THE EFFECT OF SHADE STRESS ON THE PERFORMANCE OF CORN FOR SILAGE VERSUS GRAIN

Abstract

A field study was conducted near Guelph, Ontario, to investigate the effects of shade stress on the yield of corn grown for silage versus grain. The effects of shading on the quality of whole-plant corn silage were also examined. Shade was provided by two layers of fiberglass screen, which reduced the amount of light by approximately 65%. The shade treatments were applied during either the vegetative, reproductive or grain-filling stages of development. Shading at any stage reduced whole-plant dry matter (WPDM) yield at the silage corn harvest stage and the level of this reduction was relatively independent of the stage at which the shade was applied. Grain DM yield at the grain harvest stage was also reduced by light stress, with the greatest reduction resulting from light stress during the reproductive stage. However, for silage production, high stover yield compensated for the reduction in grain yield, resulting in little reduction in whole-plant yield. Shading during either the reproductive or filling stage reduced WPDM content due to reduced grain content and higher stover moisture content.Key words: Corn, silage quality, whole-plant corn silage