hirsutum ) 的两倍L.) 棉花。由于美国东南部皮马生产经验有限，我们的主要目标是比较四种皮马基因型与高产高纤维品质商业陆地品种在灌溉和旱地条件下的生长、发育、农艺性能和纤维质量在不同的种植日期。所有 Pima 基因型的皮棉产量比 Upland 基因型 (45.7%) 低约 50%，皮棉百分比 (38.0–42.4%) 更低；然而，Pima 基因型的马克隆值始终较低，纤维强度、长度和均匀度增加。尽管灌溉并没有显着影响农艺和纤维质量性能，但在补充灌溉下生长的植物在整个季节中长出了 10% 的棉铃，主要发生在单足枝和 15 以上的主茎节位置。Pima 基因型上的棉铃比 Upland 基因型小 13-34%，并且在植物冠层的更远端和更高的节点位置发育。2019 年早期种植日期的净回报最高，显示了在美国东南部种植时及时种植 Pima 基因型的重要性。结果表明，东南部的皮马生产可能不需要灌溉，优选早播以获得最大产量，通过育种增加皮马百分比、铃数或提早可能会提高美国东南部的皮马产量。2019 年早期种植日期的净回报最高，显示了在美国东南部种植时及时种植 Pima 基因型的重要性。结果表明，东南部的皮马生产可能不需要灌溉，优选早播以获得最大产量，通过育种增加皮马百分比、铃数或提早可能会提高美国东南部的皮马产量。2019 年早期种植日期的净回报最高，显示了在美国东南部种植时及时种植 Pima 基因型的重要性。结果表明，东南部的皮马生产可能不需要灌溉，优选早播以获得最大产量，通过育种增加皮马百分比、铃数或提早可能会提高美国东南部的皮马产量。