Clemson University, Coastal Research and Education Center, Charleston, SC 29414.
Department of Horticulture, University of Georgia, Tifton, GA 31793.
Plant Dis. 2019 Jan;103(1):44-50. doi: 10.1094/PDIS-04-18-0709-RE. Epub 2018 Nov 1.
Fusarium wilt of watermelon caused by Fusarium oxysporum f. sp. niveum is a serious, widespread disease of watermelon throughout the southern United States. To investigate whether soil temperature affects disease development, three cultivars of triploid watermelon were transplanted March 17 to 21, April 7 to 11, and April 26 to May 2 in 2015 and 2016 at Charleston, SC, and Tifton, GA into fields naturally infested with F. oxysporum f. sp. niveum. Incidence of Fusarium wilt was lower with late-season than with early and midseason transplanting in all four experiments (P ≤ 0.01). Cultivar Citation had more wilted plants than the cultivars Fascination and Melody in three of four experiments (P ≤ 0.05). In South Carolina, planting date did not affect weight and number of marketable fruit ≥4.5 kg apiece. In Georgia in 2016, weight and number of marketable fruit were greater with late transplanting than with early and midseason transplanting. In both states, yield and value for Fascination and Melody were higher than for Citation. Soil temperature averaged over the 4-week period after transplanting was negatively correlated with disease incidence for all four experiments (r = -0.737, P = 0.006). Transplanting after mid-April and choosing a cultivar with resistance to F. oxysporum f. sp. niveum race 1, like Fascination, or tolerance, like Melody, can help manage Fusarium wilt of watermelon and increase marketable yields in the southern United States.
由尖孢镰刀菌佛罗里亚种引起的西瓜枯萎病是美国南部地区西瓜的一种严重且广泛发生的病害。为了研究土壤温度是否会影响病害的发展，2015 年和 2016 年，在南卡罗来纳州查尔斯顿和佐治亚州提夫顿，将三个三倍体西瓜品种分别于 3 月 17 日至 21 日、4 月 7 日至 11 日和 4 月 26 日至 5 月 2 日移栽至自然感染尖孢镰刀菌佛罗里亚种的田间。在所有四个试验中，晚季移栽的枯萎病发病率均低于早季和中季移栽（P ≤ 0.01）。在四个试验中的三个试验中，品种 Citation 的萎蔫植株比品种 Fascination 和 Melody 多（P ≤ 0.05）。在南卡罗来纳州，种植日期不影响每个重 4.5 公斤以上的商品果的重量和数量。在佐治亚州 2016 年，晚季移栽的商品果重量和数量大于早季和中季移栽。在这两个州，Fascination 和 Melody 的产量和价值都高于 Citation。移栽后 4 周内的土壤平均温度与所有四个试验的病害发生率呈负相关（r = -0.737，P = 0.006）。在 4 月中旬以后移栽，并选择对尖孢镰刀菌佛罗里亚种 1 号具有抗性的品种，如 Fascination，或对其具有耐性的品种，如 Melody，可以帮助管理美国南部地区的西瓜枯萎病，并提高商品产量。
