Herring Stephanie L, Koenning Stephen R, Heitman Joshua L
Respectively, Graduate Assistant and Research Associate Professor, Department of Plant Pathology, North Carolina State University, Raleigh, NC 27695.
J Nematol. 2010 Dec;42(4):319-23.
The effects of soil type, irrigation, and population density of Rotylenchulus reniformis on cotton were evaluated in a two-year microplot experiment. Six soil types, Fuquay sand, Norfolk sandy loam, Portsmouth loamy sand, Muck, Cecil sandy loam, and Cecil sandy clay, were arranged in randomized complete blocks with five replications. Each block had numerous plots previously inoculated with R. reniformis and two or more noninoculated microplots per soil type, one half of which were irrigated in each replicate for a total of 240 plots. Greatest cotton lint yields were achieved in the Muck, Norfolk sandy loam, and Portsmouth loamy sand soils. Cotton yield in the Portsmouth loamy sand did not differ from the Muck soil which averaged the greatest lint yield per plot of all soil types. Cotton yield was negatively related to R. reniformis PI (initial population density) in all soil types except for the Cecil sandy clay which had the highest clay content. Supplemental irrigation increased yields in the higher yielding Muck, Norfolk sandy loam, and Portsmouth loamy sand soils compared to the lower yielding Cecil sandy clay, Cecil sandy loam, and Fuquay sand soils. The Portsmouth sandy loam was among the highest yielding soils, and also supported the greatest R. reniformis population density. Cotton lint yield was affected more by R. reniformis Pi with irrigation in the Portsmouth loamy sand soil with a greater influence of Pi on lint yield in irrigated plots than other soils. A significant first degree PI × irrigation interaction for this soil type confirms this observation.
在一项为期两年的小区试验中，评估了土壤类型、灌溉以及肾形肾线虫种群密度对棉花的影响。六种土壤类型，即富奎砂质土、诺福克砂壤土、朴次茅斯壤质砂土、腐殖土、塞西尔砂壤土和塞西尔砂质黏土，按随机完全区组排列，重复五次。每个区组有许多先前接种了肾形肾线虫的小区，每种土壤类型有两个或更多未接种的小区，每个重复中一半进行灌溉，总共240个小区。在腐殖土、诺福克砂壤土和朴次茅斯壤质砂土中棉花皮棉产量最高。朴次茅斯壤质砂土的棉花产量与腐殖土没有差异，腐殖土在所有土壤类型中平均每小区皮棉产量最高。除了黏土含量最高的塞西尔砂质黏土外，在所有土壤类型中棉花产量与肾形肾线虫初始种群密度呈负相关。与产量较低的塞西尔砂质黏土、塞西尔砂壤土和富奎砂质土相比，补充灌溉提高了产量较高的腐殖土、诺福克砂壤土和朴次茅斯壤质砂土的产量。朴次茅斯壤质砂土是产量最高的土壤之一，也支持了最大的肾形肾线虫种群密度。在朴次茅斯壤质砂土中，灌溉条件下棉花皮棉产量受肾形肾线虫初始种群密度的影响更大，初始种群密度对灌溉小区皮棉产量的影响比其他土壤更大。该土壤类型显著的一阶初始种群密度×灌溉交互作用证实了这一观察结果。
