Phytopathology. 1997 Jan;87(1):26-32. doi: 10.1094/PHYTO.1997.87.1.26.
ABSTRACT Wheat was assessed at four crop growth stages for take-all (Gaeumannomyces graminis var. tritici) in a series of field trials that studied the effects of five wheat management practices: sowing date, plant density, nitrogen fertilizer dose and form, and removal/burial of cereal straw. An equation expressing disease level as a function of degree days was fitted to the observed disease levels. This equation was based on take-all epidemiology and depended on two parameters reflecting the importance of the primary and secondary infection cycles, respectively. Early sowing always increased disease frequency via primary infection cycle; its influence on the secondary cycle was variable. Primary infection and earliness of disease onset were increased by high density; however, at mid-season take-all was positively correlated to the root number per plant, which was itself negatively correlated to plant density. At late stages of development, neither plant density nor root number per plant had any influence on disease. A high nitrogen dose increased both take-all on seminal roots and severity of primary infection cycle but decreased take-all on nodal roots and secondary infection cycle. Ammonium (versus ammonium nitrate) fertilizer always decreased disease levels and infection cycles, whereas straw treatment (burial versus removal of straw from the previous cereal crop) had no influence.
摘要 在一系列田间试验中，评估了小麦在四个作物生长阶段的全蚀病（禾顶囊壳小麦变种），这些试验研究了五种小麦管理措施的影响：播种日期、种植密度、氮肥施用量和形式以及谷物秸秆的移除/掩埋。根据观察到的疾病水平拟合了一个用度日数表示疾病水平的方程。该方程基于全蚀病的流行病学，取决于分别反映主要和次要侵染循环重要性的两个参数。早期播种总是通过主要侵染循环增加疾病频率；它对次要循环的影响是可变的。高密度增加了主要侵染和疾病的早期发生；然而，在生长中期，每株植物的根数量与全蚀病呈正相关，而根数量与种植密度呈负相关。在发育后期，植物密度和每株植物的根数量都对疾病没有任何影响。高氮剂量增加了主要侵染循环的根和疾病严重度，但减少了节根和次要侵染循环的全蚀病。铵（与硝酸铵相比）肥料总是降低疾病水平和侵染循环，而秸秆处理（掩埋与从先前的谷物作物中移除秸秆）没有影响。
