肾形线虫,Rotylenchulesreniformis,是美国陆地棉(陆地棉)的主要产量限制害虫,在许多州发病率一直在稳步上升。抗肾线虫的棉花品种最近已成为棉花生产者的商业可用;然而,很少有田间试验评估其作为线虫管理工具的功效。这项研究的目的是评估肾形线虫种群的发展,植物生长,在路易斯安那州的两个线虫感染田中,抗肾形线虫的棉花品种的籽棉产量。在圣约瑟夫进行了重复的小地块田间试验,洛杉矶(NERS场)和温斯伯勒,2022年和2023年生长季节的LA(MRRS场)。2022年,评估的品种包括:(1)DP1646B2XF(易感/耐性),(2)DP2141NRB3XF(抗性),(3)PHY332W3FE(电阻),(4)PHY411W3FE(电阻),和(5)PHY443W3FE(电阻)。2023年,另一个易感棉花品种,PHY340W3FE,也包括在内。相对于易感棉花品种,评估的所有抗线虫棉花品种均抑制了肾形线虫种群的发育,相对于DP1646B2XF,收获时线虫土壤种群密度的抑制范围为49-81%。抗性品种PHY411W3FE对肾形线虫种群发育的抑制作用最一致,在两个田间地点和两个试验年收获时,降低肾形线虫土壤种群密度。相比之下,DP2141NRB3XF仅在2023年降低了NERS田地收获时的土壤种群密度。尽管与抗性棉花品种相关的线虫抑制相对一致,植物活力等级和冠层覆盖率也得到了改善,仅在2023年在NERS田地种植的PHY332W3FE和PHY411W3FE时观察到产量增加。尽管在评估的棉花品种中对肾形线虫具有很强的抗性,在种植抗性棉花品种的地块中,线虫土壤种群密度在生长季节仍然增加,强调需要额外的管理策略来使用与宿主抵抗。这项研究表明,新的抗肾形线虫的棉花品种显示出在路易斯安那州生长季节减少线虫种群发育的潜力。
The reniform nematode, Rotylenchulus reniformis, is a major yield-limiting pest of upland cotton (Gossypium hirsutum) in the United States that has been steadily increasing in incidence in many states. Reniform nematode-resistant cotton cultivars have recently become commercially available for cotton producers; however, few field trials have evaluated their efficacy as a nematode management tool. The aim of this study was to evaluate reniform nematode population development, plant growth, and seed cotton yield of reniform nematode-resistant cotton cultivars in two nematode-infested fields in Louisiana. Replicated small-plot field trials were conducted in St. Joseph, LA (NERS field) and Winnsboro, LA (MRRS field) during the 2022 and 2023 growing seasons. In 2022, cultivars evaluated included: (1) DP 1646 B2XF (susceptible/tolerant), (2) DP 2141NR B3XF (resistant), (3) PHY 332 W3FE (resistant), (4) PHY 411 W3FE (resistant), and (5) PHY 443 W3FE (resistant). In 2023, an additional susceptible cotton cultivar, PHY 340 W3FE, was also included. All nematode-resistant cotton cultivars evaluated provided suppression of reniform nematode population development relative to that of the susceptible cotton cultivars, with suppression of nematode soil population densities at harvest ranging from 49 - 81% relative to DP 1646 B2XF. The resistant cultivar PHY 411 W3FE provided the most consistent suppression of reniform nematode population development, reducing reniform nematode soil population densities at harvest in both field locations and both trial years. In contrast, DP 2141NR B3XF only reduced soil population densities at harvest in the NERS field in 2023. Despite relatively consistent nematode suppression and improvements in plant vigor ratings and canopy coverage associated with the resistant cotton cultivars, a yield increase was only observed with PHY 332 W3FE and PHY 411 W3FE planted at the NERS field in 2023. Despite strong resistance to reniform nematode in the evaluated cotton cultivars, nematode soil population densities still increased during the growing season in plots planted with resistant cotton cultivars, emphasizing the need for additional management tactics to use alongside host resistance. This study indicates that new reniform nematode-resistant cotton cultivars show promising potential to reduce nematode population development during the growing season in Louisiana.