Effects of powdery mildew and weather on winter wheat yield. 2. Effects of mildew epidemics

Abstract

Wheat yield losses caused by powdery mildew were computed based on effects of the disease on leaf photosynthesis. Powdery mildew was introduced in a crop model of wheat by quantification of five parameters, taking the vertical and horizontal distribution of mildew in the crop into account. The most important parameters were those of the mildew intensity, the distribution of mildew in the crop, and the effect of mildew on assimilation at light saturation. Measured mildew epidemics in field experiments in three different years, were used to compute yield losses. Computed losses were compared to measured losses. On average, computed yield loss approached measured, but measured yield loss was underestimated, especially in early mildew epidemics due to the computation of partitioning and reallocation of assimilates. Other processes which may cause an underestimation arc described. The use of crop models as a method to upgrade disease management systems is discussed.

The effect and molecular mechanism of powdery mildew on wheat grain prolamins

“…Powdery mildew is one of the most devastating foliar diseases suffered by wheat (Godoy et al 2000; Sancho et al 2008; Maxwell et al 2009). It changes the translocation and distribution of photosynthate, leads to leaf senescence and hence causes yield reduction (Daamen & Jorritsma 1990; Hall & Williams 2000; Sutton et al 2007). Wheat powdery mildew can also exert a far-reaching influence on the source–sink relationship of wheat (Sutton et al 2007).…”

Effects of powdery mildew and weather on winter wheat yield. 1. Variation of weather between years

“…The performance of two crop models and a combination of both, to varying weather conditions is compared with wheat yields harvested in the Netherlands in different years. In a following paper (Daamen & Jorritsma, 1990), the simulation of yield in relation to varying mildew intensities and weather conditions will be discussed.…”